Regulation Number 11

ADMINISTRATIVE MATERIALS

Copies of the following administrative materials are included in this submittal of revisions to 

Regulation Number 11. Hearing held on November 21, 2013.

• Hearing Notice and Proposed Language as Published in the CCR and on the 

Commission Website the 40 CFR Part 51 Appendix V 2.1(f)

• Meeting Agenda where Public Hearing Occurred and Notice published in the Legal 

Ads of the Denver Post 40 CFR Part 51 Appendix V 2.1(f)

• Procedural Documents of the Commission (this includes the Agenda Item Control 

Sheet, the Memorandum of Notice, the Economic Impact Analysis)

• Parties Hearing Documents (this includes a list of the parties, the parties prehearing 

statements and rebuttal statements, and any orders by the Commission - - do not 

include all the attachments from the parties)

• EPA Comments 40 CFR Part 51 Appendix V 2.1(h)

• Public Comments 40 CFR Part 51 Appendix V 2.1(h)

• Adopted Statement of Basis, Specific Statutory Authority and Purpose

• Adopted Language by the Commission (in redline & footer noting adoption date and 

page numbers)

• Colorado Air Quality Control Commission Meeting Minutes 40 CFR Part 51 

Appendix V 2.1(g)

• Legal Opinion of the Colorado State Attorney General 40 CFR Part 51 Appendix V 

2.1(c) and (e)

• Regulation or Regulation Revisions as published in the Colorado Code of Regulations 

(this is the version that is published by Lexis Nexis) 40 CFR Part 51 Appendix V 

2.1(b)
Hearing Notice and Proposed Language

as Published in the CCR

40 CFR Part 51 Appendix V 2.1(f)
STATE OF COLORADO

John W. Hickenlooper, Governor

Karin McGowan, Interim Executive Director and Chief Medical Officer

Dedicated to protecting and improving the health and environment of the people of Colorado

COLORADOAIR QUALITY CONTROL COMMISSION

http://www.cdphe.state.co.us

4300 Cherry Creek Drive South, EDO-AQCC-A5

Denver, Colorado 80246-1530

Phone (303) 692-3100

Fax (303) 691-7702

TDD (303) 691-7700

Colorado Department

of Public Health 

and Environment

NOTICE OF PUBLIC RULEMAKING HEARING

BEFORE THE 

COLORADO AIR QUALITY CONTROL COMMISSION

Regarding proposed revisions to:

Regulation Number 11

SUBJECT:

The Commission will consider revisions to Regulation Number 11 to amend language that will 

clarify provisions contained in the existing regulation concerning model year exemptions and 

program implementation dates, updating the listed repair waiver cost limit from $450 to the 

currently used $715 limit, modifying qualification criteria used to grant an economic hardship 

waiver, and incorporating a new Test Analyzer Specification for On-board Diagnostics in 

Appendix A.

HEARING SCHEDULE:

DATE: November 21, 2013

TIME: 9:00 AM

PLACE: Colorado Department of Public Health and Environment

4300 Cherry Creek Drive South, Sabin Conference Room

Denver, Colorado 80246

The hearing may be continued at such places and time as the Commission may announce. Interested 

parties may contact the Commission Office at 303-692-3476 to confirm meeting dates and times.

PUBLIC COMMENT:

The Commission encourages all interested persons to provide their views either orally at the 

hearing or in writing prior to or at the hearing. The Commission especially solicits comments 

and analyses from persons who will incur directly some cost or benefit from the proposed 

revisions. Public testimony will be taken as close to the start of the hearing as possible and 

during the hearing as necessary. Written and/or electronic submissions are requested, but not 

required to be submitted, prior to the hearing to allow review for review in advance. Written 

and/or electronic submissions should be mailed to the Commission Office at least 14 days prior 

to the hearing.
PARTY STATUS:

Any person may obtain party status for the purpose of this hearing by complying with the 

requirements of the Commission’s Procedural Rules. A petition for party status must be filed by 

electronic mail with the Office of the Air Quality Control Commission no later than close of 

business on September 16, 2013. The petition must: 1) identify the applicant; 2) provide the 

name, address, telephone and facsimile numbers, and email address of the applicants 

representative; and 3) briefly summarize what, if any, policy, factual, and legal issues the 

applicant has with the proposal(s) as of the time of filing the application. Electronically mailed 

copies must also be received, by this same date, by the Division staff person and the Assistant 

Attorneys General representing the Division and the Commission identified below. 

Any person may petition the Commission to file documents in paper copy format if they are 

unable for any reason to comply with the requirements of Subsection III.I.2. of the 

Commission’s Procedural Rules. An original and fifteen paper copies must be filed in the Office 

of the Air Quality Control Commission, Colorado Department of Public Health and 

Environment, 4300 Cherry Creek Drive South, Denver, Colorado 80246.

Individuals may also obtain party status by submitting an alternative to the proposed rule. The 

submittal of an alternative proposal must be accompanied by an electronic copy of the alternative 

proposed rule and all other associated documents as required by the Commission’s Procedural 

Rules, and must be filed by electronic mail with the Office of the Commission by September 16, 

2013 for party status requests. Alternative rules must also be filed by electronic mail with the 

Division staff person and with each of the Assistant Attorneys General.

Theresa L. Martin Doug Decker

Air Quality Control Commission Air Pollution Control Division

4300 Cherry Creek Drive South, EDO-AQCC-A5 4300 Cherry Creek Drive South, APCD-B1

Denver, CO 80246 Denver, CO 80246

Theresa.Martin@state.co.us Doug.Decker@state.co.us

Attorney for the Commission Attorneys for the Division

Tom Roan Clay Clarke

Attorney General’s Office Attorney General’s Office

1300 Broadway, 10th Floor 1300 Broadway, 10th Floor

Denver, CO 80203 Denver, CO 80203

Tom.Roan@state.co.us Clay.Clarke@state.co.us

Requests received beyond the above stated deadline shall only be considered upon a written 

motion for good cause shown. The Commission reserves the right to deny party status to anyone 

that does not comply with the Commission’s Procedural Rules.
STATUS CONFERENCE:

A status conference will be held September 24, 2013 at 11:00 a.m., at the Department of Public 

Health and Environment to ascertain and discuss the issues involved, and to ensure that parties 

are making all necessary efforts to discuss and resolve such issues prior to the submission of 

prehearing statements. Attendance at this status conference is mandatory for anyone who has 

requested party status.

PREHEARING CONFERENCE/PREHEARING STATEMENTS:

Attendance at the prehearing conference is mandatory for all parties to this hearing. A 

prehearing conference will be held October 22, 2013 at 11:00 a.m. in the Commission Offices 

at 4300 Cherry Creek Drive South, Denver. All parties must submit by electronic mail a 

prehearing statement, any alternative proposal and accompanying exhibits to the Commission 

Office by close of business October 15, 2013. In addition, electronically mailed copies of these 

documents must be delivered by that date to all persons who have requested party status. A copy 

of the prehearing statement must also be electronically mailed to the Division point of contact 

and each of the Assistant Attorneys General identified above by close of business October 15, 

2013. Rebuttals to the prehearing statement may be submitted to the Commission Office and all 

other parties by close of business October 29, 2013. 

The Commission’s Procedural Rules provide for an exception to file documents by electronic 

mail. If granted an exception to electronic filing pursuant to the provisions of Subsection III.I.3. 

of the Commissions Procedural Rules, the applicant for party status shall file an original and 

fifteen copies of the prehearing statement in the Office of the Air Quality Control Commission, 

and shall also deliver copies to each other party, applicant for party status, the Assistant 

Attorneys General representing the Commission and Division, and the Division staff person for 

the proceedings, by electronic mail or as otherwise provided by the exception granted under 

Subsection III.I.3., by that same day.

STATUTORY AUTHORITY FOR THE COMMISSION'S ACTIONS:

Sections 42-4-306 and 42-4-310, C.R.S. authorize the Air Quality Control Commission 

(“Commission”) to promulgate rules for inspection of motor vehicle emissions. Section 42-4-

306(8) authorizes the Commission to exempt motor vehicles from emission inspections. Section 

42-4-306(3)(b)(V)(B) authorizes the Commission to promulgate rules for alternative motor 

vehicle emission inspections, including on-board diagnostics (OBD) inspections. 42-4-306(6)(a) 

authorizes the Commission to promulgate rules on inspection procedures, including those related 

to OBD and evaporative gases. 
The rulemaking hearing will be conducted in accordance with Sections 24-4-103, and 

25-7-110, -110.5 and -110.8 C.R.S., as applicable and amended, with the Procedural Rules of the 

Commission, the statutory authority provided in Sections 42-4-301 through 42-4-316, C.R.S., 

and as otherwise stated in this notice. This list of statutory authority is not intended as an 

exhaustive list of the Commission’s statutory authority to act in this matter.

Dated this 20th day of August 2013 at Denver, Colorado

Colorado Air Quality Control Commission

Michael Silverstein, Administrator
DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT

Air Quality Control Commission

REGULATION NUMBER 11

MOTOR VEHICLE EMISSIONS INSPECTION PROGRAM

5 CCR 1001-13

PART A: General Provisions, Area of Applicability, and Schedules for Obtaining Certification of 

Emissions Control, Definitions, Exemptions, and Clean Screen/Remote Sensing

PART B: Standards and Procedures for the Approval, Operations, Gas Span Adjustment, 

Calibration and Certification of the Air Pollution Control Division (Division) Approved Test 

Analyzer Systems for Use in the Basic and Enhanced Program Areas, Test Analyzer Systems for 

Licensed Dealers in the Enhanced Area, and Clean Screen Test Analyzer Systems

PART C: Inspection Procedures and Requirements for Exhaust Emissions, Fuel Evaporation 

Control, Visible Smoke Emissions, Emissions Control Systems, On-Board Diagnostics Clean 

Screening; and Practices to Ensure Proper Emissions Related Adjustments and Repairs

PART D: Qualification and Licensing of Emissions Mechanics, Emissions Inspectors, and Clean 

Screen Inspectors; Licensing of Emissions Inspection and Readjustment Stations, InspectionOnly Stations, Inspection-Only Facilities, Fleets, Motor Vehicle Dealer Test Facilities and 

Enhanced Inspection Centers, Clean Screen Inspection Sites; and Registration of Emissions 

Related Repair Facilities and Technicians

PART E: Prohibited Acts and Penalties to Ensure Proper Inspection Procedures, Adherence to 

Prescribed Procedures and Effective Emissions Related Repairs

PART F: Maximum Allowable Emissions Limits for Motor Vehicle Exhaust, Evaporative and Visible 

Emissions for Light-Duty and Heavy-Duty Vehicles

PART G: Reserved

PART H: Statements of Basis, Specific Statutory Authority and Purpose

APPENDIX A: Technical Specifications

APPENDIX B: Standards and Specifications for Calibration/Span Gas Suppliers

REFERENCES

Pursuant to Section 24-4-103 (12.5), C.R.S., material incorporated by reference is available during 

normal working hours, or copies may be obtained at a reasonable cost, from the Technical Secretary of 

the Air Quality Control Commission c/o the Colorado Department of Public Health and Environment, 4300 

Cherry Creek Drive South, Denver, Colorado 80246-1530 or material incorporated by reference within 

this regulation may be examined at any state publications depository library. References do not include 

later amendments to or additions of incorporated material.
PART A General Provisions, Area of Applicability, Schedules for Obtaining Certification of 

Emissions Control, Definitions, Exemptions, and Clean Screening/Remote Sensing

I. APPLICABILITY

Subject to the provisions described in Sections I.A and I.B of this Part A and pursuant to the schedule in 

Section I.C. and V.B. of this Part A, all non-diesel fueled motor vehicles which are registered in the AIR 

Program area or which motor vehicle is owned or operated by a non-resident who meets the 

requirements of Section, 42-4-310(1)(c)(I), C.R.S., will be subject to On-Board Diagnostics and/or an 

exhaust and evaporative emissions, smoke opacity and emissions control, equipment inspection as a 

prerequisite to initial or renewal of the vehicle registration. Any person owning or operating a business 

and any post-secondary educational institution located in the program area as defined in Subsection A of 

this section shall annually inform by written notice all persons employed by such business or attending 

classes that they are required to comply with the provisions of this regulation. The provisions of this 

regulation applicable to Larimer and Weld counties shall not be included in the state implementation plan.

I.A. Geographic Areas of Applicability

This regulation shall apply to the AIR Program area as defined in Section 42-4-304(20), C.R.S. as 

amended by Senate Bill 09-003.

I.B. Vehicles Eligible for AIR Program Inspection Procedures.

This regulation shall apply to all motor vehicles as defined in Section 42-4-304(18), C.R.S.

Vehicles that are registered in a program area and are being operated outside such area but 

within another program area shall comply with the requirements of the area where such vehicles 

are being operated. Vehicles registered in a program area that are is being temporarily operated 

outside the state at the time of registration or registration renewal may apply to the department of 

revenue for a temporary exemption from program requirements. Upon return to the program 

area, such vehicles must be in compliance with all requirements within fifteen days. A temporary 

exemption shall not be granted if the vehicle will be operated in an emissions testing area in 

another state unless proof of emissions from that area is submitted.

Pursuant to Section, 42-4-310(1)(c)(I), C.R.S. motorists operating vehicles in the enhanced 

program area shall comply with the provisions of the enhanced program.

The burden of proof in establishing an exemption from inclusion in all or any part of the AIR 

Program inspection requirements is on the vehicle owner.

I.C. Schedules for Obtaining Certifications of Emissions Control

I.C.1. REPEALED

I.C.2. Inspection schedules during calendar year 1995 and thereafter, vehicles are to 

be inspected according to the schedules established in Sections, 42-4-

304(3)(b)(II), and, 42-4-310(1)(b)(II), C.R.S. as amended.

I.C.3. No used vehicle which is required to be registered in the program area shall be 

registered, unless such vehicle has a Certification of Emissions Control, or of 

Emissions Exemption. The seller of a used vehicle is required to obtain a 

Certification of Emissions Control for the new owner at the time of sale. This 

paragraph (3) does not apply to the sale of a motor vehicle that is inoperable or 

otherwise cannot be tested in accordance with this regulation if the seller of the 
motor vehicle provides a written notice to the purchaser pursuant to Section 42-

4-310(4), C.R.S. If a motor vehicle is being registered for the first time in the 

program area, the owner shall obtain the certification and submit it with the 

application for registration to the Department of Revenue or an authorized agent 

of the Department of Revenue.

I.C.3.a. On or after October 1, 1989, no used vehicle which is required to be 

registered in the program area shall be registered, unless such vehicle 

has a Certification of Emissions Control, or of Emissions Exemption. The 

seller of a used vehicle is required to obtain a Certification of Emissions 

Control for the new owner at the time of sale. This paragraph (3) does 

not apply to the sale of a motor vehicle which is inoperable or otherwise 

cannot be tested in accordance with this regulation or that is being sold 

pursuant to Part 18 (Vehicles Abandoned on Public Property) or Part 21 

(Vehicles Abandoned on Private Property) of Article 4 of Title 42, C.R.S. 

if the seller of the motor vehicle provides a written notice to the 

purchaser pursuant to Section 42-4-310(4), C.R.S. If a motor vehicle is 

being registered for the first time in the program area, the owner shall 

obtain the certification and submit it with the application for registration to 

the Department of Revenue or an authorized agent of the Department of 

Revenue.

I.C.3.b. An inspection is not required prior to the sale of a motor vehicle with at 

least twelve months remaining before the vehicle's certification of 

emissions compliance expires if such certification was issued when the 

vehicle was new.

I.C.3.c. Effective January 1, 2015 A a motor vehicle being registered in the 

program area for the first time may be registered without an inspection or 

certification if the vehicle has not yet reached its seventh model year 

pursuant to Section 42-4-310(1)(a)(II)(C)C.R.S.

I.C.4. Any motor vehicle may be voluntarily inspected and a Certification of Emissions 

Control obtained which shall be valid as specified in Section I.C.2. of this Part A.

I.C.5. (Reserved)

I.C.5.a. As it pertains specifically to federally owned or leased vehicles; tactical 

military vehicles are not required to be inspected.

I.C.5.b. Federal installation managers are to declare all federal employee-owned 

vehicles operated on the installation and demonstrate that these vehicles 

have complied with periodic inspection requirements pursuant to 40 CFR 

Section 51.356(A)(4). Inspection results shall be reported to the 

Department of Revenue AIR Program section and up-dated based on 

inspection cycles.

I.C.6. (Reserved)

I.C.7. Fleets of twenty or more eligible vehicles shall be periodically inspected, comply 

with inspection provisions and obtain a Certification of Emissions Control.
I.C.7.a. Fleets may pursue licensing as a fleet inspection station under Part D of 

this Regulation Number 11 pursuant to Section, 42-4-309, C.R.S. and 

comply with the provisions of that section.

I.C.7.b. Fleets may elect to comply with periodic inspection requirements under 

the provisions of Section 42-4-309 (2)(a), C.R.S. to include the 

inspection schedules of Sections 42-4-304(3)(b)(II) and 42-4-

310(1)(b)(II)(a), C.R.S.

I.C.7.c. As it pertains to the fleet vehicles provisions pursuant to Section, 42-4-

309, C.R.S. and this Section I.C.7., municipal fleets of twenty vehicles or 

more may comply with periodic inspection requirements as specified in 

Section 42-4-309(2)(a), C.R.S. to include inspection schedule of 

Sections 42-4-304(3)(b)(II) and 42-4-310 (1)(b)(II)(a), C.R.S.

I.C.8. New motor vehicles being registered with a Manufacturer's Statement of Origin 

(MSO), Manufacturer's Certificate of Origin (MCO) or similar document shall be 

issued a registration without a Certificate of Emissions Control.

Such new motor vehicles are to be issued a Verification of Emissions Test exemption 

windshield sticker at the time of sale and valid for up to seven (7) years. The selling 

dealer is responsible for obtaining the Verification of Emissions Test.

New vehicles under this section shall also include those new vehicles leased under an 

MSO or MCO or similar document and seven years without an inspection. After the 

seventh year or a transfer of ownership, such vehicles shall be issued a registration only 

with a Certificate of Emissions Control. The inspection schedule for these vehicles shall 

then revert to a biennial cycle.

Effective January 1, 2015 vehicles that were originally issued a Verification of Emissions 

Test exemption windshield sticker at the time of new vehicle sale that was valid for a 

period of four years shall have that time period extended to seven years.

I.C.9. Motor vehicle dealer compliance requirements.

I.C.9.a. Compliance with AIR Program inspection requirements will not be 

required for wholesale transactions between motor vehicle dealers 

licensed pursuant to Article 6 of Title 12, C.R.S.

I.C.9.b. Motor vehicle dealers shall have motor vehicles inventoried or consigned 

for retail sale inspected annually. A further inspection is not required at 

the time of sale if:

i. For a 1982 or later motor vehicle, there are at least twelve 

months remaining before the vehicle's certification of emission 

compliance expires and the dealer has had the vehicle inspected 

since acquiring it. Such a vehicle purchased from a licensed

motor vehicle dealer may be registered in the program area 

without an inspection if, on the date of vehicle registration, at 

least twelve months remain before the expiration of such 

certification.

ii. For a 1981 or earlier motor vehicle, the vehicle has a valid 

certification of emission compliance and the dealer has had the 
vehicle inspected since acquiring it. Such a vehicle purchased 

from a licensed motor vehicle dealer may be registered in the 

program area without an inspection if, on the date of vehicle 

registration, at least nine months remain before the expiration of 

such certification.

I.C.10. For purposes of Sections 42-4-304(3), 42-4-309(3) and 42-4-310, C.R.S., a 

certificate of emissions Control shall be considered to be issued at the time of 

sale or transfer of a vehicle if such certificate is issued pursuant to an inspection 

conducted no later than the date of such sale or transfer, and no earlier than one 

hundred twenty calendar days prior to such sale or transfer.

I.C.11. Eligible fleets as defined in Section 42-4-309, C.R.S. that declare not to selfinspect shall be inspected according to the same schedules, subject to the same 

emissions related repair requirements and waiver provisions as non-fleet 

vehicles.

I.C.12. For the purposes of 42-4-309(6)(B) if a vehicle fails the test or is untestable due 

to mechanical and/or electrical/electronic problem, the motorist shall have the 

same recourse as that of not passing an inspection. However, Section 42-4-

309(6), C.R.S. and the regulations implementing such provision, shall not be 

federally enforceable, and shall not be incorporated into the State 

Implementation Plan.

II. DEFINITIONS

1. “Accreditation” means certification that the instrument and instrument manufacturer meet the 

operating criteria specifications and requirements of the Colorado Department of Health, Air 

Quality Control Commissions as specified in Part B of this regulation.

2. “Air Intake Systems” are those systems that allow for the induction of ambient air (to include 

preheated air) into the engine combustion chamber for the purpose of mixing with a fuel for 

combustion.

3. “AIR Program Station” is an Automobile Inspection and Readjustment (AIR) Station that qualifies 

and is licensed to operate as an emissions inspection and readjustment station.

4. “Air System” is a system for providing supplementary air into the vehicle's exhaust system to 

promote further oxidation of HC and CO gases and to assist catalytic reaction.

5. “BAR 90” refer to the California Bureau of Automotive Repair specifications for Exhaust Gas Test 

Analyzer Systems (TAS) that became effective in 1990. “BAR 97” refers to the California Bureau 

of Automotive Repair specifications for Exhaust Gas Test Analyzer Systems (TAS) that became 

effective in 1997.

6. “Basic Engine Systems” are those parts or assemblies which provide for the efficient conversion 

of a compressed air/fuel charge into useful power to include but not limited to valve train 

mechanisms, cylinder head to block integrity, piston-ring-cylinder sealing integrity and postcombustion emissions control devise integrity.

7. “Calibration” is the process of establishing or verifying the total response curve of an exhaust gas 

analyzer. Calibration is a laboratory procedure using several different calibration gases having 

precisely known concentrations.
8. “Calibration Gases” are gases of precisely known concentration that are usually used in the 

laboratory as references for establishing or verifying the calibration curve of an exhaust gas 

analyzer.

9. “Catalytic Converter” is a post-combustion device that oxidizes HC and CO gases and/or reduces 

oxides of nitrogen.

10. “Certification” means assurance by the authorized source, whether it is a laboratory, the 

manufacturer, or the State, that a specific product or statement is in fact true and meets all 

required accreditation requirements.

11. “Certification of Emissions Control” shall have the same meaning as set forth in Section 42-4-

304(3)(1), C.R.S.

12. “Chlorofluorocarbon” (CFC) is a class I stratospheric ozone depleting compound as listed in 

Appendix A, final rule vol.57.mp 147 Federal Register, 40 CFR Part 82.

13. “Clean Screen Inspection Site” is that location within the program area as defined in Section 42-4-

304(20)(a), C.R.S., approved by the Division and the Department of Revenue.

14. “Clean Screen Inspector” is a person found qualified by the Division, and licensed by the 

Executive Director to operate Clean Screen Inspection equipment.

15. “Clean Screen Program” is that program as defined in Section 42-4-304(3.5), C.R.S.

16. “Clean Screened Vehicle” is a vehicle that is eligible for inspection, has at least two consecutive 

passing remote sensing emissions readings performed on different days or at different approved 

Clean Screen Inspection Sites prior to its registration renewal date, or for vehicles identified as 

low emitters on the low emitting vehicle index, one passing remote sensing reading prior to its 

registration date, and has otherwise complied with the provisions of Section IV of this Part A, 

Section XII of Part C and Section VI of Part F.

17. “Clean Screen Data Manager” is that person or entity that contracts with the state to provide 

clean screen data management functions. This same person or entity may also act as general 

contractor in conducting and facilitating clean screen inspections.

18. “Colorado 94” refers to those test analyzer systems that are based on BAR 90 but modified as 

specified by the Division for use in the AIR Program for the period of time after January 1,1994. 

“Colorado AIR Program BAR 97 Exhaust Gas Analyzer” or Colorado 97” refers to those test 

analyzer systems that are based on BAR 97, but modified as specified by the Division for all fleet 

inspection stations and inspection-only facilities that become licenses after May 1, 2010.

19. “Colorado Automobile Dealer Transient Mode Test Analyzer System” is a dynamometer based 

inspection system capable of performing an inspection grade (IG 240) emissions inspection 

procedure under simulated driving conditions. The procedure is intended for determining the 

compliance status for used vehicles prior to retail sale.

20. “Colorado On-Board Diagnostic (OBD) Test Analyzer System” or “OBD TAS” refers to the 

analytical and testing instrumentation used to verify automotive emissions and to prompt the 

emissions inspector through the elements of an official Colorado OBD emissions inspection.

21. “Compliance” means verification that certain submission data and hardware submitted by a 

manufacturer for accreditation consideration, meet all required accreditation requirements.
22. “Diagnostic Trouble Code (DTC)” is an alpha-numeric code representing a specific fault or 

problem identified by the OBD system on a vehicle. OBD diagnostic trouble codes are 

standardized across all vehicle manufacturers and are defined individually in the Society of 

Automotive Engineers Recommended Practice J2012.

23. “Division” is the Air Pollution Control Division of the Colorado Department of Public Health and 

Environment.

24. “Electrical, Electronic, or Electro-mechanical Span” is the adjustment of an exhaust gas analyzer 

using an electronic signal rather than a calibration or span gas as a reference source.

25. “Emissions Control Systems” are those parts, assemblies or systems originally installed by the 

manufacturer in or on a vehicle for the purpose of reducing emissions.

26. “Estes Park Area” means that part of the program area west of Range 71 West in Larimer 

County.

27. “Executive Director of the Department of Revenue” or “Executive Director” is the representative of 

the Department of Revenue or designee responsible for the field enforcement of the AIR 

Program, licensing of emissions mechanics, clean screen inspectors and inspection stations.

28. “Fuel Control Systems” are those mechanical, electro-mechanical, galvanic or electronic parts or 

assemblies that regulate the air/fuel ratio in an engine for the purpose of providing a combustible 

charge.

29. “Fuel Filler Neck Restrictor system” is the orifice and obstruction (“Flapper Door”) in the gas tank 

filler neck that prevents the insertion of a “leaded gasoline” nozzle and deters the introduction of 

“leaded fuel”.

30. “Gas Span” is the adjustment of an exhaust gas analyzer to correspond with known 

concentrations of span gases.

31. “Gas Span Check” is a procedure using known concentrations of span gases to verify the gas 

span adjustment of an analyzer.

32. “Gross Vehicle Weight (GVW) Rating” is the maximum recommended combined weight of the 

motor vehicle and its load as prescribed by the manufacturer and expressed on a permanent 

identification label affixed to the motor vehicle.

33. “Heavy Duty Vehicles (HDV)” are those motor vehicles for model years 1978 and earlier having a 

GVW rating of greater than 6000 pounds and for model years 1979 and newer, having a GVW 

rating of greater than 8,500 pounds.

34. “Idle Mode” means a condition where the vehicle engine is warm and running at the rate specified 

by the manufacturer's curb idle, where the engine is not propelling the vehicle, and where the 

throttle is in the closed or idle stop position.

35. “Ignition Systems” are those parts or assemblies that are designed to cause and time the ignition 

of a compressed air/fuel charge.

36. “Inspection Area” is the area that is occupied by the analyzer, sample hose and the vehicle being 

inspected.
37. “Inspection-only station” is that licensed station within the basic program area as defined in 

Section 42-4-304(2), C.R.S., which meets the requirements of Section 42-4-308, C.R.S., which 

facility the operator is licensed to operate by the Executive Director as an inspection-only station.

38. “Instrument” is the complete system that samples and reads out the concentration of pollutant HC 

and CO gas plus CO2 gas. The instrument includes the sample handling system, the exhaust gas 

analyzer and the enclosure cabinet.

39. “Light Duty Vehicles (LDV)” are those motor vehicles (to include trucks) for model years 1978 and 

earlier having a GVW rating of 6,000 pounds or less and for model years 1979 and newer having 

a GVW rating of 8,500 pounds or less.

40. “Low Emitting Vehicle Index” refers to a statistical table summarizing the probability of vehicles 

passing the IM 240 inspection. The statistical table will be updated annually by each July 1st. 

The low emitting vehicle index must meet the requirements of Part F, VI.B. based on a tabulation 

of the previous calendar year’s IM 240 inspection program results.

41. “Malfunction Indicator Light (MIL)” is a warning light located on the dash of vehicles equipped with 

On-Board Diagnostic (OBD) systems that notifies the motorist that a malfunction to the vehicle’s 

emissions control system has been detected.

42. “Motor Vehicle Emissions Compliance Inspectors (ECI)” are those persons employed and 

authorized by the Department of Revenue for licensing and enforcement of the AIR Program.

43. “North Front Range Area” is the portion of the Program Area located in Larimer and Weld 

Counties as set forth in Section 42-4-304(20) as amended by Senate Bill 09-003. The North Front 

Range area is a State-Only program and is not part of any State Implementation Plan with the US 

EPA.

44. “On-Board Diagnostics II (OBD or OBDII) Test” means the electronic retrieval of stored readiness 

status, diagnostic trouble codes, malfunction indicator light (MIL) illumination status, and other 

information from a vehicle’s OBD system to determine if any emission related trouble codes are 

present and if the MIL is commanded to be on, which would indicate the existence of an emission 

related malfunction with the vehicle.

45. “Original Condition” means the condition as installed by the manufacturer but not necessarily to 

the original level of effectiveness.

46. “Program Area” is that geographic area defined in Section 42-4-304(20), C.R.S. as amended by 

Senate Bill 09-003.

47. “Registration Renewal Date” is the last day of the month in which the vehicle registration expires 

as defined in Section 42-3-103, C.R.S.

48. “Span Gases” are gases of known concentration used as references to adjust or verify the 

adjustment of an exhaust gas analyzer's span settings.

49. “State Emissions Technical Center Personnel” are those persons employed by or authorized by 

the Department of Health for technical or administrative support of the AIR Program.

50. “Test Analyzer Systems” (TAS) in the context of this regulation is that analytical instrumentation 

used to measure automotive emissions and prompt the operator through other elements of an 

emissions inspection.
51. “True Concentration” is the concentration of the gases of interest as measured by a standardized 

instrument which has been calibrated with 1% precision gases traceable to the National Institute 

for Standards and Technology.

52. “Zero Gas” is a gas, usually air or nitrogen, which is used as a reference for establishing or 

verifying the zero point of an exhaust gas analyzer.

III. EXEMPTION FROM SECTION 42-4-314, C.R.S. FOR DEPARTMENT OF DEFENSE 

PERSONNEL PARTICIPATING IN THE PRIVATELY OWNED VEHICLE IMPORT CONTROL 

PROGRAM

III.A. U.S. Department of Defense (DOD) personnel participating in the DOD POV (privately 

owned vehicle) Import Control Program operating a 1975 or subsequent model year 

automobile, are exempt from the prohibition of C.R.S., 42-4-314(2), C.R.S. insofar as it 

pertains to filler neck restrictors, catalytic converter systems, and, if applicable, exhaust 

gas oxygen (O2) sensor(s), if one of the following conditions are met:

III.A.1. The automobile will be driven to the port and surrendered for exportation under 

said program within ten (10) working days of disconnection, deactivation, or 

inoperability of the restrictor, catalytic converter systems, or exhaust gas oxygen 

(O2) sensor(s); or

III.A.2. The reconnection, reactivation, or reoperability of the restrictor, catalytic 

converter systems, and, if applicable, exhaust gas oxygen (02) sensor(s), is made 

within ten (10) working days from the time the owner picked up the automobile at 

the port.

III.B. Persons disconnecting, deactivating, or rendering inoperable any filler neck restrictor, 

catalytic converter system, exhaust gas oxygen (O2) sensor(s) on 1975 or subsequent 

model year automobile of DOD personnel participating in the DOD POV Import Control 

Program which will be driven to the port and surrendered for exportation under said 

program within ten (10) working days are exempt from the prohibition of 42-4-314, C.R.S.

III.C. Unless otherwise exempt under this Section III of Part A, vehicles shall be required to be 

configured as a vehicle certified by the EPA for sale and use within the United States 

pursuant to 40 CFR, Part 86, Subpart A.

IV. CLEAN SCREEN/REMOTE EMISSIONS SENSING

IV.A. Geographic Area of Applicability

IV.A.1. (Reserved)

IV.A.2. The Division shall implement an expanded clean screen program in the 

enhanced program area.

IV.A.3. (Reserved)

IV.B. Vehicles Eligible to participate in the Clean Screen/Remote Emissions Sensing Program

IV.B.1. The clean screen program established in this Section IV. of Part A shall apply to 

eligible motor vehicles as defined in 42-4-310(5)(a), C.R.S., for which registration 

will expire within twelve months, a certificate of emissions control is a 
prerequisite to renewal and which are registered in a clean screen program 

county.

IV.B.2. The counties of Adams, Arapahoe, Boulder, Broomfield, Denver, Douglas, 

Jefferson, Larimer, and Weld are clean screen counties.

IV.C. REPEALED

IV.D. Schedule for collection of emissions inspection fees by county clerks and recorders.

The clerks and recorders for the counties of Adams, Arapahoe, Boulder, Broomfield, Denver, 

Douglas, Jefferson, Larimer and Weld shall collect an emissions inspection fee in the amount 

specified pursuant to Section 42-3-304(19)(a)(I), C.R.S. at the time of registration of a motor 

vehicle that the Department of Revenue has determined to have been clean screened, unless a 

valid certification of emissions compliance has already been issued for the vehicle being 

registered indicating that the vehicle passed the applicable emissions test at an enhanced 

inspection center, motor vehicle dealer test facility or fleet inspection station.

V. EXPANSION OF THE ENHANCED EMISSIONS PROGRAM TO THE NORTH FRONT RANGE 

AREA

V.A. Program Commencement

Beginning November 1, 2010, unless the Division comes back to the Commission and the 

Commission agrees to a later date, motor vehicles registered in the North Front Range Area, and 

vehicles operating in the North Front Range Area that meet the requirements of Section 42-4-

310(1)(c)(I), C.R.S. shall be subject to an Enhanced emissions inspection as defined in Section 

42-4-304(8.5). Notwithstanding the above, the Estes Park Area, located west of Range Seventyone (71) West, shall be excluded from the Enhanced Emissions Program. Such inspection shall 

be the same as the inspection required in the Adams, Arapahoe, Boulder, Broomfield, Denver, 

Douglas, and Jefferson county portions of the Program Area The Vehicle Emissions Inspection 

program in the North Front Range area is a State-Only program and is not part of any state 

implementation plan with the US EPA.

V.B. Requirement to Obtain Certification of Emission Control and Emissions Inspection 

Schedule

V.B.1. Except as otherwise provided in Title 42, Article 4, Part 3, C.R.S. and this 

Regulation Number 11, a motor vehicle that is subject to the North Front Range 

Area Inspection and Maintenance Program pursuant to Subsection V.A. above 

may not be registered or sold without a valid Certification of Emissions Control. 

In order to obtain a Certification of Emissions Control the vehicle must either 

pass the applicable emissions inspection or obtain a waiver from the Department 

of Revenue under this Regulation Number 11.

V.B.2. Subject to the phase-in provision in Subsection V.B.3. below, emissions 

inspections shall be conducted and Certification of Emissions Controls shall 

remain valid in accordance with the schedules set forth in Section 42-4-304(3), 

C.R.S., Section 42-4-310(1)(b)(II), C.R.S. and Part A, Section I.C. of this 

Regulation Number 11.

V.B.3. In order to better balance the number of inspections from year to year, odd 

number model year motor vehicles that require biennial inspections under 

Subsection V.B.2. above, shall be inspected commencing January 1, 2011. This 
phase-in shall not excuse a vehicle from an inspection in 2010 that is required 

due to the sale or transfer of the motor vehicle.

PART B Standards and Procedures for the Approval, Operation, Gas Span Adjustment, 

Calibration and Certification of the Division Approved Test Analyzer Systems for 

Use in the Basic and Enhanced Areas and Test Analyzer Systems for Licensed 

Dealers in the Enhanced Area

I. APPROVAL OF THE COLORADO 94 AND COLORADO 97 TEST ANALYZER SYSTEMS

I.A. From January 1, 1995 and thereafter no emissions inspection required by the AIR 

Program in the enhanced program area shall be performed unless the instrument used 

for measuring exhaust gases from motor vehicles is identified as a Colorado AIR 

Program Colorado 94 exhaust gas analyzer. For any emissions inspection station 

licensed after May 1, 2010, a Colorado BAR 97 exhaust gas analyzer must be used. 

Sources of vendors for the approved analyzers may be obtained from the Program 

Administrator, Mobile Sources Section, Air Pollution Control Division, Colorado 

Department of Public Health and Environment, 4300 Cherry Creek Drive South, Denver 

CO 80246-1530.

I.B. As an element of accreditation, the Division will accept a Certification statement for the 

exhaust gas analytical and sampling system portion of the Colorado AIR Program 

Colorado 94 exhaust gas analyzer or a Colorado BAR 97 exhaust gas analyzer from the 

California Bureau of Automotive Repair (BAR) or a recognized laboratory. The Division or 

its designee will determine the manufacturers’ compliance with the revisions and 

additions to the specifications necessary for use of the instrument within the AIR 

Program. Those testing procedures are to be included with the bid specifications.

I.C. The following statement is a requirement of the AIR Program for approval of an exhaust 

gas analyzer and is included to make manufacturers and purchasers of exhaust gas 

analyzers aware of the warranty requirements of Section 207(b) of the federal Clean Air 

Act, as amended 1981.

207(b) Warranty Requirements:

Unless an exhaust gas analyzer has been certified by the manufacturer as having met the 

specifications of 40 CFR Part 85, Subpart W as published in Part IX of the May 22, 1980 Federal 

Register, an inspection performed using that analyzer may not qualify a 1982 or later model year 

vehicle for warranty repair coverage according to the provisions of the Emission Control System 

Performance Warranty (Section 207(b) of the federal Clean Air Act).

II. APPLICATIONS FOR APPROVAL OF COLORADO 94 OR COLORADO BAR 97 TEST 

ANALYZER SYSTEMS EQUIPMENT MANUFACTURERS

Those manufacturers wishing to participate in the open bid process shall make application with the Air 

Pollution Control Division, Mobile Sources Section, of the Colorado Department of Public Health and 

Environment, 4300 Cherry Creek Drive South, Denver, CO 80246-1530 on forms provided thereby. All 

manufacturers making application shall meet the requirements as specified by the Department of 

Administration and the Procurement Code, Articles 101-112 of Title 24, C.R.S.

A manufacturer requesting the approval of an instrument for the measurement of exhaust gases for use in 

the AIR Program station shall make application therefore with the Air Pollution Control Division, 4300 

Cherry Creek Drive South, Denver, CO 80246-1530 on forms provided thereby. All manufacturers making 
application shall meet the technical specifications and administrative requirements specified by the Air 

Pollution Control Division.

III. PERFORMANCE AND DESIGN SPECIFICATIONS FOR THE COLORADO 94 AND 

COLORADO BAR 97 EXHAUST GAS ANALYZERS

Pursuant to Section 42-4-306(3)(a), C.R.S the specifications for the exhaust gas analyzer required for 

inspections conducted July 1,1987 and thereafter are attached to this regulation as Appendix A. These 

specifications include but are not limited to the provisions of California BAR 90, data collection, 

service/maintenance, requirements for replacement or loan instruments and warranty for the period of the 

agreement. These specifications are described in a separate document entitled “Colorado Department of 

Public Health and Environment Specifications for Colorado 94 Analyzer - Hardware Specifications” March 

17, 1994 as adopted by the Commission. This information is available from the Air Pollution Control 

Division, Mobile Sources Section, 4300 Cherry Creek Drive South, Denver, CO 80246-1530. Those 

manufacturers making application should refer to Section II of this Part B.

The Division in its discretion may accept substitute specifications for Test Analyzer Systems provisions 

that such substitute specifications are equivalent to those contained in Appendix A.

IV. SPAN GASES FOR USE WITH COLORADO 94 AND COLORADO BAR 97 TEST ANALYZER 

SYSTEMS

IV.A. General

The instrument manufacturer and his designated marketing vendors shall, supply span gases 

approved by the Division to any ultimate purchaser of his unit. The instrument manufacturer shall 

also provide the analyzer purchaser with a comprehensive, up-to-date list (with addresses and 

phone numbers) of gas blenders approved by the Division. Each new or used instrument sold by 

the instrument manufacturer or marketing vendor shall have full span gas containers installed and 

operational at time of delivery.

IV.B. Span Gas Blends

The span gas concentrations supplied to the AIR Program stations shall conform to the 

specifications contained in Section VI. of this Part B.

Only gas blends supplied by Division approved blenders selected pursuant to Section 42-4-

306(3)(a)(I)(C) shall be offered for sale in Colorado.

Pursuant to Section 42-4-306(3)(a)(I)(C), the Division shall select blenders authorized to provide 

span gases that comply with the standards and specifications set out in Appendix B. The 

requirement to use gases procured pursuant to the standards and specification in Appendix B 

shall not be federally enforceable, and shall not be part of the State Implementation Plan.

IV.C. Optical Correction Factor [also referred to as “C” factor, propane to hexane conversion 

factor” (P.E.F.)].

Each instrument shall be permanently labeled with its correction factor visible from the outside of 

its cabinet. The correction factor shall be carried to at least two decimal places e.g., (0.52). Factor 

confirmation shall be made on each assembled analyzer by measuring both N-hexane and 

propane on assembly line quality checks. P.E.F. limitations are described in the specifications 

document attached to this regulation as Appendix A.

IV.D. Running Changes and Equipment Updates
The Commission must approve any changes to design or performance characteristics of 

component specifications that may affect instrument performance. It will be the instrument 

manufacturer's responsibility to confirm that such changes have no detrimental effect on analyzer 

performance. All Colorado 94 exhaust gas analyzers will be updated as needed and as specified 

in the specifications document.

V. DOCUMENTATION, LOGISTICS, AND WARRANTY REQUIREMENTS

V.A. Instruction Manual

The instruction manual accompanying each analyzer shall contain at least the following:

V.A. 1. Complete technical description.

V.A.2. If available, functional schematics (mechanical and electrical).

V.A.3. Accessories and options (included and/or available).

V.A.4. Model number, identification markings and location.

V.A.5. Operating maintenance to include periodic recommendations, i.e., daily, weekly, 

monthly, and procedure for maintaining sample system integrity (leaks, hang-up, 

calibration, filters, etc.).

V.A.6. Required service schedule identifying the items needing maintenance and the 

procedures to be followed by the purchaser. The services to be performed only 

by the manufacturer shall be clearly identified.

V.A.7. Warranty provisions to include listing of warranty repair stations by name, 

address, and phone number.

V.A.8. The name, address, and phone number of the permanent Colorado 

representative offering training, service, warranties, etc.

V.A.9. Information and terms of manufacturers service contract clearly stating the 

coverage including but not limited to each party's obligation, period of coverage, 

cost, service response times, availability of loaner units. Manufacturer or 

designee performed service/maintenance provisions and costs shall be so stated 

for the duration of the program and annually up-dateable costs.

VI. CALIBRATION OF COLORADO 94 AND COLORADO BAR 97 TEST ANALYZER SYSTEMS

The Division shall use and require for use in the calibration and spanning of exhaust gas analyzers span 

gases and containers supplied by authorized blenders meeting the following parameters, blends, and 

specifications:

VI.A. Standardizing Instruments

The calibration gases for standardizing instruments shall conform to the provisions outlined in 40 

CFR, Section 86.114 (July 1, 1992) (EPA) for automotive exhaust emissions testing. Those gases 

shall be of “precision” quality, certified to be within ±1% of the labeled concentration, and 

traceable to the National Institute for Standards and Technology (NIST).

VI.B. AIR Program Station Instruments
The span gases supplied to AIR Program stations shall conform to the following:

VI.B.1. Tri-blends of HC, CO, CO2 in a carrier gas of nitrogen (N2). The hydrocarbon 

(HC) gas will be propane.

VI.B.2. The concentrations) of the span gas blends (two) shall be within limits 

established by the Division to provide for uniform exhaust gas analyzer spanning. 

The Division may establish such limits to ensure gasses are measurable based 

upon the ranges or scales of the equipment.

VI.B.3. The accuracy of the AIR Program station span gas blend shall be certified by the 

blender to be ±2% of labeled concentration and traceable to the NIST.

VI.C. AIR Program stations will calibrate the exhaust gas instrument once every 72 hours as 

determined by the instrument or as needed in order to maintain accuracy.

VI.D. All AIR Program exhaust gas analyzers will be calibrated only with span gases bearing a 

Colorado approval label.

VI.E. Additional specifications related to calibration requirements are described in the 

specifications document attached to this document as Appendix A.

VII. APPROVAL OF THE COLORADO AUTOMOBILE DEALERS TRANSIENT MODE TEST 

ANALYZER SYSTEM

Any applicable emissions inspection required by the AIR Program performed by a licensed Motor Vehicle 

Dealers Test Facility pursuant to Section 42-4-304 (19), C.R.S., in the enhanced program area, shall be 

performed utilizing a Colorado Automobile Dealer Transient Mode (IG 240) test analyzer system 

approved by the state open bid process. Sources of vendors for the approved test system may be 

obtained from the Program Administrator, Mobile Sources Section, Air Pollution Control Division, 

Colorado Department of Public Health and Environment, 4300 Cherry Creek Drive South, Denver 

Colorado 80246-1530.

This Section VII, and the associated design and performance specifications set out in Appendix A, 

Attachment III, shall not be federally enforceable and shall not be part of the State Implementation Plan.

VIII. APPLICATIONS FOR APPROVAL OF THE COLORADO AUTOMOBILE DEALERS TRANSIENT 

MODE TEST ANALYZER SYSTEM

Those manufacturers wishing to participate in the open bid process shall make application with the Air 

Pollution Control Division, Mobile Sources Section, of the Colorado Department of Public Health and 

Environment, 4300 Cherry Creek Drive South, Denver Colorado 80246-1530 on forms provided thereby. 

All manufactures making application shall meet the requirements as specified by the Department of 

Administration and Procurement Code, Articles 101-112 of Title 24, C.R.S.

The design and performance specifications for the Colorado Automobile Dealers Transient Mode Test 

Analyzer System Technical and Hardware Specification Document of January 27. 1997 attached as 

Appendix A, Attachment III. Pursuant to 42-4-306(3)(a)(I)(C), the Division shall let bids for the 

procurement of instruments that comply with such specifications. In addition to the specifications set out 

in Appendix A, attachment III, qualifying bids shall:

Include a bid for the procurement of any working/support and span gases necessary for the operation of 

such Colorado Automobile Dealers Transient Mode Test Analyzer System, unless all such gases are 

already subject to a contract issued pursuant to 42-4-306(3)(a)(I)(C). Any bid for the procurement of such 
gases shall comply with the relevant requirements of Part B, IV of the Regulation Number 11 and relevant 

requirements of Standards and Specifications for Calibration and Span Gas Suppliers, attached as 

Appendix B, including the “Gas Requirements for the Basic and Enhanced Inspection Test Programs, 

1997” as set out in Section 5 of Appendix B.

Include a comprehensive and up-to-date list of working/support and span gas suppliers subject to a 

contract issued pursuant to 42-4-306(3)(a)(I)(C). A copy of such list shall be provided to each purchaser.

Provide for the Division-approved calibration gases for calibration of the Colorado Automobile Dealers 

Transient Mode Test Analyzer System.

A service and maintenance plan, including a description of services, service response times, periodic 

maintenance schedules and annual service agreement costs inclusive of all services necessary to comply 

with the Colorado Automobile Dealers Transient Mode Test Analyzer System Technical and Hardware 

Specification Document of January 27, 1997. Service agreement costs are to be listed annually and shall 

be for the remaining period of the AIR Program.

IX. APPROVAL OF THE COLORADO ON-BOARD DIAGNOSTIC (OBD) TEST ANALYZER 

SYSTEM

Any applicable on-board diagnostic emissions inspection required by the Air Program performed shall be 

performed utilizing an on-board diagnostic (OBD) test analyzer system approved by the state. Sources of 

vendors for the approved Colorado On-Board Diagnostic Test Analyzer System may be obtained from the 

Program Administrator, Mobile Sources Section, Air Pollution Control Division, Colorado Department of 

Public Health and Environment, 4300 Cherry Creek Drive South, Denver, Colorado 80246-1530.

X. THE COLORADO ON-BOARD DIAGNOSTIC (OBD) TEST ANALYZER SYSTEM

The design and performance specifications for the Colorado On-Board Diagnostic Test Analyzer System 

are outlined in the Society of Automotive Engineers J1979 Standard.

In addition to the specifications set out in J1979 Standard, additions and/or modifications to the 

operational, data collection, data recording and quality assurance auditing functions shall be outlined in a 

Colorado On-Board Diagnostic (OBD) Test Analyzer System Requirements Specification, to be submitted 

by the Division for Air Quality Control Commission approval no later than December 31, 2013.

XI. REQUESTS FOR APPROVAL OF CLEAN SCREEN TEST ANALYZER SYSTEMS

XI.A. REPEALED

XI.B. Calibration gas blends intended for Clean Screen Test Analyzer Systems shall be verified 

and approved subject to the requirements of Standards and Specifications for Calibration 

and Span Gas Suppliers including Gas Requirements for the Basic and Enhanced 

Inspection Test Programs. 1997, (Appendix B).

Concentrations of calibration gases noted above are to be determined pending system 

configuration, operating ranges and expected emissions readings.

State audit blends for Clean Screen Test Analyzer Systems shall be of varying concentrations of 

and shall conform to the above gas blending standards.

PART C Inspection Procedures and Requirements for Exhaust Emissions, Fuel Evaporation 

Control, Visible Smoke Emissions, Emissions Control Systems, On-Board 
Diagnostics (OBD); and Practices to Ensure Proper Emissions Related 

Adjustments and Repairs

I. PRE-INSPECTION REQUIREMENTS

I.A. A licensed emissions mechanic, licensed emissions inspector or authorized emissions 

inspector must perform all aspects of the inspection. It is the responsibility of emissions 

mechanics and emissions inspectors to notify the Department of Revenue of their current 

place of employment and any subsequent transfer, and place of residence. The 

Contractor shall be responsible for its personnel and notifying the Department of all 

personnel assignments and adjustments in those assignments.

The emissions mechanic not employed by an “Inspection-Only Station” shall notify the customer 

prior to initiating an emissions inspection if he/she is unable to perform the required adjustments 

and/or repairs for that particular vehicle should that vehicle fail the inspection. Otherwise the 

emissions mechanic shall not conduct an inspection on a motor vehicle unless that emissions 

mechanic so notifies the customer or is able to perform the adjustment and/or repair procedures 

for that particular vehicle as prescribed by the manufacturer and specified by Section IV. of this 

Part C.

I.B. Inspections may only be performed on the premises of the licensed address as 

prescribed in Part D Section I. A. 2. The entire inspection shall take place within the 

reach of the analyzer hose.

I.C. In consideration of maintaining inspection integrity:

I.C.1. The temperature of the inspection area when utilizing one or more test analyzer 

systems as specified in Part B of this regulation shall be between 41°F and 

110°F (5°C and 43°C) during the inspection. Inspection area temperatures must 

be accurately recorded, and monitored in a well-ventilated location away from 

vehicle engine and exhaust heat sources and out of direct sunlight. The 

inspection area includes the vehicle being inspected.

I.C.2. The test analyzer system and other inspection equipment shall be kept in an area 

within the facility that affords adequate protection from the weather.

I.C.3. A permanent location that meets all applicable requirements of this rule to 

provide for the inspection of vehicles is required. Electrical supply must be public 

utility designated for that area and meeting the analyzer manufacturer's 

requirements for to the test analyzer system is to be dedicated to this purpose. 

Full-time connectivity to a dedicated data transmission media meeting the 

analyzer manufacturer’s requirements for the test analyzer system.

I.D. Upon a physical verification of the vehicle identification number (VIN) and license plate 

number, the emissions mechanic or emissions inspector will enter this information into 

the program database in order to match this information with the state registration record. 

In the case of a match, the emissions mechanic or emissions inspector shall proceed. If 

no match is found, a new inspection record will be created. All non-Colorado registered 

vehicles and first time registrations with the State of Colorado will require the creation of 

a new inspection record by the emissions mechanic or emissions inspector.

I.E. The emissions mechanic or emissions inspector shall ascertain from the inspection 

record data base if an initial inspection or an after-repairs inspection is to be conducted. If 

an after-repairs inspection is to be conducted, previous inspection data is required for 
comparison. Specific emissions related repair information as specified in Section VII (B) 

of this Part C shall be entered to the database. Inspections conducted within 60 days of 

the initial inspection date are to be considered an after-repairs inspection. Inspections 

conducted greater than 60 days from the initial inspection date are to be considered initial 

inspections. The emissions mechanic or emissions inspector shall accurately enter 

vehicle, and last inspection information as required for vehicle emissions inspection 

records.

I.F. The emissions mechanic or emissions inspector shall perform a cursory safety 

assessment of the motor vehicle prior to inspection. If in the opinion of the emissions 

mechanic or emissions inspector the vehicle is unsafe to inspect due to engine/drive-line 

metallic noises, or leaking fluids, the request for inspection may be refused.

II. EXHAUST EMISSIONS INSPECTION PROCEDURES

II.A. All heavy-duty vehicles and all 1981 and older model year vehicles to be inspected at 

licensed inspection-only facilities or licensed enhanced inspection centers in the 

enhanced program area shall be administered an EPA approved idle short test as 

specified in 40 CFR, Part 51, Subpart S, Appendix B.

II.A.1. The emissions mechanic or emissions inspector will use a certified TAS to select 

the appropriate idle short test cycle based upon the make, model year engine 

family and vehicle classification. These idle short tests include, but may not be 

limited to, a standard single speed idle test; the pre-idle 30-second preconditioning idle test with the high speed (2500 ± 300 RPM) pre-conditioning 

cycle before the idle mode; a standard two speed (3 - mode) idle test with the 

raised idle segment at 2500 ± 300 RPM; second chance raised idle preconditioning for 30 seconds just prior to the idle mode after an initial failure, and 

second chance restart in which the ignition is turned off for ten (10) seconds and 

then restarted to complete the emissions inspection procedure. All sampling 

modes shall (each) be thirty seconds in duration and raised engine speed modes 

be it for pre-conditioning or sampling, shall be 2500 RPM ± 300 RPM. As a 

pass/fail determination, the vehicle's emissions levels must be the same as or 

less than applicable limits at the designated engine speed(s) in order to pass.

II.A.2. The entire vehicle shall be in normal operating condition and at normal operating 

temperature, which shall be determined by carefully feeling the top radiator hose 

while the engine is not operating, by checking the temperature gauge, and/or 

operating the vehicle prior to performing the idle emissions inspection. Vehicles 

are not to be idled for extended periods of time but rather inspected in an 

expeditious manner as soon as normal operating temperature is achieved. The 

vehicle shall be inspected in an as-received condition.

II.A.3. The inspection shall be performed with the transmission in park or neutral and 

with all accessories off.

II.A.4. The analyzer probe shall be inserted at least twelve (12) inches or as 

recommended by the analyzer manufacturer for a quality sample whichever is 

greater.

II.A.5. For all vehicles equipped with a multiple exhaust system, the analyzer's dual 

exhaust procedure must be used.
II.A.6. If a baffle or screen prevents probe insertion to an adequate depth, a suitable 

probe adapter or snug fitting hose that effectively lengthens the exhaust pipe 

may be used.

II.A.7. The appropriate emissions limits specified in Part F of this regulation would be 

utilized by the certified test analyzer system. In selecting appropriate emissions 

limits, for motor vehicles of model years 1978 and earlier having a gross vehicle 

weight (GVW) rating of greater than 6000 lbs., or of model years 1979 and newer 

having a gross vehicle weight rating of greater than 8500 lbs., the emissions 

mechanic or emissions inspector shall identify that particular vehicle's GVW 

rating by examining the vehicle information (metal) plate or sticker. These motor 

vehicles will be subject to the applicable emissions limits as listed in Part F of this 

regulation. If the vehicle information plate or sticker is missing, illegible or the 

GVW rating information is not otherwise available, the emissions mechanic or 

emissions inspector shall examine the engine exhaust emissions control 

information label which is permanently affixed to the engine and determine 

heavy-duty engine/vehicle federal certification status. Vehicle engines not labeled 

as having complied with applicable U.S. EPA heavy-duty regulations by the 

manufacturer are assumed to be light-duty vehicles and subject to the emissions 

limits listed in Part F of this regulation. Emissions limits for vehicles in which the 

engine has been changed shall be based upon whichever is newest, the vehicle 

or the replacement engine, as specified on a vehicle evaluation form (DR2365) or 

bar coded label generated by emissions technical center staff or designee.

II.A.8. In the event the tachometer over-ride mode must be utilized to inspect a vehicle, 

an accurate auxiliary tachometer must be used to verify engine speeds 

mandated in Part C, Section II.A.1.

II.A.9. The vehicle will be evaluated for the presence of visible smoke emissions. The 

evaluation is to be performed during all (engine) operating conditions of the 

inspection procedures prescribed in Part C, Sections II.A.1 through II.A.11.

II.A.10. A Certification of Emissions Compliance shall be issued if the vehicle passes the 

emissions control systems inspection (for 1975 and newer model year vehicles 

only), the exhaust and evaporative emissions inspection, and there is no 

evidence of visible smoke emissions.

II.A.11. If the vehicle fails the initial emissions inspection the owner is to have appropriate 

emissions related repairs or adjustments made and may return the vehicle to an 

AIR Program station, facility or center, as appropriate, for reinspection. Within ten 

(10) calendar days of the initial test, one free reinspection shall be provided to 

the motorist if the vehicle is returned to the same station or facility at which the 

initial test was performed. A motorist shall be entitled to one free after-repairs test 

at any contractor operated center within ten (10) calendar days of the initial test 

performed at a contractor operated center. If during repairs, it is determined the 

necessary parts are not available, the motorist may be issued a temporary 

Certificate of Emissions Control by Department of Revenue personnel. Proof of 

part(s) non-availability as described in Part C, Section III.D. of this part is 

required. Motorists pursuing a temporary Certificate of Emissions Control must 

facilitate final vehicle inspection and compliance with adopted regulation.

II.B. All model year 1982 and newer light-duty vehicles, except vehicles required to be OBD 

tested pursuant to Part C, Section II.C. to be inspected at licensed enhanced inspection 

centers within the enhanced program area shall be administered an EPA approved 
transient loaded mode inspection procedure as specified in 40 CFR, Part 51 Subpart S 

Federal Register as amended to incorporated OBD testing August 6, 1996.

II.B.1. Vehicles shall be inspected in an as-received condition.

II.B.2. The inspection shall be performed with all accessories off.

II.B.3. The appropriate emissions limits as specified in Part F of this regulation shall be 

selected by the TAS based upon the model year and vehicle classification.

II.B.4. Light-duty vehicles of model year 1995 and older found to be safe but unable to 

be dynamometer tested shall be administered an idle short test as specified in 40 

CFR, Part 51, Subpart S, Appendix B. OBD equipped light-duty vehicles that are 

unable to be tested on the dynamometer shall be tested using the OBD test 

procedures in Part C, Section II.C. to include meeting passing criteria in Part F, 

Section VII. Eligibility for an alternative test procedure shall be determined by the 

Division based upon:

II.B.4.a. The vehicle wheelbase greater than 125 inches

II.B.4.b. The vehicle wheelbase less than 92 inches

II.B.4.c. The vehicle driveline, traction control system, and/or brake system, 

which have not been modified from the original configuration, cannot be 

accommodated on the dynamometer.

II.B.4.d. The vehicle is “Handicapped” plated and fitted with hand controls or 

similar apparatus to facilitate operation of the vehicle.

II.B.5. Heavy-duty vehicles to be inspected at licensed enhanced inspection centers 

within the enhanced program area shall be administered an appropriate EPA 

approved idle short test as specified in Section II (A) of this Part C.

II.B.6. The inspector may refuse to conduct the transient driving cycle dynamometer 

inspection procedure if the tires on the drive wheels are worn such that the cords 

are visible or sidewalls are peeling or blistered.

II.C. Effective January 1, 2015, light-duty vehicles, to include light-duty trucks in their eighth 

through eleventh model year, and all light-duty vehicles, to include light-duty trucks of 

model year 1996 and newer that are unable to be tested on an IM 240 test, are to be 

inspected at licensed enhanced inspection centers and shall be administered an EPA 

approved on-board diagnostic test as specified in 40 CFR, 85.2222. 

II.C.1. Vehicles shall be inspected in an as-received condition. 

II.C.2. The on-board diagnostic inspection shall be conducted with the key-on/engine 

running. 

II.C.3. The on-board diagnostic test analyzer system shall determine what monitors are 

supported by the diagnostic system and the readiness status for applicable 

monitors. 

II.C.3.a.If the readiness evaluation indicates that a vehicle has more than one 

unset (not ready) readiness monitor, and the malfunction indicator light 
(MIL) is commanded off, the vehicle shall be subjected to an IM 240 

emissions inspection immediately. 

II.C.3.b.If the vehicle’s on-board diagnostics are unable to communicate 

electronically with the Colorado OBD Test Analyzer System, the vehicle 

will be subjected to an IM 240 emissions inspection immediately.

II.C.3.c. The readiness requirement, outlined in this Part C, Section II.C.3.a. may 

be waived to accommodate for specific vehicles with known readiness 

design problems, in accordance with applicable technical service 

bulletins, EPA guidance, or division technical findings, as approved by 

the Division.

II.C.4. The OBD test analyzer system shall evaluate the malfunction indicator light 

status and record status information in the vehicle test record. 

II.C.5. All diagnostic trouble codes resulting in malfunction indicator light commandedon status shall be recorded in the vehicle test record.

II.C.6. If the vehicle meets the passing criteria for the OBD inspection as listed in Part F, 

Section VII. Of this regulation, the vehicle passes the on-board diagnostic 

inspection.

II.C.7. Vehicles in an OBD “not ready” status, or vehicles unable to communicate with 

the OBD Test Analyzer System that default to an IM 240 test as described in Part 

C, Section II.B. shall be subject to pass/fail for the applicable IM 240 pass/fail

standards in Part F, Section III. of this regulation.

II.C.8. If the malfunction indicator light is not commanded on and the vehicle passed the 

mil visual inspection, as outlined in this Part C, Section III.B., the vehicle shall 

pass the on-board diagnostic portion of the emissions inspection even if 

diagnostic trouble codes are present. 

II.C.9. The division may require no more than five percent, at random, of all OBD tested 

vehicles to undergo an IM 240 test at the time of the OBD testing. The failure of

the vehicle to pass IM 240 shall be reported to the motorist, but shall not be used 

to fail the vehicle.

III. EMISSIONS CONTROL SYSTEMS INSPECTION PROCEDURES

Motor vehicles shall be configured as required for sale or use within the United States pursuant to 40 

CFR, Part 86, Subpart A; unless specific documentation in the form of a state issued vehicle evaluation 

form (DR2365) or an EPA (EPA form 3520) or DOT exemption is submitted. To ensure compliance with 

this requirement, the emissions mechanic or emissions inspector shall inspect all model year 1975 

through 1995and newer model year vehicles and assess the integrity of the emissions control system in 

accordance with the procedures set forth in this Section III. Effective January 1, 2015, the emissions 

mechanic or emissions inspector shall inspect all model year 1975 through 1995 model year vehicles and 

assess the integrity of the emissions control system in accordance with the procedures set forth in this 

Section III.

III.A. All model year 1975 through 1995 model year vehicles shall be visually inspected for the 

presence and operability of the air system, catalytic converter system(s) and oxygen (O2) 

systems. If these parts or systems are not operating as designed, inoperable or have 

been removed or otherwise tampered with, the vehicle will not qualify for a Certification of 
Emissions Control. In assessing whether the proper emissions control systems are 

present, the emissions mechanic or emissions inspector shall examine the emissions 

control information decal within the engine compartment to determine the appropriate 

emissions control systems for that particular vehicle. If an emissions control information 

decal is missing, incomplete, illegible or is not appropriate for the specific vehicle, the 

emissions mechanic or inspector may contact a state emissions technical center for 

guidance, use other reference materials or refer the vehicle to a state emissions technical 

center for further evaluation.

For the period December 1, 2012 through December 31, 2015, in place of the visual inspection, 

the emissions control systems for model year 1996 and newer vehicles may be inspected using 

the vehicle’s on-board diagnostic (OBD) systems. To utilize this alternative inspection procedure, 

the emissions inspector must interrogate the vehicle’s OBD system using Division approved 

procedures and equipment. If the emissions inspector is unable to interrogate the OBD system, 

or if the interrogation reveals either that the malfunction indicator light (MIL) is commanded on or 

that any OBD monitors are not set, the vehicle shall be visually inspected in accordance with the 

procedures set forth in Subsection III.A.

III.B. An assessment of the emissions control system malfunction/service-maintenance 

indicator(s) performance shall be conducted by the emissions mechanic or emissions 

inspector on those vehicles so equipped.

For those vehicles equipped with “check engine” dash indicator lights or similar emissions control 

systems malfunction or service-maintenance indicator(s), the following procedure if applicable will 

be performed to assess the integrity of the system:

● Ignition Off, Engine Off = indicator(s) off

● Ignition On, Engine Off = indicator(s) on or displayed

● Ignition On, Engine Running = indicator(s) off

The failure of the system to respond as described above shall be reported to the motorist, but 

shall not be used to fail the vehicle.

III.C. The repair/replacement of catalytic converters must incorporate the same type, style and 

location on the exhaust system relative to engine as originally designed by the vehicle 

manufacturer. If a new original equipment manufacturer (OEM) part is not used, only an 

EPA “accepted” after-market component appropriate to that application may be used. 

Verification of the correct application and certification status must be performed at the 

time of reinspection. The submittal and review of repair receipts as specified in 

Subsection VII.B of this section is required in order to substantiate proper repairs of 

applicable emissions control system.

III.D. If the necessary part(s) will not be available prior to the month of expiration of the present 

vehicle registration, and the owner obtains a signed form or statement to that effect from 

a manufacturer's dealer for that make vehicle, or from an automotive parts supplier which 

in the normal course of business supplies part(s) for that vehicle, Department of Revenue 

personnel after verification may issue a temporary Certification of Emissions Control. The 

form or statement provided must specifically identify by part numbers and description, the 

necessary part(s). The owner then has until the expiration of the temporary certification to 

complete the necessary repairs or replacement.
IV. ON-BOARD DIAGNOSTIC INSPECTION PROCEDURES

Effective January 1, 2015, Lightlight-duty vehicles to include light-duty trucks of model year 1996 through 

those vehicles that have reached their eleventh model year old equipped with California on-board 

diagnostic (OBDII) or EPA on-board diagnostic systems (EPA, OBD) shall be evaluated to determine 

operability and integrity of the applicable system(s). The OBD system will be connected to the TAS and 

interrogated. Fault codes and diagnostics shall be reported to the motorist with other emissions 

inspection information but with the exception of dynamometer incompatible vehicles as noted in Part C, 

Section II.B.4. shall not be used to fail the vehicle.

V. EVAPORATIVE FUEL CONTROL INSPECTION PROCEDURES

Model year 1975 and newer vehicles shall be inspected for the presence and integrity of the gasoline 

cap(s). The gasoline cap(s) of such vehicles inspected in the nine county Front Range enhanced program 

area as defined in Section 42-4-304(9)(a)., shall also be inspected for sealing integrity as specified in Part 

F, Section IV of this regulation.

Vehicles with a missing gasoline cap(s) shall not qualify for issuance of a Certificate of Emissions Control. 

Motorists whose vehicles have gasoline cap(s) demonstrating excessive leakage shall be notified of the 

deficiency, repair/replacement and a full retest shall be mandatory.

VI. FREE REINSPECTION

Vehicles which fail any or all elements of an emissions inspection are eligible for one free reinspection 

within ten (10) calendar days if presented to the same station or facility as initially inspected and failed. In 

the case of the contractor operated enhanced inspection center network, the ten (10) day free 

reinspection shall be honored at any enhanced inspection center.

VII. REPAIR INFORMATION

Any after-repairs reinspection of a vehicle initially failed calls for the submittal of a completed official AIR 

Program emissions repair form.

VIII. CERTIFICATION OF EMISSIONS CONTROL

In order to obtain a Certificate of Emissions Control, the vehicle must meet the following conditions:

VIII.A. Certification of Emissions Compliance may be issued if:

VIII.A.1.The vehicle emissions levels are the same as or less than the applicable 

emissions limits; or

VIII.A.2.For vehicles in model years seven through ten subject to an on-board diagnostic 

inspection, the OBD system meets the passing criteria established in Part F, 

Section VII. of this regulation, and

VIII.A.3.There are no smoke emissions visible from the vehicle engine crankcase and/or 

tailpipe, and

VIII.A.4.For 1975 through 1995 model years, the vehicle passes the emissions control 

systems inspection, and

VIII.A.5.Under enhanced inspection requirements, the vehicle owner/operator of a 1995 

or newer model year vehicle shall demonstrate compliance with any federal 
emissions recall-pursuant to 40 CFR Part 85.1902 (d) or remedial repair plan 

pursuant to Section 207 (C) of the federal Clean Air Act for which owner 

notification occurs after 01 January 1995.

VIII.B. A Certification of Emissions Waiver may be issued if:

VIII.B.1.The vehicle passes the emissions control systems inspection (1975 and newer 

model year vehicles only) required by Part C, Section III. A, B and C.; and

VIII.B.2.Basic Program

For model year 1981 and earlier at least seventy-five dollars ($75) has been spent on 

emissions related adjustments and repairs as specified in Part C, Sections IX and X 

provided that proof of repair costs for that specific vehicle has been provided to 

Department of Revenue personnel or designee in the form of an itemized bill, invoice, 

work order, manifest, or statement in which emissions related parts and/or repairs, are 

specifically identified.

For model years 1982 and newer, at least two hundred dollars ($200) has been spent on 

emissions related adjustments and repairs as specified in Part C, Sections IX and X, 

provided that proof of repair costs for that specific vehicle has been provided to 

Department of Revenue personnel or their designee in the form of an itemized bill, 

invoice, work order, manifest, or statement in which emissions related parts and/or 

repairs, are specifically identified.

VIII.B.3.Enhanced Program

For model year 1968 and newer, at least four hundred and fiftyseven hundred fifteen

dollars ($450715) or as adjusted annually by the Consumers Price Index for Urban 

Consumers (CPIU) of the previous year as compared to 1989 2003 has been spent on 

emissions related adjustments and repairs as specified in Part C, Sections IX and X, 

provided that proof of repair costs for that specific vehicle has been provided to 

Department of Revenue personnel or their designee in the form of an itemized bill, 

invoice, work order, manifest, or statement in which emissions related parts and/or 

repairs, are specifically identified. The Division shall adjust the amount that must be 

expended by the motorist in order to qualify for a Certificate of Emissions Waiver, which 

amount shall be established for each calendar year through 2004 by the Division 

pursuant to the criteria specified in Section 42-4-310(1)(d)(VI),C.R.S.

For model year 1967 and earlier at least seventy-five dollars ($75) has been spent on 

emissions related adjustments and repairs as specified in Part C, Sections IX and X 

provided that proof of repair costs for that specific vehicle has been provided to and 

verified by the emissions inspector in the form of an itemized bill, invoice, work order, 

manifest, or statement in which emissions related parts and/or repairs, are specifically 

identified.

If no emissions reduction is achieved, the motorist is to be referred to the Department of 

Revenue or its designee pursuant to Sections IX. G. and X. of this Part C.

VIII.B.4.An emissions reduction as determined either by the Division-approved Colorado 

94 of Colorado BAR 97 Test Analyzer System has resulted due to emissions 

related repairs and the applicable cost limit has been met. Proof of these 

emissions related repairs are required and to be retained by the AIR Program 

station, facility or center until purged by state program personnel. The vehicle 
must have passed the emissions control systems inspection and there were no 

smoke emissions visible from the vehicle engine crankcase or exhaust system.

VIII.B.5.Engine operational parameter verification.

VIII.B.5.a. All engine parameter adjustments for idle speed, proper air/fuel 

ratio and cold enrichment, as well as proper ignition dwell and timing (if 

applicable), have been set to or verified as being set to manufacturers 

specification by a licensed mechanic or registered repair 

facility/technician.

VIII.B.5.b. For those 1981 and newer vehicles equipped with computer

based, engine management systems, also known as closed loop, 

feedback controls shall have the following additional sensors/systems 

verified to be operating within vehicle manufacturer specifications.

VIII.B.5.b.(1) As applicable to the vehicle being inspected, the oxygen 

sensor, throttle position sensor, coolant temperature sensor, 

manifold absolute pressure sensor.

VIII.B.5.b.(2) The engine management control system will be scanned 

for default/malfunction codes with those systems or components 

identified corrected.

VIII.B.5.b.(3) Primary and secondary ignition system integrity shall be 

verified for correct operation.

VIII.B.5.b.(4) A fuel delivery system utilizing a carburetor will be 

inspected for leaks, idle speed control adjustments, float 

operation and cold enrichment. A fuel delivery system utilizing 

fuel injection, be it throttle body or multiport configuration, shall 

be checked for injector function, cold enrichment and injector 

spray patterns. Fuel injectors shall also be evaluated for proper 

volume and injection pulse width. Fuel system pressure shall be 

checked for residual and running pressure.

VIII.B.5.b.(5) A cylinder leak down procedure shall be performed on all 

cylinders of the engine with the results reported to the motorist.

VIII.B.5.b.(6) With the exception of item (5) above, component/system 

deficiencies found to be out of manufacturer's operational 

specification(s) will be corrected. The cost of such repairs shall 

be creditable towards issuance of a waiver.

VIII.C. If in the opinion of a registered emissions repair facility/technician, a vehicle which is 

properly adjusted to all manufacturers emissions related specifications and all emissions 

control systems appear to be operating as required, yet the vehicle continues to exceed 

one or more emissions limits and the repair expenditure limits have not been met, a 

waiver shall be issued upon physical verification of systems operation and vehicle 

performance by emissions technical center personnel.

VIII.D. For vehicles registered and operated in the enhanced area, upon verification by a 

Department of Revenue Motor Vehicle Emissions Compliance Inspector, a waiver not to 

exceed one inspection cycle may be granted to obtain necessary emissions related 
repairs on a vehicle in the case of economic hardship when the Certificate of Emissions 

Waiver requirements of this section have not been met. It must be verified that the 

vehicle owner in question is participating in an established and recognized public 

assistance program. The provisions of this Paragraph D shall only apply to a vehicle 

once. To obtain a hardship waiver, the registered owner of the vehicle in question shall 

satisfy the following requirements:

VIII.D.1. The vehicle must fail for carbon monoxide, hydrocarbons, and/or oxides 

of nitrogen failures.

VIII.D. 2. The hardship waiver will not be approved for vehicles that are tampered, 

missing equipment, fail the evaporative inspection, or fail for visible smoke.

VIII.D. 3. The vehicle owner must be participating in an established and 

recognized public assistance program.

VIII.D. 4. The vehicle must be the sole means of transportation for the vehicle 

owner, and the only vehicle registered in the owner’s nameowner must not have 

more than two vehicles registered in his/her name.

VIII.D. 5. Such extension may be granted only once per vehicle.

VIII.E. A Certificate of Emissions Waiver will not be issued to a vehicle that is eligible for the 

Emissions Control Systems Performance Warranty, 207(b) of the federal Clean Air Act. 

Per the provisions of the 207(b) Performance Warranty, the repair costs necessary for 

compliance with AIR Program emissions limits specified in Part F of this regulation will be 

borne by the vehicle manufacturer or his authorized dealer representative.

VIII.F. The emissions mechanic or emissions inspector shall generate the appropriate vehicle 

inspection report forms, electronic records, Certificate of Emissions Control, as required 

by the Department of Revenue or the Division and distribute to the motorist and the 

Departments of Health and Revenue. The emissions mechanic or emissions inspector 

will remove all expired Verification of Emissions Test windshield stickers. The vehicle 

inspection report is to be electronically identified by the issuing emissions mechanic or 

emissions inspector.

IX. ADJUSTMENT PROCEDURES

The emissions mechanic is to secure high altitude specifications for idle speed, idle mixture, ignition 

timing, dwell, and fast idle speed for the purpose of adjustment. If no high altitude specifications are 

available through the Department of Health or other reference sources refer to the emissions decal, other 

applicable specifications guide, or sea level specifications for proper specifications.

IX.A. With a dwell meter, check to determine if the ignition dwell is within the recommended 

tolerance of ±2° of specifications. Reset if the ignition dwell is not within tolerance.

IX.B. Connect tachometer to determine if idle speed is correct. If not, set to manufacturer's 

specifications with a tolerance of ±50 rpm.

IX.C. With the engine idling at the correct speed, check ignition timing to determine if it is within 

+4° to -2° of the recommended setting, if no high altitude specifications are available.

IX.D. Using an infrared analyzer, propane enrichment kit, and/or tachometer, adjusts the idle 

air/fuel ratio using manufacturer's suggested procedures and specifications, if applicable.
IX.E. After completing the preceding steps, readjust idle speed to manufacturer's 

specifications, if not within tolerance.

IX.F. Using the manufacturer's suggested procedure, check the fast idle speed and adjust to 

manufacturer's specifications.

IX.G. If the vehicle continues to exceed applicable emissions limits, or continues to fail OBD, 

the vehicle must undergo specific emissions related adjustments and repairs. 

Adjustments and repairs must be accomplished to the point of compliance, or the 

applicable cost ceiling must have been met. If the applicable emissions related 

adjustment and repair requirements have been met but an emissions reduction has not 

resulted, the vehicle owner may be referred to a Department of Revenue Motor Vehicle 

Emissions Compliance Inspector to get a waiver. Repairs must have been reasonably 

calculated to achieve a reduction in emissions of those components of the inspection the 

vehicle failed, pursuant to manufacture's specifications as required by Sections 42-4-

306(7)(a)(II)(A) and 42-9-111,C.R.S.

X. EMISSIONS RELATED REPAIRS

X.A. Emissions related repairs generally include only those adjustments to and maintenance 

and repair of the motor vehicle that are directly related to the reduction of exhaust 

emissions necessary to comply with the applicable emissions limits and procedures. The 

expenditure for emissions related repairs does not include the inspection fee as specified 

in Section 42-4-311, C.R.S. or expenses associated with the adjustments to and 

maintenance, replacement, and repair of air pollution control equipment on the vehicle if 

the need for such adjustment, maintenance, or repair pursuant to Part C, Section III is 

due to disconnection of, tampering with, or abuse to such air pollution control equipment. 

Air pollution control equipment is any part, assembly or system originally installed by the 

manufacturer for the sole or primary purpose of reducing emissions.

X.B. Repairs and maintenance to the following systems shall qualify as emissions related 

repairs insofar as the purpose is to reduce exhaust emissions:

— Air Intake Systems

— Ignition Systems

— Fuel Control Systems

— Emissions Control Systems

— Basic Engine Systems

— For microprocessor (02) based air/fuel control systems, cooling systems.

X.C. Within the basic program, emissions related adjustments and repairs must have been 

performed by a licensed emissions mechanic or repair facility/technician registered with 

the Division pursuant to Part D of this regulation in order to be creditable to the repair 

cost waiver limits.

In order to be creditable to the enhanced repair cost limits, adjustments and repairs must have 

been performed by a repair facility/technician registered with the Division pursuant to Part D of 

this regulation.
Only the appropriate emissions failure related parts costs should apply to applicable waiver limits 

for repairs not performed at a licensed emissions inspection station or registered repair 

facility/technician.

XI. ENGINE CHANGES

XI.A. For those vehicles in which the original engine has been replaced, the emissions limits 

and applicable emissions control equipment for the year and model of the vehicle 

body/chassis, as per registration/title or replacement engine, whichever is newest, shall 

apply. For those diesel powered vehicles which have been converted to operate on 

fuel(s) other than diesel; the emissions limits and applicable emissions control equipment 

for the year, make and model of the gasoline powered engine equivalent as originally 

manufactured, for the vehicle body/chassis, per the registration or replacement engine, 

whichever is newest, shall apply as determined by emissions technical center personnel 

or designee and specified on an official AIR Program vehicle evaluation form (DR2365).

XI.B. For 1975 and newer vehicles in which the original engine has been replaced, if either the 

vehicle body/chassis original engine, as per registration/title or replacement engine as 

manufactured had a catalytic converter system, air injection reaction system, and/or 

microprocessor based air/fuel control system, these emission control systems must be 

present, intact and operational before a Certification of Emissions Control may be issued.

XI.C. For those vehicles titled/registered as model year 1975 and newer, that were assembled 

by other than a licensed manufacturer such as kit-cars, registered/titled according to 

Section(s) 42-6-108 and/or 42-5-205, C.R.S. and assigned a state or manufacturer 

specific identification number, the applicable emissions control equipment and standards 

will be based upon a determination by technical center personnel of the vintage of the 

vehicle engine. The technical center personnel may issue an affidavit and the year of the 

engine shall be presumed to be that stated by the vehicle owner unless it is determined 

by state emissions technical center personnel or designee, after physical inspection of 

the vehicle engine, that the year of the engine is other than stated by the owner.

XII. CLEAN SCREEN INSPECTION PROGRAM PROCEDURES

XII.A. Eligibility to participate

XII.A.1. Vehicles specified in Part A, Section IV.B., are eligible for participation in the 

Clean Screen Program.

XII.A.2. Clean Screen inspections applicable to the program are those performed within 

twelve months prior to an individual vehicle's registration renewal date.

XII.A.3. Vehicles are eligible for participation in the Clean Screen Program when the two 

most recent consecutive emissions readings observed during the 12-months 

prior to its registration date comply with the standards specified in Part F, Section 

VI. and: the most recent passing emissions reading occurred on a different day 

or at a different site location from the prior reading. Additionally, vehicles that are 

identified as low emitters on the low emitting vehicle index are eligible for 

participation in the clean screen program when the most recent emissions 

reading observed during the 12-months prior to their registration date complies 

with the standard specified in Part F, Section VI.

XII.A.4. The following vehicles are ineligible for participation in the Clean Screen 

Program:
XII.A.4.a. New Vehicles as specified in Section 42-4-310(b)(II)(A), C.R.S.

XII.A.4.b. Vehicles involved in a change of ownership.

XII.A.4.c. Vehicles owned by the United States government or any agency 

thereof pursuant to Section 42-4-310(l)(b)(I), C.R.S.

XII.B. All aspects of inspection must be performed by a licensed Clean Screen Inspector.

XII.C. Clean Screen Test Analyzer Systems

XII.C.1. Vehicles participating in the Clean Screen Program shall be tested as specified in 

this Part C utilizing a Clean Screen Test Analyzer System recognized by the 

Division as having complied with the performance and design requirements 

specified in Part B, Section IX. of this regulation.

XII.C.2. Clean Screen Test Analyzer Systems will be periodically calibrated and 

maintained as required in Part B, Section IX. of this regulation.

XII.C.3. The inspection data processing system(s) used by the Data Manger and Clean 

Screen Inspector will be that approved by the Division, and the Department of 

Revenue.

XII.D. Vehicle owners participating in the Clean Screen Program are not subject to the 

provisions of Part C, Sections I. through XI.

XII.E. Certification of Emissions Control.

In order to obtain a Certificate of Emissions Control the following conditions must be met:

XII.E.1. The vehicle emissions levels are the same as or less than the limits specified in 

Part F, Section VI.

XII.E.2. The most recent two consecutive emissions readings were observed within 

twelve months of the registration renewal date provided that the most recent 

passing emissions reading must have occurred on a different day or at a different 

site location from the prior reading.

XII.E.3. No non-complying emissions readings are observed between or subsequent to 

the last pair of complying readings.

XII.E.4. For vehicles that are identified as low emitters on the low emitting index the most 

recent emission reading was observed within 12-months of the registration 

renewal date. For these vehicles, identification as a low emitter on the low 

emitting vehicle index shall take the place of the second remote sensing reading 

otherwise required under Section XII.E.2., above.

PART D Qualification and Licensing of Emissions Mechanics, Emissions Inspectors, and 

Clean Screen Inspectors; Licensing of Emissions Inspection and Readjustment 

Stations, Inspection-Only Stations, Inspection-Only Facilities, Fleets, Motor Vehicle 

Dealer Test Facilities, Enhanced Inspection Centers; Qualification of Clean Screen 

Inspection Sites; and Registration of Emissions Related Repair Facilities and 

Technicians
I. LICENSING OF EMISSIONS INSPECTION AND READJUSTMENT STATIONS, INSPECTIONONLY STATIONS, INSPECTION-ONLY FACILITIES, ENHANCED INSPECTION CENTERS, 

FLEET INSPECTION STATIONS AND MOTOR VEHICLE DEALER TEST FACILITIES

I.A. Emissions Site Requirements for the Licensing of Emissions Inspection and 

Readjustment Stations, Inspection-Only Stations, Inspection-Only Facilities, Fleet 

Inspection Stations and Motor Vehicle Dealer Test Facilities:

I.A.1. Applicability

All emissions inspection and readjustment stations, inspection-only stations, inspectiononly facilities, fleet inspection stations, and motor vehicle dealer test facilities are required 

to meet all applicable standards pursuant to this Part D and the Department of Revenue's 

adopted regulations in order to qualify for licensing for operation in Colorado's AIR 

Program.

To achieve the uniformity and security needed in test site locations; in order to meet 

federal EPA regulations contained in Federal Register vol. 57, Number 215, of the 

Federal Register and meet the statutory requirements contained in Sections 42-4-301 

through 42-4-316, C.R.S.; the Air Quality Control Commission adopts this standard for 

emissions site requirements.

I.A.2. Standards for emissions inspection sites:

I.A.2.a. All facilities shall be a permanent type of structure.

I.A.2.b. All sites must be capable of receiving mail.

I.A.2.c. All test facilities shall have a minimum of two off-street parking spaces 

for staging to accommodate additional vehicles.

I.A.2.d. All test site facilities shall have a customer waiting area that provides for 

observation of the entire emissions inspection process. Observation can 

be, direct observation, observation by electronic equipment, or other 

methods that prove to be as effective with prior approval of the 

Department of Revenue. 

I.A.2.e. All test sites shall be capable of conducting all aspects of the inspection 

process within the confines of a building or structure, and maintaining 

ambient air temperatures between 41 degrees and 110 degrees 

Fahrenheit in the inspection area as defined in Section I. C. 1. of Part C 

of this regulation. Inspections are not required to be performed within the 

confines of a structure or building provided ambient temperatures are 

within such parameters.

I.A.2.f. All test site facilities shall have an adequate exhaust removal system 

which shall be designed so as to not alter the inspection results and to 

assure safe ambient air quality of the inspection area as established by 

the Occupational Safety and Health Administration pursuant to 29 CFR, 

Part 1910, Subpart Z.

I.A.3. Pursuant to Sections 42-4-306(4)(a) and 42-4-307 (8)(a), C.R.S. as amended, the 

Division shall develop or contract for the development of a training program for 

emissions mechanics and emissions inspectors. The training program shall be 
comprehensive in nature and address all aspects of vehicle inspection 

procedures specified for this regulation.

I.A.3.a. Participation by emissions inspectors intending to operate in the 

enhanced program area shall be required.

I.A.3.b. Participation by emissions mechanics intending to operate in the basic 

program area shall be voluntary.

I.A.3.c. Training classes shall be funded by tuition charged to the participants.

I.A.3.d. The following tuition rates and fees shall apply

I.A.3.d.(1) The training class fee shall be no greater than $150 per 

participant.

I.A.3.d.(2) The instructor's fee for presenting a class shall not exceed 

$400.

I.A.3.d.(3) The training manual for those emissions mechanics who 

choose not to participate in a training class shall be no greater 

than $25.

I.A.3.e. These same training provisions shall be applicable to the requalification 

provisions of Section II.B. of this Part D.

I.B. The following tools, reference manuals and diagnostic equipment shall be available for 

performance of inspections; and within the basic program, emissions related adjustments 

and repairs.

I.B.1. Division approved calibrated and spanned Test Analyzer System (TAS) or OnBoard Diagnostic Test Analyzer System (OBD TAS).

I.B.1.a. As a provision of continued license to perform AIR Program inspections, 

the TAS must be updated as required, pursuant to this regulation.

I.B.1.b. The station or facility owner or operator shall maintain a full 

service/maintenance contract with the equipment manufacturer or 

equipment manufacturer's designee valid for the duration of the program 

but renewable on an annual basis

I.B.2. Rules for the operation of AIR Program inspection stations provided by the 

Colorado Department of Revenue.

I.B.3. Tachometer capable of reading 4,6 and 8 cylinders, 0-6,000 RPM minimum at no 

greater than 10 RPM of actual speed.

I.B.4. Emissions control systems applications guide as incorporated into the TAS, and 

oxygen sensor/check engine light, systems maintenance guide in either printed 

or electronic medium.

I.B.5. Dwell meter.

I.B.6. Ignition timing light.
I.B.7. Propane enrichment kit for idle mixture adjustment and diagnostics.

I.B.8. Commercially available reference manuals giving idle speed, idle mixture, 

mixture control dwell or fuel injection duration, timing, dwell, fast idle speed 

specification, high altitude specifications and information covering the emissions 

control systems description, diagnostic and repair procedures for the year 

models of vehicles involved in the AIR Program. In either printed or electronic 

medium.

I.B.9. Sufficient hand tools including but not limited to suitable computer scanner 

diagnostic link, digital volt/ohm meter, vacuum pump and other automotive 

diagnostic equipment for proper performance of the inspections, adjustments and 

emissions related repairs as applicable to the licensed entity.

I.B.10. Division approved span gas and equipment for performing gas span checks and 

calibrations.

I.B.11. Suitable non-reactive tail pipe extenders or probe adapter for inspecting vehicles 

with screened or baffled exhaust systems, or exhaust systems with multiple tail 

pipes.

I.B.12. The analyzer manufacturer's maintenance and calibration manual must be 

retained in the inspection area.

I.B.13. (Reserved)

I.B.14. Items #5, 6, 7, 8 and 9 above are not required for licensing as an inspection-only 

station or inspection-only facility.

I.B.15. Items #2 through 11 above are not required for a vehicle fleet self inspection 

station pursuant to 42-4-309 C.R.S.

I.C. A licensed emissions mechanic or emissions inspector who has successfully completed a 

hands-on proficiency check administered by the Department of Revenue in accord with 

the Commission regulations and those of the Department of Revenue, and the criteria 

specified in Part D of this regulation is or will be available to make a proper inspection. 

Enhanced inspection centers shall be open 8:30 am - 7:30 p.m. weekdays, and Saturday 

8:00 a.m. -1:00 p.m.

I.D. An emissions inspection-only station and inspection-only facility, must so indicate same 

by posting a sign in a readily visible location, and that no emissions related adjustments 

or repair services are available should the vehicle fail the inspection procedure.

I.E. A person to whom there are twenty (20) or more vehicles registered, or to whom said 

number of vehicles are leased for not less than six continuous months, or are consigned 

for sale, may be licensed as a “fleet inspection station” or as a dealer licensed under 

Article 6 of Title 12, C.R.S., a motor vehicle dealers test facility and conduct inspections 

of that fleet or those vehicles inventoried or consigned for retail sale. As a fleet inspection 

station or motor vehicle dealer test facility, no inspections may be conducted for the 

employees or general public, but only on vehicles owned, leased by the business, or 

consigned or held in inventory for sale. A Certificate of Emissions Control issued by a 

fleet emissions inspection station will be valid for 12 months, one vehicle registration 

cycle.
I.E.1. Under the self-inspection provisions of Section 42-4-309, C.R.S. for fleets of 

twenty (20) or more vehicles, the retail sale of a fleet vehicle within the enhanced 

program area requires full compliance with applicable inspection procedures as 

performed by an enhanced inspection center or an (enhanced) inspection-only 

facility.

I.E.2. At the time of initial licensing and annually thereafter, the vehicle fleet shall be 

declared by completing a listing of all eligible vehicles by make, model year, lightheavy duty classification, vehicle identification number, license plate number, and 

if applicable unit number and state of registration on forms provided by the 

Division.

I.F. All AIR Program inspection stations, facilities and centers are required to post in a 

conspicuous location in a clearly legible fashion a sign indicating the fees charged for 

inspections and in the basic program area, and maximum fees for emissions related 

adjustments and repairs required for the issuance of a Certificate of Emissions Control.

I.G. All AIR Program inspection stations, facilities and centers are required to be linked via 

dedicated service line to the program data/communications network.

I.G.1. Basic program inspection services providers and independent inspection-only 

facilities in the enhanced area shall be linked to the data network via dedicated 

voice quality telephone lines with a dial-up back-up telephone line.

I.G.2. Enhanced inspection centers shall be linked via dedicated data quality lines with 

dedicated voice quality lines as dial-up back-up.

I.H. All sites must provide for reasonable access in order for Departments of Revenue (or if 

applicable, Health) staff to conduct periodic quality control and audit functions as 

necessary.

I.I. Upon request for a license as an emissions inspection and readjustment station, 

inspection-only station, fleet inspection station, motor vehicle dealer test facility, or 

inspection-only facility, applicants shall complete forms approved by the Department of 

Revenue which shall include but not be limited to a declaration of any past violations of 

AIR Program statute Section 42-4-301 through 42-4-316, C.R.S. as amended or any rule 

or regulation pursuant to such law.

II. QUALIFICATION AND LICENSING OF EMISSIONS MECHANICS AND EMISSIONS 

INSPECTORS

II.A. Qualification of Emissions Mechanics and Emissions Inspectors

II.A.1. Application for qualification as an emissions mechanic and emissions inspector 

shall be filed with the Air Pollution Control Division. The Division shall administer 

issuance of letters of qualification. Applications for such letters of qualification 

shall be completed on forms provided by the Division. Before an applicant may 

be given a letter of qualification, he must comply with the requirements of this 

Section II. The Division will notify applicants of the evaluation requirements prior 

to testing.

II.A.2. An applicant must demonstrate knowledge, skill, and competence concerning the 

conduct of emissions inspections, and within the basic program area the 

adjustment and repair of vehicles to manufacturers' specifications. Such 
knowledge, skill and competence will be shown by passing a written and skills 

proficiency qualification test including, but not limited to, knowledge of the 

following:

II.A.2.a. Operation and purpose of emissions control systems.

II.A.2.b. Relationship of exhaust and evaporative HC and CO to timing and 

air/fuel ratio control.

II.A.2.c. Adjustment and repair to manufacturers' and applicable high altitude 

specifications.

II.A.2.d. Rules and regulations of AIR Program and proper inspection procedures.

II.A.2.e. Contemporary diagnostic and engine tune-up procedures.

II.A.2.f. The provisions of the Emissions Control Systems Performance Warranty 

pursuant to Section 207 (A) and (b) of the federal Clean Air Act as it 

applies to the AIR Program.

II.A.2.g. Visual inspection of the required emissions control equipment for 1975 

and newer vehicles.

II.A.2.h. Operation of and proper use, care maintenance, calibration and gas 

span checking of the Division-approved inspection equipment.

II.A.2.i. Proper use of, security, and distribution of inspection forms, Certificates 

of Emissions Control, and supplemental inspection documents.

II.A.2.j. Emissions related adjustment and repair requirements for all vehicles 

failing the initial emissions inspection.

II.A.2.k. Inspecting for visible smoke emissions.

II.A.2.l. (Reserved)

II.A.2.m. Cause and effect of air pollution.

II.A.2.n. Purpose, goal and function of the AIR Program.

II.A.2.o. Exhaust and evaporative emissions inspection procedures and rationale 

for use.

II.A.2.p. Public relations and motorist assistance.

II.A.2.q. Safety procedures in the inspection lane or bay.

II.B. Requalification Requirements for all Emissions Mechanics and Emissions Inspectors

II.B.1. Upon the determination by the Commission of the necessity of technically 

updating the qualifications for emissions mechanics or emissions inspectors and, 

upon development or approval of retraining courses and retesting requirements 

for emissions mechanics to demonstrate said qualification, emissions mechanics, 

or holders of certificates of qualification, shall be required to requalify biennially.
II.B.2. Emissions mechanics and emissions inspectors shall be required to requalify 

within ninety days from the date of written notification by the Department of 

Revenue. Said notice shall be mailed to the address of record in the office of the 

Department of Revenue charged with licensing of emissions mechanics and 

inspectors, which notice shall inform the person of the necessity of requalification 

and the nature of such skills, systems, and procedures requiring the retraining for 

the continued performance of the emissions inspection. The notice shall give the 

name and location of training sources approved or accredited for purposes of 

retraining, the necessity of requalification by a certain date, and the nature and 

evidence of documentation to be filed with the Department of Revenue 

evidencing such requalification, and state that failure to requalify within said 

period of time shall result in suspension or revocation of the emissions 

mechanic's or emissions inspector's license or certification as described in the 

Department of Revenue rules and regulations.

II.B.3. The Division shall issue a letter of requalification to any person who has 

requalified to the satisfaction of the Division and according to the requalification 

regulation of the Department of Revenue.

II.C. Transmittal of Letters of Qualification and Issuance of Emissions Mechanic's and 

Emissions Inspector's Licenses

The Division shall provide a listing of all letters of qualification or letters of requalification for 

emissions mechanics or emissions inspectors to the Department of Revenue, and, upon 

application by any person qualified, the Department of Revenue shall issue an emissions 

mechanic's or emissions inspector's license or renewal license in accord with the regulations of 

that department.

II.D. Lapse of Certificate of Qualification for Emission Mechanic.

A person to whom the Division has issued a letter of qualification, who has not been issued an 

emissions mechanic's or emissions inspector's license within six (6) months from the date of 

issuance of the most recently issued letter of qualification shall be deemed to have forfeited said 

qualification and shall be required to reapply if a new letter of qualification is requested.

II.E. Program License Application Performance Review Criteria

II.E.1. Applicability

Pursuant to Sections 42-4-306(4)(c) and 42-4-308(1 )(b), C.R.S. the Commission is 

authorized to establish minimum performance criteria for licensed emissions inspectors, 

mechanics, and stations. Based on these performance criteria, Section 42-4-312, C.R.S. 

grants authority to the Executive Director of the Department of Revenue to suspend or 

revoke a license on a finding of a pattern of violations.

In order to meet federal act requirements and to provide consistent criteria for the 

Department of Revenue's review of performance based evaluations that may result in a 

denial of the license application, the Executive Director of the Department of Revenue or 

the designee shall apply criteria contained in this Section E.

II.E.2. Standards

The following criteria shall be used by the Department of Revenue's Executive Director or 

his designee in the review of any emissions license application for a mechanic, inspector, 
inspection and readjustment station, inspection-only station, inspection-only facility, fleet 

station, or motor vehicle dealer test facility.

Performance

Based on violations and penalties provided in Section 42-4-313(4)(b)(1), C.R.S. the 

following criteria will be used for the review of any emissions license application listed in 

this section:

II.E.2.a. Any substantiated violation of intentional passing of a failing vehicle.

II.E.2.b. Any substantiated violation of performance of emissions tests by an 

unlicensed mechanic, inspector, or station.

II.E.2.c. Any substantiated violation of performance of an emissions test on 

falsified emissions test equipment.

II.E.2.d. Any substantiated violation of failing of passing vehicles.

II.E.2.e. Any substantiated violation of flagrant misuse of emissions program 

control documents.

II.E.2.f. Any substantiated pattern of non-compliance with AIR Program 

regulations.

II.E.2.g. Any substantiated violation of false statements on any emissions license 

application in an attempt to conceal problems such as: administrative 

hearings held for program violations, any probation of any emissions 

license held previously or currently held, any suspension or revocation of 

any emissions license held previously or currently.

For the purposes of emissions license application review, past performance may 

entail complete program history review of any person, persons, or officers of a 

corporation, or partners of any partnership that hold or held a license with the 

AIR Program.

II.E.2.h. As a prerequisite to licensing of an emissions mechanic or emissions 

inspector, a hands-on proficiency check to address the criteria described 

in Section II. A. 2. of this Part D will be administered by the Department 

of Revenue in accord with the regulations of the Commission. This 

evaluation will be conducted at the emissions mechanic's or emissions 

inspector's place of employment and on an exhaust gas analyzer or test 

analyzer system that would be used to conduct inspections.

In order to provide for continuity and consistency with training, testing and 

licensing activities conducted per this Part D, the development and maintenance 

of the hand-on proficiency check will be coordinated between the Department of 

Revenue and the Division.

III. REGISTRATION OF EMISSIONS RELATED REPAIR FACILITIES

III.A. Automotive Emissions Related Repair Facilities May Voluntarily Register with the 

Division.
III.A.1. The repair facility/technicians agree to have the effectiveness of their emissions 

related repairs and repair costs monitored by the Division on an on-going basis.

III.A.2. Repair facility/technicians agree to have repair effectiveness listing provided to 

those motorists whose vehicles fail any element of the inspection procedures 

specified in Part C of this regulation.

III.A.3. The facility shall complete and process AIR Program repair report forms as 

approved by the Division. Repair report form processing equipment may 

incorporate PC based bar code technology such that one-dimensional “3 of 9"

and two dimensional “PDF 417” symbology can be read and written. The system 

must be capable of supporting form generation software provided by the state. 

The printer shall be an ink jet printer or equivalent capable of printing the bar 

code symbology stated. Refer to Section 2.14 of the TAS specifications attached 

as Appendix A of this regulation for microcomputers specifications. The Division 

shall determine performance equivalence.

III.B. As an aid to motorists seeking emissions related repair assistance, a means will be 

established whereby a listing of registered repair facilities whose repair effectiveness 

would be made available and presented to the motorist at the time of inspection failure. 

Repair effectiveness shall include but may not be limited to:

a. Number of vehicles repaired and retested

b. Percent passing on first retest

c. Percent requiring additional repairs and retests

d. Percent issued waivers

The listing shall document any recognized professional automotive accreditation or memberships 

that may include but not be limited to the National Institute for Automotive Service Excellence, or 

Automotive Service Association. The listing may also indicate the vehicle make(s) or vehicle 

classification that the repair facility specializes in.

III.C. Repair facilities may request removal from the listing or temporary placement on an 

inactive listing while measures are being taken to improve repair effectiveness.

III.D. It is further suggested that:

III.D.1. The repair facility/technicians will seek out appropriate training when repair 

effectiveness deficiencies are identified.

III.D.2. Repair facilities will hire and retain technicians certified under “Automotive 

Service Excellence” tests number A-1, A-6, A-8, and L-1 and that technicians will 

maintain these levels of certifications.

Ill.D.3. That the repair facility be adequately equipped and maintain a level of diagnostic 

and repair equipment necessary to perform emissions related repairs based 

upon the criteria set forth by the Automotive Service Association of Colorado, 

Incorporated.

III.D.4. The Department of Revenue performs a site evaluation of facilities that apply to 

assess compliance and confirm qualifications.
III.D.5. The facility has or could comply with the provisions established in Part D of this 

regulation and have not been subject to the penalties prescribed by Section 42-9-

111, C.R.S.

III.E. The Division will monitor and periodically report to individual repair facilities their repair 

effectiveness and average costs as compared to other registered repair facilities.

III.F. The Division shall make repair effectiveness data available to the general public upon 

request as well as periodically to the Department of Revenue.

III.G. The Division may request a site evaluation of any registered repair facility by the 

Department of Revenue for reasons of diminished repair effectiveness or noted 

consumer complaints.

III.H. The Division shall identify the level(s) of repair effectiveness that would result in 

inadequate emission(s) reductions and negatively impact consumer protection.

IV. REQUIREMENTS FOR CLEAN SCREEN/REMOTE SENSING SITES

IV.A. Applicability

Clean Screen Inspection Sites must meet all applicable standards pursuant to this Part D and the 

Department of Revenue's regulations in order to qualify for operating in Colorado's Clean Screen 

Program.

IV.B. Standards for emissions inspection sites

All sites shall comply with all applicable state and local codes/ordinances and maintain 

appropriate permits for that specific municipality and location.

IV.C. All Clean Screen Sites must provide reasonable access in order for Department of 

Revenue (and if applicable, Division) staff to conduct periodic quality control and audit 

functions as necessary.

IV.D. Applicants for a license as a Clean Screen Emissions Inspector shall complete forms 

approved by the Department of Revenue which shall include, but not be limited to, a 

declaration of any past violations of AIR Program statute Sections 42-4-301 through 42-

4-316, C.R.S., as amended or any rule or regulation pursuant to such law.

V. QUALIFICATION OF CLEAN SCREEN EMISSIONS INSPECTORS

V.A. Clean Screen Emissions Inspector applicants shall apply for letters of qualification on 

forms provided by the Division. The Division shall issue letters of qualification to 

applicants who comply with the requirements of this Section V. The Division will notify 

applicants of the evaluation requirements specified in Part D, Section V.B. prior to testing.

V.B. An applicant for a letter of qualification or requalification must demonstrate knowledge, 

skill, and competence concerning the operation of Clean Screen emissions inspections. 

Such knowledge, skill and competence will be demonstrated on actual Clean Screen 

equipment and by passing a skills proficiency qualification test including, but not limited 

to, knowledge of the following:

V.B.1. Operation of and proper use, care, maintenance, calibration and gas span 

checking of the Division-approved Clean Screen Test Analyzer System.
V.B.2. Safety procedures for the Clean Screen Inspection Site.

V.B.3. Proper setup and breakdown of the Clean Screen equipment

VI. REQUALIFICATION REQUIREMENTS FOR ALL CLEAN SCREEN EMISSIONS INSPECTORS

VI.A. Upon the determination by the Division of the necessity of updating the technical 

qualifications for Clean Screen Emissions Inspectors, holders of certificates of 

qualification shall be required to requalify biannually. The Division may waive this 

requirement should it be unnecessary.

VI.B. Clean Screen Emissions Inspectors shall be required to requalify within ninety days from 

the date of electronic notification by the Department of Revenue.

VI.C. The Division shall issue a letter of requalification to any licensed Clean Screen Emissions 

Inspector who meets the requirements of Section Part D, Section V.B.

VII. TRANSMITTAL OF LETTERS OF QUALIFICATION AND ISSUANCE OF CLEAN SCREEN 

INSPECTOR LICENSES

The Division shall provide a listing of all letters of qualification or letters of requalification for Clean Screen 

Inspectors to the Department of Revenue, and upon application by any person qualified, the Department 

of Revenue may issue a Clean Screen Inspector's license or renewal license in accordance with the 

regulations of that department.

VIII. LAPSE OF CERTIFICATE OF QUALIFICATION FOR CLEAN SCREEN INSPECTOR

A person to whom the Division has issued a letter of qualification, who has not been issued a Clean 

Screen Inspector license within six (6) months from the date of issuance of the most recently issued letter 

of qualification shall be deemed to have forfeited said qualification and shall be required to reapply if a 

new letter of qualification is requested.

IX. PROGRAM LICENSE APPLICATION PERFORMANCE REVIEW CRITERIA

IX.A. Applicability

Pursuant to Sections 42-4-306(4)(c) and 42-4-308(1 )(b), C.R.S., the Commission is authorized to 

establish minimum performance criteria for licensed Clean Screen Inspectors and Data 

Management Contractor(s). Based on these performance criteria, Section 42-4-312, C.R.S., 

grants authority to the executive director of the Department of Revenue to suspend or revoke a 

license.

In order to provide consistent criteria for the Department of Revenue's review of performance 

based evaluations that may result in a denial of a license application, or revocation of a license, 

the executive director of the Department of Revenue or the designee shall apply criteria 

contained in Sections IV through VII of this Part D.

IX.B. Requirements

The Department of Revenue’s executive director or his designee in the review of any emissions 

license application shall use the following criteria for a Clean Screen Inspector, or Clean Screen 

Data Manager.

Performance
Based on violations and penalties provided in Section 42-4-313(4)(b)(1), C.R.S., the following 

criteria will be used for the review of any license application listed in the section:

IX.B.1. Any violation of intentional passing of a failing vehicle.

IX.B.2. Any violation of performance of Clean Screen inspections by an unlicensed 

inspector, or at an unapproved/unlicensed site.

IX.B.3. Any violation of performance of a Clean Screen inspection on a falsified Clean 

Screened Test Analyzer System.

IX.B.4. Any violation of flagrant misuse of Clean Screen inspection data, control 

documents, vehicle owner information, or vehicle registration data.

IX.B.5. Any pattern of non-compliance with AIR Program regulations, including Clean 

Screen provisions.

IX.B.6. Any violation of false statements on any license application.

IX.B.7. As a prerequisite to licensing of a Clean Screen Inspector, a hands-on 

proficiency check to address the criteria described in Section V of this Part D will 

be administered by the Department of Revenue in accord with the regulations of 

the Commission. This evaluation will be conducted at a mutually agreed upon 

location and on an approved Clean Screen Test Analyzer System that would be 

used to conduct inspections.

In order to provide for continuity and consistency with qualifying and licensing activities 

conducted per this Part D, the development and maintenance of the hands-on proficiency 

check will be coordinated between the Department of Revenue and the Division.

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PART H Statements of Basis, Specific Statutory Authority and Purpose

XXXI. AMENDMENTS

ADOPTED NOVEMBER 21, 2013

This revision to Regulation Number 11 is to amend language that will clarify provisions contained in the 

existing regulation concerning model year exemptions and program implementation dates, updating the 

listed repair waiver cost limit from $450 to the currently used $715 limit, modifying qualification criteria 

used to grant an economic hardship waiver, and incorporating a new Test Analyzer Specification for Onboard Diagnostics in Appendix A.

This Statement of Basis, Specific Statutory Authority, and Purpose complies with the requirements of the 

Colorado Administrative Procedures Act, Section 24-4-103, C.R.S., and the statutory authority provided in 

Sections 42-4-301 through 42-4-316, C.R.S.

Basis and Purpose

The Commission’s November 2013 amendments are intended to clarify, amplify, and streamline the rule 

in support of previous recent changes to the Automobile Inspection and Readjustment Program. The 

proposed modifications are considered minor and will not result in any significant change in program 

costs or air quality benefits.
The basis of these modifications is to address any ambiguities that may exist in the interpretation of new 

program changes, as well as add a new Test Analyzer Specification for On-board Diagnostics as required 

by Regulation Number 11, Part B, Section X.

Federal Requirements

The current inspection and maintenance program, except in the North Front Range, is contained in 

Colorado’s ozone State Implementation Plan (SIP). Any revision to the program requires that air quality 

credits achieved from the program are not lost.

In general, EPA rules require certain nonattainment areas implement Inspection and Maintenance 

programs as part of a SIP. Under the Clean Air Amendments of 1990, the Denver metropolitan area was 

required to implement an “Enhanced” IM Program, specifically for carbon monoxide. Since that time, the 

state has come into attainment with carbon monoxide, but the program remains a necessary element of 

Colorado’s ozone SIP. The North Front Range area of the program operates as a state-only program

Specific Statutory Authority

Sections 42-4-306 and 42-4-310, C.R.S. authorize the Air Quality Control Commission (“Commission”) to 

promulgate rules for inspection of motor vehicle emissions. Section 42-4-306(8) authorizes the 

Commission to exempt motor vehicles from emission inspections. Section 42-4-306(3)(b)(V)(B) 

authorizes the Commission to promulgate rules for alternative motor vehicle emission inspections, 

including on-board diagnostics (OBD) inspections. 42-4-306(6)(a) authorizes the Commission to 

promulgate rules on inspection procedures, including those related to OBD and evaporative gases. 

Findings Pursuant to 25-7-110.8, C.R.S.

The revision of the rule is to clarify provisions contained in rule or that are administrative in nature. These 

changes do not increase the regulatory burden on the motoring public, while maintaining the current air 

quality benefits received from the program, in a cost effective manner, at similar or minimally reduced 

costs to the current program.

The rule revision is based on reasonably available, validated, reviewed, and sound scientific 

methodologies. All validated, reviewed, and sound scientific methodologies and information made 

available by interested parties has been considered. Evidence in the record supports the finding that the 

rule shall result in a continued demonstrable reduction in air pollution. The rule revision is the most costeffective alternative, provides the regulated community flexibility, and achieves the necessary reduction in 

air pollution. The revised rule will maximize the air quality benefits of the regulation in the most costeffective manner.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

APPENDIX A Technical Specifications

(Technical Specifications)

COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT

SPECIFICATIONS FOR COLORADO 94 ANALYZER

HARDWARE SPECIFICATIONS

Revised Sept 09, 1994
INTRODUCTION

The Colorado AIR Program is in the process of modifying its current automotive inspection and 

maintenance program to comply with the Clean Air Amendments of 1990. Colorado's current program is 

based upon BAR 84 inspection technology utilizing a decentralized program format encompassing nine 

fFront rRange counties. In order to achieve compliance with the Clean Air Amendments of 1990, 

Colorado will change to a program format that will have a contractor based operation conducting the IM 

240 emissions test and a population of independent inspectors conducting inspections utilizing a new 

Colorado 94 emissions analyzer. The contractor is based in the “enhanced” program area, basically the 

Denver metropolitan area and will inspect 1982 and newer vehicles. Independent inspection facilities will 

inspect vehicles of all years within the “basic” program area as well as being able to inspect 1981 and 

older vehicles within the “enhanced” area.

The demands for more accurate analytical information as well as a more automated inspection process 

with real-time data transfer has superseded the capabilities of BAR 84 technology. Current BAR 90 

analytical technology is acceptable, but other system enhancements are necessary to meet Colorado’s 

inspection needs. These enhancements and other technical details are described in the remainder of this 

document.

1.0 GENERAL

1.1 Design Goals

The specifications that have been developed are designed utilizing a personal computer system. 

The analyzer system must be capable of performing uniform and consistent emission tests for 

Colorado's Automotive Inspection and Readjustment (AIR) Program. Features of the analyzer 

include: vehicle emissions measurements of hydrocarbon (HC), carbon monoxide (CO), carbon 

dioxide (CO2)and oxygen(O2); engine RPM measurements, exhaust dilution determinations, 

pressure test system for EVAP; data entry; data retrieval tables; a dedicated printer (for vehicle 

inspection certificates) and an additional printer for diagnostics and general purpose printouts; 

data recording on double sided high density 1.44 megabyte (Mb) 3.5” floppy diskette and a 

120Mb (or greater) hard drive; modem for “on-line real time” data transmission; CRT information 

display to the inspector; bar code (2D) reader and printing capabilities; and fully menu driven, 

interactive simple microprocessor controlled operation.

Additional, automatic features required include: gas calibrations, zero and span checks, pressure 

calibrations, gas auditing procedure; leak checks, HC hang-up checks, audit menus (i.e., data 

read system), test sequencing, and low-flow checks. The analyzer shall be designed and 

constructed to provide reliable and accurate service in the automotive environment. The software 

used in the analyzer shall consist of a process control system as well as data look-up files. 

Security shall be provided to prevent unauthorized modifications to the software or test data and 

recording unauthorized entry (tampering) and locking out of the inspection process when 

detected.

The emissions analyzer software shall be designed for maximum operational simplicity.

It shall also be capable of providing emission-reading characteristics, independent of the 

inspection function, which can be used for vehicle diagnostic.

1.2 Useful Life

The useful life of the analyzer shall be a minimum of five years.

1.3 Nameplate Data
A nameplate including the following information shall be permanently affixed to the housing of the 

analyzer:

Name and Address of Manufacturer

Model Description

Serial Number

Date of Assembly

The manufacturer shall affix a stick-on type label to the analyzer that contains a toll-free 

telephone number for customer service. This number can also be included in a service software 

message.

1.4 Manuals

Each analyzer shall be delivered with the following manuals:

A. Reference Operating Instructions

B. Operation Instruction Manual

C. Maintenance Instruction Manual (limited)

D. Initial Start-up Instructions

Colorado 94 Analyzer manufacturers may consolidate manuals. The manuals shall be 

constructed of durable materials and shall not deteriorate as a result of normal use over a 

five-year period. The analyzer housing shall provide convenient storage for each manual 

in a manner that will:

E. Allow easy use.

F. Prevent accidental loss or destruction.

1.5 Certification Documentation

The analyzer software shall be fully documented. Two copies of the documentation listed below 

shall be submitted to the Colorado Department of Public Health and Environment as part of the 

certification application.

A. Complete program listings. Program listings may be on diskette. They are not 

required to be submitted with the application for certification.

B. Functional specifications.

C. Functional flowcharts of the software.

D. Example inputs and outputs from all processes.

E. Detailed interface information on system components including the identification 

of protocol and output specifications.
F. All DOS file layouts with file names, file types, file security, field names, field 

types, field sizes, and field editing criteria.

Documentation provided by the vendor to meet this requirement will be treated as 

proprietary information by the Colorado Department of Public Health and Environment.

Prior to certification of any Colorado 94 emissions analyzer for sale in Colorado, the 

manufacturer of such analyzer shall provide the Division with software source codes and 

all other technical information (including, but not limited to all working codes, schematics 

and drawings) necessary to operate, maintain, calibrate and repair such analyzer in the 

event that the manufacturer or its agent ceases providing adequate maintenance, 

calibration and repair services in Colorado. The manufacturer shall keep such information 

current, and will provide the Division with copies of any and all changes. So long as such 

maintenance, calibration and repair, services are available from the manufacturer or its 

agent, the Division shall protect such information as confidential commercial data if it is 

clearly marked as such. In the event that the manufacturer becomes insolvent or stops 

providing adequate maintenance, repair or calibration services in Colorado all such 

information shall be the property of the Division and may be released to a third party as 

necessary to repair, calibrate and maintain the analyzers.

1.6 Warranty Coverage/Mandatory Service Contract

A written warranty coverage agreement, signed by an authorized representative of the equipment 

manufacturer and the vehicle inspection station owner, which provides a complete description of 

coverage for all systems and components and all manufacturer provided services listed in Section 

1.8, must accompany the sale or lease of each Colorado 94 emissions analyzer.

An extended service contract must be available upon the expiration of the manufacturers original 

warranty period. Original manufacturer’s warranty shall be a minimum of one year from the date 

of purchase. The “service contract” shall be offered in one-year increments and is a mandatory 

condition of inspection station operation. The “service contract” agreement shall include the 

inspection station owner's name, inspection station address, telephone number, inspection 

station identification number, analyzer serial number and detailed terms of the agreement. The 

agreement must extend for at least one year with the expiration date entered to software file and 

monitored by the system clock. Approaching expiration messages must be displayed at daily 

system start-up beginning thirty days prior to expiration and massaging “30 days until expiration, 

29 days etc.” Failure to renew the “service contract agreement” will cause the analyzer to 

automatically “lock-out” from any official inspection process. Renewals shall be offered at the 

inspection station owner’s request and governed by “good business” practices between the 

parties involved. Service contract agreements must be available by the manufacturer for the 

mandated life of the Colorado AIR Program. Cost disclosures and detailed descriptions of 

coverage’s must be available in printed form and distributed to all Colorado 94 users. Cost 

disclosure shall also be made for “consumable” inventory items 1.8B. This information would 

most appropriately be presented with the original manufactures warranty.

1.7 Tampering Resistance

Controlled access design shall be the responsibility of the manufacturer and is subject to approval 

by the Colorado Department of Public Health and Environment. Analyzer service personnel, 

inspectors or others shall be prohibited, to the Colorado Department of Public Health and 

Environment satisfaction, from creating or changing any test results, programs or data files 

contained in the analyzer. Manufacturers shall utilize special BIOS partitions, or other appropriate 

software and hardware provisions, deemed necessary to protect the I/M files and programs. The 

protection features shall prevent access to the secured floppy disk drive and those portions of the 

hard disk containing I/M programs and test data or files.
The emission analyzer and the sampling system shall be made tamper-resistant to the Colorado 

Department of Public Health and Environment satisfaction. At a minimum, the manufacturer shall 

develop tamper-resistant features to prevent unauthorized access though the cabinet. 

Microswitches, keyed locks, or software algorithms requiring the use of a password, which can be 

changed by the Colorado Department of Public Health and Environment would all be acceptable 

provided the physical or logical design effectively prevents unauthorized access.

Manufacturers may offer analyzers with additional floppy disk drives that can run optional 

software application programs.

If tampering occurs, a software lockout algorithm shall be activated which aborts any existing test 

sequence and prevents further inspections until an authorized AIR Program official clears the 

lockout.

The lockout system shall be designed so that an AIR Program official from the audit menu can 

activate it. Only AIR Program Auditors may remove lockouts put in place from the audit menu. 

Manufacturers shall develop a system by which their service technicians shall be prevented from 

clearing “tamper” lockouts.

Optional software packages shall not interfere with the normal operation of the I/M inspection and 

testing software, and shall not compromise the tamper-resistant features of the analyzer.

Manufacturer field service representatives will not have access to DOS, unless assurances 

acceptable to the Colorado Department of Public Health and Environment have been provided 

that insure, integrity of the system will not be jeopardized.

1.8 Manufacturer Provided Services

The manufacturer shall agree to provide the following services to the inspection station as part of 

the manufacturer’s original warranty and thereafter as a portion of the service contract 

agreement. The cost of a service agreement is to be listed on a year-by-year basis. Future 

charges cannot exceed the amount published.

A. Delivery, installation, calibration, and verification of the proper operating condition 

of a Colorado 94 emissions analyzer.

B. Quarterly (90 days) examination, calibration, and routine maintenance of the 

analyzer and sampling systems. Full systems support and repair, including 

loaner units. Upon initial sale or loan, provide “extra” printer medium (1 ea.) 

sample filter(s)(2), sample hose (1) and sample probes (1). Maintain the “extra” 

consumable inventory upon examination and provide a software history file for 

the replacement of consumables accessible to AIR Program officials. 

Consumables and the cost(s) thereof must be disclosed in the service 

agreement.

C. Instruct all certified inspectors employed by the inspection station at the time of 

installation in the proper use, maintenance, and operation of the analyzer. The 

analyzer shall contain a feature that will allow an inspector to go through the 

complete inspection procedure without generating an official inspection record. 

This function will be used for evaluating inspector performance, by AIR Program 

officials, or by the manufacturer for demonstration purposes. The “training mode” 

shall not require the use of an inspector’s access code or allow access to 

secured areas of hardware or software. The display shall show a message 

throughout the inspection that this is not an official inspection. Vehicle inspection 
reports shall indicate to the satisfaction of the Colorado Department of Public 

Health and Environment that they are for training only. No official Certificate of 

Compliance will be generated during the training exercise.

D. On-site service response by a qualified repair technician within two (2) business 

days, (48 hours) excluding Sundays and national holidays, of a request from the 

inspection station. The names, toll-free telephone numbers, and service facility 

addresses of all manufacturer representatives responsible for equipment service 

shall be provided to the inspection station. A service representative shall be 

available at all times during normal working hours. Sundays and national 

holidays are not included. All system repairs, component replacements, and/or 

analyzer adjustments, shall be accomplished on-site within 48 hours after a 

service request has been initiated. If the completion of this work is not possible 

within this time period, a Colorado 94 loaner unit shall be provided until the 

malfunctioning unit is properly repaired and returned to service. Service 

representatives shall have a software driven menu option that allows the transfer 

of inspection station, inspector information and other applicable data files from 

one analyzer to another without manual inputs and without transfer of previous 

test files.

E. Updates of the “Functional” software will be limited to once per year at no cost.

Updates of operational software i.e., file based information will be on an “as required” 

basis. All forms of software updating will utilize modem technology for the updating 

process. File updates are at no cost and every effort will be made to minimize them.

F. The analyzer software shall be designed so that AIR Program officials can insert 

a floppy disk, prepared by the manufacturer, into the Program system host, and 

update the existing software version, via modem. A system of manual updating 

by program officials utilizing the auditor’s menu shall also be available. Look-up 

up tables and message screens shall be designed sufficiently separate from the 

main operations software so that it is not possible, to interfere in any way with the 

operations of the analyzer.

The Colorado Department of Public Health and Environment will require the manufacturer 

to render updates as necessary in the first year of the program to ensure the program 

meets all design criteria. Thereafter software updates will be limited to once per year at 

no cost. Since modem software updating will be utilized, there are no costs to the 

analyzer owner. A software version number, consisting of a four character alpha-numeric 

code made up of the last two digits of the year followed by a two character version 

number, shall be recorded in the analyzer and included on each vehicle test record. The 

analyzer manufacturer shall not modify any existing software version without obtaining 

written approval from the Colorado Department of Public Health and Environment.

The Colorado Department of Public Health and Environment may require the 

manufacturers to conduct on-site or laboratory testing of in-use analyzers in order to 

document continued compliance. When an analyzer is removed from the field, for repair 

or testing, manufacturers shall supply the inspection station from which it was removed 

with a temporary replacement unit meeting all program requirements. Manufacturers shall 

pay for all necessary shipping and transfer costs for the replacement of the analyzer 

selected for compliance testing. Manufacturers shall also pay for any required testing 

performed by their personnel or by an independent company.

The manufacturers shall provide training to AIR Program officials on all operational, 

maintenance, and quality control features of the analyzers, including full access to and 
use of inspection menus, audit menus and calibration menus, as well as optional 

programs offered to inspectors. Such training shall be conducted at the manufacturer's 

expense as a condition of certification and thereafter at reasonable intervals upon written 

request by the Colorado Department of Public Health and Environment

1.9 Certification Requirements

The manufacturer shall submit a formal certificate to the Colorado Department, of Public Health 

and Environment that states that any analyzer sold or leased by the manufacturer or its 

authorized representatives for use in the Colorado AIR Program will satisfy all design and 

performance criteria described in these specifications. The manufacturer shall also provide 

sufficient documentation to demonstrate conformance with these criteria including a complete 

description of all hardware components, the results of appropriate performance testing, and a 

point-by-point response to specific requirements. Previous certification by the California Bureau of 

Automotive Repair (BAR) is necessary for the analytical bench.

In addition, a full description of the company's service procedures and policies, as well as sample 

contracts, warranties, and extended service agreements, shall be provided as part of the 

certification application to ensure proper maintenance of all analyzers throughout their useful life. 

One fully functional analyzer shall be presented for evaluation and one additional fully functional 

analyzer for the certification process. If certified these units will remain in AIR Program 

possession for continued in-use evaluation for the life of the AIR Program. In the event that 1 % 

of overall unit sales exceed this two-unit base, in-use evaluation will require 1 % of overall unit 

sales for in use evaluation.

2.0 CONSTRUCTION DESIGN

2.1 Materials

All materials used in the fabrication of the analyzer and the appropriate housing assembly shall 

be new and of industrial quality and durability. Contact between non-ferrous and ferrous metals 

shall be avoided where possible. Suitable protective coatings shall be applied where galvanic 

action is likely. All mechanical fasteners shall have appropriate locking features. Use of selftapping screws shall be limited. All parts subject to adjustment or removal and reinstallation shall 

not be permanently deformed by the adjustment or removal-reinstallation process and this 

process shall not cause deformations to adjoining parts. Only materials that are not susceptible to 

deterioration when in contact with automobile exhaust gases shall be used.

2.2 Construction

The analyzer shall be complete and all necessary parts and equipment required for satisfactory 

operation shall be furnished. A suitable means of storing the probes and sample hose shall be 

provided. A means of storing the “spares” inventory shall be included. All parts shall be 

manufactured and assembled to permit the replacement and/or adjustment of components and 

parts without requiring the modification of any parts or the basic equipment design. Where 

practical, components and/or subassemblies shall be modularized. The analyzer cabinet finish 

shall be baked enamel or another durable finish.

2.3 Mobility

The analyzer unit shall be designed for easy and safe movement over rough surfaces and/or 

graded surfaces (15° incline). The center of gravity and wheel design shall be such that the 

analyzer can negotiate a vertical grade separation of one-half inch (1/2") without overturning 

when being moved in a prescribed manner. Industrial grade, swivel casters shall be used to 
permit 360° rotation of the unit. The caster wheels shall be equipped with oil resistant tires and 

foot operated brakes capable of preventing movement on a 15° incline.

2.4 Electrical Materials/Construction

Unless otherwise specified, all electrical components and wiring shall conform to standards 

established by the Underwriters Laboratories, Standard for Electrical and Electronic Measuring 

and Testing Equipment (U.L-1244).

The analyzer shall operate from an 115VAC, 60 hertz (Hz) supply. An input voltage variation of 

±12 volts shall not change analyzer performance more than 1 % of full scale. The analyzer must 

operate on a 15 AMP breaker. The power cable shall be equipped with a standard three-prong 

connector at the inlet, and shall have a National Electrical Code rating of SO, SJO or better with 

an overall length not to exceed 25 feet. Each emissions analyzer shall incorporate safety devices 

to prevent conditions hazardous to personnel or detrimental to equipment. The system shall be 

grounded to prevent electrical shock, and adequate circuit overload protection shall be provided. 

The analyzer shall incorporate an internal surge protector.

2.5 Sampling System

The sampling system consists of two subsystems: (1) external sampling system; and (2) internal 

sampling system. The external system shall include a sample probe, sample hose twenty-five feet 

(25') in length, a water trap, and a filtration system. The internal subsystem shall include but not 

necessarily be limited to, a sample pump and bypass pump, or an equivalent system approved by 

the Colorado Department of Public Health and Environment.

The sample probe shall incorporate a positive means of retention to prevent it from slipping out of 

the tailpipe when in use. A thermally insulated, securely attached handgrip shall be provided on 

the probe in such a manner that easy probe insertion using one hand is ensured.

The probe shall also have a smooth surface near the probe tip before the flexible portion of the 

probe to be used for sealing of the span gas adaptor necessary for field or on-board leak 

checking (vacuum or gas) or response time checking equipment. For standardization, it is 

recommended that the sealing surface be one-half inch (1/2") in outside diameter and one-half to 

one inch (1/2” to 1”) long. A probe tip cap shall be provided for the sample system leak check. A 

probe tip adapter or assembly shall be included for use with spark arrester type tail pipes.

The interconnecting hose shall be of such design and weight that the inspector can easily handle 

it. The hose shall be of non-kinking construction and fabricated of materials that will not be 

affected by or react with the exhaust gases. Molecular HC hang-up shall be minimized. The hose 

connection to the analyzer shall be reinforced at the point of maximum bending. The system shall 

be designed with a water trap in the bypass sample stream. The water trap shall be continually 

self-draining. The trap bowl shall be constructed of a durable transparent material. The water trap 

should be located as low as possible on the analyzer so that condensed water in the sample hose 

will drain into them. However, the trap must be placed in a position readily visible to the inspector. 

The sample for the analyzer shall be obtained from the top of the water trap. The sampling 

system shall be equipped with a suitable particulate filter upstream of the optical bench. There 

may be a secondary filter located in the sample hose, serviceable by the inspector. This filter 

must have sufficient capacity to filter the samples obtained during the routine testing of vehicles in 

the inspection station. Threaded connections must be used to attach the filter to the sample hose. 

A prompt shall be provided to the inspector indicating when the filter should be changed based on 

an indication of low flow (automatic lock-out) or other criteria approved by the Colorado 

Department of Public Health and Environment
The pumps shall contain corrosion resistant internal surfaces. The pumps shall have a minimum 

operational life of 2,000 hours without failure.

The sample pump system may be a single pump, multiple pumps, or a multiple stage pump or an 

equivalent system approved by the Colorado Department of Public Health and Environment. The 

sample pump shall have integral motor overload protection and be permanently lubricated. The 

bypass system shall be connected in the sample system so that any water condensed in the 

water trap is removed and dumped outside the system.

2.6 Storage Temperature

While in storage, the analyzer and all components thereof shall be undamaged from ambient air 

temperatures ranging from 0° F to 120° F.

2.7 Operating Temperature

The analyzer and all components shall operate within calibration limits in ambient air 

temperatures ranging from 41° F to 110° F.

2.8 Humidity Conditions

The analyzer shall be designed for use inside a building that is vented or open to outside ambient 

humidity. The analyzer, including all components of the analytical, sampling, and computer 

systems, shall operate within the required performance specifications at ambient conditions of up 

to 80% percent non-condensing relative humidity throughout the required temperature range, 

assuming the components are reasonably protected by the inspector from direct contact with 

water, or other condensing moisture. Failure of any component due to exposure to temperature 

and humidity extremes within this limits specified during actual use shall be corrected at the 

manufacturer's expense.

2.8.1 Temperature Control

Analyzer components that affect sensitivity and calibration shall have their internal 

temperatures controlled to maintain design temperature when exposed to prevailing 

ambient conditions. If internal operating temperatures are exceeded the analyzer will 

automatically lockout from any official inspection process.

2.9 Barometric Pressure Compensation

Barometric pressure compensation shall be provided. Compensation shall be made for elevations 

up to 6,000 feet (mean sea level). At any given altitude and temperature, errors due to barometric 

pressure changes of ±two inches (2") of mercury shall not exceed the accuracy limits specified in 

this specification. Manufacturers shall describe in writing how compensation will be 

accomplished. The method used shall be acceptable if approved by the Colorado Department of 

Public Health and Environment.

2.10 Operational Design

A. Analytical System

These analyzers shall utilize non-dispersive infrared systems for measuring 

hydrocarbons (HC), carbon monoxide (CO), and carbon dioxide (CO2). Oxygen (O2) 

shall also be measured and ambient air will be used for calibration purposes.
B. Readout Display/CRT Screen

The screen shall contain numerical HC (as hexane), CO, CO2 and O2 displays and a 

pass/fail indication at the completion of the inspection process. Pressure purge shall be a 

pass/fail indication, with pressure/time values recorded to file.

The numerical display shall be of a digital format. The resolution of the emissions display 

shall be as follows:

HC: XXXX ppm (as hexane)

CO: XX.XX%

CO2: XX.X%

O2: XX.X%

The MINIMUM display increments shall be 1 ppm HC, 0.01 % CO, 0.1% CO2, and 0.1% 

O2. The displays shall be capable of full-scale readings of 2000 ppm HC (as hexane), 

9.99% CC, 16.0% CO2 and 25.0% O2.

CRT display is to be employed for an exhaust sample validity (sample dilution). This 

indication will signal excess dilution in the exhaust system based upon measurement of 

CO + CO2 emissions.

The analyzer shall be capable of selecting the pass/fail values (limits) based on vehicle 

model year, vehicle type, or other criteria. The system shall be designed in such a 

manner that the standards and vehicle groups may be readily revised by a modem 

software update.

Specific emissions limits and vehicle model year groupings are available in this 

Regulation Number 11, Part F: maximum allowable emissions limits for motor vehicle 

exhaust, evaporative and visible emissions for Light-Duty and Heavy-Duty vehicles.

2.11 Automatic Calibrations

The analyzer shall be designed to require an automatic two-point gas calibration for HC, CO, and 

CO2, and an automatic electrical zero and span check. (O2 shall be measured by ambient air.) 

The automatic gas calibration shall be conducted every 24 or 72 hours, activated by the internal 

clock. The option of 24 HOUR calibration will be software selectable, with the default @ 72 hours. 

Electrical zero and span check (automatic) shall be required prior to each test sequence. Userfriendly prompts shall be provided to the inspector to indicate every step needed to properly 

perform the required gas calibration (including when it is necessary to turn the gas cylinder valve 

on and off).

If the system is not calibrated, or the system fails the calibration or the zero and span check, an 

error message or fault indication shall be displayed and the analyzer shall be locked out to 

prevent the performance of an emissions inspection. Lockout will remain until the system is 

property calibrated and passes a calibration check and zero and span check.

The calibration record will contain before and after calibration readings. The gas calibration shall 

ensure that accuracy specifications are satisfied and that linearity is correct at the required span 

points. The gas calibration and leak check procedures shall require no more than five (5) minutes 
to complete. The analyzer shall provide adequate prompts on the display to guide the inspector 

through the calibration procedure in a manner that minimizes the amount of calibration gas used.

The system shall have the capability of printing historical calibration data for specified date 

ranges by the AIR Program Auditor. (Audit menu, calibration history)

For HC, CO and CO2, analyzer manufacturers shall limit gas usage during the gas calibration 

procedure to two liters per point. The analyzer shall also be designed to keep the loss of 

calibration gas to an absolute minimum (less than 0.5 liters in 24 hours) if the calibration gas 

valve(s) is/are not shut off. Manufacturers shall provide an evaluation of this capability, consisting 

of at least four (4) analyzers, with their certification application materials and shall demonstrate 

this feature during certification.

The analyzer shall be equipped with a gas calibration port for the purpose of performing a probe 

to calibration port comparison for audit purposes. Gas auditing shall be accomplished by 

introducing standard gases into the analyzer either through the calibration port or through the 

probe. Span gases utilized for calibration shall be within two percent (2%) of the following points: 

Ambient air may be used to calibrate the O2 sensor.

(HC) 300 ppm propane

1.0 % carbon monoxide (CO)

6.0 % carbon monoxide (CO2)

Bal. Nitrogen (N2)

(HC) 1200 ppm propane

4.0 % carbon monoxide (CO)

12.0 % carbon monoxide (CO2)

Bal. Nitrogen (N2)

The standard gases used to calibrate, and audit the analyzers shall satisfy the criteria included in 

the Federal Clean Air Act, Section 207 (b) and described in Subpart W of Part 85 of Chapter I, 

Title 40 of the Code of Federal Regulations. In order to ensure that the quality of the standard 

gases used in the program meet these specifications, all standard gases purchased by the 

inspection facility for use in the analyzer must conform to the requirements established in 1990 by 

the California BAR for Test Analyzer System Calibration Gases. Calibration gases must be 

purchased from a vendor that has Colorado gas blender certification, REF. Colorado Regulation 

Number 11, Appendix B. These requirements include the testing and certification of the 

concentration, accuracy, precision, and purity of the standard gases to within the referenced limits 

and the labeling of individual gas canisters describing these and other specified parameters.

Automatic EVAP Pressure Calibration

The pressure test system is to be calibrated every 24 or 72 hours and zero/span checked before 

each inspection. Pressure calibration checks should be performed simultaneously with the gas 

calibration procedure. Calibration and/or zero span checks must pass or the analyzer must 

lockout from further testing until the discrepancies are corrected. All calibrations will be stored to 
the Cal.Dat file. Pressure system calibrations shall be performed in a maximum time period of 5 

minutes, calculated independently from the gas calibration and leak check. The optional 24-hour 

option shall be selectable and defaulted to 72 hours.

A. Automatic Leak Check

An automatic leak checking system shall be provided that will allow the vacuum side of 

the system to be checked for leakage. Appropriate valves lines, and switches shall be 

installed to permit this operation. Minimal activity by the inspector, such as setting the 

probe in a holder or capping the probe, is permitted, provided errors resulting from 

improper inspector action would be identified by the computer and would require 

corrective actions. Improper action would cause the system to fail a leak check, and 

automatically lockout. User-friendly prompts shall be provided to the inspector to indicate 

every step needed to properly perform the required leak check (including when it is 

necessary to turn the gas cylinder valve on and off).

A system leak check shall be accomplished every 4 or 24 hours and in conjunction with 

the gas calibration performed every 24/72 hours, activated by the internal clock. The 4-

hour option shall be software selectable with the 24 hours as the default value. Four-hour 

leak checks are required only for those facilities performing more than 4000 inspections 

per year. The analyzer shall not allow an error of more than ±3% of reading using midrange Colorado certified span gas to perform the leak check. Fittings and connectors 

used on the sample hose and probe shall be constructed to inhibit the bypass of the leak 

check. A maximum of two liters of calibration gas may be used to perform the leak check. 

If the system is not leak checked, or the system fails a leak check, an error message or 

fault indication shall be displayed, and the analyzer will be locked out to prevent the 

performance of an emission inspection, until the system is properly leak checked and 

passes.

B. Automatic HC Hang-Up Check

The analyzer shall be designed for using ambient air induced through the sample probe, 

prior to each test sequence. The analyzer shall have a CRT prompt/indicator. “Hang-up” 

activation shall cause the analyzer to automatically sample ambient air through the 

sample line and probe. The system shall continue to sample room air for a maximum of 

150 seconds or until the HC response is below 20-ppm hexane.

If the HC hang-up does not drop below 20 ppm within 150 seconds, a message shall be 

displayed indicating possible dirty filters or sample line. If after 150 seconds HC levels 

are not below specified values, the test shall be discontinued until HC hang-up is 

corrected. When the level stabilizes below this value, an indication that testing may begin 

shall be displayed. The analyzer shall be locked out from operating until the HC level is 

met.

C. Vehicle Diagnostics

During analyzer warm-up, emissions diagnostics and other gas reading functions shall be 

prohibited. After successful warm-up and for the purpose of vehicle diagnosis or repairs, 

the analyzer shall have a menu selection that will allow the analyzer to continuously 

monitor the vehicle exhaust.

The automatic data collection system shall be prevented from operating anytime the 

analyzer is not being used in the official emissions inspection mode.
D. Dilution

The analyzer manufacturer shall document to the satisfaction of the Colorado 

Department of Public health and Environment that the flow rate on the analyzer shall not 

cause more than 10% dilution during sampling of the exhaust at normal idle (10% dilution 

defined as sample of 90% exhaust and 10% ambient air). Manufacturers shall utilize the 

procedures specified by the BAR for demonstrating this dilution criterion. The analyzer 

shall be equipped with a feature to identify vehicle exhaust system leaks and sample 

dilution. The preferred method for identifying leaks is monitoring the CO & CO2 levels in 

the exhaust. Other additional techniques that can demonstrate improved sensitivity to 

leaks may also be used.

DILUTION VALUES:

All light duty vehicles: 6%

All heavy-duty vehicles: 5%

If the CO + CO2 reading is less than the limit, the inspector shall be prompted to check 

the exhaust system for leaks and to make sure that the sample probe is all the way into 

the tailpipe. If the excessive dilution is detected after the initiation of the test sequence, 

the analyzer output shall display “SAMPLE DILUTION”. If dilution continues the inspector 

shall be required to “Abort Test”. The system shall store the “Abort Test” indication.

E. Engine Tachometer

A digital display tachometer shall be CRT displayed for the purpose of measuring engine 

speed. The tachometer operation shall be by two means; (1) radio frequencies “RF” type 

transmitter/receiver that requires no direct vehicle connection and can detect engine 

RPM on vehicles utilizing “DIS” systems. (2) a cable type connection capable of detecting 

engine RPM from all forms of current O.E.M. ignition technology. Tachometer 

performance shall be no less than; RPM with a 0.5 second response time and an 

accuracy of ±3.0% of actual RPM. During an official inspection process, the software will 

prompt the inspector to shut the engine off while connecting the RPM probe (only if a 

cable connection is being made). A software “HELP” screen will be available to assist the 

inspector in locating an RPM signal. This information may be supplied or reviewed by the 

Colorado Department of Public Health and Environment. Based on the vehicle 

identification information available to the inspector, the analyzer will prompt the inspector 

as to which vehicles require a specific type or method of connection of the tachometer 

pick-up. Analyzers shall be provided with all the software and hardware that is necessary 

to make them capable of reading engine RPM from all O.E.M. ignition technologies in use 

at the time of certification, Possible updates may be required to enable future ignition 

systems to be monitored for engine RPM.

F. Analytical Bench Accuracy

Each analyzer shall meet the following analytical accuracy requirement:

Channel Range Accuracy

HC ppm 0-400 ±12 ppm
Channel Range Accuracy

401-1000 ±30 ppm

1001- ±80 ppm

2000

CO% 0-2.00 ±0.15 %

2.01-5.00 2.040%

CO2% 04.0% ±0.6

4.1-14.0 ±0.5%

14.1-16.0 ±0.6%

O2% 0-10.0 ±0.5%

0-10 ±1.3%

The analyzer display resolution electronics shall have sufficient resolution and accuracy 

to achieve the following:

HC 1 ppm HC

CO 0.01 % CO

CO2 0.1% CO2

O2 0.1% O2

G. Drift

If zero and/or calibration drift cause the infrared signal levels to move beyond the 

adjustment range of the analyzer, the inspector shall be locked out from testing and 

instructed to call for service.

H. Warm-Up

The analyzer shall reach stabilized operation in an inspection station environment within 

15 minutes at ° 41 degrees Fahrenheit from “power on”. The instrument shall be 

considered “warmed-up” when the zero and span readings for HC, CO, and CO2 have

stabilized, within ± 3% of full range of low scale, for five minutes without adjustment.

Functional operation of the gas-sampling unit shall remain disabled through a system 

lockout until the instrument meets stability and warm-up requirements. If the analyzer 

does not achieve stability with 15 minutes, from “power-on”, it shall be locked out from 

I/M testing and a message shall be displayed instructing the inspector to call for service.
During the warm-up, the Main Menu shall be displayed unless an optional functional 

menu or menus are offered. The analyzer system shall lock out all bench related 

functions during warm-up. During warm-up, a message under the main menu shall be 

prominently displayed as follows: “Warm-up in progress - checking for stability”. During 

the initial entry into the “warm-up” period, and before any other menu can be selected, 

the software will automatically enter a “bulletin display” function and display any 

messages or bulletins forwarded from the AIR Program host system via modem transfer 

in the past 72 hours. This screen will reference the inspector.dat file and require each 

inspector to enter their access code as verification of receipt, before allowing that 

inspector to Proceed with an inspection. No inspector can enter into an official inspection 

without having “logged on” as having seen the Bulletin screen. When stability is achieved 

and the warm-up requirements are satisfied, access to gas bench functions shall be 

permitted.

I. System Response Time Requirements

The response time from the probe to the display shall not exceed eight (8) seconds to 

90% of a step change in input, nor will it exceed 12 seconds to 95% of a step change in 

input. For the O2 sensor, the response time shall be no more than fifteen (15) seconds to 

90% of full scale.

J. Optical Correction Factors

The hexane/propane equivalency factor (PEF) shall be limited to values between 0.49 

and 0.52. If an optical bench is used that can demonstrate accuracy of propane/hexane 

identification within specification, using a range greater or lesser than indicated, it will be 

considered. Factor confirmation shall be made on each analyzer assembly by measuring 

both N-hexane and propane on assembly line quality checks. The PEF shall be 

permanently stored in non-volatile memory. The PEF shall be displayed on the monitor 

on request by inquiry through the menu system. The optical bench shall he marked with a 

permanent “stamped” type tag identifying its PEF.

The signal strength from the source to the detector for all channels shall be monitored 

such that when the signal degrades beyond the adjustment range of the analyzer, the 

analyzer shall be locked out from operation, i.e. fail calibration.

K. Interference Effects

The effect of extraneous gas interference on the HC, CO, and CO2 analyzers shall not 

exceed ±10 ppm HC, ± 0.05% CO, and ±0.20% for CO2.

The instrument design shall insure that readings do not vary as a result of 

electromagnetic radiation and induction devices normally found in the inspection 

environment (including high energy vehicle ignition systems, RF transmission radiation 

sources, and building electrical systems). In addition, the manufacturer shall ensure that 

the analyzer processor and memory components are sufficiently protected to prevent the 

loss of programs and test records.

2.12 Gas Calibration File

At the conclusion of each gas calibration the required data shall be placed in the CAL.DAT file.

2.13 Microcomputer Specifications
A. A standard microcomputer must be included in the analyzer and is to be used to 

control all analyzer functions. Each vendor is to develop DOS executable 

programs for each required function. These programs shall:

1. control each of the analyzer functions and time of function;

2. examine and obtain values from all of the analyzer sensors;

3. read and write information to diskette in standard DOS format; and

4. copy the analyzer, inspection station identification information from the 

hard disk onto each new floppy diskette when formatted.

The Colorado Department of Public Health and Environment reserves the right to 

add additional programs and functional performance requirements, up to the 

technical limits of the hardware, to improve the I/M program.

Sufficient flexibility shall be provided in the design of the microcomputer system 

to allow expansion of the analyzer to include, but not be limited to, the following 

additional capabilities:

1. connect and recover data from vehicle on-board diagnostic 

systems (OBD) meeting SAE specifications when they become 

available;

2. monitor vehicle recall data; identify, record and process data as 

required when an official EPA/SAE format is identified.

3. accommodate additional input channels in both analog and 

digital form. Two free slots, 16 bit capability.

The manufacturer may offer additional features that utilize the 

microcomputer as a stand-alone personal computer by providing optional 

software to perform various non-l/M functions. Such offerings must not 

interfere with the inspection requirements, or in any manner affect or 

allow the inspector to tamper with the inspection-related computer 

programming or data files.

The analyzer shall be equipped with an internal clock that operates 

independently from the power source and will provide accurate and 

automatic date and time information for the following functions:

a. each test performed;

b. automatic gas calibration and pressure test check (72 

hours); (24 hour) optional

c. automatic leak check (4 or 24 hours and every 24/72 

hours for automatic gas calibration), and leak check 

combination.

d. audit sequence:
All equipment and software submitted for Colorado certification 

must be the full and current configuration proposed for sale. 

Partial, dated, or incomplete models are not acceptable.

Acceptance of the microcomputer portion of the Colorado 94 

Analyzer system will be dependent upon the satisfactory 

performance of the full-proposed configuration meeting all the 

requirements of this specification.

The proposed hardware configuration must be fully supported by 

all software and/or operating systems listed in the acceptance 

requirements or elsewhere in these specifications. Performance 

tests to prove compatibility will be conducted. The vendor will 

bear all shipping and equipment preparation charges for the 

certification testing.

2.14 Standard Hardware: Minimum Required Configuration

1. Operating System

DOS Version 6.2 or most current

2. Processor

The microprocessor must be fully compatible with the Intel 80486 microprocessor. 

Upgradable to Pentium technology.

3. RAM Memory

The system must contain at least 2 MB of user available RAM. (expandable to 16 MB)

4. Power Up Sequence

The system must include a power up sequence that provides a self-diagnostic routine to 

check the on-line presence of critical PC components (including, at a minimum, the 

processor, firmware ROM, hard disk controller, keyboard, clock, modem, printers, bar 

code reader I/O ports, setup RAM and memory).

5. Video

The CRT display must be at least 12” in diagonal measure and operate in a VGA mode.

The software shall automatically blank the screen or use a screen saver mode, if no 

keyboard entry is made for 10 minutes. The display shall return when the inspector 

strikes any key.

6. Floppy Disk

Each unit must come with an IBM compatible floppy disk drive that will permit full usage 

of 2sHD 1.44 Mb 3.5” removable media. The drive must be located in a secured area 

accessible only to authorized AIR Program Service representatives. That secured drive 

must also include an approved method to limit logical access. Colorado Department of 

Public Health and Environment will test the system for drive security and it should not 
provide access to the secured floppy except through the approved security procedure. 

The secured floppy drive shall be designated the “A” drive.

7. Hard Disk

Each unit must come with at least 120 megabytes of hard disk storage. The vendor may 

use up to 40 megabytes for their programs and data provided at least a full 80 megabytes 

of usable storage is available for Colorado Department o1 Public Health and Environment 

and user information. The hard disk is to be self-parking (where applicable), shock 

mounted, and able to operate reliably in the inspection environment. The hard disk must 

also include a Colorado Department of Public Health and Environment approved method 

of limiting access to data and programs. The hard disk containing programs and data files 

shall be designated the “C” drive.

8. I/O Ports

The unit must include sufficient I/O ports of proper configuration to allow the connection 

of all required options and the capability to add additional I/O boards.

9. Keyboard

The Colorado 94 Analyzer keyboard must be fully interfaced with the microcomputer and 

have all of the necessary normal, numeric, cursor, control, shift, alternate, and function 

keys needed to operate a standard IBM PC compatible microcomputer, preferably 101 

keys should be provided.

10. Bar Code Scanner

The bar code scanner shall be equivalent to the PDF 1000 “HV” (High Visibility) Scanner 

from Symbol Technologies. Performance specifications are included in Technical 

Specification Appendix A. The PDF 1000 “HV” is a scanner capable of reading both 1 -D 

and PDF-417(2-D) bar codes.

11. Hard Disk Expansion

System must include a hard disk interface that will fully support a second internal disk 

drive of the same type as the original type drive or a functional equivalent approved by 

the Colorado Department of Public Health and Environment that does not compromise 

tamper-resistance.

12. Additional Storage

3.5” 1.44 Mb Floppy Disk Drive IBM Optical disk drive, floptical, CD ROM reader etc., 

these options would be for manufacturer offered look up tables, service information or 

other options requiring additional storage capability.

13. Communications

Hayes compatible modem at 14,400B, M.N.P. Level 5. Error correction: Microcom 

networking protocol (M.N.P.) levels 1-4 and V.42 data compression: M.N.P. level 5 and 

V.32BIS/V.42BIS. Protocol will be provided within the operational software package. 

Modem communications will be necessary during the inspection process for V.I.N. 

verification, multiple “I” Test Control, vehicle recall etc., from the Network System Host 

Computer.
2.15 Required Printers

A. Diagnostic printer:

A 24 pin impact printer shall be supplied which is dedicated to the task of printing 

designated information on a VEHICLE DIAGNOSTIC FORM, or other repair type 

information. Continuous, fanfold, preprinted (ghost printed certificates) will be used. The 

printer shall print information on the certificate using 12 characters per inch and 80 

characters per line.

B. Certificate Printer:

The certificate printer is to be a “thermal transfer” technology printer, capable of 

producing PDF 417, two dimensional bar code and Code 39, one-dimensional bar code. 

As of date, Standard Register produces a model of printer that meets or exceeds all 

requirements necessary to print upon the required certificate. This model is a PT650 

Thermal/Thermal Transfer Printer. Specifications of the certificate printer shall be 

Standard Register FT650 or equivalent. With equivalency being defined as successful 

completion of printing, security, storing and dispensing of the required certificate. Final 

acceptance of alternative printers lies with written State approval.

Standard Register PT650 technical specifications are included in the Technical 

Specification Appendix B.

PHYSICAL SPECIFICATIONS OF CERTIFICATE:

Physical specifications of the certificate, to include print fields, physical design, materials 

and sizing are to be determined by the Department of Revenue.

C. Certificate Security:

The inspection certificate printer and certificate storage area shall be located in a secured 

area. Access to the area securing the printer and certificates shall be available only to the 

licensed inspector at the station. The certificate storage area shall have a redundant 

security system utilizing both a hardware lock and a software lock that meets Colorado 

Department of Public Health and Environment approval. Certificates will be prevented 

from being “pulled” through the printer. A form of printer locking must be utilized. The 

secured area containing certificates and the certificate printer, shall be designed so that 

the same key can be used to open any access doors that secure any optional storage 

media. If any of these doors are opened, a microswitch (or equivalent) shall be used 

which prevents the printing of certificates and records each event with time and date to 

an entry.dat file.

The purpose of the software lock is to restrict access to the printer with the following 

exceptions: loading and aligning certificates prior to printing, clearing paper misfeed or 

jam problems, etc., and to provide a record of the personnel performing those functions.

The area containing the certificates shall be located so that proper routing is maintained 

on the certificates as they are fed through the printer.

If tampering occurs, a software lockout algorithm shall be activated which aborts any 

existing test sequence and prevents further emission testing until an AIR Program official 

clears the lockout.
There shall be easy access to the vehicle diagnostic report printer so that the inspector 

can easily replace paper, clear paper jams and change ribbons.

2.16 Clock/Calendar

The analyzer unit shall have a real time clock/calendar which shall make available the current 

date and time. Date will be in month, day, year format and time will be in 24-hour format. The AIR 

Program system host computer shall update both time and date during each transfer of data via 

the system modem.

The date/time, along with the time the test started and when it ended, is to be included on the test 

record. The start time is when the inspector’s access code is entered and the end time is when 

the analyzer data is written to the test file.

If the clock/calendar fails or becomes unstable (as referenced to the program host system during

modem data transfer), the analyzer unit shall be locked out from I/M testing and a message shall 

be displayed indicating that service is required.

Resetting of the clock, independent of the host updating, shall require controlled access.

2.17 Lockout Notification

The analyzer shall alert the inspector of any lockout situation by prominently displaying a 

message on the CRT. Any lockout condition will be stored to file.

2.18 Vehicle Diagnosis

The analyzer shall be capable of menu selection that will allow the analyzer to be used as an 

ordinary garage type emissions analyzer for general automotive repair work and diagnostics.

2.19 Software Loading

The inspector shall not have to load the microcomputer's operating or applications software to 

operate the analyzer. On each POWER ON of the analyzer, the analyzer shall automatically do 

all microcomputer component self-diagnostics, memory checking, and loading of all necessary 

operating software without inspector intervention. Upon satisfactory computer component check 

out, the applications software is to present a menu of available analyzer operations. All offered 

features are to be menu-driven. For each feature, a context sensitive, on-line help facility is to be 

provided which can be accessed preferably with a single keystroke.

3.0 DISPLAY PROMPTS AND PROGRAMMING CRITERIA REQUIREMENTS

Operational software requirements will be available from the Division upon request.

ATTACHMENT I TO THE TECHNICAL SPECIFICATION APPENDIX A PDF 1000 Scanner

This document is contained in the Air Pollution Control Division’s Emissions Technical Center Procedures 

Manual and is incorporated by reference.

PDF 1000 SCANNER

PERFORMANCE CHARACTERISTICS

Type: Raster scanning, retro-collective
Scan Element Low mass, single mirror, resonant

Light Source: 675 nm. Laser diode

Pattern Size: At 9 in. (22.8 cm) from the nose of the scanner, the pattern is 7 in. (17.8 

cm) horizontally and 2.6 in. (6.6 cm) vertically

Scan Rate: 560 scans/sec. 280 Hz + 10 Hz (horizontal)

Frame Rate: 22 frames/sec. 11 Hz + 1 Hz (vertical)

Optical Resolution Can decode a 6.6 mil X-dimension symbol (PDF417); Y-dimension must 

be 3X

Haz Size of PDF 417: 5.9 in. (15cm) wide x 2.3 in. (5.8 cm) high (928 code words, at security 

level 0-8)

PHYSICAL CHARACTERISTICS

Pitch Tolerance: + 30” (“front and back”)

Skew: + 15” plane parallel to symbol (“side to side”)

Rotational Tolerance: + 3” (assuming 3:1 codeword module aspect ratio)

Dead Zone/Optical Throw Print: + 2” (1 D symbologies) or + 9” (PDF417) from beam direction

Print Contrast Resolution (min): 25% (1-D symbologies) or 35% (PDF417) absolute dark/light 

reflectance differential, measured at 675 nm

Ambient Light Immunity: 8000 ft-candles (86100 LUX) of sunlight

Humidity: 5 to 95% relative humidity (non-condensing)

Shock: Unit functions normally after 4ft (1.2m) drop to concrete

Environmental Scaling: MIL-STD-810d windblown dust and rain

Operating Temperature: 14° to 104° F (-10° to 40°C)

Storage Temperature: -40° to 140° F (-40° to 60°C)

Coil Cable Length: 6 ft. (183cm)

Weight 10.4 oz (295gm) without cable

Dimensions: 7.2 in. (18.2 cm) H x 4.2 in. (10.7cm) Lx L7 in. (4.3 cm) W

Laser Class: CDRH Class II, IEC 825 Class II

PL 140 Decoder/Interface

Decode Capabilities: 2-D symbologyPDF417 (up to 928 code words at security level 0-8). 1-
D Symbologies: UPC-A, UPC-E, EAN-8, EAN-13, Code 39, Code 39 

Full ASCII, Code 128, Interleaved 2 of 5, Codabar.

Memory: 64K x 32-bit PROM; 32K x32-bit RAM (128K ram OPTION); 256 X 16 

bits EEPROM for system parameters

Humidity: 5-95% relative humidity (non-condensing)

Shock: 4-ft. (1.2m) drop to concrete

Environmental Sealing: Environmentally sealed against dust and rain (with battery pack 

attached)

Operating Temperature: 14° to 104° F (-10° to 40° C)

Storage Temperature: -40° to 140° F (-40° to 60°C)

Weight: 11.2 oz. (318 gm) With batter pack 27.8 oz. (788.13 gm)

Dimensions: 4.0 in. (10.2 cm) high x 4.0 in. (10.2cm) long x 1.4 in. 13.6 cm wide (2.8 

in (7.1 cm wide with batter pack)

Agency Approvals: FCC Class A, UL, CSA, VDE

Power Requirements: DC Power: 11 VDC from wall transformer or 6 VDC from Battery Pack. 

Wall transformer power requirements: 115 VAC @ .15A, 220/240 VAC 

@ .075A, 100V @ .15A. Pack will support several thousand scans per 

8-hour shift. Actual number depends on PDF417 symbol size and mix 

of 1D bar codes scanned.

ATTACHMENT II TO THE TECHNICAL SPECIFICATION APPENDIX A Thermal Transfer Printer

This document is contained in the Air Pollution Control Division’s Emissions Technical Center Procedures 

Manual and is incorporated by reference.

THERMAL TRANSFER PRINTER

STANDARD FEATURES

● On line/Off line Operation

● Thermal/Thermal Transfer

● Extremely High doc density (203 dots/inch. 8 dots/mm

● Print speed 6 inches plus per second

● Media width 5.25

● Print width 5.10"

● Large maximum media size 5.25-W X 60 L

● User-selectable bar code ratios
● Internal take-up mechanism

● External rewind mechanism

● Print material. Label and lag stock

● Label presentation

● Print head temperatures software selectable

● Easy - load ribbon

● Alpha-numeric keypad

● LCD Display 2X20

● 512K of on board Ram Expandable to 8 MB

● Rotation of text and bar codes 90. 18O and 270 including human readable

● Date and Time Clock

● Label back feed for cutting and dispensing modes

● Intelligent Formats

PRINT MODES

Three print modes are standard

● Batch - printing one or more labels with or without backing paper

● Rewind - printing a batch of labels and rewinding

● Present Mode - Present sensor stops each label for presentation before delivering the next label

BAR CODES

● Code 39

● Interleave 2 of 5

● Codabar

● Code 128 A. B, and C subsets

● UPC-A and E

● UPC addendum codes 2 and 5 digit

● UPC random weight

● EAN 13 and 8
● Code93

● Universal shipping contained symbology (with fixed or random weight codes) code 39 variations to 

produce all industry standards such as LOGMARS. HIBCC. and AIAG

● Bar code modulus (“x” dimensions): 5 mil to 10 mil in picket or ladder orientation

● Bar codes printed with or without human readable interpretation

FONT STYLES

● 12 Scalable Fonts On-Board

● Downloadable font support

● Downloadable graphics

● Inverse text support

● International language support different language character sets

● Inverse image support

MEDIA SPECIFICATIONS

● Media type: Roll-fed, die-cut continuous or fan-fold labels, tags or tickets

● Material: plain paper thermal transfer or thermal sensitive paper

● Sensing: adjustable transmissive sensor for die cut labels or tags.

● Reflective sensor for use with black marks

● Programmable top of form

● Maximum media width: 5.25

● Minimum media width: 0. 50”

● Maximum media length: 60.0”

● Minimum media length: 0.50”

● Thickness: 0.0023” to 0.012” (including liner)

● Supply roll capacity. 8"(203mm)

● Internal rewind capacity: 6"( 152mm)

● External rewind capacity: 8"(203mm)

● Fanfold stock internal and external capabilities

PRINT HEADS
● Standard width: 5.1"( 128mm) 8 dot/mm (203 dots/inch. 8 dots/M)

● Optional widths available

● Optional Dot Densities available

PRINT SPEED

● Standard speed :6"(152mm) plus per second

● Programmable print speeds of 1.5" (38 mm) 3"(72mm) up to 6"(1.52mm) plus per second

COMMUNICATION INTERFACE

● RS-232C.RS-422. RS-185

● Centronics parallel interface

● Robust XON/XOFF. CTS, DTR handshake

● Programmable 7 or 8 bit length

● Multidrop protocol

● Bidirectional Printer to Host

OPTIONS

● Ribbon Saver

● Cutter mechanism and Tray

● Font Data Cards (up to 1MB)

● Application Cards (up to 1 MB)

● Graphics Display

● Full Alphanumeric keyboard

● Scanner Support

● User Data Support Cards (up to 1MB)

● Twinax & Coax IBM Inter faces

MECHANICAL

● Height: 10"(254mm)

● Width: 11"(279mm)

● Depth: 16"(406mm)
● Weight: 35 lbs. (16 kg)

ELECTRICAL

● Power 110/220 VAC + or - 10% 5O/60 Hz at 2 amps maximum 100 VAC on request

● Built to ULCSA and TUV-GS safety standards and VDE Class B and FCC Class A emissions standard

ENVIRONMENTAL

● Operating Temperature: 32° F to 100° F (0° to40° C)

● Storage Temperature:-40F to 140° F (-40° Cto60° C)

● Humidity. 10% to 90% non-condensing

● Ventilation: Free air movement

● Dust: non-conducting, non-corrosive

ATTACHMENT III TO TECHNICAL SPECIFICATION, APPENDIX A Colorado Automobile Dealers 

Transient Mode Test Analyzer System

This document is contained in the Air Pollution Control Division’s Emissions Technical Center Procedures 

Manual and is incorporated by reference.

COLORADO AUTOMOBILE DEALERS TRANSIENT MODE TEST ANALYZER SYSTEM

TRANSIENT MODE TEST SYSTEM TECHNICAL AND HARDWARE SPECIFICATIONS

COLORADO AUTOMOBILE DEALERS TRANSIENT MODE TEST ANALYZER SYSTEM

(IG 240)

TEST SYSTEM TECHNICAL AND HARDWARE SPECIFICATIONS

JANUARY 27, 1997

INTRODUCTION

This document contains technical specifications for a Colorado Automobile Dealers Transient Mode IG 

240 Test Analyzer System. The technical specifications of the system are based upon the Environmental 

Protection Agency High-Tech I/M Test Procedures dated June 1996, Emission Standards, Quality Control 

Requirements and Equipment Specifications: IM 240 and Functional Evaporative System Tests technical 

guidance document EPA-AA-RSPD-IM-96-1, dated June 1996. The technical concept allows for the use 

of technologies of similar application but of a lower monetary cost. Utilizing lower cost technologies and 

identifying equipment required to directly address the requirements of the Colorado Enhanced Inspection 

Program, the system can perform transient loaded mode testing in the Motor Vehicle Dealer Test Facility 

pursuant to Section 42-4-309 (3)(B), C.R.S.

In review of these specifications, sections may indicate that they are not applicable. Not applicable 

indicates that the content of that section does not apply to the Colorado system. Not applicable sections 

remain within this specification, as they provide insight into the systems total capability with hardware 

often sharing functionality with another test process. This specification is intended to act as a guide to 
hardware requirements, provides insight into the application of the hardware, and provides testing and 

quality control requirements and to provide a general overview of the operating system software 

requirements. Numerical references to methodology or procedures refer to sections so indicated within 

the code of federal regulations (40 CFR 85.2 July 1996) (EPA).

This attachment III establishes equipment specifications, test procedures and test standards. In order to 

qualify for the Colorado Automobile Dealers Transient Mode IG 240 Test Analyzer System must comply 

with the equipment specifications, must be capable of performing all applicable elements of the test 

procedure, and must be capable of measuring, calculating, displaying and recording each test standard.

Table of Contents

Introduction

Test Standards

(a) Transient Mode Emissions Limits

(b) Transient Test Score Calculations

(c) Evaporative System Pressure Test Standards

Transient Mode and Evaporative System Purge Test Procedures

(a) General Requirements

(b) Pre-inspection and Preparation

(c) Equipment Positioning and Settings

(d) Vehicle Conditioning

(e) Vehicle Emission Test Sequence

(f) Emission Measurements

Evaporative System Pressure Test Procedures

(a) General Requirements

(b) Pre-inspection and Preparation

(c) Canister-End Pressure Test - NOT APPLICABLE

(d) Fuel Inlet Pressure Test -- NOT APPLICABLE

(e) Fuel Cap Leak Test - Pressure Decay Method

(f) Fuel Cap Leak Test - Flow Rate Method.

Colorado Automobile Dealers Transient Mode Equipment Specifications

(a) Dynamometer Specifications
(b) Constant Volume Sampler

(c) Analytical Instruments

(d) Colorado Specific Hardware

Evaporative System Inspection Equipment

(a) General Requirements

(b) Evaporative Purge System - NOT APPLICABLE

(c) Evaporative System Pressure Test Equipment

Transient Mode Test Quality Control Requirements and Acceptance

Testing Procedures

(a) General Requirements

(b) Dynamometer

(c) Constant Volume Sampler

(d) Analysis System

(e) Gases Calibration, Working and Span Gases Shall Conform to Regulation Number 11, Appendix

(f) Quality Control Data Files

Test Report

(a) Acceptance Test Reporting for Transient Mode Evaluation

Terms

(a) Definitions

(b) Abbreviations

Test Standards

(a) Transient Mode Emissions Limits - Regulation Number 11, Part F “Maximum Allowable 

Emissions Limits”

EMISSIONS LIMITS

M/Y CO HC NOx
M/Y CO HC NOx

LDV:

1982

1983-84

1985

1986-90

1991-94

1995 & newer

65

50

25

25

20

20

5

5

5

4

4

4

8

8

8

6

6

4

LDT 1-2:

1982-83

1984-85

1986-90

1991 & newer

107

80

67

53

8

8

6

6

12

12

9

9

Emissions limits are subject to periodic revision and as such provisions must be made for ease of 

adjustments

(b) Transient Test Score Calculations

(1) Composite Scores. The composite scores for the test shall be determined by dividing the 

sum of the mass of each exhaust component obtained in each second of the test by the 

number of miles driven in the test. The first data point is the sample taken from t=0 to t=l. 

The composite test value shall be calculated by the equation in (b)(l)(i):

(i)

Transient Test Score Calculations - Composite Scores
(2) Second-by-Second Mass Calculations. The mass of each exhaust component shall be 

calculated to five significant digits for each second of the test using the following 

equations:

(i) Hydrocarbon mass: HCMASS = VMIX * DENSITYHC * HCconc

 -----------------

 1000000

(ii) Carbon Monoxide mass: COMASS = VMIX * DENSITYco *COconc

 -----------------

 1000000

(iii) Oxides of Nitrogen mass: NOxMASS = VMIX * DENSITYNO2* KH NOxconc

 -----------------

 1000000

(iv) Carbon Dioxide mass: CO2MASS = VMIX *DENSITYCO2 *CO2conc

 -----------------

100

(3) Meaning of Terms.

(i) HCmass = Hydrocarbon emissions in grams per second.

(ii) DensityHC = Density of hydrocarbons is 16.33 grams per cubic foot assuming an 

average carbon to hydrogen ratio of 1:1.85 at 68° F and 760 mm Hg pressure.

(iii) HCconc = Average hydrocarbon concentration per second of the dilute exhaust 

sample measured as described in Section 85.2226(c)(4), and corrected for 

background, in ppm carbon equivalent, i.e., equivalent propane * 3.

(A) HCconc = HCe-HCd(1-) Where:

(B) HCe = Hydrocarbon concentration of the dilute exhaust sample as 

measured in ppm carbon equivalent.

(C) HCd = Background hydrocarbon concentration of the dilution air, sampled 

as described in Section 85.2221(b)(5), as measured in ppm carbon 

equivalent.
(D) 13.4

DF = -------------------------- calculated on a second-by-second basis

CO2e + (HCe + COe)*10-4

(iv) Vmix = The CVS flow rate in cubic feet per second corrected to standard 

temperature and pressure.

(v) COmass = Carbon monoxide emissions in grams per second.

(vi) DensityCO = Density of carbon monoxide is 32.97 grams per cubic foot at 68 °F 

and 760 mm Hg pressure.

(vii) COconc = Average carbon monoxide concentration per second of the dilute 

exhaust sample measured as in Section 85.2226(c)(4), and corrected for 

background, water vapor, and CO2 extraction, in ppm.

(A)

 1

COconc = COe - COd (1- ----- )

 DF

(B) COe = Carbon monoxide concentration of the dilute exhaust in ppm.

(C) COd = Background carbon monoxide concentration of the dilution air, 

sampled as described in Section 85.12221(b)(5), in ppm.

(viii) NOxmass = Oxides of nitrogen emissions in grams per second.

(ix) DensityN02 = Density of oxides of nitrogen is 54.16 grams per cubic foot assuming 

they are in the form of nitrogen dioxide at 68 °F and 760 mm Hg pressure.

(x) NOxconc = Average concentration of oxides of nitrogen per second of the dilute 

exhaust sample measured as described in Section 85.2226(c)(4), and corrected 

for background in ppm.

(A)

 1

NOxconc = NOxe - NOxd (1- ----- )

 DF

(B) NOxe = Oxides of nitrogen concentration of the dilute exhaust sample as 

measure in ppm.

(C) NOxd = Background oxides of nitrogen concentration of the dilution air, 

sampled as described in Section 85.2221(b)(5), measured in ppm.

(xi) KH = humidity correction factor.

(A)

 1

KH ----------------------

 1 - 0.0047 (H - 75)

(B) H = Absolute humidity in grains of water per pound of dry air.
(C)

(43.478)Ra * Pd

H = ------------------------

 Ra

PB - (Pd * --------)

 100

(D) Ra = Relative humidity of the ambient air, percent.

(E) Pd = Saturated vapor pressure, mm Hg at the ambient dry bulb 

temperature. If the temperature is above 86° F, then it shall be used in 

lieu of the higher temperature, until EPA supplies final correction factors.

(F) PB = Barometric pressure, mm Hg.

(xii) CO2mass = Carbon dioxide emissions in grams per second.

(xiii) DensityCO2 = Density of carbon dioxide is 51.81 grams per cubic foot at 68°F and 

760 mm Hg.

(xiv) CO2conc = Average carbon dioxide concentration per second of the dilute exhaust 

sample measured as described in Section 85.2226(c), and corrected for 

background in percent.

(A)

 1

CO2conc = CO2e - CO2d (1- ---- )

 DF

(B) CO2d = Background carbon dioxide concentration of the dilution air, 

sampled as described in Section 85.2221(b)(5), measured in percent.

(C)(d) Evaporative System Pressure Test Standards

(1) Visual Check. The vehicle shall fail the evaporative system visual check if any part of the 

system is missing, damaged, improperly connected, or disconnected as described in 

Section 85.2222(b).

(2) Canister End Pressure Test Standards. NOT APPLICABLE The vehicle shall fail the 

pressure test if the system cannot maintain a pressure above eight inches of water for up 

to two minutes after being pressurized to 14 ± 0.5 inches of water. The vehicle shall also 

fail if it does not possess a check valve, as identified in the Look-up Table, and if no 

pressure drop is detected when the fuel cap is loosened as described in Section 

85.2222(c)(4).

(3) Fuel Inlet Pressure Test. NOT APPLICABLE

(i) Pass/Fail Determination. Flow rate, fill pressure, and decay pressure shall be 

measured at 2 Hz, averaged over 1 second intervals, and curve fitted using a 

least squares technique. If the volume compensated pressure drop is more than 

the pressure loss determined from starting and ending pressures in the Pressure 

Decay Reference Equation in Section 85.22C5(c)(3)(ii), the vehicle shall fail. 

Otherwise the vehicle shall pass. If not using volume compensation, the vehicle 

shall fail if the loss in pressure exceeds 6 inches of water.
(ii) Pressure Decay Reference Equation. This equation provides pressure loss 

values equivalent to a loss of pressure from 14 to 8 inches of water when the 

starting pressure is other than 14 inches of water.

P = 40 * ( 0.9967 - 2.7 * 10-6 * t )t

Where:

P = Starting or ending pressure, in inches of water,

t = Time, in seconds.

(iii) Fast-Pass. Fast-pass determinations may be made anytime during the pressure 

decay between 20 and 120 seconds if the measured pressure exceeds the 

corresponding Pressure Test Reference Equation cut point, from Section 

85.2205 (c)(3)(ii), by 1 inch of water pressure. The cut point is determined by 

adding 1 inch of water to the pressure value at a. time t. The pressure at time t 

corresponds to the pressure at the equivalent “start time” plus the time in 

seconds between 20 and 120 when the fast pass determination is made. The 

State may propose and the Division may approve other fast pass algorithms 

provided they minimize false results.

(iv) Pressure Drop. For vehicles without vapor control valves (burp valves), the 

clamp(s) shall be removed from the hose(s) and the system shall be monitored 

for a gradual pressure drop. If no pressure drop is detected, the vehicle shall fail 

the test. If the Pressure Test Look-up Table identifies the vehicle as possessing a 

vapor control valve, the system shall not be monitored for a loss of pressure.

(4) Fuel Cap Test. (Part F, Subpart IV of Regulation Number 11)

(i) Pressure Decay Method. If pressure decays by 6 inches of water or more during 

the 10-second period, the vehicle shall fail the fuel cap integrity test.

(ii) Flow Rate Method. The fuel cap leak rate shall be compared 1:0 an orifice with a 

National Institute of Standards and Technology traceable flow rate which will 

result in a pass/fail flow rate threshold of 60 cubic centimeters per minute of air at 

30 inches of water column. If the leak rate exceeds 60 cubic centimeters per 

minute at a pressure of 30 inches of water column, the cap shall fail the test.

Transient Mode and Evaporative System Purge Test Procedures

(a) General Requirements

(1) Data Collection. The following information shall be determined for the vehicle being 

tested and used to automatically select the dynamometer inertia and power absorption 

settings:

(i) Vehicle type: LDGV, LDGT1, LDGT2, and others as needed,

(ii) Chassis model year,

(iii) Make,

(iv) Model,
(v) Number of cylinders, or cubic inch displacement of the engine

(vi) Transmission type.

(2) Ambient Conditions. The ambient temperature, absolute humidity, and barometric 

pressure shall be recorded continuously during the transient or as a single set of readings 

up to 4 minutes before the start of the transient driving cycle.

(3) Restart. If shut off, the vehicle shall be restarted as soon as possible before the test and 

shall be running at least 30 seconds prior to the transient driving cycle.

(b) Pre-inspection and Preparation

(1) Accessories. All accessories (air conditioning, heat, defogger, radio, automatic traction 

control if switchable, etc.) shall be turned off (if necessary, by the inspector).

(2) Leaks. The vehicle shall be inspected for exhaust leaks. Gas measurement of carbon 

dioxide or other gases shall be acceptable. Vehicles with leaking exhaust systems shall 

be rejected from testing.

(3) Operating Temperature. The vehicle temperature gauge, if equipped and operating, shall 

be checked to assess temperature. If the temperature gauge indicates that the engine is 

not at normal operating temperature, the vehicle shall be inspected and shall get a 

second-chance emission test if it fails the initial test for any criteria exhaust component. 

Vehicles in overheated condition shall be rejected from testing.

(4) Tire Condition. Vehicles shall be rejected from testing if the tire cords, bubbles, cuts, or 

other damage are visible. Vehicles shall be rejected that have space-saver spare tires on 

the drive axle. Vehicles may be rejected that do not have reasonably sized tires. Vehicle 

tires shall be visually checked for adequate pressure level. Drive wheel tires that appear 

low shall be inflated to approximately 30 psi, or to tire sidewall pressure, or 

manufacturer's recommendation.

(5) Ambient Background. Background concentrations of hydrocarbons, carbon monoxide, 

oxides of nitrogen, and carbon dioxide (HC, CO, NOx, and CO2, respectively) shall be 

sampled as specified in Section 85.2226(b)(2)(iv) to determine background concentration 

of constant volume sampler dilution air. The sample shall be taken for a minimum of 15 

seconds within 120 seconds of the start of the transient driving cycle, using the same 

analyzers used to measure tailpipe emissions except as provided in Section 

85.2221(f)(3). Average readings over the 15 seconds for each gas shall be recorded in 

the test record. Testing shall be prevented until the average ambient background levels 

are less than 20 ppm HC, 30 ppm CO, and 2 ppm NOx, or outside ambient air levels (not 

influenced by station exhaust), which ever are greater.

(6) Sample System Purge. While a system is in operation, the CVS shall continuously purge 

the CVS hose between tests, and the sample system shall be continuously purged when 

not taking measurements.

(7) Negative Values. Negative gram per second readings shall be integrated as zero and 

recorded as such.

(c) Equipment Positioning and Settings
(1) Purge Equipment. NOT APPLICABLE If an evaporative system purge test is to be 

performed:

(i) The evaporative canister shall be checked unless the canister is inaccessible. A 

missing or obviously damaged canister shall result in failure of the visual 

evaporative system check.

(ii) The evaporative system shall be visually inspected for the appearance of proper 

hose routing and connection of hoses, unless the canister is inaccessible. If any 

evaporative system hose is disconnected, then the vehicle shall fail the visual 

evaporative system check. All hoses disconnected for the test shall be 

reconnected after a purge flow test is performed.

(iii) The purge flow measurement equipment shall be connected in series between 

the evaporative canister and the engine, preferably on the canister end of the 

hose. For vehicles equipped with a service port for evaporative functional testing, 

the measurement equipment shall be connected to the port.

(2) Roll Rotation. The vehicle shall be maneuvered onto the dynamometer with the drive 

wheels positioned on the dynamometer rolls. Prior to test initiation, the rolls shall be 

rotated until the vehicle laterally stabilizes on the dynamometer. Drive wheel tires shall be 

dried if necessary to prevent slippage during the initial acceleration.

(3) Cooling System. Testing shall not begin until the test-cell cooling system is positioned 

and activated. The cooling system shall be positioned to direct air to the vehicle cooling 

system, but shall not be directed at the catalytic converter.

(4) Vehicle Restraint. Testing shall not begin until the vehicle is restrained. Any restraint 

system shall meet the requirements of Section 85.2226(a)(5)(ii). In addition, the parking 

brake shall be set for front wheel drive vehicles prior to the start of the test.

(5) Dynamometer Settings. Dynamometer power absorption and inertia weight settings shall 

be automatically chosen from a Division supplied electronic look-up table that will be 

referenced based upon the vehicle identification information obtained in (a)(l). Vehicles 

not listed shall be tested using default power absorption and inertia settings as follows:

DYNAMOMETER DEFAULT SETTINGS

vehicle type number of cylinders track road load 

horsepower

test inertia weight

All 3 12:1 2000

All 4 12.8 2500

All 5 14.5 3000

All 6 14.5 3000

LDGV 8 16.2 3500

LDGT 8 17.7 4000
vehicle type number of cylinders track road load 

horsepower

test inertia weight

LDGV 10 16.2 3500

LDGT 10 19.2 4500

LDGV 12 17.7 4000

LDGT 12 20.7 5000

(6) Exhaust Collection System. The exhaust collection system shall be positioned to insure 

complete capture of the entire exhaust stream from the tailpipe during the transient 

driving cycle. The system shall meet the requirements of Section 85.2226(b)(2).

(d) Vehicle Conditioning

(1) Second-chance Retest. A vehicle shall get a second-chance emission test if it fails the 

initial test and all criteria exhaust components are at or below 2.0 times the applicable 

standards.

(2) Program Evaluation. NOT APPLICABLE Vehicles being tested for the purpose of 

program evaluation under Section 51.353(c) shall receive two full transient emission tests 

(i.e., a full 240 seconds each). Results from both tests and the test order shall be 

separately recorded in the test record. Emission scores and results provided to the 

motorist may be from either test.

(3) Discretionary Preconditioning. Any vehicle may be preconditioned using any of the 

following methods:

(i) Non-loaded Preconditioning. Increase engine speed to approximately 2500 rpm, 

for up to 4 minutes, with a tachometer.

(ii) Loaded Preconditioning. Drive the vehicle on the dynamometer at 30 miles per 

hour for up to 240 seconds at road-load.

(iii) Transient Preconditioning. After maneuver the vehicle onto the dyno, drive a 

transient cycle consisting of speed, time, acceleration, and relative load as 

determined by the Division.

(e) Vehicle Emission Test Sequence

(1) Transient Driving Cycle. The vehicle shall be driven over the following cycle:

Time Speed Time Speed Time Speed Time Speed Time Speed

0 0 48 25.7 96 0 144 24.6 192 54.6

1 0 49 26.1 97 0 145 24.6 193 54.8
Time Speed Time Speed Time Speed Time Speed Time Speed

2 0 50 26.7 98 3.3 146 25.1 194 55.1

3 0 51 27.5 99 6.6 147 25.6 195 55.5

4 0 52 28.6 100 9.9 148 25.7 196 55.7

5 3 53 29.3 101 13.2 149 25.4 197 56.1

6 5.9 54 29.8 102 16.5 150 24.9 198 56.3

7 8.6 55 30.1 103 19.8 151 25 199 56.6

8 11.5 56 30.4 104 22.2 152 25.4 200 56.7

9 14.3 57 30.7 105 24.3 153 26 201 56.7

10 16.9 58 30.7 106 25.8 154 26 202 56.3

11 17.3 59 30.5 107 26.4 155 25.7 203 56

12 18.1 60 30.4 108 25.7 156 26.1 204 55

13 20.7 61 30.3 109 25.1 157 26.7 205 53.4

14 21.7 62 30.4 110 24.7 158" 27.3 206 51.6

15 22.4 63 30.8 111 25.2 159 30.5 207 51.8

16 22.5 64 30.4 112 25.4 160 33.5 208 52.1

17 22.1 65 29.9 113 27.2 161 36.2 209 52.5

18 21.5 66 29.5 114 26.5 162 37.3 210 53

19 20.9 67 29.8 115 24 163 39.3 211 53.5

20 20.4 68 30.3 116 22.7 164 40.5 212 54

21 19.8 69 30.7 117 19.4 165 42.1 213 54.9

22 17 70 30.9 118 17.7 166 43.5 214 55.4

23 14.9 71 31 119 17.2 167 45.1 215 55.6

24 14.9 72 30.9 120 18.1 168 46 216 56

25 15.2 73 30.4 121 18.6 169 46.8 217 56
Time Speed Time Speed Time Speed Time Speed Time Speed

26 15.5 74 29.8 122 20 170 47.5 218 55.8

27 16 75 29.9 123 20.7 171 47.5 219 55.2

28 17.1 76 30.2 124 21.7 172 47.3 220 54.5

29 19.1 77 30.7 125 22.4 173 47.2 221 53.6

30 21.1 78 31.2 126 22.5 174 47.2 222 52.5

31 22.7 79 31.8 127 22.1 175 47.4 223 51.5

32 22.9 80 32.2 128 21.5 176 47.9 224 50.5

33 22.7 81 32.4 129 20.9 177 48.5 225 48

34 22.6 82 32.2 130 20.4 178 49.1 226 44.5

35 21.3 83 31.7 131 19.8 179 49.5 227 41

36 19 84 28.6 132 17 180 50 228 37.5

37 17.1 85 25.1 133 17.1 181 50.6 229 34

38 15.8 86 21.6 134 15.8 182 51 230 30.5

39 15.8 87 18.1 135 15.8 183 51.5 231 27

40 17.7 88 14.6 136 17.7 184 52.2 232 23.5

41 19.8 89 11.1 137 19.8 185 53.2 233 20

42 21.6 90 7.6 138 21.6 186 54.1 234 16.5

43 23.2 91 4.1 139 22.2 187 54.6 235 13

44 24.2 92 0.6 140 24.5 188 54.9 236 9.5

45 24.6 93 0 141 24.7 189 55 237 6

46 24.9 94 0 142 24.8 190 54.9 238 2.5

47 25 95 0 143 24.7 191 54.6 239 0

(2) Driving Trace. The inspector shall follow an electronic, visual depiction of the 

time/speed relationship of the transient driving cycle (hereinafter, the trace). The visual 

depiction of the trace shall be of sufficient magnification and adequate detail to allow 
accurate tracking by the driver and shall permit the driver to anticipate upcoming speed 

changes. The trace shall also clearly indicate gearshifts as specified in Section 

85.2221(e)(3).

(3) Shift Schedule. For vehicles with manual transmissions, inspectors shall shift gears 

according to the following shift schedule:

Shift Sequence gear Speed miles per hour Nominal Cycle Time 

seconds

1- 2 15 9.3

2-3 25 47.0

De-clutch 15 87.9

1-2 15 101.6

2-3 25 105.5

3-2 17 119.0

2-3 25 145.8

3-4 40 163.6

4-5 45 167.0

5-6 50 180.0

De-clutch 15 234.5

Gearshifts shall occur at the points in the driving cycle where the specified speeds are obtained. 

For vehicles with fewer than six forward gears the same schedule shall be followed with shifts 

above the highest gear disregarded.

(4) Speed Excursion Limits.Speed excursion limits shall apply as follows:

(i) The upper limit is 2 mph higher than the highest point on the trace within 1 

second of the given time.

(ii) The lower limit is 2 mph lower than the lowest point on the trace within 1 second 

of the given time.

(iii) Speed variations greater than the tolerances (such as may occur luring gear 

changes) are acceptable provided they occur for no more than 2 seconds on any 

occasion.
(iv) Speeds lower than those prescribed during accelerations are acceptable 

provided the vehicle is operated at maximum available power during such 

accelerations until the vehicle speed is within the excursion limits.

(v) Exceedances of the limits in Section 85.2221(i) through Section 85.2221(iii) shall 

automatically result in a void test. Tests shall be aborted if the upper excursion 

limits are exceeded. Tests may be aborted if the lower limits are exceeded.

(5) Speed Variation Limits.

(i) A linear regression of feedback value on reference value shall be performed on 

each transient driving cycle for each speed using the method of least squares, 

with the best fit equation having the form: y = mx + b, where:

(A) y = The feedback (actual) value of speed;

(B) m = The slope of the regression line;

(C) x = The reference value; and

(D) b = The y-intercept of the regression line.

(ii) The standard error of estimate (SE) of y on x shall be calculated for each 

regression line. A transient driving cycle lasting the full 240 seconds that exceeds 

the following criteria shall be void and the test shall be repeated:

(A) SE = 2.0 mph maximum.

(B) m = 0.96-1.01.

(C) r

2 = 0.97 minimum.

(D) b = ± 2.0 mph.

(iii) A transient driving cycle that ends before the full 240 seconds that exceeds the 

following criteria shall be void and the test shall be repeated:

(A) SE = (NOT APPLICABLE)

(B) m = (NOT APPLICABLE)

(C) r

2 = (NOT APPLICABLE)

(D) b = (NOT APPLICABLE)

(6) Distance Criteria. The actual distance traveled for the transient driving cycle and the 

equivalent vehicle speed (i.e., roll speed) shall be measured. If the absolute difference 

between the measured distance and the theoretical distance for the actual test exceeds 

0.05 miles, the test shall be void.

(7) Vehicle Stalls. Vehicle stalls during the test shall result in a void and a new test. More 

than 3 stalls shall result in test failure.
(8) Dynamometer Controller Check. For each test, the measured horsepower, and inertia if 

electric simulation is used, shall be integrated from 55 seconds to 81 seconds (divided by 

26 seconds), and compared with the theoretical road-load horsepower (for the vehicle 

selected) integrated over the same portion of the cycle. The same procedure shall be 

used to integrate the horsepower between 189 seconds to 201 seconds (divided by 12 

seconds). The theoretical horsepower shall be calculated based on the observed speed 

during the integration interval. If the absolute difference between the theoretical 

horsepower and the measured horsepower exceeds 0.5 hp, the test shall be void. 

Alternate error checking methods may be used if shown to be equivalent and approved 

by the Division.

(9) Inertia Weight Selection. Operation of the inertia weight selected for the vehicle shall be 

verified as specified in Section 85.2226(a)(4)(iii). For systems employing electrical inertia 

simulation, an algorithm identifying the actual inertia force applied during the transient 

driving cycle shall be used to determine proper inertia simulation. For all dynamometers, 

if the observed inertia is more than 1 % different from the required inertia, the test shall 

be void.

(10) CVS Operation. The CVS operation shall be verified for each test for a CFV-type CVS by 

measuring either the absolute pressure difference across the venturi or measuring the 

blower vacuum behind the venturi for minimum levels needed to maintain choke flow for 

the venturi design. The operation of an SSV-type CVS shall be verified throughout the 

test by monitoring the difference in pressure between upstream and throat pressure. The 

minimum values shall be determined from system calibrations. Monitored pressure 

differences below the minimum values shall void the test.

(11) Fuel Economy. For each test, the health of the overall analysis system shall be evaluated 

by checking a test vehicle's fuel economy for reasonableness, relative to upper and lower 

limits, representing the range of fuel economy values normally encountered for the test 

inertia and horsepower selected. For each inertia selection, the upper fuel economy limit 

shall be determined using the lowest horsepower setting typically selected for the inertia 

weight, along with statistical data, test experience, and engineering judgment. A similar 

process for the lower fuel economy limit shall be used with the highest horsepower 

setting typically selected for the inertia weight. For test inertia selections where the range 

of horsepower settings is greater than 5 horsepower, at least two sets of upper and lower 

fuel economy limits shall be determined and appropriately used for the selected test 

inertia. Tests with fuel economy results in excess of 1.5 times the upper limit shall result 

in a void test.

(f) Emission Measurements

(1) Exhaust Measurement. The emission analysis system shall sample and record dilute 

exhaust HC, CO, CO2, and NOx during the transient driving cycle as described in 

Section 85.2226(c).

(2) Purge Measurement. NOT APPLICABLE The analysis system shall sample and record 

the purge flow in standard liters per second and total volume of flow in standard liters 

over the course of the actual driving cycle as described in - Section 85.2227(b).

(3) Integrity Measurement. The analysis system shall measure and record the integrity of the 

fuel cap as described in Section 85.2227(c).

Evaporative System Pressure Test Procedures NOT APPLICABLE
(a) General Requirements

(1) The on-vehicle pressure tests described in Section 85.2222(c) and (d) shall be performed 

after any tailpipe emission test to be performed on a vehicle. Fuel cap tests described in 

Section 85.2222(e).and (f) may be performed before or after the tailpipe emission test.

(2) The pressure test shall be conducted in a manner that minimizes changes in 

temperature, since pressure measurements are affected by changes in the vapor space 

temperature.

(3) The Look-up Table identifies which cm-vehicle pressure test to perform on a given 

vehicle. Vehicles receiving the canister end pressure test specified in Section 85.2222(c) 

do not need to receive any other pressure tests. Vehicles receiving the feel inlet pressure 

test specified in Section 85.2222(d) should also be given one of the fuel cap pressure 

tests specified in Sections 85.2222(e) and (f).

(4) Alternative procedures may be used if they are shown to be equivalent or better to the 

satisfaction of the Division. Any damage done to the evaporative emission control system 

during this test shall be repaired.

(b) Pre-inspection and Preparation

(1) The evaporative canister(s) shall be visually checked to the degree practical. A missing 

or obviously damaged canister(s) shall fail the visual evaporative system check.

(2) The evaporative system hoses shall be visually inspected for the appearance of proper 

routing, connection, and condition, to the degree practical. If any evaporative system 

hose is misrouted, disconnected, or damaged, the vehicle shall fail the visual evaporative 

system check.

(3) If the fuel cap is missing, obviously defective or the wrong style cap for the vehicle, the 

vehicle shall fail the visual evaporative system check.

(c) Canister-End Pressure Test NOT APPLICABLE

(1) Equipment Set-up. Test equipment shall be connected to the fuel tank canister hose at 

the canister end. The fuel cap shall be checked to ensure that it is properly, but not 

excessively tightened, and shall be tightened if necessary.

(2) Pressure Value. The system shall be pressurized to 14 ± 0.5 inches of water without 

exceeding 26 inches of water system pressure.

(3) Stability. Close off the pressure source, seal the evaporative system and monitor 

pressure decay for up to two minutes.

(4) Depressurization. Loosen the fuel cap after a maximum of two minutes and monitor for a 

sudden pressure drop, indicating that the fuel tank was pressurized.

(5) Reconnection. The inspector shall carefully ensure that all items disconnected or 

loosened in the course of the test are properly reconnected at the conclusion of the test.

(d) Fuel Inlet Pressure Test NOT APPLICABLE
(1) Equipment Set-up. The vapor vent line(s) from the fuel tank to the canister(s) shall be 

clamped off as close to the canister(s) as practical without damaging evaporative system 

hardware. If the line(s) cannot be clamped (for example a rigid line), they shall be 

removed at the canister(s) and capped or plugged. Dual fuel tanks shall be checked 

individually if pressurizing from the fill pipe interface of only one fuel tank cannot access 

the complete vapor control system. A fuel inlet adapter, as specified in Section 

85.2227(c), appropriate to the style of fuel inlet on the vehicle (not the fuel cap on the 

vehicle) shall be selected based on a software prompt and shall be installed on the 

vehicle's fuel inlet.

(2) Pressure Value. The fuel tank shall be pressurized to a value at or slightly above the 

minimum test pressure specified in the Look-up Table.

(3) Stability. Pressure stability shall be maintained for a period of 10 seconds prior to the 

start of the pressure decay measurement. Pressure shall not increase by more than 0.5 

inches of water during the first 20 seconds of the decay measurement. Alternate 

definitions of stability may be proposed by the state and approved by the Administrator 

provided they minimize the risk of false results.

(4) Volume Compensation. (Optional) Pressure decay measurements are affected by the 

vapor volume (fuel tank level) in the fuel tank. Volume-compensated pressure decay 

measurements will increase test repeatability, and are therefore recommended. Measure 

the volume-compensated pressure decay for up to 120 seconds after stability is 

achieved, using the equation in Section 85.2222(d)(5) This equation is based on 

normalizing the pressure decay measurements to a vapor volume of 50 liters. The 

Division may approve other methods of compensation for differences in fuel tank vapor 

volume.

(5)

V

P = P0 * K ( t * ------ )

VS

Where:

P = Pressure, in inches of water at time t, compensated for 

differences in fuel tank vapor space volume.

P0 = The stabilized pressure at the start of the decay portion of the 

pressure test, in niches of water.

k = A constant derived from curve fitting the pressure/time data from 

the decay portion of the pressure test, using the equation:

P = P0 * kt

t = Time measured from the start of the decay portion of the 

pressure test, in seconds.

Vs = Reference volume of the fuel vapor space, 50 liters.

V = Volume of the fuel vapor space, in liters, calculated using the 

following equation:

 ÆP ÆV
V = ( Pb * 13.6 + ------ ) * -------------------

 2 (ÆP + ÆPI)

Where:

Pb = Barometric pressure, in inches of Hg.

ÆP = Pressure increase during the fill period, in inches of water.

ÆV = The flow meter measured volume of gas which pressurizes the 

vapor space, in liters at 20 C and 1 atmosphere.

ÆPL = The loss in pressure due to the presence of a leak during the fill 

process, in inches of water.

Evaporative System Pressure Test Procedures – Fuel Inlet Pressure Test Equation

Where:

_ = Summation of the second-by-second pressure loss during the fill 

period.

P0 = The stabilized pressure at the start of the decay portion of the 

pressure test, in inches of water.

k = A constant derived from curve fitting the pressure/time data from 

the decay portion of the pressure test, using the equation:

P = P0 * kt

Pt = Pressure values reported in one second intervals during the fill

period, in inches of water.

(e) Fuel Cap Leak Test - Pressure Decay Method

(1) The fuel cap shall be removed from the fuel Met and installed on a test rig with a nominal 

1 liter head space and be pressurized to 28+1.0 inch of water.

(2) The pressure decay shall be monitored as specified in this Regulation Number 11, Part F, 

Subpart IV.

(3) The fuel cap shall be replaced on the fuel inlet and tightened appropriately.

(f) Fuel Cap Leak Test - Flow Rate Method
(1) The fuel cap shall be removed from the fuel inlet and installed on the flow test device 

using the adapter appropriate for the fuel cap, as specified in Section 85.2227(c).

(2) The fuel cap flow rate shall be monitored as specified in this Regulation Number 11, Part 

F, Subpart IV.

(3) The fuel cap shall be replaced on the fuel inlet and tightened appropriately.

Colorado Automobile Dealers Transient Mode Test Analyzer System Equipment Specifications

(a) Dynamometer Specifications

(1) General Requirements.

(i) The dynamometer structure (e.g., bearings, rollers, pit plates, etc.) shall 

accommodate all light-duty vehicles and light-duty trucks up to 8500 pounds 

GVWR.

(ii) Road load horsepower and inertia simulation shall be automatically selected 

based on the vehicle parameters in the test record.

(iii) Alternative dynamometer specifications or designs may be proposed to the state 

and approved based upon a determination that, for the purpose of properly 

conducting an approved Transient Mode inspection, the evidence supporting 

such deviations will not cause improper vehicle loading.

(2) Power Absorption.

(i) Coefficients. The coefficients AV, BV, and CV, from vehicle track coast down 

testing, and referenced in the equations in this section are those specified during 

new car certification, or as specified by a vehicle class designator determined by 

the Division. Coefficients shall be calculated to a minimum of five (5) significant 

digits by the equations specified in Section 85.2226(a)(2)(i)(A) through Section 

85.2226(a)(2)(i)(C). Power fractions determined from track coast-down data shall 

be calculated to a minimum of two (2) significant digits as specified in Section 

85.2226(a)(2)(i). In the absence of new car certification coefficients information or 

a vehicle class designator identifying a power fraction, the default power fractions 

in Section 85.2226(a)(2)(i)(J) shall be used.

(A) Av = * (TRLHP@ 50 mph) hp/mph

(B) Bv = * (TRLHP@ 50 mph) hp/mph2

(C) Cv = * (TRLHP@ 50 mph) hp/mph3

(D) Where AVPF, BvPF, and CvPF are power fractions (PF), and indicate the 

fraction of the total power reflected by each coefficient Av, Bv, and Cv.

(E) AvPF + BvPF + CvPF = 1

(F) Derivation of AVPF, BVPF, and CVPF from known track coast-down 

curves shall be computed as follows:

(1)
AV (50)

AVPF = ------------------------------------------------

 {AV (50) + BV (2500) + CV (125,000)}

(2)

BV (2500)

BVPF = ------------------------------------------------

 {AV (50) + BV (2500) + CV (125,000)}

(3)

CV (125,000)

CVPF = ------------------------------------------------

 {AV (50) + BV (2500) + CV (125,000)}

(4) Default values:

AVPF = 0.35

BVPF = 0.10

CVPF = 0.55

(ii) Vehicle Loading. The true vehicle loading used during the transient driving cycle 

shall follow the equation in Section 85.2226(a)(2)(iii) between 10 and 60 mph. 

The dynamometer

controls shall set the dynamometer loading to achieve the coast-down target time 

(± 1 second) with the vehicle on the dynamometer using the vehicle-specific 

inertia test weights. A conversion equation or table of target time versus 

horsepower for the dynamometer design shall be used. Target time shall be 

converted to horsepower by the equation Section 85.2226(a)(2)(iv) or pre-defined 

horsepower values may be used.

(iii) TRLHP@ Obmph = {Av * Obmph} + {Bv * Obmph2} + {Cv * Obmph3}

Av, Bv, Cv = Coefficients specified in Section 85.2226(a)(2)(i) for vehicle 

track coast down curves.

Obmph = Observed mph

TRLHP = Track Road Load Horsepower, which includes loading 

contributions from the power absorber, parasitic losses, and tire/roll 

interface losses.

(iv)

Colorado Automobile Dealers Transient Mode Equipment Specifications – Dynamometer Specifications
ET = Elapsed time for the vehicle on the road to coast down from 55 to 

45 mph, and from 22 to 18 mph

ETW = Inertia weight in pounds

V1 = Initial velocity in feet/second (i.e., velocity at either 55 or 22 mph)

V2 = Final velocity in feet/second (i.e., velocity at either 45 or 18 mph)

(v) In practice, the true vehicle loading is derived from equations of “force” (i.e., 

F=MA). In determining vehicle load on a dynamometer, applied loads in units of 

force tangential to the roll surface are not dependent on the roll diameter used, 

whereas applied loads in units of torque of horsepower are dependent on the roll 

diameter. The equation in Section 85.2226(a)(2)(vi) may be used to convert track 

road-load horsepower values in Section 85.2226(a)(2)(iii) to units of force.

(vi) TRLF@ Obmph = {Af} + {Bf * Obmph} + (Cf * Obmph2}

TRLF = Track Road-Load Force (in units of pounds)

Af = 375 * AV (AV in HP/mph2 units)

Bf = 375 * BV (BV in HP/mph3 units)

Cf = 375 * CV (CV in HP/mph units)

Af, Bf, Cf = Equivalent force coefficients to the coefficients specified in 

Section 85.2226(a)(2)(i) for vehicle track coast down curves.

(vii) Range and Curve of Power Absorber. The range of power absorber at 50 mph 

shall be sufficient to cover track road-load horsepower (TRLHP) values between 

4 and 35 horsepower. The absorption shall be adjustable across the required 

horsepower range at 50 mph in 0.1 horsepower increments. The accuracy of the 

power absorber shall be ± 0.25 horsepower or ± 2% of point whichever is 

greater.

(viii) Parasitic Losses (General Requirements). The parasitic losses in each 

dynamometer system (such as windage, bearing friction, and system drive 

friction) shall be characterized between 10 and 60 mph upon initial acceptance. 

There shall be no sudden discontinuities in parasitic losses below 10 mph. 

Further, when added to the lowest possible loading of the power absorber 

(dynamometer motoring is considered a negative load), the parasitic losses must 

be sufficiently small such that proper loading will occur between 10 and 60 mph 

for a vehicle with a 50 mph track road-load horsepower value of 4 horsepower. 

The parasitic horsepower losses shall be characterized either digitally in five mph 

increments and linearly interpolated in-between, or the data at 10 mph 
increments shall fit the equation in Section 85.2226(a)(2)(ix) to within 2 percent of 

point.

(ix) PLHP = {Ap * (Obmph)} + {(Bp) * (Obmph)2} + {(Cp) * (Obmph)3}

PLHP = Dynamometer parasitic losses.

Ap, Bp, and Cp are curve coefficients necessary to properly characterize 

the dynamometer parasitic losses for the inertia weight(s) used.

(x) Parasitic Losses (Low Speed Requirements). The coast down time of the 

dynamometer between 8 and 12 mph shall be greater than or equal to the value 

calculated by the equation in Section 85.2226(a)(2)(xi) when the dynamometer is 

set for a 2000-pound vehicle with a track road-load horsepower of 4 horsepower 

at 50 mph.

(xi) Low Speed Loading. The following procedure is used to determine if a 

dynamometer system is correctly loading a vehicle with an ETW of 2000 pounds 

and a TRLHP of 6.0 horsepower at low speeds. Use “default” coefficients from 

Section 85.2226(a)(2)(i)(F)(4). Dynamometer must be warmed up prior to this 

procedure.

(A) Select vehicle with a driven axle weight between 1200 and 1300 pounds 

(sandbags or other ballast may be used to achieve this weight). Record 

vehicles driven axle weight to the nearest pound.

(B) Calculate the actual tire/roll interface losses (ATRL) using the following 

sub procedure.

(1) Determine PLHP for dynamometer system being tested.

(2) Calculate GTRL using equations from Sections 

85.2226(a)(2)(xiii) and (xv) or (xvi).

(3) Calculate IHP using the following formula:

IHP = TRLHP-PLHP-GTRL

(4) Set dynamometer based on IHP calculated is step C above.

(5) Perform dynamometer coast down with vehicle selected in step 1 

correctly positioned on rolls. Record coast down time from 12 

mph to 8 mph.

(6) Calculate new TRLHP based on 12 mph to 8 mph coast

(7) Calculate actual tire/roll interface losses (ATRL) using the 

following equation.

ATRL = TRLHP-PLHP-IHP

(C) Using calculated ATRL determine new IHP using the following formula:

IHP = TRLHP-PLHP-ATRL
(D) Set dynamometer based on IHP calculated is step 3 above.

(E) Perform dynamometer coast down with vehicle selected in step 1 

correctly positioned on rolls. Record coast down tune from 12 mph to 8 

mph.

(F) The maximum, average, and minimum time limits for the ondynamometer coast-down window at 10 mph shall be calculated by the 

following equations.

Colorado Automobile Dealers Transient Mode Equipment Specifications – Dynamometer Specifications

(xii) Tire/Roll Interface Losses. Generic tire/roll interface losses shall be determined 

for each dynamometer design used, and applied to obtain proper vehicle loading. 

A means to select or determine the appropriate generic tire/roll interface loss for 

each test vehicle shall be employed. Dynamometer design parameters include 

roll diameter, roll spacing, and roll surface finish. Generic tire/roll interface losses 

may be determined by the acceptance procedures in Section 85.2234(b)(4). 

Alternatively, generic values determined by the Division, or by a procedure 

accepted by the Division, may be used. The equation in Section 

85.2226(a)(2)(xiii) may be used to quantify tire/roll interface losses. Coefficients 

for equation in Section 85.2226(a)(2)(xiii) shall be calculated to a minimum of five 

(5) significant digits by the equations specified in Section 85.2226(a)(2)(xiii)(A) 

through Section 85.2226(a)(2)(xiii)(I). Tire loss power fractions determined from 

track coast-down data shall be calculated to a minimum of two (2) significant 

digits as specified in Section 85.2226(a)(2)(xiii)(J). In the absence of new car 

certification information or a vehicle class designator identifying a tire loss power 

fraction, the default tire loss power fractions indicated equations Section 

85.2226(a)(2)(xiii)(E) through Section 85.2226(a)(2)(xiii)(I) shall be used as 

specified in Section 85.2226(a)(2)(xiii)(J).

(xiii) GTRL@ Obmph = {At * (Obmph)} + {Bt * (Obmph)2} + {Ct * (Obmph)3}

GTRL@ Obmph = Generic Tire/Roll Interface losses at the observed mph
Where: At, Bt, and Ct are curve coefficients necessary to properly 

characterize the tire/roll interface losses.

(A) At = * (GTRL@ 50 mph) hp/mph

(B) Bt = * (GTRL@ 50 mph) hp/mph2

(C) Ct = * (GTRL@ 50 mph) hp/mph3

(D) At8= * (GTRL@ 50 mph) hp/mph

(E) Bt8= * (GTRL@ 50 mph) hp/mph2

(F) Ct8= * (GTRL@ 50 mph) hp/mph3

(G) At20= * (GTRL@ 50 mph) hp/mph

(H) Bt20= * (GTRL@ 50 mph) hp/mph2

(I) Ct20= * (GTRL@ 50 mph) hp/mph3

(J) Where:

(1) At, Bt, and Ct are curve coefficients necessary to properly 

characterize the tire/roll interface losses.

(2) At8, Bt8, and Ct8 are curve coefficients when using twin 8.625 inch 

diameter rolls.

(3) At20, Bt20, and Ct20 are curve coefficients when using twin 20.0 

inch diameter rolls.

(4) AtPF, BtPF, and CtPF indicate the fraction of the total tire loss 

power fraction reflected by each coefficient At, Bt, and Ct.

(5) AtPF + BtPF + CtPF = 1

(6) Derivation of AtPF, BtPF, and CtPF from known track or 

dynamometer data shall be computed as follows:

Colorado Automobile Dealers Transient Mode Equipment Specifications – Dynamometer Specifications
(xiv) In the absence of new car certification GTRL@ 50 mph or a vehicle class designator, 

the GTRL@ 50 mph shall be calculated

(A) by the equation in Section 85.2226(a)(2)(xv) when using twin 8.625-inch

diameter rolls

(B) by the equation in Section 85.2226(a)(2)(xvi) when using twin 20.0-inch 

diameter rolls

(xv) For 8.625” dynamometers:

GTRL@ 50 mph = (-0.378193) + {(0.0033207) * (DAXWT)}

Where: DAXWT = Axle weight on the drive tires

GTRL@ 50 mph = Losses for 8.625 inch diameter roll

(xvi) For 20” dynamometers:

GTRL@ 50 mph = (0.241645) + {(0.0020844) * (DAXWT)}

Where: DAXWT = Axle weight on the drive tires

GTRL@ 50 mph = Losses for 20.0 inch diameter roll

(xvii) Indicated Horsepower. The power absorption for each test shall be selected at 50 

mph. The indicated power absorption (IHP) at 5C mph after accounting for 

parasitic and generic tire losses shall be determined by the equation in Section 

85.2226(a)(2)(xv).

(xviii) IHP@ 50 mph = TRLHP@ 50 mph - PLHP@ 50 mph - GTRL@ 50 mph

(xix) In systems where the power absorption is actively controlled, the indicated 

horsepower at each speed between 0 and 60 mph shall conform 1:0 the equation 

in Section 85.2226(a)(2)(xvii). Approximations for a smooth curve with no 

discontinuities may be used between 0 and 10 mph.

(xx) IHP@ Obmph = TRLHP@ Obmph - PLHP@ Obmph - GTRL@ Obmph

(3) Rolls.

(i) Size and Type. The dynamometer shall be equipped with twin rolls. The rolls 

shall be coupled side to side. In addition, the front and rear rolls shall be coupled. 

The dynamometer roll diameter shall be between 8.5 and 21.0 inches. The 

spacing between the roll centers shall comply with the equation in Section 

85.2226(a)(3)(ii) to within +0.5 inches and -0.25 inches. The parasitic and generic 

tire/roll interface losses for the specific roll diameter, spacing, and surface finish 

used shall be determined as indicated in Section 85.2226(a)(2)(viii), (a)(2)(ix), 

and Section 85.2226(a)(2)(xii) as necessary to properly load vehicles as defined 

in Section 85.2226(a)(2)(ii) and Section 85.2226(a)(2)(iii). The dynamometer rolls 

shall accommodate an inside track width of 30 inches and an outside track width 

of at least 100 inches.

(ii) Roll Spacing = (24.375 + D) * SIN 31.5153_
D = dynamometer roll diameter.

Roll spacing and dynamometer roll diameter are expressed in inches.

(iii) Design. The roll size, surface finish, and hardness shall be such that tire slippage 

on the first acceleration of the transient driving cycle is minimized under all 

weather conditions; that the specified accuracy of the distance measurement is 

maintained; and that tire wear and noise are minimized.

(4) Inertia.

(i) Mechanical Inertia Simulation. NOT APPLICABLE The dynamometer shall be 

equipped with mechanical flywheels providing test inertia weights between at 

least 2000 to 5500 pounds, in increments of no greater than 500 pounds. The 

tolerance on the base inertia weight and the flywheels shall be within 1 % of the 

specified test weights. The proper inertia weight for any test vehicle shall be 

selectable.

(ii) Electric Inertia Simulation. Electric inertia simulation, or a combination of electric 

and mechanical simulation may be used in lieu of mechanical flywheels, provided 

that the performance of the electrically simulated inertia complies with the 

following specifications. Exceptions to these specifications may be allowed upon 

a determination by the Division that such exceptions would not significantly 

increase vehicle loading or emissions for the purpose of properly conducting an 

approved IG 240 test.

(A) System Response. The torque response to a step change shall be at 

least 90% of the requested change within 100 milliseconds after a step 

change is commanded by the dynamometer control system, and shall be 

within 2 percent of the commanded torque by 300 milliseconds after the 

command is issued. Any overshoot of the commanded torque value shall 

not exceed 25 percent of the torque value.

(B) Simulation Error. An inertia simulation error (ISE) shall be continuously 

calculated any time the actual dynamometer speed is above 10 MPH 

and below 60 MPH. The ISE shall be calculated by the equation in 

Section 85.2226(a)(4)(ii)(C), and shall not exceed 1 percent of the inertia 

weight selected (IWS) for the vehicle under test.

(C) ISE = (IWS - It) / (IWS) * 100

(D) It = Im +

Where:

It = Total inertia being simulated by the dynamometer (kg)

It (lb force) = It (kg) * 2.2046

Im = Base (mechanical inertia of the dynamometer (kg)

V = Measured roll speed (m/s)

Fm = Force measured by the load cell (translated to the roll surface) (N)
Frl = Road load force (N) required by IHP at the measured roll speed (V)

t = Time (sec)

(iii) Inertia Weight Selection. NOT APPLICABLE For dynamometer systems 

employing mechanical inertia flywheels, the test system shall be equipped with a 

method, independent from the flywheel selection system that identifies which 

inertia weight flywheels are actually rotating during the transient driving cycle.

(5) Other Requirements.

(i) Test Distance and Vehicle Speed. The total number of dynamometer roll 

revolutions shall be used to calculate the distance traveled. Pulse counters may 

be used to calculate the distance directly if there are at least 16 pulses per 

revolution. The measurement of the actual roll distance for the composite and 

each phase of the transient driving cycle shall be accurate to within ±0.01 mile. 

The measurement of the roll speed shall be accurate to within ±0.1 mph. Roll 

speed measurement systems shall be capable of accurately measuring a 3.3 

mph per second acceleration rate over a one second period with a starting speed 

of 10 mph.

(ii) Vehicle Restraint. The vehicle shall be restrained during the transient driving 

cycle. The restraint system shall be designed to minimize vertical and horizontal 

force on the drive wheels such that emission levels are not significantly affected.

(iii) Vehicle Cooling. The test system shall provide for a method to prevent 

overheating of the vehicle. The cooling method shall direct air to the cooling 

system of the test vehicle. The cooling system capacity shall be 5400 ±300 

SCFM within 12 inches (30.5 cm) of the intake to the vehicle's cooling system. 

The cooling system design shall avoid improper cooling of the catalytic converter.

(iv) Four-Wheel Drive. OPTIONAL If used, four-wheel drive dynamometers shall 

insure the application of correct vehicle loading as defined in Section 

85.2226(a)(2) and shall not damage the four-wheel drive system of the vehicle. 

Front and rear wheel rolls shall maintain speed synchronization within 0.2 mph.

(v) Augmented Braking. NOT APPLICABLE Fully automatic augmented braking 

shall be used from seconds 85 through 95 and after second 223 of the driving 

cycle. Fully automatic augmented braking may be used in other deceleration 

periods of the driving cycle with the approval of the Division. During the periods 

of augmented braking the operator shall be made aware that augmented braking 

is occurring and shall be trained not to use the vehicle accelerator during these 

periods. It shall be automatically interlocked such that it can be actuated only 

while the vehicle brakes are applied. Simultaneous engine acceleration is 

systematically prevented through periodic quality assurance.

(b) Constant Volume Sampler

(1) General Design Requirements.

(i) Venturi Type. A constant volume sampling (CVS) system of the critical flow 

venturi (CFV), sub-sonic venturi (SSV), or square edged orifice (SEO) type shall 

be used to collect vehicle exhaust samples. The CVS system and components 

shall generally conform to the specifications in Section 86.109-90.
(ii) CVS Flow Size. The CVS system shall be sized in a manner that prevents 

condensation in the dilute sample over the range of ambient conditions to be 

encountered during testing. A minimum 325 SCFM CVS system and heated lines 

or sample conditioning system (dryer) may be used to eliminate condensation 

and to increase measured concentrations for better resolution. Should the heated 

sample lines be used, the sample line and components (e.g., filters, etc.) shall be 

heated to a minimum of 120° F and a maximum of 250°F, which shall be 

monitored during the transient driving cycle.

(iii) CVS Compressor. The CVS compressor flow capacity shall be sufficient to 

maintain proper flow in the main CVS venturi with an adequate margin. For CFV 

CVSs the margin shall be sufficient to maintain choke flow. The capacity of the 

blower relative to the CFV flow capacity shall not be so large as to create a 

limited surge margin.

(iv) Materials. All materials in contact with exhaust gas shall be unaffected by and 

shall not affect the sample (i.e., the materials shall not react with the sample, and 

neither shall they taint the sample as a result of out gassing). Acceptable 

materials include stainless steel, Teflon, silicon rubber, and Tedlar.

(v) Alternative Approaches. Alternative CVS specifications, materials, or designs 

may be allowed upon a determination by the Division, that for the purpose of 

properly conducting an approved short test, the evidence supporting such 

deviations will not significantly affect the proper measurement of emissions.

(2) Sample System.

(i) Sample Probe. The sample probe within the CVS shall be designed such that a 

continuous and adequate volume of sample is collected for analysis. The system 

shall have a method for determining if the sample collection system has 

deteriorated or malfunctioned such that an adequate sample is not being 

collected, or that the response tune has deteriorated such that the tune 

correlation for each emission constituent is no longer valid.

(ii) CVS Mixing Tee.

(A) Design and Effect. The mixing tee for diluting the vehicle exhaust with 

ambient air shall be at the vehicle tailpipe exit as in Section 86.109-

90(a)(2)(iv). The dilution-mixing tee shall be capable of collecting 

exhaust from all light-duty vehicle and light-duty truck exhaust systems. 

The design used shall not cause static pressure in the tailpipe to change 

such that the emission levels are significantly affected. A change of ±1.0 

inch of water, or less, shall be acceptable.

(B) Locating Device. The mixing tee shall have a device for positively 

locating the tee relative to the tailpipe with respect to distance from the 

tailpipe, and with respect to positioning the exhaust stream from the 

tailpipe(s) in the center of the mixing tee flow area. The locating device, 

or the size of the entrance to the tee shall be such that if a vehicle moves 

laterally from one extreme position on the dynamometer to the other 

extreme, that mixing tee will collect all of the exhaust sample.

(iii) Dual Exhaust. For dual exhaust systems, the design used shall insure that each 

leg of the sample collection system maintains equal flow. Equal flow will be 
assumed if the design of the “Tee” intersection for the dual CVS hoses is a “Y” 

that minimizes the flow loss from each leg of the “Y,” if each leg of the dual 

exhaust collection system is approximately equal in length (± 1 foot), and if the 

dilution area at the end of each leg is approximately equal. In addition, the CVS 

flow capacity shall be such that the entrance flow velocity for each leg of the dual 

exhaust system is sufficient to entrain all of the vehicle's exhaust from each 

tailpipe.

(iv) Background Sample. The mixing tee shall be used to collect the background 

sample. The position of the mixing tee for taking the background sample shall be 

within 12 lateral and 12 longitudinal feet of the position during the transient 

driving cycle, and approximately 4 vertical feet from the floor.

(v) Integrated Sample. A continuous dilute sample shall be provided for integration 

by the analytical instruments in a manner similar to the method for collecting bag 

samples as described in Section 86.109.

(c) Analytical Instruments

(1) General Requirements.

(i) The emission analysis system shall automatically sample, integrate, and record 

the specified emission values for HC, CO, CO2, and NOx. Performance of the 

analytical instruments with respect to accuracy and precision, drift, interferences, 

noise, etc. shall be similar to instruments used for testing under Section 86 

Subparts B, D, and N. Analytical instruments shall perform in this manner in the 

full range of operating conditions in the system environment.

(ii) Alternative analytic equipment specifications, materials, designs, or detection 

methods may be allowed upon a determination by the Division, that for the 

purpose of properly conducting an approved short test, the evidence supporting 

such deviations will not significantly affect the proper measurement of emissions.

(2) Detection Methods and Instrument Ranges.

(i) Total Hydrocarbon Analysis. A flame ionization detector shall determine total 

hydrocarbon analysis. If a 325 SCFM CVS is used, the analyzer calibration curve 

shall cover at least the range of 0 ppmC to 4,000 ppmC. Use of a different CVS 

flow capacity shall require an adjustment to these ranges. Appropriate 

documentation supporting any adjustment in ranges shall be available. Such 

documentation shall also address the ability of any altered ranges to accurately 

measure all cutpoints, including cutpoints for vehicles older than those specified 

in Section 85.2205(a) that may be used in the specific I/M program for which the 

altered ranges are proposed to be used. The calibration curve must comply with 

the quality control specifications in Section 85.2234(d).

(ii) Carbon Monoxide Analysis. CO analysis shall be determined using a nondispersive infrared analyzer. If a 325 SCFM CVS is used, CO analysis shall 

cover at least the range of 0 ppm to 20,000 ppm (2%). ppm. Use of a different 

CVS flow capacity shall require an adjustment to these ranges. Appropriate 

documentation supporting any adjustment in ranges shall be available. Such 

documentation shall also address the ability of any altered ranges to accurately 

measure all cutpoints, including cutpoints for vehicles older than those specified 

in Section 85.2205(a) that may be used in the specific I/M program for which the 
altered ranges are proposed to be used. The calibration curve must comply with 

the quality control specifications in Section 85.2234(d).

(iii) Carbon Dioxide Analysis. CO2 analysis shall be determined using an NDIR 

analyzer. If a 325 SCFM CVS is used, CO2 analysis shall cover at least the 

range of 0 ppm to 80,000 ppm (8%). Use of a different CVS flow capacity shall 

require an adjustment to these ranges. Appropriate documentation supporting 

any adjustment in ranges shall be available. Such documentation shall also 

address the ability of any altered ranges to accurately measure all cutpoints, 

including cutpoints for vehicles older than those specified in Section 85.2205(a) 

that may be used in the specific I/M program for which the altered ranges are 

proposed to be used. The calibration curve must comply with the quality control 

specifications in Section 85.2234(d).

(iv) Oxides of Nitrogen Analysis. NOx analysis shall be determined using 

chemiluminescence. The NOx measurement shall be the sum of nitrogen oxide 

and nitrogen dioxide. If a 325 SCFM CVS is used, the NOx analysis shall cover 

at least the range of 0 ppm to 1000 ppm. Use of a different CVS flow capacity 

shall require an adjustment to these ranges. Appropriate documentation 

supporting any adjustment in ranges : shall be available. Such documentation 

shall also address the ability of any altered ranges to accurately measure all 

cutpoints, including cutpoints for vehicles older than those specified in this 

Regulation Number 11, Part F, that may be used for which the altered ranges are 

proposed to be used. The calibration curve must comply with the quality control 

specifications in Section 85.2234(d).

(3) System Response Requirements. The governing requirement for system response is the 

ability of the integration system to measure vehicle emissions to within ±5 % of that 

measured from a bag sample simultaneously collected over the same integration period, 

on both clean and dirty vehicles. Historically, continuously integrated emission analyzers 

have been required to have a response time of 1.5 seconds or less to 90% of a step 

change, where a step change was 60% of full scale or better. System response tunes 

between a step change at the probe and reading 90% of the change have generally been 

less than 4-10 seconds. Systems proposed that exceed these historical values shall 

provide an engineering explanation as to why the slower system response of the 

integrated system will compare to the bag reading within the specified 5 %.

(4) Integration Requirements.

(i) The analyzer voltage responses, CVS pressure(s), CVS temperature(s), 

dynamometer speed, and dynamometer power shall be sampled as a frequency 

of no less than 5 Hertz, and the voltage levels shall be averaged over 1 second 

intervals.

(ii) The system shall properly tune correlate each analyzer signal, CVS signals and 

dynamometer signals to the driving trace (test time). The driving trace update 

rate from the computer shall be at a rate to produce a smooth transition from one 

data point to another.

(iii) The one-second average analyzer voltage levels shall be converted to 

concentrations by the analyzer calibration curves. Corrected concentrations for 

each gas shall be derived by subtracting the pre-test background concentrations 

from the measured concentrations, according to the method in Section 

85.2205(b). The corrected concentrations shall be converted to grams for each 

second using the equations specified in Section 85.2205(b) to combine the 
concentrations with the CVS flow over the same interval. The grams of emissions 

per test phase shall be determined using the equations in Section 85.2205(b).

(iv) When multiple analyzers are used for any constituent, the integration system 

shall simultaneously integrate both analyzers. The integrated values for the 

lowest analyzer in range shall be used for each second.

(v) For all constituents, the background concentration levels from the lowest range 

analyzer shall be used, including the case where multiple analyzers may have 

been used.

(5) Analytical System Design.

(i) Materials. All materials in contact with exhaust gas prior to and throughout the 

measurement portion of the system shall be unaffected by and shall not affect 

the sample (i.e., the materials shall not react with the sample, and neither shall 

they taint the sample as a result of out gassing). Acceptable materials include 

stainless steel, Teflon, silicon rubber, and Tedlar.

(ii) Bag Ports. All analysis systems shall have provisions for reading a sample bag. 

A portable pump for sampling such bags is permitted.

(iii) System Filters. The sample system shall have an easily replaceable filter 

element to prevent particulate matter from reducing the reliability of the analytical 

system. The filter element shall provide for reliable sealing after filter element 

changes. If the sample line is heated, the filter system shall also be heated.

(iv) Availability of Intermediate Calculation Variables. Upon request prior to a test, all 

intermediate calculation variables shall be available to be downloaded to 

electronic files or hard copy. These variables shall include those that calculate 

the vehicle emission test results, perform emission analyzer and dynamometer 

function checks, and perform quality assurance and quality control 

measurements.

(d) Colorado Automobile Dealers Transient Mode Test Analyzer System Specific Hardware

General Design Requirements.

(i) Computer System. Minimum CPU system to include; 90MHZ Pentium processor, 

Memory 16MB, Secondary Cache 256 KB, Video Type SVGA, Video Card 2 MB 

memory, 15” Color Monitor (drivers aid), Diskette drive A 1.44 MB, Hard-disk 

drive C 1.6 GB, Parallel Port (1), Serial Port (1), Mouse Port (1), 104 Key 

Keyboard, Expansion Slots (4). Port configurations noted may not reflect the 

necessary number or type to support subsystem requirements or options.

(ii) Modem. Minimum requirement. Hayes compatible able to operate at 14.400B 

M.N.P. level 5. Error correction, Microcom networking protocol (M.N.P.) levels 1-

4 with V.42 data compression. M.N.P. level 5 - V.32BIS/V.42BIS.

(iii) Printer. Vehicle Inspection Report. 24 pin impact printer operating at 12 

characters per inch and 80 characters per line.

(iv) Printer. Diagnostic Report, (customer option) 24-pin impact printer operating at 

12 characters per inch and 80 characters per line.
(v) Printer. Certificate/Sticker. A Standard Register PT-640, thermal transfer printer.

(vi) Barcode Scanner. Symbol Technologies PDF 1000 HV or equivalent.

(1) Fuel cap Tester. An internal or external unit capable of performing either the pressure 

decay method or flow rate method of fuel cap testing as defined in Evaporative System 

Test Procedures, Sections (e) and (f).

(2) System Security. Access to the analytical system, computer system, official state 

documents shall be prevented by locked enclosure and monitored by micro switches or 

other similar means to assure that unauthorized access is denied. Detection of 

unauthorized access shall result in automatic inspection system lock out.

(3) Manufacturer Options installed to operate independent of an official inspection processes 

may be utilized and configured into the hardware as necessary. An example would be a 

CD-ROM for vehicle diagnostics or software supported programs.

Evaporative System Inspection Equipment

(a) General Requirements

(1) Equipment Design. Automated and computerized test systems shall be used for the 

evaporative system tests. Pass/fail decisions shall be made automatically. The systems 

shall be tamper resistant and designed to avoid damage to the vehicle during installation, 

testing, and removal.

(2) Alternative Systems. Alternative purge or pressure test equipment, specifications, 

materials, or designs, may be proposed and approved upon a determination by the 

Division that, for the purpose of properly conducting an approved Transient Mode test, 

the evidence supporting such deviations will not appreciably or adversely affect the 

proper determination of system integrity, the proper measurement of purge, or the proper 

operation of the vehicle.

(b) Evaporative Purge System NOT APPLICABLE

(1) General Requirements. The evaporative purge analysis system shall measure the 

instantaneous purge flow in standard liters/minute, and shall compute the total volume of 

the flow in standard liters over the transient driving cycle.

(2) Specifications. The purge flow measuring system shall comply with the following 

requirements.

(i) Flow Capacity. A minimum of 50 liters per minute.

(ii) Pressure Drop. Maximum of 16 inches of water at 50 liters per minute for the 

complete system including hoses necessary to connect the system to the vehicle.

(iii) Totaled Flow. 0 to 100 liters of volume

(iv) Response Time. 410 milliseconds maximum to 90% of a step change between 

approximately 2 and 10 liters per minute measured with air.

(v) Accuracy.
(A) ±2.0 liters per minute between 10 and 50 liters per minute (rate)

(B) ±0.15 liters per minute between 0 and 10 liters per minute (rate)

(C) ±4% of 50 standard liters total flow volume between 10 and 50 liters total 

flow volume over one minute.

(D) ±1.5% of 10 standard liters between 0 and 10 liters total volume flow 

over one minute.

(vi) Noise. The maximum noise shall be less than 0.001 liters per second

(vii) Calibration Gas. Air

(3) Automatic Operation. Vehicle purge flow shall be monitored with a computerized system 

at a minimum sample rate of 1 Hz, shall automatically capture average (if sampled faster 

than 1 Hz) second-by-second readings, and shall automatically derive a pass/fail 

decision. In determining the total volume of flow, the monitoring system shall not count 

signal noise as flow volume. The test sequence shall be automatically initiated when the 

transient driving cycle test is initiated.

(4) Adaptability. The purge flow system shall have sufficient adapters to connect in a leaktight manner with the variety of evaporative systems and hose deterioration conditions in 

the vehicle fleet. The purge measurement system shall not substantially interfere with 

purge flow.

(c) Evaporative System Pressure Test Equipment ITEMS 1-4 NOT APPLICABLE

(1) General Requirements.

(i) Pressure Gas. Nitrogen (N2), or equivalent non-toxic, non-greenhouse, inert gas, 

shall be used for pressurizing the evaporative system.

(ii) Automatic Operation. The process for filling the evaporative system, monitoring 

compliance, recording data, and making a pass/fail decision shall be automatic. 

After the determination that the evaporative system has been filled to the specific 

pressure level, and upon initiation of the test, the pressure level in the 

evaporative system shall be recorded at a frequency of no less than 1 Hertz until 

the conclusion of the test.

(iii) Test Abort. The system shall be equipped with an abort system that positively 

shuts off and relieves pressure. The abort system shall be capable of being 

activated quickly and conveniently by the inspector should the need arise.

(2) Adapters and Clamps.

(i) Canister Hose Adapters. The system shall have sufficient adapters to connect in 

a leak-tight manner with the variety of evaporative systems and hose 

deterioration conditions in the vehicle fleet.

(ii) Fuel Inlet Adapters. Fuel inlet adapters that fit on the vehicles fuel inlet in a 

manner similar to the fuel cap and designed to admit a pressurized source of gas 

into the fuel tank shall be used for the fuel inlet pressure test specified in 

85.222(d). Inlet specific adapters shall be available for at least 95 percent of the 
fuel inlets that are used on U.S. light duty vehicles and light duty trucks for the 

model years Specified in Part F of this Regulation. Varying internal volumes of 

the adapter assemblies shall not affect the accuracy of the test results. Adapters 

shall be made available within two years of the introduction of new model year 

vehicles.

(iii) Hose Clamp. The hose clamp used for the fuel inlet pressure test shall be 

designed to apply only enough pressure to close the hose without damaging it. 

The nose of the clamp shall be smooth-surfaced or otherwise designed to avoid 

abrasion of the vehicle hose.

(3) Pressure Gauge. The device for measuring pressure in the vehicle's evaporative system 

shall have a minimum range of 0 to 50 inches of water and an accuracy of +-0.3 inches of 

water (2 % of 15) or better.

(4) Flow Meter. A flow meter with a range of at least 0 to 10 liters per minute and +-5% 

accuracy shall be used for the measurement of flow.

(5) Fuel Cap Tester. The tester shall provide a visual or digital signal that the required air 

supply pressure is within the acceptable range and the flow comparison test is ready to 

be conducted. The tester shall incorporate an upstream maintainable filter. If the tester is 

battery powered, it must be equipped with an automatic shutoff and a low-battery 

indicator. A NIST traceable reference passing fuel cap of nominal 52-56 cubic 

centimeters per minute, and a NIST traceable reference failing fuel cap of nominal 64-68 

cubic centimeters per minute shall be supplied with the tester for daily test verification. 

Leak rate measurements shall be accurate to ±3 cubic centimeters per minute.

(6) Flow Standard. The flow standard shall be a square edged circular orifice with a NIST 

traceable flow rate that in combination with the comparison circuitry will produce a 

pass/fail threshold of 60 cubic centimeters at 30 inches of water column. Transducers 

used in the comparison circuitry shall have accuracy traceable to NIST. The supply 

pressure may be obtained using room air and any convenient low-pressure source. The 

tester shall control the supply pressure and prevent over pressurization.

Quality Control Requirements and Acceptance Testing Procedures

(a) General Requirements

(1) Minimums. The frequency and standards for quality control specified here are minimum 

requirements, unless modified as specified in Section 85.2234(2). Greater frequency or 

tighter standards may be used as determined by the Division.

(2) Statistical Process Control. Reducing the frequency of the quality control checks, 

modifying the procedure or specifications, or eliminating the quality control checks 

altogether may be allowed if the Division determines, for the purpose of properly 

conducting an approved short test, that sufficient Statistical Process Control (SPC) data 

exist to make a determination, that the SPC data support such action, and that taking 

such action will not significantly reduce the quality of the emission measurements. Should 

emission measurement performance or quality deteriorate as a result of allowing such 

actions, the approval shall be suspended, and the frequencies, procedures, 

specifications, or checks specified here or otherwise approved shall be reinstated, 

pending further determination by the Division.
(3) Modifications. The Division may modify the frequency and standards contained in this 

section if found to be impractical.

(b) Dynamometer

(1) Coast Down Check.

(i) The calibration of each dynamometer shall be checked on a weekly basis by a 

dynamometer coast-down equivalent that in Section 86.118-78 (for reference see 

EOD Test Procedures TP-302A and TP-202) between the speeds of 55 to 45 

mph, and between 22 to 18 mph. All rotating dynamometer components shall be 

included in the coast-down check for the inertia weight selected.

(ii) The base dynamometer and the base plus each prime inertia weight flywheel, if 

any, shall be checked with at least two horsepower settings within the normal 

range of the inertia weight. For dynamometers that use electrical inertia 

simulation and have a base inertia outside of the range of 3000 pounds to 4500 

pounds, the coast-down check shall be conducted with at least two horsepower 

settings at the base inertia, and two settings at either 2500 pounds or 4500 

pounds, whichever is furthest from the base inertia weight. For both mechanical 

flywheel dynamometers and electrical inertia simulation dynamometers, the 

horsepower settings selected shall correspond to a vehicle/engine category that 

matches the inertia weight selected for the coast-down test. Where the base 

inertia, or the base inertia plus the smallest flywheel results in a coast-down 

inertia of less than 2250 pounds, only one horsepower setting is required for the 

check.

(iii) The coast-down procedure shall be of a self-motoring method. If the difference 

between the measured coast-down tune and the theoretical coast-down time is 

greater than ±1 second on the 55 to 45 mph coast-down as calculated by Section 

85.2234(b)(l)(iii)(A) or (B), official testing shall automatically be prevented, and 

corrective action shall be taken to bring the dynamometer into calibration. Official 

testing shall also automatically be prevented, and corrective action shall be taken 

to bring the dynamometer into calibration, if the difference between the measured 

coast-down time and the theoretical coast-down time for 22 to 18 mph is outside 

of the time window calculated by Section 85.2234(b)(l)(iii)(C) or (D). For tests 

using inertia weights of 8500 lbs. and above, if the difference between the 

measured coast-down time and the theoretical coast-down time is outside of the 

time window calculated by Section 85.2234(b)(l)(iii)(O) or (D) for the 22 mph to 

the 18 mph coast-down when substituting 0.27 HP for the allowable force-error 

(equivalent to 5.0 pounds-force at 20 mph), official testing shall automatically be 

prevented, and corrective action shall be taken to bring the dynamometer into 

calibration.

(A) The off-dynamometer target coast-down time at 50 mph (DBT@50 mph.g) 

for dynamometers with 8.265-inch rolls shall be calculated as follows.

Transient Mode Test Quality Control Requirements and Acceptance Testing Procedures
(B) The off-dynamometer target coast-down time at 50 mph (DBT@50 mph-2o) 

for dynamometers with 20.0-inch rolls shall be calculated as follows.

Transient Mode Test Quality Control Requirements and Acceptance Testing Procedures

(C) The maximum and minimum time limits for the off-dynamometer coastdown window at 20 mph (DTMax@20 mph-8, DTMin@20 mph-8) for 

dynamometers with 8.265-inch rolls shall be calculated by the following 

equations. The TRLHP and GTRL used in these calculations shall be 

determined from the same vehicle/engine category used to determine 

the 50 mph off-dynamometer target coast-down time. If the calculated 

maximum value (DTMax@20 mph-8) exceeds twice the target value 

calculated for a specific vehicle/engine category (DT Ave@20 mph-8),or if 

the maximum value is a negative number, a value equal to twice the 

target value shall be substituted for the maximum time limit.

Transient Mode Test Quality Control Requirements and Acceptance Testing Procedures
(D) The maximum and minimum time limits for the off-dynamometer coastdown window at 20 mph (DTMax@20mph-20, DTMin@20 mph-20) for 

dynamometers with 20.0-inch rolls shall be calculated by the following 

equations. The TRLHP and GTRL used in these calculations shall be 

determined from the same vehicle/engine category used to determine 

the 50 mph off-dynamometer target coast-down time.

Transient Mode Test Quality Control Requirements and Acceptance Testing Procedures

(E) Where:
DET@ 50 mph-dd = Off-dynamometer target coast-down time (seconds) at 

50 mph for a dynamometer with a roll diameter corresponding to the 

designator “dd”

DTMax@20 mph-dd = Upper off-dynamometer target coast-down time limit 

(seconds) at 20 mph for a dynamometer with a roll diameter 

corresponding to the designator “dd”

DTAve @20 mph-dd = Off-dynamometer target coast-down time (seconds) at 

20 mph for a dynamometer with a roll diameter corresponding to the 

designator “dd”

DTMin @ 20 mph-dd = Lower off-dynamometer target coast-down time limit 

(seconds) at 20 mph for a dynamometer with a roll diameter 

corresponding to the designator “dd”

TRLHP@ 50 mph = Track Road Load Horsepower at 50 mph for a specific 

vehicle engine category selected for the coast down check.

TRLHP@ 20 mph = Track Road Load Horsepower at 20 mph for the 

corresponding specific vehicle engine category selected for the 50 mph 

coast down check.

GTRL@ 50 mph-dd = Generic Tire/Roll Horsepower loss at 50 mph for a 

dynamometer with “dd” roll size, and corresponding to the specific 

vehicle engine category selected for the 50 mph coast down check.

GTRL@ 20 mph-dd = Generic Tire/Roll Horsepower loss at 20 mph for a 

dynamometer with “dd” roll size, and corresponding to the specific 

vehicle engine category selected for the 50 mph coast down check.

ETW = Equivalent Test Weight (i.e., inertia weight) in pounds 

corresponding to the specific vehicle engine category selected for the 50 

mph coast down check.

Vxx2 = Velocity in feet per second corresponding to the mph value “xx”

0.17 HP = Horsepower representation of an allowable force-error of 3.3 

pounds-force at 20 mph. This allowable force-error is approximately 

equivalent to a ± 2-second tolerance in the off-dynamometer target 

coast-down time at 50 mph for a dynamometer with 8.625” rolls when 

using a TRLHP computed from the EPA on-dynamometer target coastdown time. This force-error is approximately equivalent 1:0 a ± 1.25-

second tolerance in the off-dynamometer target coast-down time at 50 

mph for a dynamometer with 20.0' rolls.

(iv) The clock used to check the coast-down time shall be accurate to 0.1 percent of 

reading between 10 and 1000 seconds with a resolution of 0.01 seconds.

(v) The results of each dynamometer coast-down check performed shall be 

automatically computed and recorded on electronic media with a date and time 

stamp.
(2) Roll Speed. Roll speed and roll counts shall be checked each operating day by an 

independent means (e.g., photo tachometer). Deviations of greater than ±0.2 mph or a 

comparable tolerance in roll counts shall require corrective action. Alternatively, a 

redundant roll speed transducer independent of the primary transducer may be used in 

lieu of the daily comparison. Accuracy of redundant systems shall be checked monthly.

(3) Warm-Up. Dynamometers shall be in a warmed up condition for use in official testing. 

Warm-up is defined as sufficient operation that allows the dynamometer to meet the 

coast down time (within 3 seconds) identified for the specific dynamometer during 

calibration. The reference coast-down time shall be the value for 55 to 45 mph with the 

lightest inertia weight and lowest horsepower for that weight used during weekly 

calibrations. Alternatively, the reference coast-down time shall be the value for 22 to 18 

mph with the lightest inertia weight and lowest horsepower for that weight used during 

weekly calibration, with a time standard of +20%. Comparing the measured parasitic 

losses at least 25 mph to reference values established during calibration may check 

warm-up.

(4) Acceptance Testing. Upon initial installation and prior to beginning official testing, the 

performance of each dynamometer and dynamometer design shall be verified for 

compliance with the requirements in Section 85.2226(a). Specific acceptance verification 

requirements are described in Section 85.2234(b)(4)(i) through Section 85.2234(b)(4)(v).

(i) Coast Down/Vehicle Loading Check Following Installation. The coast down 

performance of each dynamometer shall be checked to verify the ability of the 

dynamometer and dynamometer load setting system to meet dynamometer 

target coast down times prior to beginning official testing. The performance shall 

be checked by the procedure defined in Section 85.2234(b)(4)(i)(A) through 

Section 85.2234(b)(4)(i)(J), or by a comparable procedure approved by the 

Division.

(A) The dynamometer shall be warmed-up by the dynamometer 

manufacturer's procedure.

(B) At least three vehicle/engine categories shall be selected from the LookUp table for vehicle loading. The vehicle/engine categories should cover 

the range of expected test vehicles.

(C) The dynamometer shall be set for the first vehicle/engine category 

selected based on the variables used to uniquely index the vehicle 

engine category (e.g., model year, manufacturer, model, number of 

cylinders, engine size, and transmission type).

(D) The dynamometer shall be coasted down from 65 mph to 5 mph with the 

settings pre-selected in Section 85.2234(b)(4)(i)(C).

(E) The 55 mph to 45 mph, and the 22 mph to 18 mph coast down tunes 

shall be recorded for the data collected in Section 85.2234(b)(4)(i)(D).

(F) The dynamometer shall be coasted down from 65 mph to 5 mph after 

having been adjusted for each of the other two vehicle engine 

categories, and the 55 mph to 45 mph, and the 22 mph to 1 mph coast 

down times shall be recorded for each coast-down.
(G) The coast-downs specified in Section 85.2234(b)(4)(i)(C) through 

Section 85.2234 (b)(4)(i)(F) shall be replicated for a total of three coastdown tests for each vehicle inertia category. The replications of the 

coast-downs for each vehicle engine category shall be run in random 

sequence.

(H) The off-dynamometer target coast-down tune at 50 mph (DET@ 50 mph-dd) 

for each vehicle/engine category shall be calculated as specified in 

Section 85.2234(b)(l)(iii)(A) or (B) for the applicable dynamometer roll 

size.

(I) The upper and lower off-dynamometer coast-down time limits at 20 mph 

(DTMax @ 20 mph-dd, DTMin @ 20 mph-dd) for each vehicle/engine category shall 

be calculated as specified in Section 85.2234(b)(l)(iii)(C) or (D) for the 

applicable dynamometer roll size.

(J) The dynamometer vehicle loading is considered acceptable if each 

measured 55 mph to 45 mph coast-down tune for each vehicle/engine 

category tested is within ±1 second of the off-dynamometer target coastdown time determined in (b)(4)(i)(H) above, and if each measured 22 

mph to 18 mph coast-down tune for each vehicle/engine category tested 

is within the off-dynamometer target coast-down time limits determined in 

(b)(4)(i)(I) above.

(ii) Vehicle Loading Check of Dynamometer Design. For each dynamometer design 

used, the Division shall obtain and maintain a report verifying the ability of the 

dynamometer design to properly load vehicles as specified in Section 

85.2226(a). The dynamometer manufacturer may prepare the report. The report 

shall identify how each requirement in Section 85.2226(a) is performed by the 

specific dynamometer design used. In addition, where specific performance 

levels or characterizations are specified {e.g., Section 85.2226 (a)(2)(viii), 

Section 85.2226(2)(x), Section 85.2226(4)(ii) and Section 85.2226(a)(5)}, test 

data with supporting analysis verifying compliance shall be included. At a 

minimum, the test data shall include a comparison and analysis of the expected 

coast-down times versus the actual vehicle on-dynamometer coast-down times 

for at least three vehicles spanning the range of drive axle weights and 

horsepower. Actual track coast-down data and curves shall be available for the 

makes and models of vehicles selected from which the expected coast-down 

times shall be derived. The analysis shall also graphically compare the track 

horsepower curves to curves generated from the on-dynamometer coast-down 

testing. Reasons for variations in time, equivalent to one horsepower, between 

the expected coast-down times and the actual vehicle on-dynamometer coastdown times, or variations between the curves of more than one horsepower shall 

be explained in the report.

(iii) Alternative Coast Down/Vehicle Loading Check. This procedure may be used in 

lieu of the procedures in Section 85.2234(b)(4)(i). The coast down performance 

of each dynamometer shall be checked with at least two categories of vehicles to 

verify the ability of the dynamometer and dynamometer load setting system to 

meet dynamometer target coast down times. The coast down performance of 

each dynamometer design used shall be checked with at least 6 categories of 

vehicles to determine the ability of the dynamometer design to properly load the 

vehicle over the required speed range as defined in Section 85.2226(a)(2). The 

performance of the design shall be checked by the procedure defined Section 
85.2234(b)(4)(ii)(A) through Section 85.2234(b)(4)(ii)(L), or by a comparable 

procedure proposed by the Division.

(A) The dynamometer shall be warmed-up by the dynamometer 

manufacturer's procedure, and the tires and drive train on the test car 

shall be warmed-up by operating the vehicle at 50 mph for 20 minutes. 

The tire pressure in the test vehicles shall be at 45 psi.

(B) The dynamometer indicated power (IHP) and inertia weight for the 

vehicle should be selected for the test vehicle.

(C) The test vehicle shall be coasted down from 65 mph to 5 mph on the 

dynamometer with the settings pre-selected in 

Section85.2234(b)(4)(i)(B).

(D) The 55 mph to 45 mph, and the 22 mph to 18 mph coast down times 

shall be recorded for the data collected in Section 85.2234(b)(4)(i)(C).

(E) The test vehicle shall again be coasted down from 65 mph to 5 mph on 

the dynamometer with the dynamometer power absorber reset to a load 

of zero.

(F) A speed versus horsepower equation of the form in Section 

85.2226(a)(2)(iii) shall be determined for the data collected in Section 

85.2234(b)(4)(i)(E).

(G) The test vehicle shall be removed from the dynamometer, and the 

dynamometer shall be coasted down from 65 mph to 5 mph with the 

dynamometer power absorber set to a load of zero.

(H) A speed versus horsepower equation of the form in Section 

85.2226(a)(2)(ix) for parasitic losses (PLHP) shall be determined for the 

data collected in Section 85.2234(b)(4)(i)(G).

(I) The tire/roll interface losses shall be determined by subtracting the 

horsepower curve determined in Section 85.2234(b)(4)(i)(H) from the 

horsepower curve determined in Section 85.2234(b)(4)(i)(F). The tire 

loss curve (GTRL) shall be in the form specified in Section 

85.2226(a)(2)(xiii).

(J) Repeat the steps in Section 85.2234(b)(4)(i)(B) through Section 

85.2234(b)(4)(i)(I) to obtain a total of three sets of data for each test 

vehicle. The dynamometer and vehicle may be warmed-up as needed to 

meet the requirements in Section 85.2234(b)(4)(i)(A).

(K) For each test vehicle, compute the average 55 mph to 45 mph coast 

down tune, the average 22 mph to 18 mph coast down time, and the 

average tire/roll interface loss curve as measured in Section 

85.2234(b)(4)(i)(B) through Section 85.2234(b)(4)(i)(J).

(L) The dynamometer vehicle loading is considered acceptable if, for each 

test vehicle, the average values determined in Section 

85.2234(b)(4)(i)(K) are within ±1 second of the 55 mph to 45 mph for the 

target time specified in Section 85.2226(a)(2)(ii), are within ±7 percent of 
the 22 mph to 18 mph that is calculated from Section 85.2226(a)(2)(iii) 

and Section 85.2226(a)(2)(iv), and within ±15 percent of a generic tire/roll 

loss curve for the category of vehicle.

(iv) Load Measuring Device Check. The load measuring device on each 

dynamometer shall be checked by a dead-weight method (or equivalent) at least 

six points across the range of loads used for vehicle testing. Physical checking 

weights shall be traceable to NIST standards to within ±0.5 percent. Equivalent 

methods shall document the method used to verify equivalent accuracy. The 

accuracy of the interpreted value used for calculation or control shall be within ±1 

percent of full scale.

(v) Vehicle Inertia Loading. The actual inertia applied to the vehicle by each inertia 

weight, in combination with the base inertia, shall be verified for each 

dynamometer to insure compliance with the requirements in Section 

85.2226(a)(4)(i) or Section 85.2226(a)(4)(ii) as applicable.

(vi) Parasitic loss check between 8 and 12 mph. The coast down tune of each 

dynamometer between 8 and 12 mph shall be verified for compliance with the 

requirements of Section 85.2226(a)(2)(x).

(vii) Speed and Distance Check. The performance of the speed and distance 

measuring system of each dynamometer shall be verified for compliance with the 

requirements of Section 85.2226(a)(5)(i). The ability to resolve acceleration as 

specified in Section 85.2226(a)(5)(i) need only be generically verified for the 

design used. If more than one design is used, each design shall be verified.

(viii) Warm-up System Check. The dynamometer warm-up system shall be checked 

for compliance with the requirements in Section 85.2234(b)(3) by conducting a 

coast down check immediately following completion of the warm-up specified by 

the dynamometer manufacturer or the system. The design of the warm-up 

system should be checked across the range of temperatures experience in-use, 

and particularly at the lower speeds.

(5) Coast-down Times. Following acceptance, 55 to 45 mph, and 22 to 18 mph coast-down 

times shall be determined for quality control purposes with the vehicle off the 

dynamometer for each inertia weight and for at least 2 horsepower settings within the 

normal range of the inertia weight as required in Section 85.2234(b)(l)(ii). These quality 

control values shall be determined when the dynamometer has been set to meet either 

the coast-down target times with the vehicle on the dynamometer (i.e., 55 to 45 mph and 

22 to 18 mph), or the equation coefficients. The Division, may however, select different 

vehicle/engine categories to check coast-down times as in Section 85.2234(b)(4)(i) for 

audit purposes.

(c) Constant Volume Sampler

(1) Flow Calibration. The flow of the CVS shall be calibrated at six flow rates upon initial 

installation, 6 months following installation, and every 12 months thereafter. The flow 

rates shall include the nominal rated flow-rate and a rate below the rated flow-rate for 

both critical flow Venturis and subsonic Venturis, and a flow-rate above the rated flow for 

sub-sonic Venturis. The flow calibration points shall cover the range of variation in flow 

that typically occurs when testing. A complete calibration shall be performed following 

repairs to the CVS that could affect flow.
(2) System Check. CVS flow calibration at the nominal CVS design flow shall be checked 

once per operating day using a procedure that identifies deviations in flow from the true 

value. A procedure equivalent to that in Section 86.119(c) shall be used. Deviations 

greater than ±4% shall result in automatic lockout of official testing until corrected.

(3) Cleaning Flow Passages. The sample probe shall be checked at least once per month 

and cleaned if necessary to maintain proper sample flow. CVS venturi passages shall be 

checked once per year and cleaned if necessary.

(4) Probe Flow. The indicator identifying the presence of proper probe flow for the system 

design (e.g., proportional flow for CFV systems, minimum flow for time correlation of 

different analyzers) shall be checked on a daily basis. Lack of proper flow shall require 

corrective action.

(5) Leak Check. The vacuum portion of the sample system shall be checked for leaks on a 

daily basis and each time the system integrity is violated (e.g., changing a filter).

(6) Bag Sample Check. On a quarterly basis, vehicle exhaust shall be collected in sample 

bags with simultaneous integrated measurement of the sample. At least one bag each for 

Phase 1 and for Phase 2 of the transient test cycle shall be conducted. Differences 

between the two measurement systems greater than 10% shall result in system lockout 

until corrective action is taken. For the purposes of acceptance testing, the differences 

shall be no greater than 5 %.

(7) Response Time Check. The response time of each analyzer shall be checked upon initial 

installation, during each check for compliance with Section 85.2234(c)(6), after each 

repair or modification to the flow system that would reasonably be expected to affect the 

response time, and as determined by the Division. The check shall include the complete 

sample system from the sample probe to the analyzer. Statistical process control shall be 

used to monitor compliance and establish fit for use limits based on the requirements in 

Section 85.2226(c). At a minimum, response time measurements that deviate 

significantly from the average response time for all CVS systems designed to the same 

specification in the program shall require corrective action before testing may resume.

(8) Mixing Tee Acceptance Test.

(i) The design of the mixing tee shall be evaluated by running the transient driving 

cycle on at least two vehicles, representing the high and low ends of engine 

displacement and inertia. Changes in the static tailpipe pressure with and without 

CVS, measured on a second-by-second basis within 3 inches of the end of the 

tailpipe, shall not exceed ±1.0 inch of water.

(ii) The ability of the mixing tee design to capture all of the exhaust as a vehicle 

moves laterally from one extreme position on the dynamometer to the other 

extreme shall be evaluated with back-to-back testing of three vehicles, 

representing the high and low ends of engine displacement and inertia. The 

back-to-back testing shall be done with the mixing tee at the tailpipe and with an 

airtight connection to the tailpipe (i.e., the mixing tee will be effectively moved 

downstream, as in typical FTP testing). The difference in carbon-balance fuel 

economy between the mixing tee located at the vehicle and the positive 

connection shall be no greater than 6%.

(iii) The design of the dual exhaust system shall be evaluated with back-to-back 

testing of three vehicles, representing the high and low ends of engine 
displacement and inertia, with an airtight connection to the tailpipe (i.e., the 

mixing tee will be effectively moved downstream, as in typical FTP testing, for 

these qualification tests). The difference in carbon-balance fuel economy 

between the two methods shall be no greater than 5%.

(d) Analysis System

(1) Calibration Curve Generation.

(i) Upon initial installation, calibration curves shall be generated for each analyzer. If 

an analyzer has more than one measurement transducer, each transducer shall 

be considered as a separate analyzer in the analysis system for the purposes of 

curve generation and analysis system checks.

(ii) The calibration curve shall consider the entire range of the analyzer as one 

curve.

(iii) A ten (10)-point equal distribution calibration curve is required of each analyzer. 

The calibration zero gas shall be used to set the analyzer to zero.

(iv) Gas dividers may be used to obtain the intermediate points for the general range 

classifications specified.

(v) The calibration curves generated shall be a polynomial of the best fit and no 

greater than 4th order, and shall fit the data within 2.0% at each calibration point 

as specified in Section 86.121-90, Section 86.122-78, Section 86.123-78, and 

Section 86.124-78.

(vi) Each curve shall be verified for each analyzer with a confirming calibration 

standard between 40-80% of full scale that is not used for curve generation. 

Each confirming standard shall be measured by the curve within 2.5%.

(2) Spanning Frequency. The zero and up-scale span points shall be checked at 2 hour 

intervals following the daily mid-scale curve check specified in Section 85.2234(d)(4) and 

adjusted if necessary. If the up-scale span point drifts by more than 2.0% from the 

previous check or, for the first check performed after the daily calibration check described 

in Section 85.2234(d)(4), from the daily check official testing shall be prevented and 

corrective action shall be taken to bring the system into compliance. If the zero point drifts 

by more than 2 ppm HC, 1 ppm NOx, 10 ppm CO, or 40 ppm CO2, official testing shall 

be prevented and corrective action shall be taken to bring the system into compliance. 

Or, the unit may be zeroed prior to each test.

(3) Limit Check. The tolerance on the adjustment of the up-scale span point shall be 0.4% of 

point. A software algorithm to perform the zero and span adjustment and subsequent 

calibration curve adjustment shall be used. Cumulative software up-scale zero and span 

adjustments greater than ±10% from the latest calibration curve shall cause official 

testing to be prevented and corrective action shall be taken to bring the system into 

compliance.

(4) Daily Calibration Checks. The curve for each analyzer shall be checked and adjusted to 

correctly read zero using a working zero gas, and an up-scale span gas within the 

tolerance in Section 85.2234(d)(3), and then by reading a mid-scale span gas within 

2.5% of point, on each operating day prior to vehicle testing. If the analyzer does not read 

the mid-scale span point within 2.5% of point, the analyzer shall automatically be 
prevented from official testing. The up-scale span gas concentration for each analyzer 

shall correspond to approximately 80% of full scale, and the mid-point concentration shall 

correspond to approximately 15% of full scale.

(5) Weekly NOx Converter Checks. The converter efficiency of the NO2 to NO converter 

shall be checked on a weekly basis or as determined by the Division. The check shall be 

equivalent to Section 86.123-78 (for reference see EOD Form 305-01) except that the 

concentration of the NO gas shall be in the range of 100-300 ppm. Alternative methods 

may be used if approved by the Division.

(6) Weekly NO/NOx Flow Balance. The flow balance between the NO and NOx test modes 

shall be checked weekly or as determined by the Division. The check may be combined 

with the NOx converter check as illustrated in EPA NVFEL Form 305-01.

(7) Monthly Calibration Checks. The basic calibration curve shall be verified monthly by the 

same procedure used to generate the curve in Section 85.2234(d)(l), and to the same 

tolerances.

(8) FID Check.

(i) Upon initial operation, and after maintenance to the detector, each FID shall be 

checked, and adjusted if necessary, for proper peaking and characterization 

using the procedures described in SAE Paper Number 70141 or by analyzer 

manufacturer recommended procedures.

(ii) The response of each FID to a methane concentration of approximately 50 ppm 

CH4 shall be checked once per month. If the response is outside of the range of 

1.00 to 1.30, corrective action shall be taken to bring the FID response within this 

range. The response shall be computed by the equation in Section 

85.2234(d)(9)(iii).

(iii) Ratio of Methane Response =

(9) Integrator Checks. Upon initial operation, emissions from a vehicle with transient cycle 

test values between 60% and 400% of the 1984 LDGV standard shall be simultaneously 

sampled by the normal integration method and by the bag method in each system. The 

data from each method shall be put into a historical database for determining normal and 

deviant performance for each test system. Specific deviations between the integrator and 

bag readings exceeding ±10% shall require corrective action.

(10) Cross-Checks. NOT APPLICABLE On a quarterly basis, and whenever gas bottles are 

changed, each analyzer in a given facility shall analyze a sample of a test gas. The test 

gas shall be independent of the gas used for the daily calibration check in Section 

85.2234(d)(4), in independent bottles. The same test gas, or gas mixture shall be used 

for all analyzers. The concentration of the gas shall be one of three values corresponding 

to approximately 0.5 to 3 times the cut point (in gpm) for 1984 and later model year 

vehicles for the constituent. One of the three values shall be at the lower end of the 

range, another shall be at the higher end of the range, and the other shall be near the 

middle of the range. The values selected shall be rotated in a random manner for each 

crosscheck. A gas divider may determine the value of the checking sample. The 

deviation in analysis from the concentration of the checking sample for each analyzer 

shall be recorded and compared to the historical mean and standard deviation for the 

analyzers at the network and at all facilities. Any reading exceeding 3 sigma shall cause 

the analyzer to be placed out of service.
(11) Interference, Laboratory Testing. The design of each CO, CO2, and NOx analyzer shall 

be checked for water vapor interference prior to initial service. The interference limits in 

this paragraph shall apply to analyzers used with a CVS of 700 SCFM or greater. For 

analyzers used with lower flow rate CVS units, the allowable interference response shall 

be proportionately adjusted downward.

(i) CO Analyzer. A gas mixture of 4% CO2 in N2 bubbled through water with a 

saturated-mixture temperature of 40°C shall produce a response on the CO 

analyzer of no greater than 15 ppm at 40°C. Also, a gas mixture of 4 percent 

CO2 in N2 shall produce a response on the CO analyzer of no greater than 10 

ppm at 40°C.

(ii) CO2 Analyzer. A calibration zero gas bubbled through water with a saturatedmixture temperature of 40°C shall produce a response on the CO2 analyzer of no 

greater than 60 ppm.

(iii) NOx Analyzer. A calibration zero gas bubbled through water with a saturatedmixture temperature of 40°C shall produce a response on the NOx analyzer of no 

greater than 1 ppm. Also, a gas mixture of 4 percent CO2 in either N2 or air shall 

produce a response on the NOx analyzer of no greater than 1.0 ppm at 40°C.

(12) Interference — Field Testing. Each CO, CO2, and NOx analyzers shall be checked for 

water vapor interference prior to initial service, and on a yearly basis thereafter. The infield check prior to initial service and the yearly checks shall be performed on a high 

ambient temperature summer day (or simulated conditions). For analyzers used with 

lower flow rate CVS units, the allowable interference response shall be proportionately 

adjusted downward. The allowable interference level shall be adjusted to coincide with 

the saturated-mixture temperature used. For the CO analyzer, a rejection ratio of 9,000 to 

1 shall be used for this calculation. A ratio of 2000 to 1 shall be used for CO2 analyzers. 

A ratio of 90,000 to 1 shall be used for NOx analyzers.

(e) Gases

Calibration, Working and Span Gases Shall Conform to Regulation Number 11, Appendix B

(f) Quality Control Data Files for Individual Test Systems. In general, quality files control for 

individual test systems shall include parameters that will allow the cause for abnormal 

performance of a test system to be pinpointed to individual systems or components. Test system 

control charts shall include at a minimum:

(i) Overall number of voided tests

(ii) Number of voided tests by type

(iii) Level of difference between theoretical and measured coast-down times

(iv) Level of difference between theoretical and measured CVS flow

(v) Level of up-scale span change from last up-scale span (not required if software 

corrections are tracked)

(vi) Level of mathematical or software correction to the calibration curve as a result of an upscale span change (if used)
(vii) Level of difference between the analyzer response to the daily crosscheck, and the test 

gas concentration

(viii) Level of difference between the integrated measurements 2nd the bag measurements

(ix) The system response time

(x) Level of the FID CH4 response ratio

(xi) Level of the ambient background concentrations

(xii) The average, median, 10th percentile and 90th percentile of the composite emissions (HC, 

CO, CO2, and NOx) measured over the defined periodic basis

(xiii) Average number of passing vehicles, and average number of failing vehicles over the 

defined periodic basis

(xiv) Level of difference between theoretical or measured values for other parameters 

measured during quality assurance procedures

Test Report

(a) Acceptance Test Reporting for System Evaluation

(1) Test Types and Standards. The test report shall indicate the types of tests performed on 

the vehicle and the test standards for each. Test standards shall be displayed to the 

appropriate number of significant digits as in Section 85.2205(a). The reported standards 

shall be the composite test standards.

(2) Test Scores. The test report shall show the scores for each test performed. Test scores 

shall be displayed to the same number of significant digits as the standards.

(3) Transient Mode Test Scores. The reported score for the Transient Mode shall be in units 

of grams per mile and shall be selected based upon the following:

(i) If the emissions of any exhaust component of the composite Transient Test are 

below the applicable standard in Pan F of this regulation, then the vehicle shall 

pass for that constituent and the composite score shall be reported.

(ii) If the emissions of any exhaust component on the composite Transient Test 

exceed the applicable standard in Part F of this regulation, but are below the 

Phase 2 standard, then the vehicle shall pass for that component and the Phase 

2 score shall be reported.

Terms

(a) Definitions

(1) Track coast-down target time: The new vehicle certification track coast-down time 

between 55 and 45 mph.

(2) Road load horsepower: The power required for a vehicle to maintain a given constant 

speed taking into account power losses due to such things as wind resistance, tire 

losses, bearing friction, etc.
(3) Tier 1: New gaseous and particulate tailpipe emission standards for use in certifying new 

light duty vehicles and light duty trucks phased in beginning with the 1994 model year.

(1) CVS hose: The hose, connecting to the tailpipe of the vehicle that carries exhaust and 

dilution air to the stationary portion of the CVS system.

(1) The Division: Colorado Department of Public Health and Environment, Air Pollution 

Control Division.

(5)(b) Abbreviations

(1) CFV: Critical flow venturi

(2) CH4: Methane

(3) CO2: Carbon dioxide

(4) CO: Carbon monoxide

(5) CRM: Certified reference material

(6) CVS: constant volume sampler

(7) FID: Flame ionization detector

(8) gpm: Grams per mile

(9) GVWR: Gross Vehicle Weight Rating

(10) HC: Hydrocarbons

(11) HDGT: Heavy-Duty Gasoline-powered Truck greater than 8500 pounds GVWR

(12) hp: horsepower

(13) Hz: cycles per second (Hertz)

(14) I/M: Inspection and Maintenance

(15) IW: Inertia weight

(16) LDGT1: Light-Duty Gasoline-powered Truck from 0 to 6000 pounds GVWR

(17) LDGT2: Light-Duty Gasoline-powered Truck from 6001 to 8500 pounds GVWR

(18) LDGV: Light-Duty Gasoline-powered Vehicle

(19) LVW Loaded Vehicle Weight

(20) mph: Miles per hour

(21) NDIR: non-dispersive infrared

(22) NIST: National Institute for Standards and Technology
(23) NO2: Nitrogen dioxide

(24) NO: Nitrogen oxide

(25) NOx: Oxides of nitrogen

(26) NVFEL: National Vehicle and Fuel Emissions Laboratory

(27) Obmph: Observed dynamometer speed in mph of the loading roller, if rolls are not 

coupled

(28) PLHP: Parasitic horsepower loss at the observed dynamometer speed in mph

(29) ppm: parts per million by volume

(30) ppmC: parts per million, carbon

(31) psi: Pounds per square inch

(32) RFP: Request for Proposal

(33) RLHP Road Load Horsepower

(34) rpm: revolutions per minute

(1) SCFM: standard cubic feet per minute

(1) SEO: square edged orifice

(37) SPC: Statistical process control

(38) SRM: Standard reference material

(39) SSV: Subsonic venturi

(40) TRLHP: Track road-load horsepower

ATTACHMENT IV TO THE TECHNICAL SPECIFICATION APPENDIX A Specifications for 

Colorado 97 Analyzer

COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT

SPECIFICATIONS FOR COLORADO 97 ANALYZER

INTRODUCTION

Colorado's current enhanced I/M program contains a two-speed idle (TSI) emissions testing component, 

the Colorado 94 Test Analyzer System that is based upon BAR 90 technology. The TSI program utilizes a 

decentralized, independent inspection only format encompassing the seven nine Denver Metro Area 

(DMA) Front Range counties. The DMA program is expanding to the North Front Range counties of Weld 

and Larimer in 2010. This inspection only population of independent inspectors will conduct inspections 

utilizing a new Colorado 97 emissions analyzer. 
The demands for more accurate analytical information as well as a more automated inspection process 

with real-time data transfer has superseded the capabilities of BAR 90 (Colorado 94) technology. System 

enhancements are necessary to meet Colorado’s inspection needs. These enhancements and other 

technical details are described in this document.

1.0 GENERAL

It is expected that the Colorado 97 software will be Colorado 94 software upgraded to BAR 97 and SAE 

J1978 and J1979 compliance. 

1.1 Design Goals 

The specifications that have been developed are designed utilizing a personal computer system. 

The analyzer system must be capable of performing uniform and consistent emission tests for 

Colorado's Automotive Inspection and Readjustment (AIR) Program. Features of the analyzer 

include: vehicle emissions measurements of hydrocarbon (HC), carbon monoxide (CO), carbon 

dioxide (CO2)and oxygen(O2); engine RPM measurements, exhaust dilution determinations, 

pressure test system for EVAP; OBD II monitor readiness and diagnostic trouble code retrieval; 

data entry; data retrieval tables; a dedicated printer (for vehicle inspection certificates; data 

recording on hard drive or removable media ; modem for “on-line real time” data transmission; 

monitor information display to the inspector; bar code reader and printing capabilities; and fully 

menu driven, interactive simple microprocessor controlled operation. 

Additional, automatic features required include: gas calibrations, zero and span checks, pressure 

calibrations, gas auditing procedure; leak checks, HC hang-up checks, audit menus (i.e., data 

read system), test sequencing, and low-flow checks. The analyzer shall be designed and 

constructed to provide reliable and accurate service in the automotive environment. The software 

used in the analyzer shall consist of a process control system as well as data look-up files. 

Security shall be provided to prevent unauthorized modifications to the software or test data and 

recording unauthorized entry (tampering) and locking out of the inspection process when 

detected. 

The emissions analyzer software shall be designed for maximum operational simplicity. 

It shall also be capable of providing emission-reading characteristics, independent of the 

inspection function, which can be used for vehicle diagnostic. 

1.2 Useful Life 

The useful life of the analyzer shall be a minimum of five years. 

1.3 Nameplate Data 

A nameplate including the following information shall be permanently affixed to the housing of the 

analyzer: 

Name and Address of Manufacturer 

Model Description 

Serial Number 

Date of Assembly 
The manufacturer shall affix a stick-on type label to the analyzer that contains a toll-free 

telephone number for customer service. This number can also be included in a service software 

message. 

1.4 Manuals 

Each analyzer shall be delivered with the following manuals: 

A. Reference Operating Instructions 

B. Operation Instruction Manual 

C. Maintenance Instruction Manual (limited) 

D. Initial Start-up Instructions 

Colorado 97 Analyzer manufacturers may consolidate manuals. The manuals shall be 

constructed of durable materials and shall not deteriorate as a result of normal use over a fiveyear period. The analyzer housing shall provide convenient storage for each manual in a manner 

that will: 

E. Allow easy use. 

F. Prevent accidental loss or destruction. 

1.5 Certification Documentation 

The analyzer software shall be fully documented. Two copies of the documentation listed below 

shall be submitted to Colorado Department of Public Health and Environment as part of the 

certification application. 

A. Complete program listings. Program listings may be on disk. They are not 

required to be submitted with the application for certification. 

B. Functional specifications. 

C. Functional flowcharts of the software. 

D. Example inputs and outputs from all processes. 

E. Detailed interface information on system components including the identification 

of protocol and output specifications. 

F. All file layouts with file names, file types, file security, field names, field types, 

field sizes, and field editing criteria. 

Documentation provided by the vendor to meet this requirement will be treated as proprietary 

information by Colorado Department of Public Health and Environment. 

Prior to certification of any Colorado 97 emissions analyzer for sale in Colorado, the manufacturer 

of such analyzer shall provide the Division with software source codes and all other technical 

information (including, but not limited to all working codes, schematics and drawings) necessary 

to operate, maintain, calibrate and repair such analyzer in the event that the manufacturer or its 

agent ceases providing adequate maintenance, calibration and repair services in Colorado. The 
manufacturer shall keep such information current, and will provide the Division with copies of any 

and all changes. So long as such maintenance, calibration and repair, services are available from 

the manufacturer or its agent, the Division shall protect such information as confidential 

commercial data if it is clearly marked as such. In the event that the manufacturer becomes 

insolvent or stops providing adequate maintenance, repair or calibration services in Colorado all 

such information shall be the property of the Division and may be released to a third party as 

necessary to repair, calibrate and maintain the analyzers. 

1.6 Warranty Coverage/Service Contract 

A written warranty coverage agreement, signed by an authorized representative of the equipment 

manufacturer and the vehicle inspection station owner, which provides a complete description of 

coverage for all systems and components and all manufacturer provided services listed in Section 

1.8, must accompany the sale or lease of each Colorado 97 emissions analyzer. 

An extended service contract shall be available upon the expiration of the manufacturers original 

warranty period. Original manufacturer’s warranty shall be a minimum of one year from the date 

of purchase. The “service contract” shall be offered in one-year increments. The “service 

contract” agreement shall include the inspection station owner's name, inspection station 

address, telephone number, inspection station identification number, analyzer serial number and 

detailed terms of the agreement. The agreement must extend for at least one year and if 

purchased, the expiration date must be entered to software file and monitored by the system 

clock. Approaching expiration messages must be displayed at daily system start-up beginning 

thirty days prior to expiration and messaging “30 days until expiration, 29 days etc.” Renewals 

shall be offered at the inspection station owner’s request and governed by “good business” 

practices between the parties involved. Service contract agreements must be available by the 

manufacturer for the mandated life of Colorado AIR Program. Cost disclosures and detailed 

descriptions of coverage’s must be available in printed form and distributed to all Colorado 97 

users. Cost disclosure shall also be made for “consumable” inventory items 1.8B. This 

information would most appropriately be presented with the original manufactures warranty. 

1.7 Tampering Resistance 

Controlled access design shall be the responsibility of the manufacturer and is subject to approval 

by Colorado Department of Public Health and Environment. Analyzer service personnel, 

inspectors or others shall be prohibited, to Colorado Department of Public Health and 

Environment satisfaction, from creating or changing any test results, programs or data files 

contained in the analyzer. Manufacturers shall utilize special BIOS partitions, or other appropriate 

software and hardware provisions, deemed necessary to protect the I/M files and programs. The 

protection features shall prevent access to the secured floppy disk drive and those portions of the 

hard disk containing I/M programs and test data or files. 

The emission analyzer and the sampling system shall be made tamper-resistant to the Colorado 

Department of Public Health and Environment satisfaction. At a minimum, the manufacturer shall 

develop tamper-resistant features to prevent unauthorized access through the cabinet. 

Microswitches, keyed locks, or software algorithms requiring the use of a password which can be 

changed by the Colorado Department of Public Health and Environment would all be acceptable 

provided the physical or logical design effectively prevents unauthorized access. 

Manufacturers may offer analyzers with additional disk drives that can run optional software 

application programs. 

If tampering occurs, a software lockout algorithm shall be activated which aborts any existing test 

sequence and prevents further inspections until an authorized AIR Program official clears the 

lockout. 
The lockout system shall be designed so that an AIR Program official from the audit menu can 

activate it. Only AIR Program Auditors may remove lockouts put in place from the audit menu. 

Manufacturers shall develop a system by which their service technicians shall be prevented from 

clearing “tamper” lockouts. 

Optional software packages shall not interfere with the normal operation of the I/M inspection and 

testing software, and shall not compromise the tamper-resistant features of the analyzer. 

Manufacturer field service representatives will not have access to DOS, unless assurances 

acceptable to Colorado Department of Public Health and Environment have been provided that 

insure, integrity of the system will not be jeopardized. 

1.8 Manufacturer Provided Services 

The manufacturer shall agree to provide the following services to the inspection station as part of 

the manufacturer’s original warranty and thereafter as a portion of the service contract 

agreement. The cost of a service agreement is to be listed on a year-by-year basis. Future 

charges cannot exceed the amount published. 

A. Delivery, installation, calibration, and verification of the proper operating condition 

of a Colorado 97 emissions analyzer. 

B. Quarterly (90 days) examination, calibration, and routine maintenance of the 

analyzer and sampling systems. Full systems support and repair, including 

loaner units. Upon initial sale or loan, provide “extra” printer medium (1 ea.) 

sample filter(s) (2), sample hose (1) and sample probes (1). Maintain the “extra” 

consumable inventory upon examination and provide a software history file for 

the replacement of consumables accessible to AIR Program officials. 

Consumables and the cost(s) thereof must be disclosed in the service 

agreement. 

C. Instruct all certified inspectors employed by the inspection station at the time of 

installation in the proper use, maintenance, and operation of the analyzer. The 

analyzer shall contain a feature that will allow an inspector to go through the 

complete inspection procedure without generating an official inspection record. 

This function will be used for evaluating inspector performance, by AIR Program 

officials, or by the manufacturer for demonstration purposes. The “training mode” 

shall not require the use of an inspector’s access code or allow access to 

secured areas of hardware or software. The display shall show a message 

throughout the inspection that this is not an official inspection. Vehicle inspection 

reports shall indicate to the satisfaction of Colorado Department of Public Health 

and Environment that they are for training only. No official Certificate of 

Compliance will be generated during the training exercise. 

D. On-site service response by a qualified repair technician within two (2) business 

days, (48 hours) excluding Sundays and national holidays, of a request from the 

inspection station. The names, toll-free telephone numbers, and service facility 

addresses of all manufacturer representatives responsible for equipment service 

shall be provided to the inspection station. A service representative shall be 

available at all times during normal working hours. Sundays and national 

holidays are not included. All system repairs, component replacements, and/or 

analyzer adjustments, shall be accomplished on-site within 48 hours after a 

service request has been initiated. If the completion of this work is not possible 

within this time period, a Colorado 97 loaner unit shall be provided until the 

malfunctioning unit is properly repaired and returned to service. Service 
representatives shall have a software driven menu option that allows the transfer 

of inspection station, inspector information and other applicable data files from 

one analyzer to another without manual inputs and without transfer of previous 

test files. 

E. Updates of the “Functional” software will be limited to once per year at no cost. 

Updates of operational software, i.e., file based information will be on an “as required” 

basis. All forms of software updating will utilize modem technology for the updating 

process. File updates are at no cost and every effort will be made to minimize them. 

F. The analyzer software shall be designed so that AIR Program officials can insert 

a disk, prepared by the manufacturer, into the Program system host, and update 

the existing software version, via modem. A system of manual updating by 

program officials utilizing the auditor’s menu shall also be available. Look-up up 

tables and message screens shall be designed sufficiently separate from the 

main operations software so that it is not possible, to interfere in any way with the 

operations of the analyzer. 

Colorado Department of Public Health and Environment will require the manufacturer to 

render updates as necessary in the first year of the program to ensure the program 

meets all design criteria. Thereafter software updates will be limited to once per year at 

no cost. Since modem software updating will be utilized, there are no costs to the 

analyzer owner. A software version number, consisting of a four character alpha-numeric 

code made up of the last two digits of the year followed by a two character version 

number, shall be recorded in the analyzer and included on each vehicle test record. The 

analyzer manufacturer shall not modify any existing software version without obtaining 

written approval from Colorado Department of Public Health and Environment. 

Colorado Department of Public Health and Environment may require the manufacturers 

to conduct on-site or laboratory testing of in-use analyzers in order to document 

continued compliance. When an analyzer is removed from the field, for repair or testing, 

manufacturers shall supply the inspection station from which it was removed with a 

temporary replacement unit meeting all program requirements. Manufacturers shall pay 

for all necessary shipping and transfer costs for the replacement of the analyzer selected 

for compliance testing. Manufacturers shall also pay for any required testing performed 

by their personnel or by an independent company. 

The manufacturers shall provide training to AIR Program officials on all operational, 

maintenance, and quality control features of the analyzers, including full access to and 

use of inspection menus, audit menus and calibration menus, as well as optional 

programs offered to inspectors. Such training shall be conducted at the manufacturer's 

expense as a condition of certification and thereafter at reasonable intervals upon written 

request by Colorado Department of Public Health and Environment 

1.9 Certification Requirements 

The manufacturer shall submit a formal certificate to Colorado Department, of Public 

Health and Environment that states that any analyzer sold or leased by the manufacturer 

or its authorized representatives for use in Colorado AIR Program will satisfy all design 

and performance criteria described in these specifications. The manufacturer shall also 

provide sufficient documentation to demonstrate conformance with these criteria 

including a complete description of all hardware components, the results of appropriate 

performance testing, and a point-by-point response to specific requirements. Previous 
certification by the California Bureau of Automotive Repair (BAR) is necessary for the 

analytical bench. 

In addition, a full description of the company's service procedures and policies, as well as 

sample contracts, warranties, and extended service agreements, shall be provided as 

part of the certification application to ensure proper maintenance of all analyzers 

throughout their useful life. One fully functional analyzer shall be presented for evaluation 

and one additional fully functional analyzer for the certification process. If certified these 

units will remain in AIR Program possession for continued in-use evaluation for the life of 

the AIR Program. In the event that 1 % of overall unit sales exceed this two-unit base, inuse evaluation will require 1 % of overall unit sales for in use evaluation. 

2.0 HARDWARE SPECIFICATIONS

2.1 General

Colorado 97 hardware shall be compliant with the BAR 97 Section 2 specification, the August 

2008 revision available at: 

http://www.smogcheck.ca.gov/70_siteWideInfo/Library/09_IndustryResources.html

And/or current SAE on-board diagnostic “J” standards including but not limited to J1978 and 

J1979 available from SAE.

NOTE: The Colorado 97 is not an ASM system. ASM hardware, i.e. the dynamometer and NOx 

sensor, are not needed. By extension, ASM software is also unnecessary.

2.2 Span Gases

The Colorado 97 shall use the same span gases utilized for calibration of the Colorado 94 TAS 

namely:

AIR 94 Low Range:

300 ppm propane

1.0% carbon monoxide

6.0% carbon monoxide

Balance: oxygen-free nitrogen

AIR 94 Mid Range:

1200 ppm propane

4.0% carbon monoxide

12.0% carbon monoxide

Balance: oxygen-free nitrogen

2.3 Audit Gases
Audit gases shall be those described in Colorado Air Quality Control Commission Regulation 

Number 11.

3.0 SOFTWARE COMPONENTS

3.1 Communication and Data Field Specification

Operational software requirements at a minimum must support the existing Colorado 94 

Communication Protocol and Data Field Specification. See Appendix A.For inquiries referencing 

the Communication and Data Field Specification, please contact the Colorado Air Pollution 

Control Division.

3.2 Society of Automotive Engineers (SAE) “J” Standards

The Colorado 97 shall be compliant with current SAE on-board diagnostic “J” standards including 

but not limited to J1978 and J1979.

3.3 OBD II

The Colorado 97 must be capable of accessing OBD II readiness monitors and diagnostic trouble 

codes. The operational software requirements will be available from the Division upon request.

3.4 Forms

The Colorado 97 shall be capable of completing the current, pre-printed, continuous form-fedprint 

on demand Vehicle Inspection Report (VIR) form. Examples of the VIR and the Vehicle Repair 

Form (VRF) are in Appendix Bare following this Section 3.0.

3.5 Upgrades

Software shall be updated/upgraded per Section 1.8 aboveof this Attachment IV.

Colorado 94 Communications and Data Fields Specification

Vehicle Inspection Report – Passing Form-Front

Vehicle Inspection Report – Failing Form-Back (Vehicle Repair Form)
Vehicle Inspection Report Form-Completed
ATTACHMENT V Specifications for Colorado On-Board Diagnostic (OBD) Stand-Alone 

Analyzer

APPENDIX B Standards and Specifications for Calibration/Span Gas Suppliers

STATE OF COLORADO
DEPARTMENT OF PUBLIC HEALTH & ENVIRONMENT

COLORADO AIR PROGRAM

STANDARDS AND SPECIFICATIONS FOR CALIBRATION/SPAN GAS SUPPLIERS

INCLUDING 

GAS REQUIREMENTS FOR THE BASIC AND ENHANCED INSPECTION

TEST PROGRAMS

1997

INTRODUCTION

This Appendix B describes the standards and specifications for the suppliers of span and calibration 

gases to the Colorado AIR Program, including facility requirements and documentation required of 

potential suppliers.

CONTENTS

SECTION 1: Definitions

BASIC AND ENHANCED IDLE AIR PROGRAM

SECTION 2: Basic and Enhanced Idle Air Program - Technical rRequirements

SECTION 3: Calibration/sSpan gGas aApproval & lLabeling

SECTION 4: Cylinder tTracking and & rRecall

ENHANCED IM & IG 240 AIR PROGRAM

SECTION 5: Enhanced IM & IG 240 Air Program - Technical rRequirements

SECTION 6: Calibration/span gas approval & labelingColorado Approval Process

AIR PROGRAM/BASIC AND ENHANCED

SECTION 7: Blender fFacility rRequirements & dDocumentation

ATTACHMENT I

Program Contact/Addresses/Phone Numbers

ATTACHMENT HII

“Colorado Approved” Label Samples

SECTION 1 DEFINITIONS

AIR: Colorado's “Automotive Inspection & Readjustment” Program.
ANALYTICAL ACCURACY: The relative percent deviation of the stated concentration of the components 

of a gas blend from the “true” value as determined by comparison with Colorado AIR Program standards.

(% DEV = STATED CONC - “TRUE” CONC/“TRUE” CONC X 100)

AUDIT GAS: Reference gas standards with direct traceability to NIST and/or EPA, to be used by AIR 

Program QA/QC personnel.

APCD: Colorado “Air Pollution Control Division”.

AUTHORIZED GAS BLENDER: A blender of precision gas products selected to provide such products 

pursuant to the requirements of 42-4-306(3)(A)(l)(C).

BALANCE GAS: The balance or makeup gas for Colorado AIR Program gases shall be as follows: for 

basic program tri-blend span gases, nitrogen shall be the balance gas. For the enhanced IM 240 program 

standards and span gases, air shall be the balance gas. The balance gas for mixtures containing nitric 

oxide (NO) shall be nitrogen.

BAR: California “Bureau of Automotive Repair”

BLEND TOLERANCE: Deviation between the requested or nominal concentration and the measured or 

certified concentration of a gas mixture.

CALIBRATION STANDARD: A precision blended gas used to generate calibration curves, with an 

analytical accuracy of +/- 1%, traceable to NIST gas standards. (Enhanced Program)

CALIBRATION/SPAN GAS: A blend of carbon monoxide (CO), carbon dioxide (CO2), and propane, with 

a balance gas of nitrogen (NO2), which is used to calibrate the Colorado 94 test analyzers. (Basic 

program)

CALIBRATION ZERO AIR: The gas used as a diluent for gas dividers or to establish analyzer zero during 

calibration curve generation. Impurities shall not exceed 0.1 ppm carbon response, 0.5 ppm CO, 1 ppm 

CO2, 0.1 ppm NOx, and 1 ppm moisture. Blended air shall have oxygen content between 20.6% and 21%

CALIBRATION ZERO NITROGEN: The gas used as a diluent for gas dividers or to establish analyzer 

zero during calibration curve generation shall have a minimum purity of 99.997% with impurities not to 

exceed 0.1 ppm carbon response, 0.5 ppm CO, 1 ppm CO2, 0.1 ppm NOx, 1 ppm moisture and 0.5 ppm 

O2.

CAPSL: Colorado AIR Program Standards Lab.

CDPHE: Colorado Department of Public Health & Environment.

CERTIFIED GAS BLENDER: A blender of precision gas products, approved by the Colorado AIR 

Program. A certified blender has met or exceeded the requirements set forth by the CDPHE to provide a 

consistently high quality calibration and span gas to both the Basic and Enhanced Air Program.

CGA: Compressed Gas Association

CRM: Certified Reference Material

DOT: Department of Transportation

FID: HC analyzer using a flame ionization detector
FED FUEL: A mixture of 40% hydrogen (+/- 2%) and 60% helium

FID OXIDIZER: Zero grade air with oxygen content between 20.6% And 21 %

GOLD STANDARDS: NIST traceable air program standards named by EPA at the National Vehicle Fuels 

and Emission lab (NVFEL), Ann Arbor, Michigan

NIST: National Institute of Standards and Technology

STATE: The State of Colorado

SRM: Standard reference material. The highest integrity gas standard, prepared by, and only available 

from, NIST.

VETC: Vehicle Emission Technical Center, 15608 East 18th Avenue, Aurora, Colorado 80011.

WORKING SPAN GAS: Gases used in the enhanced IM 240 Air Program for high and mid-scale span 

checks and/or adjustments as well as analyzer cross-checks. These gases shall have an analytical 

accuracy of +/- 2%.

WORKING ZERO GAS: Air or nitrogen used in the daily zeroing of enhanced program analyzers. 

Impurities shall not exceed 1 ppm carbon response, 2 ppm CO, 0.04% C02, 0.3 ppm NOx, and 1% 

moisture. Air shall have oxygen content between 20.6% and 21%. Nitrogen shall contain a maximum of 

0.5% O2.

SECTION 2 BASIC & ENHANCED IDLE AIR PROGRAM/TECHNICAL REQUIREMENTS

2.0 GENERAL

This section describes the calibration/span gas requirements, specifications for these gases, and types of 

cylinders allowed. Such specifications shall be included in any request for bids issued pursuant to 42-4-

306(3)(a)(l)(c).

2.1 GAS REQUIREMENTS

The following identifies the calibration/span gas blends required for the Colorado basic & enhanced idle 

AIR Program:

CALIBRATION/SPAN GASES

AIR94LOW

300 ppm Propane (as THC)

1.0 % Carbon Monoxide

6.0 % Carbon Dioxide

Balance Nitrogen

AIR94MID

1200 ppm Propane (as THC)
4.0 % Carbon Monoxide

12.0 % Carbon Dioxide

Balance Nitrogen

2.2 GAS BLEND ACCURACIES

The combined errors due to blending and naming of the above calibration/span gases shall not exceed 

+/- 2% for each component.

2.3 ANALYTICAL ACCURACY

The analytical accuracies for idle air program gases are:

(A) Calibration/span gas: +/-2% of nominal value

(B) Audit gases: +/- 1% of nominal value

2.4 BLEND TOLERANCE

Zero blend tolerance is required for basic & enhanced idle AIR Program calibration span gases.

2.5 BLENDER REFERENCE STANDARDS

Each authorized gas blender shall present documentation of its own internal standards for approval. The 

state provides two methods for standard documentation:

(I) Blender may prepare a reference cylinder of each gas blend intended for the AIR 

Program to be named vs. Colorado's gold standards. Cylinder(s) shall be sent to the 

state for naming and labeling. This standard will become the blender's reference 

standard for the analysis of production span gases.

NOTE: The associated costs of shipping reference cylinders to and from Colorado will be the 

responsibility of the blender. No shipping costs will be borne by the state.

(II) Blenders certified by the State of California, Bureau of Automotive Repair, may elect to 

submit copies of their current certification including a listing of all SRM's, CRM's, or other 

reference gases accepted by bar, as pertaining to the analysis of I/M span gases. BAR 

acceptance of these standards will be sufficient to obtain approval of same for the AIR 

Program.

2.6 CYLINDERS

The cylinders to be used in the Colorado 94 analyzers in the field shall be low pressure, non refillable, 

disposable canisters.

High pressure, refillable cylinders will be used by AIR Program audit/QC teams and, in some cases, by 

analyzer manufacturers. Approval of span gas in high pressure cylinders will be on an individual basis. 

(See Section 3)

2.7 DISPOSABLE CYLINDERS
(A) Disposable cylinders shall be in accordance with dot specification 39 for non refillable, 

disposable cylinders. (260 PSIG service pressure, 325 PSIG test pressure, 650 PSIG 

minimum burst pressure) [CFR Title 49, Part 178, Section 178.65, Oct 1, 1996]

(B) Nominal size shall not exceed 750 cubic inches +/- 5% (approximately 9 inches inside 

diameter by 16 inches high, providing an equivalent water capacity of 27 lbs.) As a 

minimum, cylinders shall contain 7.5 cubic feet of gas blend at 260 PSIG cylinder 

pressure.

(C) Cylinders shall be designed with an integral stand to facilitate upright storage.

(D) Cylinder outlet shall be CGA 165, 1/4” SAE flare, 45 degree male. Shutoff valves shall be 

of the non refillable type.

(E) Cylinders shall be equipped with a safety relief device in accordance with DOT 

regulations [CFR 49, 173.34,(D), Oct, 1996]. The safety relief device must comply with 

the requirements of the compressed gas association pamphlet S.1.1, 8th Edition, 1994.

(F) Cylinders shall have a built in safety shield to protect the shut off valve.

(G) No material shall be used in cylinder fabrication or assembly, or in cylinder charging 

equipment, which is incompatible with the gas blend as to cause contamination or 

degradation.

(H) Blenders must comply with applicable DOT specifications for the shipment of cylinders. 

[CFR Title 49, Volume 2, Part 173, Subpart B, Oct, 1996].

2.8 HIGH PRESSURE REFILLABLE CYLINDERS

(A) Refillable cylinders must be aluminum and made in accordance with DOT specifications 

3AA or 3AL [CFR Tide 49, Volume 2, Part 178, Subpart C, Oct, 1996], whichever is 

applicable.

(B) All cylinders must comply with applicable DOT Regulations and requirements for safety 

and shipment. [CFR Title 49, Volume 2, Part 173, Subpart B, Oct, 1996]

2.9 LABELING

(A) Caution labels shall be affixed to all cylinders and shall comply with applicable DOT and 

OSHA regulations.

(B) “Colorado Approved” labels will be provided by the Colorado AIR Program (Section 3) 

and shall be affixed to the upper portion of the canisters.

2.10 EXPIRATION

Triblend span gas cylinders containing CO, CO2, and propane in nitrogen, shall have an expiration date 

of 36 months after date of fill.

2.11 QUALITY ASSURANCE

All gas blenders shall have in place a fully documented and implemented quality assurance program as a 

prerequisite to certification. This QA program shall include, but not be limited to:
(A) Regular equipment maintenance and calibration, performed in accordance with 

manufacturer guidelines, as a minimum.

(B) Documentation of the analysis of each batch or lot of gas produced. A copy of the 

certificate of analysis from each batch or lot shall accompany each approval request.

(C) Blender may choose to retain a cylinder from each batch/lot for internal documentation. 

However, one cylinder from each batch/lot must accompany each request for “Colorado 

Approved” labels. This sample cylinder will not be returned.

(D) Documentation of maintenance and calibration of equipment and instrumentation shall be 

made available upon request.

2.12 BREACH OF TERMS

Each contract entered into pursuant to 42-4-306(3)(a)(l)(C), shall authorize the APCD to suspend the 

blender's authority to supply precision gas products to inspection and readjustment stations, inspectiononly facilities, fleet inspection stations, motor vehicle dealer facilities and enhanced inspection centers in 

the event the gas blender violates the terms of the contract and this appendix B. The APCD may 

terminate such a suspension once the blender corrects the problems that led to the violation. An onsite 

inspection of the blender's facility by an APCD representative may be required to ensure that the relevant 

requirements are being observed.

SECTION 3 CALIBRATION/SPAN GAS APPROVAL & LABELING

3.0 GENERAL

Information in this section describes the calibration/span gas approval process as well as the procedure 

for obtaining “Colorado Approved” labels.

3.1 CALIBRATION SPAN GAS APPROVAL PROCEDURE

Batches or lots of span gas will be produced referencing procedures and specifications contained herein. 

Authorized blender shall analyze a representative number of cylinders from each batch or lot. Authorized 

blender shall then request from the CDPHE a number of Colorado approved labels corresponding to the 

number of cylinders in that batch or lot. The request for labels must include:

(I) Analytical report to contain:

(A) Actual analysis of samples in batch

(B) Number of cylinders in batch

(C) Fill date

(D) Number of labels required

(E) Batch or lot number

(II) One representative cylinder from each batch or lot of span gas produced to be verified by 

analysis and retained for future reference.
NOTE: This sample cylinder will not be returned. Cylinder will be archived by the state until the 

expiration date expires (36 months from fill date). This sample may be analyzed as a spot check 

or reference gas in matters concerning potential inquiries into batch integrity.

Upon approval, blender will be sent an appropriate number of “Colorado Approved” labels to be 

affixed to cylinders in that batch or lot.

Samples, along with request for “Colorado Approved” labels, should be sent to: CDPHE

VEHICLE EMISSION TECHNICAL CENTER

15608 E. 18TH AVENUE

AURORA, COLORADO 80011

ATTN: SPAN GAS VERIFICATION PROGRAM

3.2 CALIBRATION/SPAN GAS APPROVAL/HIGH PRESSURE CYLINDERS

Approval of calibration/span gases in high pressure cylinders will be done on an individual basis. Each 

cylinder seeking approval must be submitted for verification against AIR Program standards. A certificate 

of analysis shall accompany each cylinder and shall contain the following information:

(A) Cylinder number

(B) Components contained

(C) Analytical results

(D) Analytical accuracy

(E) Statement of traceability

(F) Analysis date

(G) Fill date

Upon approval, blender will be notified that the cylinder is ready for pickup by the purchaser. Approved 

cylinder, with “Colorado Approved” label attached, may be picked up during normal business hours (8:00 

am - 5:00 pm) Monday through Friday. Cylinders shall be sent to the above address.(See 3.1)

3.3 SHIPPING COSTS

Blenders shall provide for the shipping of all cylinders seeking Colorado approval for use in the AIR 

Program. The pick-up and delivery of individual high pressure cylinders is also the responsibility of the 

blender and/or the purchaser of that cylinder. These cylinders are expected to be picked-up within 30 

days of notification of approval. No costs pertaining to the pick-up or delivery of span gases shall be 

borne by the state.

3.4 LABELING

“Colorado Approved” labels will be provided by the State of Colorado. These labels will include 

information necessary to track span gases throughout the system as well as identify each cylinder as 

Colorado approved. Information contained on the label will include:
(A) Blender name

(B) Blending facility

(C) Batch or lot number

(D) Identify “low” (yellow label) or “mid” (white label) SPAN GAS

(E) Fill date

(F) Expiration date

(G) AIR Program number

(H) Bar code containing cylinder tracking information

(For a sample of the “Colorado Approved” labels, see attachment II)

3.5 AIR PROGRAM NUMBER

“Colorado Approved” labels will contain an AIR Program number. Each certified blender will be assigned 

a letter code that will precede the numbering of batch cylinders. These coded numbers will be generated 

by the state and assigned to each cylinder as batches of span gas are produced. Cylinder numbers will 

be held on file for the life span of the cylinder to assist in tracking, auditing and accounting purposes.

SECTION 4 CYLINDER TRACKING & RECALL

4.0 GENERAL

This section describes the method of tracking calibration/span gas throughout the AIR Program area. This 

system protects the inspection stations and provides for a replacement, in an expedient manner, should a 

non-conforming calibration/span gas be discovered.

4.1 TRACKING CYLINDERS VIA BAR CODE

Each “Colorado Approved” label will contain a bar code to be scanned whenever a cylinder of 

calibration/span gas is put into service on a Colorado 94 analyzer or Motor Vehicle Dealer Transient 

Mode Test Analyzer System. Scanned information will be stored in a file, accessible through a host 

computer linking all inspection stations. AIR Program QA/QC personnel will be able to locate individual 

cylinders, track batches of span gas, etc., throughout the program area.

Label bar codes will be generated at the time of batch or lot approval and will contain information 

necessary to facilitate the tracking process. Blenders are required to continue to track internally, the 

whereabouts of “Colorado Approved” batches of calibration/span gas prior to retail sale. In the event of a 

recall of a batch of non-conforming calibration/span gas, the blender, through procedure described herein 

(see 4.2), will begin recall. In-use calibration/span gas affected will be identified by bar cod; information 

through system host and replacement procedures will begin.

4.2 RECALL PROCEDURE

In the event a non-conforming cylinder of calibration/span gas is discovered at an AIR Program inspection 

station, the following recall procedure will begin:

(A) Suspected non-conforming span gas confiscated by AIR Program Q/C personnel;
(B) Cylinder brought to the Colorado AIR Program Standards Lab (CAPSL) for analysis;

(C) Exposed non-conforming cylinder cross referenced by air number go blender and batch;

(D) Archived sample retrieved and analyzed vs. suspected non-conforming cylinder. Blender 

advised of results;

(E) Through host system, the state identifies whereabouts of any non-conforming cylinders 

on line. Blender provided with a listing of affected inspection stations;

(F) Blender shall immediately begin recall of all remaining unsold cylinders from batch in 

question and, simultaneously, begin process of supplying known conforming cylinder(s) 

to affected inspection stations by overnight service;

(G) A total recall and replacement of all cylinders in affected batch must be completed within 

10 days. A detailed report of the recall procedure and analysis of cause of the nonconforming product entering the system will be provided to the state within 15 days.

(H) The state may elect to withhold certification of future batches until such time as blender 

shows problems have been corrected.

(I) The state may also suspend the contract with the blender if information obtained 

suggests blending procedures were violated, pending a correction of the problems that 

caused the violation.

SECTION 5 ENHANCED IM & IG 240 AIR PROGRAM / TECHNICAL REQUIREMENTS

5.0 GENERAL

This section addresses the calibration gases, technical requirements, cylinder specifications and 

documentation required for IM & IG 240 testing.

5.1 GASES

Gases used in the calibration and support of IM & IG 240 testing shall conform to the provisions outlined 

in CFR Title 40, Part 86, Subpart B, Section 114, as revised July 1, 1992, for exhaust emission testing. 

Concentrations for IM 240 gases are as follows:

5.2 CALIBRATION GASES/CURVE GENERATION

(I) High tri-blends: (+/-1% analytical accuracy)

CO:9000 ppm

C02:3.6%

Propane:600 ppm

Balance: Air

(II) High NOx: (+/-1%)

NOx:450 ppm
Balance: Nitrogen

5.2.1 MID-SCALE CALIBRATION GASES/CURVE CONFORMATION

(I) Mid tri-blend: (+1-1%)

CO:4500 ppm

C02:1.8 %

Propane:300 ppm

Balance: Air

(II) Mid NOx tri-blend: (+/-1%)

NOx:225 ppm

Balance: Nitrogen

5.2.2 CALIBRATION ZERO GASES

(I) Calibration zero AIR

HC : < 0.1 ppm

CO : < 0.5 ppm

C02 : < 1.0 ppm

NOx : < 0.1 ppm

Moisture : < 1.0 ppm

02: 20.6 % - 21.0 %

(II) Calibration zero Nitrogen

Purity : 99.997 %

HC : < 0.1 ppm

CO : < 0.5 ppm

CO2 : < 1.0 ppm

NOx : < 0.1 ppm

Moisture : < 1.0 ppm

O2 : < 0.5 ppm

5.3 DAILY SPAN GASES
(I) High tri-blend span (+/-2% analytical accuracy)

CO : 8000 ppm

C02 : 3.2 %

Propane : 535 ppm

Balance : Air

(II) NOx mid span (+/-2%)

NOx : 75 ppm

Balance : Nitrogen

5.4 WORKING ZERO GASES

(I) Working zero AIR

HC : < 0.1 ppm

CO : < 2.0 ppm

CO2 < 400 ppm

NOx < 0.3 ppm

Moisture < 1.0 ppm

OY2 : 20.6-21.0 %

(II) Working zero Nitrogen

Purity : 99.997%

HC : < 1.0 ppm

CO : < 2.0 ppm

C02 : < 400 ppm

NOx : < 0.3 ppm

Moisture : < 1.0 ppm

02 : < 0.5 ppm

5.5 SUPPORT GASES

A variety of miscellaneous support gases are required for IM & IG 240 testing. Among these are:
GAS USAGE

Propane : 99.5% (min) CVS system flow checks

Methane : 50 ppm/AIR FID check gas

FID Fuel: 40% H2/60% HE FID burner fuel

N02 : 200 ppm/N2 NOx converter efficiency 

test gas

AIR : 18%-21% NOx ozonator gas

5.6 IG 240 GASES

Calibration, span, working and support gases required by IG 240 systems, are among the gases listed 

(5.2 thru 5.5). Additional gases of specific concentrations and blend make-up may be required pending 

final configuration of the IG system.

5.7 CYLINDERS

Calibration and working gas tri or quad-blends used for IM & IG 240 testing, must be supplied in 

aluminum cylinders as well as all no or NOx blends. Other gases may be supplied in steel or aluminum 

cylinders as appropriate.

High pressure refillable cylinders shall be manufactured in accordance with DOT specifications 3AL or 

3AA [CFR Title 49, Volume 2, Part 178, Subpart C, Oct l, 1996], whichever is applicable.

Approved valves and relief devices, appropriate for the intended use, shall be used on all high pressure 

cylinders. [CFR Title 49, Volume 2, Subpart B, Section 173.124, Oct 1, 1996]

All cylinders shall have appropriate labeling to comply with all DOT regulations concerning transportation 

and safety. [CFR 49, Volume 2, Part 173, Subpart B, Oct 1, 1996].

5.8 MISCELLANEOUS

A full line of gas products shall be made available to the enhanced AIR Program contractor(s) to insure 

safe handling and storage of gas cylinders, such as regulators, carts, restraints, and leak detection 

equipment. The contractor(s), as well as state QA/QC personnel, may also request a variety of gas 

blends, tri-blends, and other specialty gas products associated with automotive emission testing. Blender 

must demonstrate the ability to provide the above gases, equipment and associated products, in order to 

be designated as an approved blender to the Colorado enhanced AIR Program.

5.9 CERTIFICATES OF ANALYSIS

Each calibration gas, working span gas, and calibration zero gas shall be documented by a certificate of 

analysis to include; cylinder number, components, analytical results, accuracy, traceability and analysis 

date. A batch analysis certificate stating purity may document zero grade air and nitrogen. (Zero AIR 

certificate must also provide documentation of oxygen content.)

The enhanced program contractor(s) must produce documentation of cylinder contents of the above upon 

request of state QA/QC personnel.
5.9.1 TRACKING CYLINDERS VIA BAR CODE

Each “Colorado Approved” label will contain a bar code to be scanned whenever a cylinder of 

calibration/span gas is put into service on a Colorado 94 analyzer or Motor Vehicle Dealer Transient 

Mode Test Analyzer System scanned information will be stored in a file, accessible through a host 

computer linking all inspection stations. AIR Program QA/QC personnel will be able to locate individual 

cylinders, track batches of span gas, etc., throughout the program area.

Label bar codes will be generated at the time of batch or lot approval and will contain information 

necessary to facilitate the tracking process. Blenders are required to continue to track internally, the 

whereabouts of “Colorado Approved” batches of calibration/span gas prior to retail sale. In the event of a 

recall of a batch of non-conforming calibration/span gas, the blender, through procedure described herein 

(see 4.2), will begin recall. In-use calibration/span gas affected will be identified by bar code information 

through system host and replacement procedures will begin.

SECTION 6 COLORADO APPROVAL PROCESS

6.0 CALIBRATION STANDARDS AND AUDIT GASES

All calibration standards used in the Colorado Enhanced IM & IG 240 AIR Program must be submitted by 

the contractor to the state for approval and labeling as “Colorado Approved”. In addition, all audit gases 

utilized by AIR Program QA/QC teams will undergo the same verification and/or renaming process that 

will take place at the Colorado AIR Program standards lab (CAPSL) in Broomfield, Colorado. At CAPSL, 

each standard and/or audit gas will be read vs. program gold standards, named by EPA's NVFEL, in an 

effort to tie all primary gases to one source, regardless of manufacturer.

Each calibration standard and audit gas will receive a “Colorado Approved” label displaying the 

concentration of each major component as determined by analysis comparing such calibration standard 

or audit gas to the program gold standards. Labeled values are to be used in curve generation by the 

contractor and by audit teams to verify analyzer accuracy.

6.1 ZERO AIR/OXYGEN CONTENT

On a random basis, cylinders of zero air will be analyzed at CAPSL to verify oxygen content. As 

previously stated, the oxygen content of artificial blended air shall be 20.6 to 21 %. This is necessary to 

insure that an air cylinder used as a backup to a zero air generator (zag), will provide air as close to 

ambient in 02 as possible, should a zag be taken offline. FID response has been shown to be greatly 

affected by the O2 content of oxidizer air. Random analysis will provide verification that O2 content in 

zero air is within specifications.

SECTION 7 BLENDER FACILITY REQUIREMENTS & DOCUMENTATION

7.0 GENERAL

(A) A gas blender who intends to supply calibration/span gas to the Colorado AIR Program 

basic inspection stations and/or enhanced program contractor(s), must be selected by 

the Colorado Department of Public Health & Environment pursuant to 42-4-

306(3)(A)(l)(C).

(B) If a company has more than one facility that will be providing gases to Colorado, each 

must be included in the selection. The selection of one blending facility owned by a 

company does not imply or impart authority to other facilities within that company to 

supply precision gas products in Colorado.
(C) The CDPHE shall be notified of a pending sale of a blending facility at least 60 days prior 

to change of ownership.

(D) Contracts shall be for a one year period, but may be renewed annually.

7.1 CONTRACT PROPOSAL PACKET

The certification request packet shall contain information described in the following paragraphs. 

Information submitted should be as complete as possible. However, should some information be 

unavailable, so indicate and provide reasons, therefore, for AIR Program consideration.

7.2 CONFIDENTIAL AND COMMERCIAL INFORMATION

To the extent authorized by 24-72-101, C.R.S., the Colorado Department of Public Health & Environment 

shall maintain the confidentiality of any information which is included in the blender's bid and which is 

clearly marked as proprietary or confidential.

7.3 APPLICATION

The following items are to be included in blenders request for air program approved status:

(A) COVER SHEET - An application cover sheet must be signed by the President or Chief 

Financial Officer of the gas blending company.

(B) BLENDING FACILITY DESCRIPTION-Provide a complete description of the blending 

facility to include:

— Facility location

— Physical dimensions of lab and production areas

— Number of employees

— General description of blending facility and procedures

(C) INSTRUMENTATION - Provide description of all instrumentation utilized in the blending 

and analysis of AIR Program calibration/span gases. Provide instrumentation brand, 

model, type (NDIR, FID, GC, etc.). As well as calibration and maintenance schedules and 

personnel responsible.

(D) REFERENCE STANDARDS - Indicate the cylinder numbers, SRM/CRM numbers, 

concentrations and expiration dates for each NIST traceable reference standard to be 

used in the preparation and/or naming of AIR Program gases.

(E) BUSINESS STATUS REPORT - Application for certification shall contain information to 

verify blending facility's status as a bona fide blender of precision gases. Include 

evidence that applicant is a registered corporation in Colorado and/or a registered out-ofstate corporation.

(F) DISTRIBUTORS AND MARKETING - Applicant shall provide a description of expected 

distribution and marketing plans for providing calibration/span gas to the basic AIR 

program. Include a current listing of the names, addresses and phone numbers of the 

distributors used by the applicant. Such information shall be updated as necessary and 
notification of any change provided to the state in a timely manner. Lists of distributors 

will be made available to AIR Program inspection stations.

(G) RECALL OF NON-CONFORMING GASES/BASIC PROGRAM - Certified blenders shall 

be responsible for the recall and replacement of non-conforming calibration/span gases. 

Blenders will be required to replace suspected non-conforming cylinders by overnight 

service. Should such a discovery extend past a single cylinder to a batch or lot, a total 

recall of all cylinders will take place. (See Section 4).

Applicant shall provide procedures intended for use should such a recall be necessary.

(H) QUALITY ASSURANCE - Applicant shall include information regarding internal quality 

assurance program(s). Provide details of techniques, methodology and documentation 

utilized in QA program. Include calibration and maintenance schedules for all equipment 

and instrumentation used.

(I) SAFETY REGULATIONS - Certification application must include assurance the applicant 

is in compliance with all applicable DOT and OSHA regulations and standards.

(J) LIABILITY - Provide a copy of product liability insurance demonstrating adequate 

protection (minimum $300,000) exists for catastrophic failure situations (e.g., cylinder or 

valve rapture, noxious gas leakage, etc.). Evidence of bonding coverage shall be 

provided upon request.

APPENDIX B

ATTACHMENT I TO THE CALIBRATION AND SPAN GAS CERTIFICATION PROCEDURES

Program Contact/Addresses/Phone Numbers

ATTACHMENT I

PROGRAM CONTACT/ADDRESSES/PHONE NUMBERS

PROGRAM CONTACT; The main contact on matters concerning air program gases, requirements and 

specifications is:

COLORADO DEPARTMENT OF PUBLIC HEALTH & ENVIRONMENT

VEHICLE EMISSION TECHNICAL CENTER

15608 EAST 18TH AVENUE

AURORA, COLORADO 80011

(303) 364-4135

ATTN: SPAN GAS VERIFICATION PROGRAM

ORor

COLORADO AIR PROGRAM STANDARDS LAB

11609 TELLER STREET

BROOMFIELD, COLORADO 80020

(303) 404-0268.

APPENDIX B
ATTACHMENT IITO THE CALIBRATION AND SPAN GAS CERTIFICATION PROCEDURES

“Colorado Approved” Label Samples

Appendix B – Attachment II

Meeting Agenda where Public Hearing Occurred and 

Notice published in the Legal Ads of the Denver Post

40 CFR Part 51 Appendix V 2.1(f)
STATE OF COLORADO

John W. Hickenlooper, Governor

Larry Wolk, MD, MSPH

Executive Director and Chief Medical Officer

COLORADOAIR QUALITY CONTROL COMMISSION

http://www.cdphe.state.co.us

4300 Cherry Creek Drive South

EDO-AQCC-A5

Denver, Colorado 80246-1530

Phone (303) 692-3100

Fax (303) 691-7702

TDD (303) 691-7700

Colorado Department

of Public Health 

and Environment

Notice of Meeting and Agenda

Air Quality Control Commission

November 21, 2013

Colorado Department of Public Health & Environment

4300 Cherry Creek Drive South, Sabin Room

Denver, Colorado

9:00 a.m.

Call to Order: Determination of a quorum and approval of the meeting’s agenda.

Public Comment: The public is invited to comment on any air pollution issue not on 

the agenda. The Commission will not take action on issues 

discussed under this item today; however, items may be scheduled 

for further discussion or action.

CONSENT AGENDA

The Commission will vote on Agenda Items 1 and 2 as part of a Consent Agenda. Adoption of a 

Consent Agenda allows the Commission to consolidate voting on agenda items that do not need to be 

discussed individually and for which presentation of additional information is not required. 

APPROVAL OF MINUTES

1. October 17, 2013 Meeting Minutes

Review and approval of the October 17, 2013 meeting minutes of the Air Quality Control 

Commission.

RULEMAKING HEARING

2. Regulation Number 11

The Commission will consider housekeeping changes to the vehicle inspection and 

maintenance program.
2

REGULAR AGENDA

REQUEST FOR RULEMAKING HEARING – FEBRUARY 19, 20 & 21, 2014

(15 minutes presentation, 105 minutes discussion)

3.a. Regulation Number 3, Parts A, B, C

The Division will request that the Commission set a rulemaking hearing to consider 

proposed changes to Regulation 3, Parts A, B and C, to simplify emissions reporting and 

permitting requirements, including removing the “catchall” provisions and removing the 

crude oil storage tank permit exemptions. These revisions support the Division’s proposal to 

fully adopt NSPS OOOO.

3.b. Regulation Number 6, Part A

The Division will request that the Commission set a rulemaking hearing to consider 

proposed changes to Regulation 6, Part A to fully incorporate by reference NSPS OOOO, 

including recent amendments and the provisions not incorporated during the partial adoption 

(natural gas well green completion provisions and requirements for affected facilities below 

current reporting and permitting thresholds).

3.c. Regulation Number 7

The Division will request that the Commission set a rulemaking hearing to consider 

proposed changes to Regulation 7 to enhance the condensate tank control requirements and 

to address differences and overlaps with NSPS OOOO as incorporated into Regulation 

Number 6, Part A. The Division is also proposing revisions to Regulation Number 7 that 

establish controls and requirements for oil and natural gas operations that exceed the 

requirements in NSPS OOOO.

Once the Division completes its presentation and responds to Commissioners’ questions, public 

comments can be offered. The Commission has allotted 90 minutes for public comment on this 

agenda item and requests that individuals and groups each provide comments within a three 

minute period. Any handouts for the Commission should be directly provided to Commission

staff or submitted via email at cdphe.aqcc-comments@state.co.us (please be sure to put in the 

subject line “presentation”).

Please note that all comments provided to the Commission and Division prior to or at this 

meeting are for the general benefit of the Commission but will not be included in the record of 

any rulemaking for these proposals. Comments for the record must be submitted according to the 

provisions of a “Notice of Rulemaking Hearing” which becomes effective upon publication by 

the Secretary of State.

Commissioner motions to set a rulemaking hearing for the proposed revisions to Regulation 

Number 3, Parts A, B, C; Regulation Number 6, Part A; and Regulation Number 7 will then be 

entertained.
3

WORKING SESSION

4. Climate Change and Greenhouse Gas Workgroup

(120 minutes discussion)

• Professor Scott Denning from Colorado State University will provide his perspectives on 

the science of global climate change and solutions

• Patrick Cummins Executive Director, Western Climate Initiative, Inc. will provide an

overview of WCI’s efforts and recent developments to reduce GHG emissions in the 

West

• The Commission Administrator will describe the analysis required for proposed 

regulations that are considered to be “more stringent than federal requirements”

• The Commission Administrator will describe “economic impact analysis” requirements 

for any proposed regulation

• Public Comment

PUBLIC HEARING

5. Designations for PM2.5 Annual Standard

(15 minutes presentation, 10 minutes discussion)

On December 14, 2012, the U.S. Environmental Protection Agency revised the annual 

National Ambient Air Quality Standard (NAAQS) for fine particulate matter (PM2.5), 

lowering the annual standard to 12 μg/m3

. As a result, states are required to submit area 

designations to EPA by December 12, 2013. The Division is proposing that the entire state, 

except for tribal lands, be designated as attainment/unclassifiable.

BRIEFINGS, DISCUSSIONS AND REPORTS

6. Regulation Number 9: Annual Update

(15 minutes presentation, 15 minutes discussion)

The Division will provide an annual update to the Commission on the projected costs for the 

Smoke Management Program.

7. Commissioner Informational Items

Commissioners are invited to discuss activities that they have participated in over the past 

month and any issues relevant to Commission business.

8. Division Director’s Report – Will Allison

• Monthly activities report

9. Attorney General’s Report – Tom Roan

• Update of any recent court actions on air quality issues

10. Administrator’s Report – Mike Silverstein

• Review of Action Items from today’s meeting

• There will be no December meeting of the Commission; the January meeting agenda will 

be devoted to Climate Change and Greenhouse Workgroup activities

Adjourn
The Denver Newspaper Agency 

PUBLISHER'S AFFIDAVIT 

City and County of Denver 

State of Colorado 

The undersigned Jean Birch 

being first duly sworn under oath, states 

and affirms as follows: 

1. He/she is the legal Advertising Reviewer 

of the Denver Newspaper Agency, publisher 

of The Denver Post and Your Hub. 

2. The Denver Post and Your Hub are 

newspapers of general circulation that 

have been published continuously and 

without interruption for at least 

fifty-two weeks in Denver County 

and meet the legal requisites for a legal 

newspaper under Colo. Rev. Stat. 24-70-103. 

3. The notice that is attached hereto 

is a true copy, published in The Denver Post 

on the following date(s): 

C_ Aj4..t7)C-3-1/D-z71 3_ 

4674 

Signature 

Subscribed and sworn to before me this 3 

day of September 2013. 

J2,6k t 

Notary Public 

JAMIE LYNN KITTELSON 

NOTARY PUBLIC 

STATE OF COLORADO 

NOTARY ID 20054026395 

MY COMMISSION EXPIRES JULY 6, 2017 

(SEAL) 

Notice of Public and Rulemaking Hearings 

and Public Comment Hearings 

PUBLISH 08/31/13 

The Colorado Air Quality Control Commission will hold the following 

Adjudicatory Hearings: 

DATE: October 17,2013 

TIME: 9:00 AM 

PLACE: Colorado Department of Public Health and Environment 

4300 Cherry Creek Drive South - Sabin Conference Room 

Denver, CO 80246 

Tarango 

The Commission will consider the petition for appeal submitted by 

Tarango Inc., Charles E. Counts regarding a Notice of Violation 

and Demand for Payment issued by the Air Pollution Control Division for violation of Regulation Number 3, Parts A and B and Regulation Number 7. 

Tullio Environmental Services 

The Commission will consider a Request for Adjudicatory Hearing 

submitted by Tullio Environmental Services regarding compliance orders and assessments of civil penalties issued by the Air 

Pollution Control Division for violation of Regulation Number 8, 

Part B. 

The Colorado Air Quality Control Commission will hold the following 

Rulemaking Hearing: 

DATE: November 21,2013 TIME: 9:00 AM 

PLACE: Colorado Department of Public Health and Environment 

4300 Cherry Creek Drive South - Sabin Conference Room 

Denver, CO 80246 

Regulation Number 11 

The Commission will consider revisions to Regulation Number 11 to 

amend language that will clarify provisions contained in the existing regulation concerning model year exemptions and program 

implementation dates, updating the listed repair waiver cost limit 

from $450 to the currently used $715 limit, modifying qualification 

criteria used to grant an economic hardship waiver, and incorporating a new Test Analyzer Specification for On-board Diagnostics in Appendix A. 

The Colorado Air Quality Control Commission will hold the following 

Adjudicatory Hearing: 

DATE: November 21,2013 

TIME: 9:00 AM 

PLACE: Colorado Department of Public Health and Environment 

4300 Cherry Creek Drive South - Sabin Conference Room 

Denver, CO 80246 

PDC Energy Inc. 

The Commission will consider the petition for appeal of the compliance determinations and assessment of civil penalties issued to 

PDC Energy Inc. by the Air Pollution Control Division on June 27, 2013 and June 28, 2013 regarding the requirements of .Regulation Number 7. 
Procedural Documents of the Commission

- Agenda Item Control Sheet

- Memorandum of Notice

- Economic Impact Analysis (initial and final)

- Fact Sheet






Regulation Number 11 Memorandum of Notice 

Submitted August 1, 2013 Page 1

Memorandum of Notice

Regulation Number 11 Motor Vehicle Emissions Inspection Program

August 15, 2013

Explanation of the Proposed Rule:

The proposed rule will clarify certain provisions contained in Regulation Number 11. 

Specifically they will clarify, amplify, and streamline the rule in support of recent 

changes that have been made to the Automobile Inspection and Readjustment Program.

There are six changes that are being proposed. They are as follows:

A. Revise Part A I.C.3.c. to clarify that the seven year new vehicle exemption applies 

retroactively to existing vehicles in their fourth, fifth, and sixth years of service.

B. Clarify that the seven year new vehicle exemption, OBD testing, and other changes made to 

the rule in December 2012 go into effect January 1, 2015.

C. The emissions inspection contract is currently out for bid for program continuation for the 

2015-2019 timeframe. If an alternative proposal for a clean screen remote sensing program 

is submitted and that bid is awarded, various clean screen program sections in Part C and Part 

F will need to be modified, to accommodate a different technology and different operating 

procedures. This is not expected to affect vehicle owners, only the inspection contractor.

D. Modify Part C section VIII.D.4 regarding qualifying criteria for an economic hardship 

waiver, to allow a household to own two vehicles, rather than restricting hardship waivers to 

households owning only one vehicle.

E. Amend Appendix A, attachment IV “Colorado Department of Public Health and 

Environment Specification for Colorado 97 Analyzer” to include a new Test Analyzer 

Specification for On-board Diagnostics for licensed fleets who self-inspect their own 

vehicles. Note: Part B section X requires this Test Analyzer Specification to be in place by 

December 31, 2013.

F. Codify in regulation the repair cost waiver amount of $715 in Part C VIII.B.3. The 

Commission directed the Division to change the amount from $450 to $715 in November 

2002, which was done. However retaining the $450 amount language in rule creates conflict 

and dissent, since there is no place in rule staff can point to that says the cost limit is $715.
Regulation Number 11 Memorandum of Notice 

Submitted August 1, 2013 Page 2

These proposed changes will allow the public and regulated parties to more easily understand the 

provisions contained in Regulation No. 11, and their interpretation. None have any addition cost 

to the public or to the state. Nor is there any additional administrative effort or workload 

associated with these proposed changes. Other non-substantive housekeeping modifications are 

also included in these revisions.

The proposed rule was developed under existing statutory authority.

Disclosure of materials contained within the proposed rule:

Most of the proposed modifications to Regulation No. 11 are interpretive or clarifying in nature 

and do not substantively change Regulation No. 11. The one area of substantive change is the 

inclusion in the rule’s appendix of a proposed technical specification for an On-board 

Diagnostics Test Analyzer System.

The Division internally developed a technical specification for an On-board Diagnostics Test 

Analyzer System to be incorporated as an Appendix A, attachment 4, to this rule. Regulation 

No. 11, Part B, section X requires this Test Analyzer Specification to be in place by December 

31, 2013.

Problem Identification/Resolution:

It has been identified that there is some ambiguity about the meaning of certain requirements 

contained in Regulation No.11, especially concerning model-year exemptions and revised 

program start dates. The proposed changes clarify these issues.

The $715 repair waiver was authorized by the Commission, but is not stated in the regulation. A 

proposed modification replaces the mentioned $450 minimum waiver amount mentioned in the 

regulation, with the actual $715.

Additionally there is a proposed change in regards to the hardship waiver. In the past this has 

been limited to families owning one vehicle. At the suggestion of the Department of Revenue 

AIR Program staff this is being recommended to be expanded to a family owning up to two 

vehicles. This is expected to increase the number of hardship waivers from the 225 approved in 

2012 to approximately 280.

Finally, Regulation No. 11, Part B, section X requires that a Test Analyzer Specification be 

included into Regulation No. 11 by December 31, 2013.

Meeting Plan
Regulation Number 11 Memorandum of Notice 

Submitted August 1, 2013 Page 3

The proposed changes to Regulation No. 11 are thought to be non controversial and limited in 

scope. The Division does not currently plan to hold additional meetings on the proposed 

revisions outside of the pre-hearing process.

Process to Develop Proposed Rule

The proposed rule was developed by the Air Pollution Control Division under the specific 

direction of the Commission. 

Differences with Adjacent States/Federal Program

Utah has four county-operated Inspection and Maintenance programs, each being slightly 

different. OBD inspections are the rule for 1996 and newer vehicles in three of four counties, the 

fourth county uses OBD for 1998 and newer. For older vehicles, three counties utilize two-speed 

idle tailpipe testing, while the fourth county utilizes the ASM (Acceleration Simulation Mode) 

test cycle.

Arizona has two separate IM programs, both employ OBD for 1996 and newer vehicles. The 

Phoenix program utilizes an IM147 test (the second phase of the IM240) for 1981 – 1995 

vehicles. Older vehicles in Phoenix, and all 1995 and older vehicles in the Tucson program 

utilize the two-speed idle test.

New Mexico’s I/M Program utilizes OBD for all 1996 and newer vehicles, with a two speed idle 

test for all 1995 and older.

Federal EPA guidance and regulations strongly promote the use of OBD testing for all 1996 and 

newer vehicles. However these same rules and guidance documents allow for tailpipe testing. 

Rule Implementation 

The proposed revisions will be implemented with existing staff resources as part of normal 

administration of the AIR Program.

Initial Economic Impact Analysis

The initial economic impact analysis is contained as an attachment elsewhere in this packet.

Contacts

Primary Contact:
Regulation Number 11 Memorandum of Notice 

Submitted August 1, 2013 Page 4

Doug Decker, Mobile Sources Director

Air Pollution Control Division

CO Department of Public Health and Environment

(303) 692-3126

Secondary Contact:

Garrison Kaufman, Deputy Director

Air Pollution Control Division

CO Department of Public health and Environment

(303) 692-3269

No Action Analysis

Should the commission take no action on the proposed rule, the current vehicle emissions 

inspection program will continue to operate in its present form. 
Initial Economic Impact Analysis 

Submitted August 15, 2013 Page 1

INTIAL ECONOMIC IMPACT ANALYSIS

Per C.R.S. 25-7-110.5(4)(c)(I)

for 

Revisions to AQCC Regulation Number 11: 

Motor Vehicle Emissions Inspection Program

August 15, 2013

INTRODUCTION

The Division has prepared this initial economic impact analysis to better quantify the 

economic impacts of proposed changes to the existing vehicle emissions Inspection 

Maintenance (IM) program.

Modifications to Regulation Number 11 being proposed are:

A. Revise Part A I.C.3.c. to clarify that the seven year new vehicle exemption applies 

retroactively to existing vehicles in their fourth, fifth, and sixth years of service.

B. Clarify that the seven year new vehicle exemption, OBD testing, and other 

changes made to the rule in December 2012 go into effect January 1, 2015.

C. The emissions inspection contract is currently out for bid for program 

continuation for the 2015-2019 timeframe. If an alternative proposal for a clean 

screen remote sensing program is submitted and that bid is awarded, various clean 

screen program sections in Part C and Part F will need to be modified, to 

accommodate a different technology and different operating procedures. This is 

not expected to affect vehicle owners, only the inspection contractor.

D. Modify Part C section VIII.D.4 regarding qualifying criteria for an economic 

hardship waiver, to allow a household to own two vehicles, rather than restricting 

hardship waivers to households owning only one vehicle.

E. Amend Appendix A, attachment IV “Colorado Department of Public Health and 

Environment Specification for Colorado 97 Analyzer” to include a new Test 

Analyzer Specification for On-board Diagnostics for licensed fleets who selfinspect their own vehicles. Note: Part B section X requires this Test Analyzer 

Specification to be in place by December 31, 2013.

F. Codify in regulation the repair cost waiver amount of $715 in Part C VIII.B.3. 

The Commission directed the Division to change the amount from $450 to $715 

in November 2002, which was done. However retaining the $450 amount 

language in rule creates conflict and dissent, since there is no place in rule staff 

can point to that says the cost limit is $715.
Initial Economic Impact Analysis 

Submitted August 15, 2013 Page 2

All of the proposed modifications with the exceptions of item D, and possibly C, are 

technical in nature and have no impact on program costs or air quality benefit. Item C is 

not subject to this regulatory action (at this point) and therefore is not discussed in this 

draft analysis, but could be subject to any final economic impact analysis.

Item D (hardship waivers) is the only item that is thought to have any costs or cost 

savings associated with it at this point, and so is the only item to be further analyzed.

Expanding Number of Family Owned Vehicles for Hardship Waivers

Currently to receive a hardship waiver from emissions inspection repair requirements, a 

person is limited to owning only one vehicle. This has resulted in some families being 

denied a hardship waiver, when they own more than one vehicle.

For many families this is a burden, since members of a family may individually have jobs 

that require each member to have access to a vehicle. Denying a hardship waiver may 

result in the family being reduced to the operation of one vehicle, thus incurring practical

hardship in maintaining two or more jobs for the two (or more) family members.

Number of Hardship Waivers Issued

Using AIR Program results for 2012, there were 225 hardship waivers issued. It is 

expected that this number will increase to 280 when expanding the number of vehicles a 

family may own and still qualify for a hardship waiver, based on the number of families 

denied a hardship waiver due to multiple vehicle ownership. The proposed modification 

will thus result in an increase of 55 hardship waivers.

Cost Savings

The average cost of repair for a vehicle failing an IM240 exhaust emissions inspection 

was $320.81. Assuming an additional 55 hardship waivers are issued, and they all fail for 

excess exhaust emissions, there will be a savings of $17,644.55 in repair costs. However, 

vehicles failing exhaust emissions cutpoints demonstrate decreased fuel economy. In 

2012 this averaged $179.79 in increased fuel costs per vehicle over the two year 

inspection cycle.

Based upon this, it is expected that expanding the number of vehicles eligible for a 

hardship waiver to two vehicles per household, will result in a cost savings of $7756.10 

over the two year waiver period. However, the direct out-of-pocket savings would be 

only the cost of repair, and so would be $17,644.55.
Initial Economic Impact Analysis 

Submitted August 15, 2013 Page 3

It is assumed in this analysis that not properly repairing the vehicle will not result in 

further damage to the vehicle. In reality neglected or deferred repairs quite probably 

result in further vehicle degradation and damage, negating any cost savings.

Air Quality Impact

Vehicles that fail their emissions test generally have higher emissions than vehicles that 

pass. Issuing a hardship waiver in many cases prevents this vehicle from being properly

repaired. Not repairing hardship waiver vehicles results in continued excess emissions 

from these vehicles.

To calculate what these excess emissions are, this analysis utilizes the average emissions 

difference between vehicles failing the exhaust emissions portion of the IM240 

inspection versus the average emissions of vehicles failing and then passing an IM240 

retest after repair. It is assumed in this analysis that hardship wavered vehicles have 

average failing vehicle emissions. 

Table 1 shows the average emissions from all vehicles that fail their initial I/M240 

inspections and pass a subsequent retest, including the percent reduction by pollutant and 

vehicle type.

Table 1 – Passed Retest Inspection Results (2012)

Vehicle 

Type

Failed Initial Inspection Passed Retest Percent Reduction

HC 

gpm

CO 

gpm

NOx 

gpm

HC 

gpm

CO 

gpm

NOx 

gpm

HC CO NOx

Cars 1.58 19.43 1.78 0.36 4.21 0.82 67.40 70.53 43.13

Trucks 2.00 24.17 2.42 0.55 6.40 1.28 59.61 62.70 35.31

TOTAL 1.81 22.00 2.13 0.46 5.40 1.07 62.74 65.93 38.28

Utilizing 2012 program statistics and an average VMT of 18.12 miles per day for each 

vehicle, it is calculated that the additional 55 hardship waivers will result in increase

emissions of, 2.97 pounds per day of HC, 36.47 pounds per day for carbon monoxide, 

and 2.33 pounds per day for nitrogen oxides. Combining these emissions into an average 

ozone precursor (HC + 1/60 CO + NOx) results in 5.91additional pounds of ozone 

precursors a day, a negligible amount. This is easily within the error band of this 

analysis, so is stated to be zero.

COST EFFECTIVENESS ANALYSIS

As detailed above, the small amount of overall cost savings and emissions involved in 

this analysis, it is difficult to categorically come up with a more specific cost 

effectiveness for this analysis. 
Final Economic Impact Analysis 

Submitted November 21, 2013 Page 1

FINAL ECONOMIC IMPACT ANALYSIS

Per C.R.S. 25-7-110.5(4)(c)(I)

for 

Revisions to AQCC Regulation Number 11: 

Motor Vehicle Emissions Inspection Program

November 21, 2013

INTRODUCTION

The Division has prepared this final economic impact analysis to better quantify the 

economic impacts of proposed changes to the existing vehicle emissions Inspection 

Maintenance (IM) program.

Modifications to Regulation Number 11 being proposed are:

A. Revise Part A I.C.3.c., to clarify that the seven year new vehicle exemption (as 

adopted by the Commission December 2012) takes effect January 1, 2015, and 

that this exemption applies retroactively to existing vehicles in their fourth, fifth

and sixth years of service.

B. Revise Part A I.C.8; I.C.9; and I.C.10, to clarify ambiguous, contradictory and 

obsolete rule language concerning issuance of, and duration periods for 

Verification of Emissions Test exemption windshield stickers issued by vehicle 

dealers. I.C.8 further clarifies that vehicles in their fourth fifth, and sixth years of 

service will have the seven year exemption applied retroactively. 

C. Clarify that the seven year new vehicle exemption, OBD testing, and other 

changes made to the rule in December 2012 go into effect January 1, 2015, while 

retaining the current visual inspection procedures through December 2014. (Part 

A I.C.3, Part C III and IV.)

D. Codify in regulation the repair cost waiver amount of $715 in Part C VIII.B.3. 

The Commission directed the Division to change the amount from $450 to $715 

in November 2002, which was done. However the Commission at that time 

declined to note the changed amount in the text of the rule.

E. Modify Part C section VIII.D.4 regarding qualifying criteria for an economic 

hardship waiver, to allow a household to own two vehicles, rather than restricting 

hardship waivers to households owning only one vehicle.

F. Amend Appendix A as follows:
Final Economic Impact Analysis 

Submitted November 21, 2013 Page 2

a. Removing the text of obsolete technical specifications in attachments I, II, 

and III to be incorporated by reference; 

b. Updating attachment IV “Colorado Department of Public Health and 

Environment Specification for Colorado 97 Analyzer” to reflect 

technological changes to data specifications, communications protocols, 

and forms generation.

c. Including a new Attachment V “Test Analyzer Specification for On-board 

Diagnostics” for licensed fleets who self-inspect their own vehicles. 

Note: Part B section X requires this Test Analyzer Specification to be in 

place by December 31, 2013.

G. Appendix B, Attachment II Calibration Span gas labels have been updated to 

show the current version of the official labels.

H. Formatting and other non-substantive changes have been made throughout the 

proposed rule.

All of the proposed modifications with the exception of item E are technical in nature and 

have no impact on program costs or air quality benefit.

Item E (hardship waivers) is the only item that is thought to have any costs or cost 

savings associated with it, and so is the only item to be further analyzed.

Expanding Number of Family Owned Vehicles for Hardship Waivers

Currently to receive a hardship waiver from emissions inspection repair requirements, a 

person is limited to owning only one vehicle. This has resulted in some families being 

denied a hardship waiver, when they own more than one vehicle.

For many families this is a burden, since members of a family may individually have jobs 

that require each member to have access to a vehicle. Denying a hardship waiver may 

result in the family being reduced to the operation of one vehicle, thus incurring practical

hardship in maintaining two or more jobs for the two (or more) family members.

Number of Hardship Waivers Issued

Using AIR Program results for 2012, there were 225 hardship waivers issued. Based on 

the number of families denied a hardship waiver in 2012 due to multiple vehicle 

ownership, it is expected that this number will increase by 55 vehicles to 280 when 

expanding the number of vehicles a family may own and still qualify for a hardship 

waiver. .
Final Economic Impact Analysis 

Submitted November 21, 2013 Page 3

Cost Savings

The average cost of repair for a vehicle failing an IM240 exhaust emissions inspection 

was $320.81. Assuming an additional 55 hardship waivers are issued, and they all fail for 

excess exhaust emissions, there will be a total savings of $17,644.55 in repair costs over 

the 55 vehicles. However, vehicles failing exhaust emissions cutpoints demonstrate 

decreased fuel economy. In 2012 this averaged $179.79 in increased fuel costs per 

vehicle over the two year inspection cycle.

Based upon this, it is expected that expanding the number of vehicles eligible for a 

hardship waiver to two vehicles per household, will result in a cost savings of $7756.10 

over the two year waiver period. However, the direct out-of-pocket savings would be 

only the cost of repair, and so would be $17,644.55.

It is assumed in this analysis that not properly repairing the vehicle will not result in 

further damage to the vehicle. In reality neglected or deferred repairs quite probably 

result in further vehicle degradation and damage, negating any cost savings.

Air Quality Impact

Vehicles that fail their emissions test generally have higher emissions than vehicles that 

pass. Issuing a hardship waiver in many cases prevents this vehicle from being properly

repaired. Not repairing hardship waiver vehicles results in continued excess emissions 

from these vehicles.

To calculate these excess emissions, this analysis utilizes the average emissions 

difference between vehicles failing the exhaust emissions portion of the IM240 

inspection versus the average emissions of vehicles failing and then passing an IM240 

retest after repair. It is assumed in this analysis that hardship waivered vehicles have 

average failing vehicle emissions. 

Table 1 shows the average emissions from all vehicles that fail their initial I/M240 

inspections and pass a subsequent retest, including the percent reduction by pollutant and 

vehicle type.
Final Economic Impact Analysis 

Submitted November 21, 2013 Page 4

Table 1 – Passed Retest Inspection Results (2012)

Vehicle 

Type

Failed Initial Inspection Passed Retest Percent Reduction

HC 

gpm

CO 

gpm

NOx 

gpm

HC 

gpm

CO 

gpm

NOx 

gpm

HC CO NOx

Cars 1.58 19.43 1.78 0.36 4.21 0.82 67.40 70.53 43.13

Trucks 2.00 24.17 2.42 0.55 6.40 1.28 59.61 62.70 35.31

TOTAL 1.81 22.00 2.13 0.46 5.40 1.07 62.74 65.93 38.28

Utilizing 2012 program statistics and an average VMT of 18.12 miles per day for each 

vehicle, it is calculated that the additional 55 hardship waivers will result in a total 

increase emissions of 2.97 pounds per day of HC, 36.47 pounds per day for carbon 

monoxide, and 2.33 pounds per day for nitrogen oxides. Combining these emissions into 

an average ozone precursor (HC + 1/60 CO + NOx) results in 5.91additional pounds of 

ozone precursors a day, a negligible amount. This is easily within the error band of this 

analysis, so is stated to be zero.

COST EFFECTIVENESS ANALYSIS

As detailed above, the small amount of overall cost savings and emissions involved in 

this analysis, it is difficult to categorically come up with a cost effectiveness for this 

analysis.
Proposed Rule Language – Revisions to Regulation Number 11

Clarify and codify existing Rules – Implementation dates, waivers, OBD TAS, etc

Highlighted sections are new from 8/13 Request published ver.

Page Part/Section Change

1 TOC added Appendix A and B

2 A I.B 2nd para SOS version error – no change from current

3 A I.C.3.c Effective date for 7 Model year exemption

4-5 A I.C.8 Exemption is retroactive for years 4,5,& 6 some

new text, some from SOS version

6 A II.20 OBD Test Analyzer System defined

20-21 C III. Interim 1996 & newer OBD/Visual still in effect

(Div error from 8/5 version)

21 C IV. SOS version error- Effective date for OBD 

testing

23 C VIII.B.3 Repair Waiver amount $715

25 C VIII.D.4 Hardship waiver – two cars allowed

30 D I.B.1 OBD TAS

31 D I.B.15 OBD TAS – Div error from 8/5 version

40 H Stmt of Basis New SBP with changes

59-113 Appendix A Att I, II, III, and IV Incorporate by ref

118 Appendix A Att IV sect 2.1 Add “or” to read “And/or”

119 Appendix A Att IV sect 3.1 SOS error – retain existing sentence

120-125 Appendix A Att IV Revised headers & replaced w/new forms

125-133 Appendix A Att V New; OBD TAS specification

133-150 Appendix B Formatting corrections

149-150 Appendix B New span gas labels (in SOS version)

Typographic, formatting and grammatical corrections throughout the document are not noted here.
Parties Hearing Documents

− None Submitted
EPA Comments

40 CFR Part 51 Appendix V 2.1(h)

− None Submitted
Public Comments

40 CFR Part 51 Appendix V 2.1(h)

− None Submitted
Adopted Statement of Basis,

Specific Statutory Authority and Purpose 
XXXI. AMENDMENTS

ADOPTED NOVEMBER 21, 2013

This revision to Regulation Number 11 is to amend language that will clarify provisions contained in the 

existing regulation concerning model year exemptions and program implementation dates, updating the 

listed repair waiver cost limit from $450 to the currently used $715 limit, modifying qualification criteria 

used to grant an economic hardship waiver, and incorporating a new Test Analyzer Specification for Onboard Diagnostics in Appendix A. Obsolete technical specifications and procedures are being deleted 

and formatting, grammatical and typographical corrections are being made.

This Statement of Basis, Specific Statutory Authority, and Purpose complies with the requirements of the 

Colorado Administrative Procedures Act, Section 24-4-103, C.R.S., and the statutory authority provided in 

Sections 42-4-301 through 42-4-316, C.R.S.

Basis and Purpose

The Commission’s November 2013 amendments are intended to clarify, amplify, and streamline the rule 

in support of previous recent changes to the Automobile Inspection and Readjustment Program. The 

proposed modifications are considered minor and will not result in any significant change in program 

costs or air quality benefits.

The basis of these modifications is to address any ambiguities that may exist in the interpretation of new 

program changes, as well as add a new Test Analyzer Specification for On-board Diagnostics as required 

by Regulation Number 11, Part B, Section X.

Federal Requirements

The current inspection and maintenance program is contained in Colorado’s ozone State Implementation 

Plan (SIP), with the exception of Larimer and Weld Counties in the North Front Range. Any revision to 

the program requires that air quality credits achieved from the program are not lost.

In general, EPA rules require certain nonattainment areas implement Inspection and Maintenance 

programs as part of a SIP. Under the Clean Air Amendments of 1990, the Denver metropolitan area was 

required to implement an “Enhanced” IM Program, specifically for carbon monoxide. Since that time, the 

state has come into attainment with carbon monoxide, but the program remains a necessary element of 

Colorado’s ozone SIP. The North Front Range area of the program operates as a state-only program

Specific Statutory Authority

Sections 42-4-306 and 42-4-310, C.R.S. authorize the Air Quality Control Commission (“Commission”) to 

promulgate rules for inspection of motor vehicle emissions. Section 42-4-306(8) authorizes the 

Commission to exempt motor vehicles from emission inspections. Section 42-4-306(3)(b)(V)(B) 

authorizes the Commission to promulgate rules for alternative motor vehicle emission inspections, 

including on-board diagnostics (OBD) inspections. 42-4-306(6)(a) authorizes the Commission to 

promulgate rules on inspection procedures, including those related to OBD and evaporative gases. 

Findings Pursuant to 25-7-110.8, C.R.S.

The revision of the rule is to clarify provisions contained in rule or that are administrative in nature. These 

changes do not increase the regulatory burden on the motoring public, while maintaining the current air 

quality benefits received from the program, in a cost effective manner, at similar or minimally reduced 

costs to the current program.
The rule revision is based on reasonably available, validated, reviewed, and sound scientific 

methodologies. All validated, reviewed, and sound scientific methodologies and information made 

available by interested parties has been considered. Evidence in the record supports the finding that the 

rule shall result in a continued demonstrable reduction in air pollution. The rule revision is the most costeffective alternative, provides the regulated community flexibility, and achieves the necessary reduction in 

air pollution. The revised rule will maximize the air quality benefits of the regulation in the most costeffective manner.
Adopted Language by the Commission

(in redline & footer noting adoption date and page numbers)
Regulation Number 11

Adopted: November 21, 2013 Page 1

DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT

Air Quality Control Commission

REGULATION NUMBER 11

MOTOR VEHICLE EMISSIONS INSPECTION PROGRAM

5 CCR 1001-13

PART A: General Provisions, Area of Applicability, and Schedules for Obtaining Certification of 

Emissions Control, Definitions, Exemptions, and Clean Screen/Remote Sensing

PART B: Standards and Procedures for the Approval, Operations, Gas Span Adjustment, 

Calibration and Certification of the Air Pollution Control Division (Division) Approved Test 

Analyzer Systems for Use in the Basic and Enhanced Program Areas, Test Analyzer Systems for 

Licensed Dealers in the Enhanced Area, and Clean Screen Test Analyzer Systems

PART C: Inspection Procedures and Requirements for Exhaust Emissions, Fuel Evaporation 

Control, Visible Smoke Emissions, Emissions Control Systems, On-Board Diagnostics Clean 

Screening; and Practices to Ensure Proper Emissions Related Adjustments and Repairs

PART D: Qualification and Licensing of Emissions Mechanics, Emissions Inspectors, and Clean 

Screen Inspectors; Licensing of Emissions Inspection and Readjustment Stations, InspectionOnly Stations, Inspection-Only Facilities, Fleets, Motor Vehicle Dealer Test Facilities and 

Enhanced Inspection Centers, Clean Screen Inspection Sites; and Registration of Emissions 

Related Repair Facilities and Technicians

PART E: Prohibited Acts and Penalties to Ensure Proper Inspection Procedures, Adherence to 

Prescribed Procedures and Effective Emissions Related Repairs

PART F: Maximum Allowable Emissions Limits for Motor Vehicle Exhaust, Evaporative and Visible 

Emissions for Light-Duty and Heavy-Duty Vehicles

PART G: Reserved

PART H: Statements of Basis, Specific Statutory Authority and Purpose

APPENDIX A: Technical Specifications

APPENDIX B: Standards and Specification for Calibration/Span Gas Suppliers

REFERENCES

Pursuant to Section 24-4-103 (12.5), C.R.S., material incorporated by reference is available during 

normal working hours, or copies may be obtained at a reasonable cost, from the Technical Secretary of 

the Air Quality Control Commission c/o the Colorado Department of Public Health and Environment, 4300 

Cherry Creek Drive South, Denver, Colorado 80246-1530 or material incorporated by reference within 

this regulation may be examined at any state publications depository library. References do not include 

later amendments to or additions of incorporated material.
Regulation Number 11

Adopted: November 21, 2013 Page 2

PART A General Provisions, Area of Applicability, Schedules for Obtaining Certification of 

Emissions Control, Definitions, Exemptions, and Clean Screening/Remote Sensing

I. APPLICABILITY

Subject to the provisions described in Sections I.A and I.B of this Part A and pursuant to the schedule in 

Section I.C. and V.B. of this Part A, all non-diesel fueled motor vehicles which are registered in the AIR 

Program area or which motor vehicle is owned or operated by a non-resident who meets the 

requirements of Section, 42-4-310(1)(c)(I), C.R.S., will be subject to On-Board Diagnostics and/or an 

exhaust and evaporative emissions, smoke opacity and emissions control, equipment inspection as a 

prerequisite to initial or renewal of the vehicle registration. Any person owning or operating a business 

and any post-secondary educational institution located in the program area as defined in Subsection A of 

this section shall annually inform by written notice all persons employed by such business or attending 

classes that they are required to comply with the provisions of this regulation. The provisions of this 

regulation applicable to Larimer and Weld counties shall not be included in the state implementation plan.

I.A. Geographic Areas of Applicability

This regulation shall apply to the AIR Program area as defined in Section 42-4-304(20), C.R.S. as 

amended by Senate Bill 09-003.

I.B. Vehicles Eligible for AIR Program Inspection Procedures.

This regulation shall apply to all motor vehicles as defined in Section 42-4-304(18), C.R.S.

Vehicles that are registered in a program area and are being operated outside such area but 

within another program area shall comply with the requirements of the area where such vehicles 

are being operated. Vehicles registered in a program area that are is being temporarily operated 

outside the state at the time of registration or registration renewal may apply to the department of 

revenue for a temporary exemption from program requirements. Upon return to the program 

area, such vehicles must be in compliance with all requirements within fifteen days. A temporary 

exemption shall not be granted if the vehicle will be operated in an emissions testing area in 

another state unless proof of emissions from that area is submitted.

Pursuant to Section, 42-4-310(1)(c)(I), C.R.S. motorists operating vehicles in the enhanced 

program area shall comply with the provisions of the enhanced program.

The burden of proof in establishing an exemption from inclusion in all or any part of the AIR 

Program inspection requirements is on the vehicle owner.

I.C. Schedules for Obtaining Certifications of Emissions Control

I.C.1. REPEALED

I.C.2. Inspection schedules during calendar year 1995 and thereafter, vehicles are to 

be inspected according to the schedules established in Sections, 42-4-

304(3)(b)(II), and, 42-4-310(1)(b)(II), C.R.S. as amended.

I.C.3. No used vehicle which is required to be registered in the program area shall be 

registered, unless such vehicle has a Certification of Emissions Control, or of 

Emissions Exemption. The seller of a used vehicle is required to obtain a 

Certification of Emissions Control for the new owner at the time of sale. This 
Regulation Number 11

Adopted: November 21, 2013 Page 3

paragraph (3) does not apply to the sale of a motor vehicle that is inoperable or 

otherwise cannot be tested in accordance with this regulation if the seller of the 

motor vehicle provides a written notice to the purchaser pursuant to Section 42-

4-310(4), C.R.S. If a motor vehicle is being registered for the first time in the 

program area, the owner shall obtain the certification and submit it with the 

application for registration to the Department of Revenue or an authorized agent 

of the Department of Revenue.

I.C.3.a. On or after October 1, 1989, no used vehicle which is required to be 

registered in the program area shall be registered, unless such vehicle 

has a Certification of Emissions Control, or of Emissions Exemption. The 

seller of a used vehicle is required to obtain a Certification of Emissions 

Control for the new owner at the time of sale. This paragraph (3) does 

not apply to the sale of a motor vehicle which is inoperable or otherwise 

cannot be tested in accordance with this regulation or that is being sold 

pursuant to Part 18 (Vehicles Abandoned on Public Property) or Part 21 

(Vehicles Abandoned on Private Property) of Article 4 of Title 42, C.R.S. 

if the seller of the motor vehicle provides a written notice to the 

purchaser pursuant to Section 42-4-310(4), C.R.S. If a motor vehicle is 

being registered for the first time in the program area, the owner shall 

obtain the certification and submit it with the application for registration to 

the Department of Revenue or an authorized agent of the Department of 

Revenue.

I.C.3.b. An inspection is not required prior to the sale of a motor vehicle with at 

least twelve months remaining before the vehicle's certification of 

emissions compliance expires if such certification was issued when the 

vehicle was new.

I.C.3.c. Effective January 1, 2015, A a motor vehicle being registered in the 

program area for the first time may be registered without an inspection or 

certification if the vehicle has not yet reached its seventh model year 

pursuant to Section 42-4-310(1)(a)(II)(C)C.R.S.

I.C.4. Any motor vehicle may be voluntarily inspected and a Certification of Emissions 

Control obtained which shall be valid as specified in Section I.C.2. of this Part A.

I.C.5. (Reserved)

I.C.5.a. As it pertains specifically to federally owned or leased vehicles; tactical 

military vehicles are not required to be inspected.

I.C.5.b. Federal installation managers are to declare all federal employee-owned 

vehicles operated on the installation and demonstrate that these vehicles 

have complied with periodic inspection requirements pursuant to 40 CFR 

Section 51.356(A)(4). Inspection results shall be reported to the 

Department of Revenue AIR Program section and up-dated based on 

inspection cycles.

I.C.6. (Reserved)
Regulation Number 11

Adopted: November 21, 2013 Page 4

I.C.7. Fleets of twenty or more eligible vehicles shall be periodically inspected, comply 

with inspection provisions and obtain a Certification of Emissions Control.

I.C.7.a. Fleets may pursue licensing as a fleet inspection station under Part D of 

this Regulation Number 11 pursuant to Section, 42-4-309, C.R.S. and 

comply with the provisions of that section.

I.C.7.b. Fleets may elect to comply with periodic inspection requirements under 

the provisions of Section 42-4-309 (2)(a), C.R.S. to include the 

inspection schedules of Sections 42-4-304(3)(b)(II) and 42-4-

310(1)(b)(II)(a), C.R.S.

I.C.7.c. As it pertains to the fleet vehicles provisions pursuant to Section, 42-4-

309, C.R.S. and this Section I.C.7., municipal fleets of twenty vehicles or 

more may comply with periodic inspection requirements as specified in 

Section 42-4-309(2)(a), C.R.S. to include inspection schedule of 

Sections 42-4-304(3)(b)(II) and 42-4-310 (1)(b)(II)(a), C.R.S.

I.C.8. New motor vehicles being registered with a Manufacturer's Statement of Origin 

(MSO), Manufacturer's Certificate of Origin (MCO) or similar document shall be 

issued a registration without a Certificate of Emissions Control.

Such new motor vehicles are to be issued a Verification of Emissions Test exemption 

windshield sticker at the time of sale and valid for up tothat shall be valid for a period of

seven (7) years. The selling dealer is responsible for obtaining the Verification of 

Emissions Test.

New vehicles under this section shall also include those new vehicles leased under an 

MSO or MCO or similar document and seven years without an inspection. Such new 

leased vehicles are to be issued a Verification of Emissions Test exemption windshield 

sticker at the time of initiation of the lease that shall be valid for a period of seven (7) 

years.

After the seventh year or a transfer of ownership, such vehicles shall be issued a 

registration only with a Certificate of Emissions Control. The inspection schedule for 

these vehicles shall then revert to a biennial inspection cycle.

A used motor vehicle may be registered in the program area without an inspection if, on 

the date of vehicle registration, at least twelve months remain before the expiration of the 

Verification of Emissions Test exemption if such certification was issued when the vehicle 

was new.

Effective January 1, 2015 vehicles that were originally issued a Verification of Emissions 

Test exemption windshield sticker at the time of new vehicle sale that was valid for a 

period of four years shall have that time period extended to seven years.

I.C.9.a. Compliance with AIR Program inspection requirements will not be 

required for wholesale transactions between motor vehicle dealers 

licensed pursuant to Article 6 of Title 12, C.R.S.
Regulation Number 11

Adopted: November 21, 2013 Page 5

I.C.9.b. Motor vehicle dealers shall have motor vehicles inventoried or consigned 

for retail sale inspected annually. A further inspection is not required at 

the time of sale if:

i. For a 1982 or later motor vehicle, there are at least twelve 

months remaining before the vehicle's certification of emission 

compliance expires and the dealer has had the vehicle inspected 

since acquiring it. Such a vehicle purchased from a licensed 

motor vehicle dealer may be registered in the program area 

without an inspection if, on the date of vehicle registration, at 

least twelve months remain before the expiration of such 

certification.

ii. For a 1981 or earlier motor vehicle, the vehicle has a valid 

certification of emission compliance and the dealer has had the 

vehicle inspected since acquiring it. Such a vehicle purchased 

from a licensed motor vehicle dealer may be registered in the 

program area without an inspection if, on the date of vehicle 

registration, at least nine months remain before the expiration of 

such certification.

I.C.10. For purposes of Sections 42-4-304(3), 42-4-309(3) and 42-4-310, C.R.S., a 

certificate of emissions Control shall be considered to be issued at the time of 

sale or transfer of a vehicle if such certificate is issued pursuant to an inspection 

conducted no later than the date of such sale or transfer, and no earlier than one 

hundred twenty calendar days prior to such sale or transfer.Reserved

I.C.11. Eligible fleets as defined in Section 42-4-309, C.R.S. that declare not to selfinspect shall be inspected according to the same schedules, subject to the same 

emissions related repair requirements and waiver provisions as non-fleet 

vehicles.

I.C.12. For the purposes of 42-4-309(6)(B) if a vehicle fails the test or is untestable due 

to mechanical and/or electrical/electronic problem, the motorist shall have the 

same recourse as that of not passing an inspection. However, Section 42-4-

309(6), C.R.S. and the regulations implementing such provision, shall not be 

federally enforceable, and shall not be incorporated into the State 

Implementation Plan.

II. DEFINITIONS

1. “Accreditation” means certification that the instrument and instrument manufacturer meet the 

operating criteria specifications and requirements of the Colorado Department of Health, Air 

Quality Control Commissions as specified in Part B of this regulation.

2. “Air Intake Systems” are those systems that allow for the induction of ambient air (to include 

preheated air) into the engine combustion chamber for the purpose of mixing with a fuel for 

combustion.

3. “AIR Program Station” is an Automobile Inspection and Readjustment (AIR) Station that qualifies 

and is licensed to operate as an emissions inspection and readjustment station.
Regulation Number 11

Adopted: November 21, 2013 Page 6

4. “Air System” is a system for providing supplementary air into the vehicle's exhaust system to 

promote further oxidation of HC and CO gases and to assist catalytic reaction.

5. “BAR 90” refer to the California Bureau of Automotive Repair specifications for Exhaust Gas Test 

Analyzer Systems (TAS) that became effective in 1990. “BAR 97” refers to the California Bureau 

of Automotive Repair specifications for Exhaust Gas Test Analyzer Systems

6. “Basic Engine Systems” are those parts or assemblies which provide for the efficient conversion 

of a compressed air/fuel charge into useful power to include but not limited to valve train 

mechanisms, cylinder head to block integrity, piston-ring-cylinder sealing integrity and postcombustion emissions control devise integrity.

(TAS) that became 

effective in 1997.

7. “Calibration” is the process of establishing or verifying the total response curve of an exhaust gas 

analyzer. Calibration is a laboratory procedure using several different calibration gases having 

precisely known concentrations.

8. “Calibration Gases” are gases of precisely known concentration that are usually used in the 

laboratory as references for establishing or verifying the calibration curve of an exhaust gas 

analyzer.

9. “Catalytic Converter” is a post-combustion device that oxidizes HC and CO gases and/or reduces 

oxides of nitrogen.

10. “Certification” means assurance by the authorized source, whether it is a laboratory, the 

manufacturer, or the State, that a specific product or statement is in fact true and meets all 

required accreditation requirements.

11. “Certification of Emissions Control” shall have the same meaning as set forth in Section 42-4-

304(3)(1), C.R.S.

12. “Chlorofluorocarbon” (CFC) is a class I stratospheric ozone depleting compound as listed in 

Appendix A, final rule vol.57.mp 147 Federal Register, 40 CFR Part 82.

13. “Clean Screen Inspection Site” is that location within the program area as defined in Section 42-4-

304(20)(a), C.R.S., approved by the Division and the Department of Revenue.

14. “Clean Screen Inspector” is a person found qualified by the Division, and licensed by the 

Executive Director to operate Clean Screen Inspection equipment.

15. “Clean Screen Program” is that program as defined in Section 42-4-304(3.5), C.R.S.

16. “Clean Screened Vehicle” is a vehicle that is eligible for inspection, has at least two consecutive 

passing remote sensing emissions readings performed on different days or at different approved 

Clean Screen Inspection Sites prior to its registration renewal date, or for vehicles identified as 

low emitters on the low emitting vehicle index, one passing remote sensing reading prior to its 

registration date, and has otherwise complied with the provisions of Section IV of this Part A, 

Section XII of Part C and Section VI of Part F.

17. “Clean Screen Data Manager” is that person or entity that contracts with the state to provide 

clean screen data management functions. This same person or entity may also act as general 

contractor in conducting and facilitating clean screen inspections.
Regulation Number 11

Adopted: November 21, 2013 Page 7

18. “Colorado 94” refers to those test analyzer systems that are based on BAR 90 but modified as 

specified by the Division for use in the AIR Program for the period of time after January 1,1994. 

“Colorado AIR Program BAR 97 Exhaust Gas Analyzer” or Colorado 97” refers to those test 

analyzer systems that are based on BAR 97, but modified as specified by the Division for all fleet 

inspection stations and inspection-only facilities that become licenses after May 1, 2010.

19. “Colorado Automobile Dealer Transient Mode Test Analyzer System” is a dynamometer based 

inspection system capable of performing an inspection grade (IG 240) emissions inspection 

procedure under simulated driving conditions. The procedure is intended for determining the 

compliance status for used vehicles prior to retail sale.

20. “Colorado On-Board Diagnostic (OBD) Test Analyzer System” or “OBD TAS” refers to the 

analytical and testing instrumentation used to verify automotive emissions and to prompt the 

emissions inspector through the elements of an official Colorado OBD emissions inspection.

21. “Compliance” means verification that certain submission data and hardware submitted by a 

manufacturer for accreditation consideration, meet all required accreditation requirements.

22. “Diagnostic Trouble Code (DTC)” is an alpha-numeric code representing a specific fault or 

problem identified by the OBD system on a vehicle. OBD diagnostic trouble codes are 

standardized across all vehicle manufacturers and are defined individually in the Society of 

Automotive Engineers Recommended Practice J2012.

23. “Division” is the Air Pollution Control Division of the Colorado Department of Public Health and 

Environment.

24. “Electrical, Electronic, or Electro-mechanical Span” is the adjustment of an exhaust gas analyzer 

using an electronic signal rather than a calibration or span gas as a reference source.

25. “Emissions Control Systems” are those parts, assemblies or systems originally installed by the 

manufacturer in or on a vehicle for the purpose of reducing emissions.

26. “Estes Park Area” means that part of the program area west of Range 71 West in Larimer 

County.

27. “Executive Director of the Department of Revenue” or “Executive Director” is the representative of 

the Department of Revenue or designee responsible for the field enforcement of the AIR 

Program, licensing of emissions mechanics, clean screen inspectors and inspection stations.

28. “Fuel Control Systems” are those mechanical, electro-mechanical, galvanic or electronic parts or 

assemblies that regulate the air/fuel ratio in an engine for the purpose of providing a combustible 

charge.

29. “Fuel Filler Neck Restrictor system” is the orifice and obstruction (“Flapper Door”) in the gas tank 

filler neck that prevents the insertion of a “leaded gasoline” nozzle and deters the introduction of 

“leaded fuel”.

30. “Gas Span” is the adjustment of an exhaust gas analyzer to correspond with known 

concentrations of span gases.

31. “Gas Span Check” is a procedure using known concentrations of span gases to verify the gas 

span adjustment of an analyzer.
Regulation Number 11

Adopted: November 21, 2013 Page 8

32. “Gross Vehicle Weight (GVW) Rating” is the maximum recommended combined weight of the 

motor vehicle and its load as prescribed by the manufacturer and expressed on a permanent 

identification label affixed to the motor vehicle.

33. “Heavy Duty Vehicles (HDV)” are those motor vehicles for model years 1978 and earlier having a 

GVW rating of greater than 6000 pounds and for model years 1979 and newer, having a GVW 

rating of greater than 8,500 pounds.

34. “Idle Mode” means a condition where the vehicle engine is warm and running at the rate specified 

by the manufacturer's curb idle, where the engine is not propelling the vehicle, and where the 

throttle is in the closed or idle stop position.

35. “Ignition Systems” are those parts or assemblies that are designed to cause and time the ignition 

of a compressed air/fuel charge.

36. “Inspection Area” is the area that is occupied by the analyzer, sample hose and the vehicle being 

inspected.

37. “Inspection-only station” is that licensed station within the basic program area as defined in 

Section 42-4-304(2), C.R.S., which meets the requirements of Section 42-4-308, C.R.S., which 

facility the operator is licensed to operate by the Executive Director as an inspection-only station.

38. “Instrument” is the complete system that samples and reads out the concentration of pollutant HC 

and CO gas plus CO2 gas. The instrument includes the sample handling system, the exhaust gas 

analyzer and the enclosure cabinet.

39. “Light Duty Vehicles (LDV)” are those motor vehicles (to include trucks) for model years 1978 and 

earlier having a GVW rating of 6,000 pounds or less and for model years 1979 and newer having 

a GVW rating of 8,500 pounds or less.

40. “Low Emitting Vehicle Index” refers to a statistical table summarizing the probability of vehicles 

passing the IM 240 inspection. The statistical table will be updated annually by each July 1st. 

The low emitting vehicle index must meet the requirements of Part F, VI.B. based on a tabulation 

of the previous calendar year’s IM 240 inspection program results.

41. “Malfunction Indicator Light (MIL)” is a warning light located on the dash of vehicles equipped with 

On-Board Diagnostic (OBD) systems that notifies the motorist that a malfunction to the vehicle’s 

emissions control system has been detected.

42. “Motor Vehicle Emissions Compliance Inspectors (ECI)” are those persons employed and 

authorized by the Department of Revenue for licensing and enforcement of the AIR Program.

43. “North Front Range Area” is the portion of the Program Area located in Larimer and Weld 

Counties as set forth in Section 42-4-304(20) as amended by Senate Bill 09-003. The North Front 

Range area is a State-Only program and is not part of any State Implementation Plan with the US 

EPA.

44. “On-Board Diagnostics II (OBD or OBDII) Test” means the electronic retrieval of stored readiness 

status, diagnostic trouble codes, malfunction indicator light (MIL) illumination status, and other 

information from a vehicle’s OBD system to determine if any emission related trouble codes are 

present and if the MIL is commanded to be on, which would indicate the existence of an emission 

related malfunction with the vehicle.
Regulation Number 11

Adopted: November 21, 2013 Page 9

45. “Original Condition” means the condition as installed by the manufacturer but not necessarily to 

the original level of effectiveness.

46. “Program Area” is that geographic area defined in Section 42-4-304(20), C.R.S. as amended by 

Senate Bill 09-003.

47. “Registration Renewal Date” is the last day of the month in which the vehicle registration expires 

as defined in Section 42-3-103, C.R.S.

48. “Span Gases” are gases of known concentration used as references to adjust or verify the 

adjustment of an exhaust gas analyzer's span settings.

49. “State Emissions Technical Center Personnel” are those persons employed by or authorized by 

the Department of Health for technical or administrative support of the AIR Program.

50. “Test Analyzer Systems” (TAS) in the context of this regulation is that analytical instrumentation 

used to measure automotive emissions and prompt the operator through other elements of an 

emissions inspection.

51. “True Concentration” is the concentration of the gases of interest as measured by a standardized 

instrument which has been calibrated with 1% precision gases traceable to the National Institute 

for Standards and Technology.

52. “Zero Gas” is a gas, usually air or nitrogen, which is used as a reference for establishing or 

verifying the zero point of an exhaust gas analyzer.

III. EXEMPTION FROM SECTION 42-4-314, C.R.S. FOR DEPARTMENT OF DEFENSE 

PERSONNEL PARTICIPATING IN THE PRIVATELY OWNED VEHICLE IMPORT CONTROL 

PROGRAM

III.A. U.S. Department of Defense (DOD) personnel participating in the DOD POV (privately 

owned vehicle) Import Control Program operating a 1975 or subsequent model year 

automobile, are exempt from the prohibition of C.R.S., 42-4-314(2), C.R.S. insofar as it 

pertains to filler neck restrictors, catalytic converter systems, and, if applicable, exhaust 

gas oxygen (O2) sensor(s), if one of the following conditions are met:

III.A.1. The automobile will be driven to the port and surrendered for exportation under 

said program within ten (10) working days of disconnection, deactivation, or 

inoperability of the restrictor, catalytic converter systems, or exhaust gas oxygen 

(O2) sensor(s); or

III.A.2. The reconnection, reactivation, or reoperability of the restrictor, catalytic 

converter systems, and, if applicable, exhaust gas oxygen (02) sensor(s), is made 

within ten (10) working days from the time the owner picked up the automobile at 

the port.

III.B. Persons disconnecting, deactivating, or rendering inoperable any filler neck restrictor, 

catalytic converter system, exhaust gas oxygen (O2) sensor(s) on 1975 or subsequent 

model year automobile of DOD personnel participating in the DOD POV Import Control 

Program which will be driven to the port and surrendered for exportation under said 

program within ten (10) working days are exempt from the prohibition of 42-4-314, C.R.S.
Regulation Number 11

Adopted: November 21, 2013 Page 10

III.C. Unless otherwise exempt under this Section III of Part A, vehicles shall be required to be 

configured as a vehicle certified by the EPA for sale and use within the United States 

pursuant to 40 CFR, Part 86, Subpart A.

IV. CLEAN SCREEN/REMOTE EMISSIONS SENSING

IV.A. Geographic Area of Applicability

IV.A.1. (Reserved)

IV.A.2. The Division shall implement an expanded clean screen program in the 

enhanced program area.

IV.A.3. (Reserved)

IV.B. Vehicles Eligible to participate in the Clean Screen/Remote Emissions Sensing Program

IV.B.1. The clean screen program established in this Section IV. of Part A shall apply to 

eligible motor vehicles as defined in 42-4-310(5)(a), C.R.S., for which registration 

will expire within twelve months, a certificate of emissions control is a 

prerequisite to renewal and which are registered in a clean screen program 

county.

IV.B.2. The counties of Adams, Arapahoe, Boulder, Broomfield, Denver, Douglas, 

Jefferson, Larimer, and Weld are clean screen counties.

IV.C. REPEALED

IV.D. Schedule for collection of emissions inspection fees by county clerks and recorders.

The clerks and recorders for the counties of Adams, Arapahoe, Boulder, Broomfield, Denver, 

Douglas, Jefferson, Larimer and Weld shall collect an emissions inspection fee in the amount 

specified pursuant to Section 42-3-304(19)(a)(I), C.R.S. at the time of registration of a motor 

vehicle that the Department of Revenue has determined to have been clean screened, unless a 

valid certification of emissions compliance has already been issued for the vehicle being 

registered indicating that the vehicle passed the applicable emissions test at an enhanced 

inspection center, motor vehicle dealer test facility or fleet inspection station.

V. EXPANSION OF THE ENHANCED EMISSIONS PROGRAM TO THE NORTH FRONT RANGE 

AREA

V.A. Program Commencement

Beginning November 1, 2010, unless the Division comes back to the Commission and the 

Commission agrees to a later date, motor vehicles registered in the North Front Range Area, and 

vehicles operating in the North Front Range Area that meet the requirements of Section 42-4-

310(1)(c)(I), C.R.S. shall be subject to an Enhanced emissions inspection as defined in Section 

42-4-304(8.5). Notwithstanding the above, the Estes Park Area, located west of Range Seventyone (71) West, shall be excluded from the Enhanced Emissions Program. Such inspection shall 

be the same as the inspection required in the Adams, Arapahoe, Boulder, Broomfield, Denver, 

Douglas, and Jefferson county portions of the Program Area The Vehicle Emissions Inspection 
Regulation Number 11

Adopted: November 21, 2013 Page 11

program in the North Front Range area is a State-Only program and is not part of any state 

implementation plan with the US EPA.

V.B. Requirement to Obtain Certification of Emission Control and Emissions Inspection 

Schedule

V.B.1. Except as otherwise provided in Title 42, Article 4, Part 3, C.R.S. and this 

Regulation Number 11, a motor vehicle that is subject to the North Front Range 

Area Inspection and Maintenance Program pursuant to Subsection V.A. above 

may not be registered or sold without a valid Certification of Emissions Control. 

In order to obtain a Certification of Emissions Control the vehicle must either 

pass the applicable emissions inspection or obtain a waiver from the Department 

of Revenue under this Regulation Number 11.

V.B.2. Subject to the phase-in provision in Subsection V.B.3. below, emissions 

inspections shall be conducted and Certification of Emissions Controls shall 

remain valid in accordance with the schedules set forth in Section 42-4-304(3), 

C.R.S., Section 42-4-310(1)(b)(II), C.R.S. and Part A, Section I.C. of this 

Regulation Number 11.

V.B.3. In order to better balance the number of inspections from year to year, odd

number model year motor vehicles that require biennial inspections under 

Subsection V.B.2. above, shall be inspected commencing January 1, 2011. This 

phase-in shall not excuse a vehicle from an inspection in 2010 that is required 

due to the sale or transfer of the motor vehicle.

PART B Standards and Procedures for the Approval, Operation, Gas Span Adjustment, 

Calibration and Certification of the Division Approved Test Analyzer Systems for 

Use in the Basic and Enhanced Areas and Test Analyzer Systems for Licensed 

Dealers in the Enhanced Area

I. APPROVAL OF THE COLORADO 94 AND COLORADO 97 TEST ANALYZER SYSTEMS

I.A. From January 1, 1995 and thereafter no emissions inspection required by the AIR 

Program in the enhanced program area shall be performed unless the instrument used 

for measuring exhaust gases from motor vehicles is identified as a Colorado AIR 

Program Colorado 94 exhaust gas analyzer. For any emissions inspection station 

licensed after May 1, 2010, a Colorado BAR 97 exhaust gas analyzer must be used. 

Sources of vendors for the approved analyzers may be obtained from the Program 

Administrator, Mobile Sources Section, Air Pollution Control Division, Colorado 

Department of Public Health and Environment, 4300 Cherry Creek Drive South, Denver 

CO 80246-1530.

I.B. As an element of accreditation, the Division will accept a Certification statement for the 

exhaust gas analytical and sampling system portion of the Colorado AIR Program 

Colorado 94 exhaust gas analyzer or a Colorado BAR 97 exhaust gas analyzer from the 

California Bureau of Automotive Repair (BAR) or a recognized laboratory. The Division or 

its designee will determine the manufacturers’ compliance with the revisions and 

additions to the specifications necessary for use of the instrument within the AIR 

Program. Those testing procedures are to be included with the bid specifications.
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Adopted: November 21, 2013 Page 12

I.C. The following statement is a requirement of the AIR Program for approval of an exhaust 

gas analyzer and is included to make manufacturers and purchasers of exhaust gas 

analyzers aware of the warranty requirements of Section 207(b) of the federal Clean Air 

Act, as amended 1981.

207(b) Warranty Requirements:

Unless an exhaust gas analyzer has been certified by the manufacturer as having met the 

specifications of 40 CFR Part 85, Subpart W as published in Part IX of the May 22, 1980 Federal 

Register, an inspection performed using that analyzer may not qualify a 1982 or later model year 

vehicle for warranty repair coverage according to the provisions of the Emission Control System 

Performance Warranty (Section 207(b) of the federal Clean Air Act).

II. APPLICATIONS FOR APPROVAL OF COLORADO 94 OR COLORADO BAR 97 TEST 

ANALYZER SYSTEMS EQUIPMENT MANUFACTURERS

Those manufacturers wishing to participate in the open bid process shall make application with the Air 

Pollution Control Division, Mobile Sources Section, of the Colorado Department of Public Health and 

Environment, 4300 Cherry Creek Drive South, Denver, CO 80246-1530 on forms provided thereby. All 

manufacturers making application shall meet the requirements as specified by the Department of 

Administration and the Procurement Code, Articles 101-112 of Title 24, C.R.S.

A manufacturer requesting the approval of an instrument for the measurement of exhaust gases for use in 

the AIR Program station shall make application therefore with the Air Pollution Control Division, 4300 

Cherry Creek Drive South, Denver, CO 80246-1530 on forms provided thereby. All manufacturers making 

application shall meet the technical specifications and administrative requirements specified by the Air 

Pollution Control Division.

III. PERFORMANCE AND DESIGN SPECIFICATIONS FOR THE COLORADO 94 AND 

COLORADO BAR 97 EXHAUST GAS ANALYZERS

Pursuant to Section 42-4-306(3)(a), C.R.S the specifications for the exhaust gas analyzer required for 

inspections conducted July 1,1987 and thereafter are attached to this regulation as Appendix A. These 

specifications include but are not limited to the provisions of California BAR 90, data collection, 

service/maintenance, requirements for replacement or loan instruments and warranty for the period of the 

agreement. These specifications are described in a separate document entitled “Colorado Department of 

Public Health and Environment Specifications for Colorado 94 Analyzer - Hardware Specifications” March 

17, 1994 as adopted by the Commission. This information is available from the Air Pollution Control 

Division, Mobile Sources Section, 4300 Cherry Creek Drive South, Denver, CO 80246-1530. Those 

manufacturers making application should refer to Section II of this Part B.

The Division in its discretion may accept substitute specifications for Test Analyzer Systems provisions 

that such substitute specifications are equivalent to those contained in Appendix A.

IV. SPAN GASES FOR USE WITH COLORADO 94 AND COLORADO BAR 97 TEST ANALYZER 

SYSTEMS

IV.A. General

The instrument manufacturer and his designated marketing vendors shall, supply span gases 

approved by the Division to any ultimate purchaser of his unit. The instrument manufacturer shall 

also provide the analyzer purchaser with a comprehensive, up-to-date list (with addresses and 
Regulation Number 11

Adopted: November 21, 2013 Page 13

phone numbers) of gas blenders approved by the Division. Each new or used instrument sold by 

the instrument manufacturer or marketing vendor shall have full span gas containers installed and 

operational at time of delivery.

IV.B. Span Gas Blends

The span gas concentrations supplied to the AIR Program stations shall conform to the 

specifications contained in Section VI. of this Part B.

Only gas blends supplied by Division approved blenders selected pursuant to Section 42-4-

306(3)(a)(I)(C) shall be offered for sale in Colorado.

Pursuant to Section 42-4-306(3)(a)(I)(C), the Division shall select blenders authorized to provide 

span gases that comply with the standards and specifications set out in Appendix B. The 

requirement to use gases procured pursuant to the standards and specification in Appendix B 

shall not be federally enforceable, and shall not be part of the State Implementation Plan.

IV.C. Optical Correction Factor [also referred to as “C” factor, propane to hexane conversion 

factor” (P.E.F.)].

Each instrument shall be permanently labeled with its correction factor visible from the outside of 

its cabinet. The correction factor shall be carried to at least two decimal places e.g., (0.52). Factor 

confirmation shall be made on each assembled analyzer by measuring both N-hexane and 

propane on assembly line quality checks. P.E.F. limitations are described in the specifications 

document attached to this regulation as Appendix A.

IV.D. Running Changes and Equipment Updates

The Commission must approve any changes to design or performance characteristics of 

component specifications that may affect instrument performance. It will be the instrument 

manufacturer's responsibility to confirm that such changes have no detrimental effect on analyzer 

performance. All Colorado 94 exhaust gas analyzers will be updated as needed and as specified 

in the specifications document.

V. DOCUMENTATION, LOGISTICS, AND WARRANTY REQUIREMENTS

V.A. Instruction Manual

The instruction manual accompanying each analyzer shall contain at least the following:

V.A. 1. Complete technical description.

V.A.2. If available, functional schematics (mechanical and electrical).

V.A.3. Accessories and options (included and/or available).

V.A.4. Model number, identification markings and location.

V.A.5. Operating maintenance to include periodic recommendations, i.e., daily, weekly, 

monthly, and procedure for maintaining sample system integrity (leaks, hang-up, 

calibration, filters, etc.).
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Adopted: November 21, 2013 Page 14

V.A.6. Required service schedule identifying the items needing maintenance and the 

procedures to be followed by the purchaser. The services to be performed only 

by the manufacturer shall be clearly identified.

V.A.7. Warranty provisions to include listing of warranty repair stations by name, 

address, and phone number.

V.A.8. The name, address, and phone number of the permanent Colorado 

representative offering training, service, warranties, etc.

V.A.9. Information and terms of manufacturers service contract clearly stating the 

coverage including but not limited to each party's obligation, period of coverage, 

cost, service response times, availability of loaner units. Manufacturer or 

designee performed service/maintenance provisions and costs shall be so stated 

for the duration of the program and annually up-dateable costs.

VI. CALIBRATION OF COLORADO 94 AND COLORADO BAR 97 TEST ANALYZER SYSTEMS

The Division shall use and require for use in the calibration and spanning of exhaust gas analyzers span 

gases and containers supplied by authorized blenders meeting the following parameters, blends, and 

specifications:

VI.A. Standardizing Instruments

The calibration gases for standardizing instruments shall conform to the provisions outlined in 40 

CFR, Section 86.114 (July 1, 1992) (EPA) for automotive exhaust emissions testing. Those gases 

shall be of “precision” quality, certified to be within ±1% of the labeled concentration, and 

traceable to the National Institute for Standards and Technology (NIST).

VI.B. AIR Program Station Instruments

The span gases supplied to AIR Program stations shall conform to the following:

VI.B.1. Tri-blends of HC, CO, CO2 in a carrier gas of nitrogen (N2). The hydrocarbon 

(HC) gas will be propane.

VI.B.2. The concentrations) of the span gas blends (two) shall be within limits 

established by the Division to provide for uniform exhaust gas analyzer spanning. 

The Division may establish such limits to ensure gasses are measurable based 

upon the ranges or scales of the equipment.

VI.B.3. The accuracy of the AIR Program station span gas blend shall be certified by the 

blender to be ±2% of labeled concentration and traceable to the NIST.

VI.C. AIR Program stations will calibrate the exhaust gas instrument once every 72 hours as 

determined by the instrument or as needed in order to maintain accuracy.

VI.D. All AIR Program exhaust gas analyzers will be calibrated only with span gases bearing a 

Colorado approval label.

VI.E. Additional specifications related to calibration requirements are described in the 

specifications document attached to this document as Appendix A.
Regulation Number 11

Adopted: November 21, 2013 Page 15

VII. APPROVAL OF THE COLORADO AUTOMOBILE DEALERS TRANSIENT MODE TEST 

ANALYZER SYSTEM

Any applicable emissions inspection required by the AIR Program performed by a licensed Motor Vehicle 

Dealers Test Facility pursuant to Section 42-4-304 (19), C.R.S., in the enhanced program area, shall be 

performed utilizing a Colorado Automobile Dealer Transient Mode (IG 240) test analyzer system 

approved by the state open bid process. Sources of vendors for the approved test system may be 

obtained from the Program Administrator, Mobile Sources Section, Air Pollution Control Division, 

Colorado Department of Public Health and Environment, 4300 Cherry Creek Drive South, Denver 

Colorado 80246-1530.

This Section VII, and the associated design and performance specifications set out in Appendix A, 

Attachment III, shall not be federally enforceable and shall not be part of the State Implementation Plan.

VIII. APPLICATIONS FOR APPROVAL OF THE COLORADO AUTOMOBILE DEALERS TRANSIENT 

MODE TEST ANALYZER SYSTEM

Those manufacturers wishing to participate in the open bid process shall make application with the Air 

Pollution Control Division, Mobile Sources Section, of the Colorado Department of Public Health and 

Environment, 4300 Cherry Creek Drive South, Denver Colorado 80246-1530 on forms provided thereby. 

All manufactures making application shall meet the requirements as specified by the Department of 

Administration and Procurement Code, Articles 101-112 of Title 24, C.R.S.

The design and performance specifications for the Colorado Automobile Dealers Transient Mode Test 

Analyzer System Technical and Hardware Specification Document of January 27. 1997

Include a bid for the procurement of any working/support and span gases necessary for the operation of 

such Colorado Automobile Dealers Transient Mode Test Analyzer System, unless all such gases are 

already subject to a contract issued pursuant to 42-4-306(3)(a)(I)(C). Any bid for the procurement of such 

gases shall comply with the relevant requirements of Part B, IV of the Regulation Number 11 and relevant 

requirements of 

attached as 

Appendix A, Attachment III. Pursuant to 42-4-306(3)(a)(I)(C), the Division shall let bids for the 

procurement of instruments that comply with such specifications. In addition to the specifications set out 

in Appendix A, attachment III, qualifying bids shall:

Standards and Specifications for Calibration and Span Gas Suppliers,

Include a comprehensive and up-to-date list of working/support and span gas suppliers subject to a 

contract issued pursuant to 42-4-306(3)(a)(I)(C). A copy of such list shall be provided to each purchaser.

attached as 

Appendix B, including the “Gas Requirements for the Basic and Enhanced Inspection Test Programs, 

1997” as set out in Section 5 of Appendix B.

Provide for the Division-approved calibration gases for calibration of the Colorado Automobile Dealers 

Transient Mode Test Analyzer System.

A service and maintenance plan, including a description of services, service response times, periodic 

maintenance schedules and annual service agreement costs inclusive of all services necessary to comply 

with the Colorado Automobile Dealers Transient Mode Test Analyzer System Technical and Hardware 

Specification Document of January 27, 1997.

IX. APPROVAL OF THE COLORADO ON-BOARD DIAGNOSTIC (OBD) TEST ANALYZER 

SYSTEM

Service agreement costs are to be listed annually and shall 

be for the remaining period of the AIR Program.
Regulation Number 11

Adopted: November 21, 2013 Page 16

Any applicable on-board diagnostic emissions inspection required by the Air Program performed shall be 

performed utilizing an on-board diagnostic (OBD) test analyzer system approved by the state. Sources of 

vendors for the approved Colorado On-Board Diagnostic Test Analyzer System may be obtained from the 

Program Administrator, Mobile Sources Section, Air Pollution Control Division, Colorado Department of 

Public Health and Environment, 4300 Cherry Creek Drive South, Denver, Colorado 80246-1530.

X. THE COLORADO ON-BOARD DIAGNOSTIC (OBD) TEST ANALYZER SYSTEM

The design and performance specifications for the Colorado On-Board Diagnostic Test Analyzer System 

are outlined in the Society of Automotive Engineers J1979 Standard.

In addition to the specifications set out in J1979 Standard, additions and/or modifications to the 

operational, data collection, data recording and quality assurance auditing functions shall be outlined in a 

Colorado On-Board Diagnostic (OBD) Test Analyzer System Requirements Specification, to be submitted 

by the Division for Air Quality Control Commission approval no later than December 31, 2013.

XI. REQUESTS FOR APPROVAL OF CLEAN SCREEN TEST ANALYZER SYSTEMS

XI.A. REPEALED

XI.B. Calibration gas blends intended for Clean Screen Test Analyzer Systems shall be verified 

and approved subject to the requirements of Standards and Specifications for Calibration 

and Span Gas Suppliers including Gas Requirements for the Basic and Enhanced 

Inspection Test Programs. 1997,

Concentrations of calibration gases noted above are to be determined pending system 

configuration, operating ranges and expected emissions readings.

(Appendix B).

State audit blends for Clean Screen Test Analyzer Systems shall be of varying concentrations of 

and shall conform to the above gas blending standards.

PART C Inspection Procedures and Requirements for Exhaust Emissions, Fuel Evaporation 

Control, Visible Smoke Emissions, Emissions Control Systems, On-Board 

Diagnostics (OBD); and Practices to Ensure Proper Emissions Related 

Adjustments and Repairs

I. PRE-INSPECTION REQUIREMENTS

I.A. A licensed emissions mechanic, licensed emissions inspector or authorized emissions 

inspector must perform all aspects of the inspection. It is the responsibility of emissions 

mechanics and emissions inspectors to notify the Department of Revenue of their current 

place of employment and any subsequent transfer, and place of residence. The 

Contractor shall be responsible for its personnel and notifying the Department of all 

personnel assignments and adjustments in those assignments.

The emissions mechanic not employed by an “Inspection-Only Station” shall notify the customer 

prior to initiating an emissions inspection if he/she is unable to perform the required adjustments 

and/or repairs for that particular vehicle should that vehicle fail the inspection. Otherwise the 

emissions mechanic shall not conduct an inspection on a motor vehicle unless that emissions 

mechanic so notifies the customer or is able to perform the adjustment and/or repair procedures 

for that particular vehicle as prescribed by the manufacturer and specified by Section IV. of this 

Part C.
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Adopted: November 21, 2013 Page 17

I.B. Inspections may only be performed on the premises of the licensed address as 

prescribed in Part D Section I. A. 2. The entire inspection shall take place within the 

reach of the analyzer hose.

I.C. In consideration of maintaining inspection integrity:

I.C.1. The temperature of the inspection area when utilizing one or more test analyzer 

systems as specified in Part B of this regulation shall be between 41°F and 

110°F (5°C and 43°C) during the inspection. Inspection area temperatures must 

be accurately recorded, and monitored in a well-ventilated location away from 

vehicle engine and exhaust heat sources and out of direct sunlight. The 

inspection area includes the vehicle being inspected.

I.C.2. The test analyzer system and other inspection equipment shall be kept in an area 

within the facility that affords adequate protection from the weather.

I.C.3. A permanent location that meets all applicable requirements of this rule to 

provide for the inspection of vehicles is required. Electrical supply must be public 

utility designated for that area and meeting the analyzer manufacturer's 

requirements for to the test analyzer system is to be dedicated to this purpose. 

Full-time connectivity to a dedicated data transmission media meeting the 

analyzer manufacturer’s requirements for the test analyzer system.

I.D. Upon a physical verification of the vehicle identification number (VIN) and license plate 

number, the emissions mechanic or emissions inspector will enter this information into 

the program database in order to match this information with the state registration record. 

In the case of a match, the emissions mechanic or emissions inspector shall proceed. If 

no match is found, a new inspection record will be created. All non-Colorado registered 

vehicles and first time registrations with the State of Colorado will require the creation of 

a new inspection record by the emissions mechanic or emissions inspector.

I.E. The emissions mechanic or emissions inspector shall ascertain from the inspection 

record data base if an initial inspection or an after-repairs inspection is to be conducted. If 

an after-repairs inspection is to be conducted, previous inspection data is required for 

comparison. Specific emissions related repair information as specified in Section VII (B) 

of this Part C shall be entered to the database. Inspections conducted within 60 days of 

the initial inspection date are to be considered an after-repairs inspection. Inspections 

conducted greater than 60 days from the initial inspection date are to be considered initial 

inspections. The emissions mechanic or emissions inspector shall accurately enter 

vehicle, and last inspection information as required for vehicle emissions inspection 

records.

I.F. The emissions mechanic or emissions inspector shall perform a cursory safety 

assessment of the motor vehicle prior to inspection. If in the opinion of the emissions 

mechanic or emissions inspector the vehicle is unsafe to inspect due to engine/drive-line 

metallic noises, or leaking fluids, the request for inspection may be refused.

II. EXHAUST EMISSIONS INSPECTION PROCEDURES

II.A. All heavy-duty vehicles and all 1981 and older model year vehicles to be inspected at 

licensed inspection-only facilities or licensed enhanced inspection centers in the 
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Adopted: November 21, 2013 Page 18

enhanced program area shall be administered an EPA approved idle short test as 

specified in 40 CFR, Part 51, Subpart S, Appendix B.

II.A.1. The emissions mechanic or emissions inspector will use a certified TAS to select 

the appropriate idle short test cycle based upon the make, model year engine 

family and vehicle classification. These idle short tests include, but may not be 

limited to, a standard single speed idle test; the pre-idle 30-second preconditioning idle test with the high speed (2500 ± 300 RPM) pre-conditioning 

cycle before the idle mode; a standard two speed (3 - mode) idle test with the 

raised idle segment at 2500 ± 300 RPM; second chance raised idle preconditioning for 30 seconds just prior to the idle mode after an initial failure, and 

second chance restart in which the ignition is turned off for ten (10) seconds and 

then restarted to complete the emissions inspection procedure. All sampling 

modes shall (each) be thirty seconds in duration and raised engine speed modes 

be it for pre-conditioning or sampling, shall be 2500 RPM ± 300 RPM. As a 

pass/fail determination, the vehicle's emissions levels must be the same as or 

less than applicable limits at the designated engine speed(s) in order to pass.

II.A.2. The entire vehicle shall be in normal operating condition and at normal operating 

temperature, which shall be determined by carefully feeling the top radiator hose 

while the engine is not operating, by checking the temperature gauge, and/or 

operating the vehicle prior to performing the idle emissions inspection. Vehicles 

are not to be idled for extended periods of time but rather inspected in an 

expeditious manner as soon as normal operating temperature is achieved. The 

vehicle shall be inspected in an as-received condition.

II.A.3. The inspection shall be performed with the transmission in park or neutral and 

with all accessories off.

II.A.4. The analyzer probe shall be inserted at least twelve (12) inches or as 

recommended by the analyzer manufacturer for a quality sample whichever is 

greater.

II.A.5. For all vehicles equipped with a multiple exhaust system, the analyzer's dual 

exhaust procedure must be used.

II.A.6. If a baffle or screen prevents probe insertion to an adequate depth, a suitable 

probe adapter or snug fitting hose that effectively lengthens the exhaust pipe 

may be used.

II.A.7. The appropriate emissions limits specified in Part F of this regulation would be 

utilized by the certified test analyzer system. In selecting appropriate emissions 

limits, for motor vehicles of model years 1978 and earlier having a gross vehicle 

weight (GVW) rating of greater than 6000 lbs., or of model years 1979 and newer 

having a gross vehicle weight rating of greater than 8500 lbs., the emissions 

mechanic or emissions inspector shall identify that particular vehicle's GVW 

rating by examining the vehicle information (metal) plate or sticker. These motor 

vehicles will be subject to the applicable emissions limits as listed in Part F of this 

regulation. If the vehicle information plate or sticker is missing, illegible or the 

GVW rating information is not otherwise available, the emissions mechanic or 

emissions inspector shall examine the engine exhaust emissions control 

information label which is permanently affixed to the engine and determine 
Regulation Number 11

Adopted: November 21, 2013 Page 19

heavy-duty engine/vehicle federal certification status. Vehicle engines not labeled 

as having complied with applicable U.S. EPA heavy-duty regulations by the 

manufacturer are assumed to be light-duty vehicles and subject to the emissions 

limits listed in Part F of this regulation. Emissions limits for vehicles in which the 

engine has been changed shall be based upon whichever is newest, the vehicle 

or the replacement engine, as specified on a vehicle evaluation form (DR2365) or 

bar coded label generated by emissions technical center staff or designee.

II.A.8. In the event the tachometer over-ride mode must be utilized to inspect a vehicle, 

an accurate auxiliary tachometer must be used to verify engine speeds 

mandated in Part C, Section II.A.1.

II.A.9. The vehicle will be evaluated for the presence of visible smoke emissions. The 

evaluation is to be performed during all (engine) operating conditions of the 

inspection procedures prescribed in Part C, Sections II.A.1 through II.A.11.

II.A.10. A Certification of Emissions Compliance shall be issued if the vehicle passes the 

emissions control systems inspection (for 1975 and newer model year vehicles 

only), the exhaust and evaporative emissions inspection, and there is no 

evidence of visible smoke emissions.

II.A.11. If the vehicle fails the initial emissions inspection the owner is to have appropriate 

emissions related repairs or adjustments made and may return the vehicle to an 

AIR Program station, facility or center, as appropriate, for reinspection. Within ten 

(10) calendar days of the initial test, one free reinspection shall be provided to 

the motorist if the vehicle is returned to the same station or facility at which the 

initial test was performed. A motorist shall be entitled to one free after-repairs test 

at any contractor operated center within ten (10) calendar days of the initial test 

performed at a contractor operated center. If during repairs, it is determined the 

necessary parts are not available, the motorist may be issued a temporary 

Certificate of Emissions Control by Department of Revenue personnel. Proof of 

part(s) non-availability as described in Part C, Section III.D. of this part is 

required. Motorists pursuing a temporary Certificate of Emissions Control must 

facilitate final vehicle inspection and compliance with adopted regulation.

II.B. All model year 1982 and newer light-duty vehicles, except vehicles required to be OBD 

tested pursuant to Part C, Section II.C. to be inspected at licensed enhanced inspection 

centers within the enhanced program area shall be administered an EPA approved 

transient loaded mode inspection procedure as specified in 40 CFR, Part 51 Subpart S 

Federal Register as amended to incorporated OBD testing August 6, 1996.

II.B.1. Vehicles shall be inspected in an as-received condition.

II.B.2. The inspection shall be performed with all accessories off.

II.B.3. The appropriate emissions limits as specified in Part F of this regulation shall be 

selected by the TAS based upon the model year and vehicle classification.

II.B.4. Light-duty vehicles of model year 1995 and older found to be safe but unable to 

be dynamometer tested shall be administered an idle short test as specified in 40 

CFR, Part 51, Subpart S, Appendix B. OBD equipped light-duty vehicles that are 

unable to be tested on the dynamometer shall be tested using the OBD test 
Regulation Number 11

Adopted: November 21, 2013 Page 20

procedures in Part C, Section II.C. to include meeting passing criteria in Part F, 

Section VII. Eligibility for an alternative test procedure shall be determined by the 

Division based upon:

II.B.4.a. The vehicle wheelbase greater than 125 inches

II.B.4.b. The vehicle wheelbase less than 92 inches

II.B.4.c. The vehicle driveline, traction control system, and/or brake system, 

which have not been modified from the original configuration, cannot be 

accommodated on the dynamometer.

II.B.4.d. The vehicle is “Handicapped” plated and fitted with hand controls or 

similar apparatus to facilitate operation of the vehicle.

II.B.5. Heavy-duty vehicles to be inspected at licensed enhanced inspection centers 

within the enhanced program area shall be administered an appropriate EPA 

approved idle short test as specified in Section II (A) of this Part C.

II.B.6. The inspector may refuse to conduct the transient driving cycle dynamometer 

inspection procedure if the tires on the drive wheels are worn such that the cords 

are visible or sidewalls are peeling or blistered.

II.C. Effective January 1, 2015, light-duty vehicles, to include light-duty trucks in their eighth 

through eleventh model year, and all light-duty vehicles, to include light-duty trucks of 

model year 1996 and newer that are unable to be tested on an IM 240 test, are to be 

inspected at licensed enhanced inspection centers and shall be administered an EPA

approved on-board diagnostic test as specified in 40 CFR, 85.2222. 

II.C.1. Vehicles shall be inspected in an as-received condition. 

II.C.2. The on-board diagnostic inspection shall be conducted with the key-on/engine 

running.

II.C.3. The on-board diagnostic test analyzer system shall determine what monitors are 

supported by the diagnostic system and the readiness status for applicable 

monitors. 

II.C.3.a.If the readiness evaluation indicates that a vehicle has more than one 

unset (not ready) readiness monitor, and the malfunction indicator light 

(MIL) is commanded off, the vehicle shall be subjected to an IM 240 

emissions inspection immediately.

II.C.3.b.If the vehicle’s on-board diagnostics are unable to communicate 

electronically with the Colorado OBD Test Analyzer System, the vehicle

will be subjected to an IM 240 emissions inspection immediately.

II.C.3.c. The readiness requirement, outlined in this Part C, Section II.C.3.a. may 

be waived to accommodate for specific vehicles with known readiness 

design problems, in accordance with applicable technical service 

bulletins, EPA guidance, or division technical findings, as approved by 

the Division.
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Adopted: November 21, 2013 Page 21

II.C.4. The OBD test analyzer system shall evaluate the malfunction indicator light 

status and record status information in the vehicle test record. 

II.C.5. All diagnostic trouble codes resulting in malfunction indicator light commandedon status shall be recorded in the vehicle test record.

II.C.6. If the vehicle meets the passing criteria for the OBD inspection as listed in Part F, 

Section VII. Of this regulation, the vehicle passes the on-board diagnostic 

inspection.

II.C.7. Vehicles in an OBD “not ready” status, or vehicles unable to communicate with 

the OBD Test Analyzer System that default to an IM 240 test as described in Part 

C, Section II.B. shall be subject to pass/fail for the applicable IM 240 pass/fail 

standards in Part F, Section III. of this regulation.

II.C.8. If the malfunction indicator light is not commanded on and the vehicle passed the 

mil visual inspection, as outlined in this Part C, Section III.B., the vehicle shall 

pass the on-board diagnostic portion of the emissions inspection even if 

diagnostic trouble codes are present. 

II.C.9. The division may require no more than five percent, at random, of all OBD tested 

vehicles to undergo an IM 240 test at the time of the OBD testing. The failure of 

the vehicle to pass IM 240 shall be reported to the motorist, but shall not be used 

to fail the vehicle.

III. EMISSIONS CONTROL SYSTEMS INSPECTION PROCEDURES

Motor vehicles shall be configured as required for sale or use within the United States pursuant to 40 

CFR, Part 86, Subpart A; unless specific documentation in the form of a state issued vehicle evaluation 

form (DR2365) or an EPA (EPA form 3520) or DOT exemption is submitted. To ensure compliance with 

this requirement, for all inspections performed through December 31, 2014, the emissions mechanic or 

emissions inspector shall inspect all model year 1975 through 1995 and newer model year vehicles and 

assess the integrity of the emissions control system in accordance with the procedures set forth in this 

Section III. Effective January 1, 2015, the emissions mechanic or emissions inspector shall inspect all 

model year 1975 through 1995 model year vehicles and assess the integrity of the emissions control 

system in accordance with the procedures set forth in this Section III.

III.A. All model year 1975 through 1995 model year vehicles shall be visually inspected for the 

presence and operability of the air system, catalytic converter system(s) and oxygen (O2) 

systems. If these parts or systems are not operating as designed, inoperable or have

been removed or otherwise tampered with, the vehicle will not qualify for a Certification of 

Emissions Control. In assessing whether the proper emissions control systems are 

present, the emissions mechanic or emissions inspector shall examine the emissions 

control information decal within the engine compartment to determine the appropriate 

emissions control systems for that particular vehicle. If an emissions control information 

decal is missing, incomplete, illegible or is not appropriate for the specific vehicle, the 

emissions mechanic or inspector may contact a state emissions technical center for 

guidance, use other reference materials or refer the vehicle to a state emissions technical 

center for further evaluation.

For the period December 1, 2012 through December 31, 2015, in place of the visual inspection, 

the emissions control systems, model year 1996 and newer vehicles may be inspected using the 
Regulation Number 11

Adopted: November 21, 2013 Page 22

vehicle’s on-board diagnostic (OBD) systems. To utilize this alternative inspection procedure, the 

emissions inspector must interrogate the vehicle’s OBD system using Division approved 

procedures and equipment. If the emissions inspector is unable to interrogate the OBD system, 

or if the interrogation reveals either that the malfunction indicator light (MIL) is commanded on or 

that any OBD monitors are not set, the vehicle shall be visually inspected in accordance with the 

procedures set forth in Subsection III.A.

III.B. An assessment of the emissions control system malfunction/service-maintenance 

indicator(s) performance shall be conducted by the emissions mechanic or emissions 

inspector on those vehicles so equipped.

For those vehicles equipped with “check engine” dash indicator lights or similar emissions control 

systems malfunction or service-maintenance indicator(s), the following procedure if applicable will 

be performed to assess the integrity of the system:

● Ignition Off, Engine Off = indicator(s) off

● Ignition On, Engine Off = indicator(s) on or displayed

● Ignition On, Engine Running = indicator(s) off

The failure of the system to respond as described above shall be reported to the motorist, but 

shall not be used to fail the vehicle.

III.C. The repair/replacement of catalytic converters must incorporate the same type, style and 

location on the exhaust system relative to engine as originally designed by the vehicle 

manufacturer. If a new original equipment manufacturer (OEM) part is not used, only an 

EPA “accepted” after-market component appropriate to that application may be used. 

Verification of the correct application and certification status must be performed at the 

time of reinspection. The submittal and review of repair receipts as specified in 

Subsection VII.B of this section is required in order to substantiate proper repairs of 

applicable emissions control system.

III.D. If the necessary part(s) will not be available prior to the month of expiration of the present 

vehicle registration, and the owner obtains a signed form or statement to that effect from 

a manufacturer's dealer for that make vehicle, or from an automotive parts supplier which 

in the normal course of business supplies part(s) for that vehicle, Department of Revenue 

personnel after verification may issue a temporary Certification of Emissions Control. The 

form or statement provided must specifically identify by part numbers and description, the 

necessary part(s). The owner then has until the expiration of the temporary certification to 

complete the necessary repairs or replacement.

IV. ON-BOARD DIAGNOSTIC INSPECTION PROCEDURES

Effective January 1, 2015, Llight-duty vehicles to include light-duty trucks of model year 1996 through 

those vehicles that have reached their eleventh model year old equipped with California on-board 

diagnostic (OBDII) or EPA on-board diagnostic systems (EPA, OBD) shall be evaluated to determine 

operability and integrity of the applicable system(s). The OBD system will be connected to the TAS and 

interrogated. Fault codes and diagnostics shall be reported to the motorist with other emissions 
Regulation Number 11

Adopted: November 21, 2013 Page 23

inspection information but with the exception of dynamometer incompatible vehicles as noted in Part C, 

Section II.B.4. shall not be used to fail the vehicle.

V. EVAPORATIVE FUEL CONTROL INSPECTION PROCEDURES

Model year 1975 and newer vehicles shall be inspected for the presence and integrity of the gasoline 

cap(s). The gasoline cap(s) of such vehicles inspected in the nine county Front Range enhanced program 

area as defined in Section 42-4-304(9)(a)., shall also be inspected for sealing integrity as specified in Part 

F, Section IV of this regulation.

Vehicles with a missing gasoline cap(s) shall not qualify for issuance of a Certificate of Emissions Control. 

Motorists whose vehicles have gasoline cap(s) demonstrating excessive leakage shall be notified of the 

deficiency, repair/replacement and a full retest shall be mandatory.

VI. FREE REINSPECTION

Vehicles which fail any or all elements of an emissions inspection are eligible for one free reinspection 

within ten (10) calendar days if presented to the same station or facility as initially inspected and failed. In 

the case of the contractor operated enhanced inspection center network, the ten (10) day free 

reinspection shall be honored at any enhanced inspection center.

VII. REPAIR INFORMATION

Any after-repairs reinspection of a vehicle initially failed calls for the submittal of a completed official AIR 

Program emissions repair form.

VIII. CERTIFICATION OF EMISSIONS CONTROL

In order to obtain a Certificate of Emissions Control, the vehicle must meet the following conditions:

VIII.A. Certification of Emissions Compliance may be issued if:

VIII.A.1.The vehicle emissions levels are the same as or less than the applicable 

emissions limits; or

VIII.A.2.For vehicles in model years seven through ten subject to an on-board diagnostic 

inspection, the OBD system meets the passing criteria established in Part F, 

Section VII. of this regulation, and

VIII.A.3.There are no smoke emissions visible from the vehicle engine crankcase and/or 

tailpipe, and

VIII.A.4.For 1975 through 1995 model years, the vehicle passes the emissions control 

systems inspection, and

VIII.A.5.Under enhanced inspection requirements, the vehicle owner/operator of a 1995 

or newer model year vehicle shall demonstrate compliance with any federal 

emissions recall-pursuant to 40 CFR Part 85.1902 (d) or remedial repair plan 

pursuant to Section 207 (C) of the federal Clean Air Act for which owner 

notification occurs after 01 January 1995.

VIII.B. A Certification of Emissions Waiver may be issued if:
Regulation Number 11

Adopted: November 21, 2013 Page 24

VIII.B.1.The vehicle passes the emissions control systems inspection (1975 and newer 

model year vehicles only) required by Part C, Section III. A, B and C.; and

VIII.B.2.Basic Program

For model year 1981 and earlier at least seventy-five dollars ($75) has been spent on 

emissions related adjustments and repairs as specified in Part C, Sections IX and X 

provided that proof of repair costs for that specific vehicle has been provided to 

Department of Revenue personnel or designee in the form of an itemized bill, invoice, 

work order, manifest, or statement in which emissions related parts and/or repairs, are 

specifically identified.

For model years 1982 and newer, at least two hundred dollars ($200) has been spent on 

emissions related adjustments and repairs as specified in Part C, Sections IX and X, 

provided that proof of repair costs for that specific vehicle has been provided to 

Department of Revenue personnel or their designee in the form of an itemized bill, 

invoice, work order, manifest, or statement in which emissions related parts and/or 

repairs, are specifically identified.

VIII.B.3.Enhanced Program

For model year 1968 and newer, at least four hundred and fiftyseven hundred fifteen

dollars ($450715) or as adjusted annually by the Consumers Price Index for Urban 

Consumers (CPIU) of the previous year as compared to 1989 2003 has been spent on 

emissions related adjustments and repairs as specified in Part C, Sections IX and X, 

provided that proof of repair costs for that specific vehicle has been provided to 

Department of Revenue personnel or their designee in the form of an itemized bill, 

invoice, work order, manifest, or statement in which emissions related parts and/or 

repairs, are specifically identified. The Division shall adjust the amount that must be 

expended by the motorist in order to qualify for a Certificate of Emissions Waiver, which 

amount shall be established for each calendar year through 2004 by the Division 

pursuant to the criteria specified in Section 42-4-310(1)(d)(VI),C.R.S.

For model year 1967 and earlier at least seventy-five dollars ($75) has been spent on 

emissions related adjustments and repairs as specified in Part C, Sections IX and X 

provided that proof of repair costs for that specific vehicle has been provided to and 

verified by the emissions inspector in the form of an itemized bill, invoice, work order, 

manifest, or statement in which emissions related parts and/or repairs, are specifically 

identified.

If no emissions reduction is achieved, the motorist is to be referred to the Department of 

Revenue or its designee pursuant to Sections IX. G. and X. of this Part C.

VIII.B.4.An emissions reduction as determined either by the Division-approved Colorado 

94 of Colorado BAR 97 Test Analyzer System has resulted due to emissions 

related repairs and the applicable cost limit has been met. Proof of these 

emissions related repairs are required and to be retained by the AIR Program 

station, facility or center until purged by state program personnel. The vehicle 

must have passed the emissions control systems inspection and there were no 

smoke emissions visible from the vehicle engine crankcase or exhaust system.

VIII.B.5.Engine operational parameter verification.
Regulation Number 11

Adopted: November 21, 2013 Page 25

VIII.B.5.a. All engine parameter adjustments for idle speed, proper air/fuel 

ratio and cold enrichment, as well as proper ignition dwell and timing (if 

applicable), have been set to or verified as being set to manufacturers 

specification by a licensed mechanic or registered repair 

facility/technician.

VIII.B.5.b. For those 1981 and newer vehicles equipped with computer 

based, engine management systems, also known as closed loop, 

feedback controls shall have the following additional sensors/systems 

verified to be operating within vehicle manufacturer specifications.

VIII.B.5.b.(1) As applicable to the vehicle being inspected, the oxygen 

sensor, throttle position sensor, coolant temperature sensor, 

manifold absolute pressure sensor.

VIII.B.5.b.(2) The engine management control system will be scanned 

for default/malfunction codes with those systems or components 

identified corrected.

VIII.B.5.b.(3) Primary and secondary ignition system integrity shall be 

verified for correct operation.

VIII.B.5.b.(4) A fuel delivery system utilizing a carburetor will be 

inspected for leaks, idle speed control adjustments, float 

operation and cold enrichment. A fuel delivery system utilizing 

fuel injection, be it throttle body or multiport configuration, shall 

be checked for injector function, cold enrichment and injector 

spray patterns. Fuel injectors shall also be evaluated for proper 

volume and injection pulse width. Fuel system pressure shall be 

checked for residual and running pressure.

VIII.B.5.b.(5) A cylinder leak down procedure shall be performed on all 

cylinders of the engine with the results reported to the motorist.

VIII.B.5.b.(6) With the exception of item (5) above, component/system 

deficiencies found to be out of manufacturer's operational 

specification(s) will be corrected. The cost of such repairs shall 

be creditable towards issuance of a waiver.

VIII.C. If in the opinion of a registered emissions repair facility/technician, a vehicle which is 

properly adjusted to all manufacturers emissions related specifications and all emissions 

control systems appear to be operating as required, yet the vehicle continues to exceed 

one or more emissions limits and the repair expenditure limits have not been met, a 

waiver shall be issued upon physical verification of systems operation and vehicle 

performance by emissions technical center personnel.

VIII.D. For vehicles registered and operated in the enhanced area, upon verification by a 

Department of Revenue Motor Vehicle Emissions Compliance Inspector, a waiver not to 

exceed one inspection cycle may be granted to obtain necessary emissions related 

repairs on a vehicle in the case of economic hardship when the Certificate of Emissions 

Waiver requirements of this section have not been met. It must be verified that the 

vehicle owner in question is participating in an established and recognized public 
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Adopted: November 21, 2013 Page 26

assistance program. The provisions of this Paragraph D shall only apply to a vehicle 

once. To obtain a hardship waiver, the registered owner of the vehicle in question shall 

satisfy the following requirements:

VIII.D.1. The vehicle must fail for carbon monoxide, hydrocarbons, and/or oxides 

of nitrogen failures.

VIII.D. 2. The hardship waiver will not be approved for vehicles that are tampered, 

missing equipment, fail the evaporative inspection, or fail for visible smoke.

VIII.D. 3. The vehicle owner must be participating in an established and 

recognized public assistance program.

VIII.D. 4. The vehicle must be the sole means of transportation for the vehicle 

owner, and the only vehicle registered in the owner’s nameowner must not have 

more than two vehicles registered in his/her name.

VIII.D. 5. Such extension may be granted only once per vehicle.

VIII.E. A Certificate of Emissions Waiver will not be issued to a vehicle that is eligible for the 

Emissions Control Systems Performance Warranty, 207(b) of the federal Clean Air Act. 

Per the provisions of the 207(b) Performance Warranty, the repair costs necessary for 

compliance with AIR Program emissions limits specified in Part F of this regulation will be 

borne by the vehicle manufacturer or his authorized dealer representative.

VIII.F. The emissions mechanic or emissions inspector shall generate the appropriate vehicle 

inspection report forms, electronic records, Certificate of Emissions Control, as required 

by the Department of Revenue or the Division and distribute to the motorist and the 

Departments of Health and Revenue. The emissions mechanic or emissions inspector 

will remove all expired Verification of Emissions Test windshield stickers. The vehicle 

inspection report is to be electronically identified by the issuing emissions mechanic or 

emissions inspector.

IX. ADJUSTMENT PROCEDURES

The emissions mechanic is to secure high altitude specifications for idle speed, idle mixture, ignition 

timing, dwell, and fast idle speed for the purpose of adjustment. If no high altitude specifications are 

available through the Department of Health or other reference sources refer to the emissions decal, other

applicable specifications guide, or sea level specifications for proper specifications.

IX.A. With a dwell meter, check to determine if the ignition dwell is within the recommended 

tolerance of ±2° of specifications. Reset if the ignition dwell is not within tolerance.

IX.B. Connect tachometer to determine if idle speed is correct. If not, set to manufacturer's 

specifications with a tolerance of ±50 rpm.

IX.C. With the engine idling at the correct speed, check ignition timing to determine if it is within 

+4° to -2° of the recommended setting, if no high altitude specifications are available.

IX.D. Using an infrared analyzer, propane enrichment kit, and/or tachometer, adjusts the idle 

air/fuel ratio using manufacturer's suggested procedures and specifications, if applicable.
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IX.E. After completing the preceding steps, readjust idle speed to manufacturer's 

specifications, if not within tolerance.

IX.F. Using the manufacturer's suggested procedure, check the fast idle speed and adjust to 

manufacturer's specifications.

IX.G. If the vehicle continues to exceed applicable emissions limits, or continues to fail OBD, 

the vehicle must undergo specific emissions related adjustments and repairs. 

Adjustments and repairs must be accomplished to the point of compliance, or the 

applicable cost ceiling must have been met. If the applicable emissions related 

adjustment and repair requirements have been met but an emissions reduction has not 

resulted, the vehicle owner may be referred to a Department of Revenue Motor Vehicle 

Emissions Compliance Inspector to get a waiver. Repairs must have been reasonably 

calculated to achieve a reduction in emissions of those components of the inspection the 

vehicle failed, pursuant to manufacture's specifications as required by Sections 42-4-

306(7)(a)(II)(A) and 42-9-111,C.R.S.

X. EMISSIONS RELATED REPAIRS

X.A. Emissions related repairs generally include only those adjustments to and maintenance 

and repair of the motor vehicle that are directly related to the reduction of exhaust 

emissions necessary to comply with the applicable emissions limits and procedures. The 

expenditure for emissions related repairs does not include the inspection fee as specified 

in Section 42-4-311, C.R.S. or expenses associated with the adjustments to and 

maintenance, replacement, and repair of air pollution control equipment on the vehicle if 

the need for such adjustment, maintenance, or repair pursuant to Part C, Section III is 

due to disconnection of, tampering with, or abuse to such air pollution control equipment. 

Air pollution control equipment is any part, assembly or system originally installed by the 

manufacturer for the sole or primary purpose of reducing emissions.

X.B. Repairs and maintenance to the following systems shall qualify as emissions related 

repairs insofar as the purpose is to reduce exhaust emissions:

— Air Intake Systems

— Ignition Systems

— Fuel Control Systems

— Emissions Control Systems

— Basic Engine Systems

— For microprocessor (02) based air/fuel control systems, cooling systems.

X.C. Within the basic program, emissions related adjustments and repairs must have been 

performed by a licensed emissions mechanic or repair facility/technician registered with 

the Division pursuant to Part D of this regulation in order to be creditable to the repair 

cost waiver limits.
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Adopted: November 21, 2013 Page 28

In order to be creditable to the enhanced repair cost limits, adjustments and repairs must have 

been performed by a repair facility/technician registered with the Division pursuant to Part D of 

this regulation.

Only the appropriate emissions failure related parts costs should apply to applicable waiver limits 

for repairs not performed at a licensed emissions inspection station or registered repair 

facility/technician.

XI. ENGINE CHANGES

XI.A. For those vehicles in which the original engine has been replaced, the emissions limits 

and applicable emissions control equipment for the year and model of the vehicle 

body/chassis, as per registration/title or replacement engine, whichever is newest, shall 

apply. For those diesel powered vehicles which have been converted to operate on 

fuel(s) other than diesel; the emissions limits and applicable emissions control equipment 

for the year, make and model of the gasoline powered engine equivalent as originally 

manufactured, for the vehicle body/chassis, per the registration or replacement engine, 

whichever is newest, shall apply as determined by emissions technical center personnel 

or designee and specified on an official AIR Program vehicle evaluation form (DR2365).

XI.B. For 1975 and newer vehicles in which the original engine has been replaced, if either the 

vehicle body/chassis original engine, as per registration/title or replacement engine as 

manufactured had a catalytic converter system, air injection reaction system, and/or 

microprocessor based air/fuel control system, these emission control systems must be 

present, intact and operational before a Certification of Emissions Control may be issued.

XI.C. For those vehicles titled/registered as model year 1975 and newer, that were assembled 

by other than a licensed manufacturer such as kit-cars, registered/titled according to 

Section(s) 42-6-108 and/or 42-5-205, C.R.S. and assigned a state or manufacturer 

specific identification number, the applicable emissions control equipment and standards 

will be based upon a determination by technical center personnel of the vintage of the 

vehicle engine. The technical center personnel may issue an affidavit and the year of the 

engine shall be presumed to be that stated by the vehicle owner unless it is determined 

by state emissions technical center personnel or designee, after physical inspection of 

the vehicle engine, that the year of the engine is other than stated by the owner.

XII. CLEAN SCREEN INSPECTION PROGRAM PROCEDURES

XII.A. Eligibility to participate

XII.A.1. Vehicles specified in Part A, Section IV.B., are eligible for participation in the 

Clean Screen Program.

XII.A.2. Clean Screen inspections applicable to the program are those performed within 

twelve months prior to an individual vehicle's registration renewal date.

XII.A.3. Vehicles are eligible for participation in the Clean Screen Program when the two 

most recent consecutive emissions readings observed during the 12-months 

prior to its registration date comply with the standards specified in Part F, Section

VI. and: the most recent passing emissions reading occurred on a different day 

or at a different site location from the prior reading. Additionally, vehicles that are 

identified as low emitters on the low emitting vehicle index are eligible for 
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Adopted: November 21, 2013 Page 29

participation in the clean screen program when the most recent emissions 

reading observed during the 12-months prior to their registration date complies 

with the standard specified in Part F, Section VI.

XII.A.4. The following vehicles are ineligible for participation in the Clean Screen 

Program:

XII.A.4.a. New Vehicles as specified in Section 42-4-310(b)(II)(A), C.R.S.

XII.A.4.b. Vehicles involved in a change of ownership.

XII.A.4.c. Vehicles owned by the United States government or any agency 

thereof pursuant to Section 42-4-310(l)(b)(I), C.R.S.

XII.B. All aspects of inspection must be performed by a licensed Clean Screen Inspector.

XII.C. Clean Screen Test Analyzer Systems

XII.C.1. Vehicles participating in the Clean Screen Program shall be tested as specified in 

this Part C utilizing a Clean Screen Test Analyzer System recognized by the 

Division as having complied with the performance and design requirements 

specified in Part B, Section IX. of this regulation.

XII.C.2. Clean Screen Test Analyzer Systems will be periodically calibrated and 

maintained as required in Part B, Section IX. of this regulation.

XII.C.3. The inspection data processing system(s) used by the Data Manger and Clean 

Screen Inspector will be that approved by the Division, and the Department of 

Revenue.

XII.D. Vehicle owners participating in the Clean Screen Program are not subject to the 

provisions of Part C, Sections I. through XI.

XII.E. Certification of Emissions Control.

In order to obtain a Certificate of Emissions Control the following conditions must be met:

XII.E.1. The vehicle emissions levels are the same as or less than the limits specified in 

Part F, Section VI.

XII.E.2. The most recent two consecutive emissions readings were observed within 

twelve months of the registration renewal date provided that the most recent 

passing emissions reading must have occurred on a different day or at a different 

site location from the prior reading.

XII.E.3. No non-complying emissions readings are observed between or subsequent to 

the last pair of complying readings.

XII.E.4. For vehicles that are identified as low emitters on the low emitting index the most 

recent emission reading was observed within 12-months of the registration 

renewal date. For these vehicles, identification as a low emitter on the low 
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Adopted: November 21, 2013 Page 30

emitting vehicle index shall take the place of the second remote sensing reading 

otherwise required under Section XII.E.2., above.

PART D Qualification and Licensing of Emissions Mechanics, Emissions Inspectors, and 

Clean Screen Inspectors; Licensing of Emissions Inspection and Readjustment 

Stations, Inspection-Only Stations, Inspection-Only Facilities, Fleets, Motor Vehicle 

Dealer Test Facilities, Enhanced Inspection Centers; Qualification of Clean Screen 

Inspection Sites; and Registration of Emissions Related Repair Facilities and 

Technicians

I. LICENSING OF EMISSIONS INSPECTION AND READJUSTMENT STATIONS, INSPECTIONONLY STATIONS, INSPECTION-ONLY FACILITIES, ENHANCED INSPECTION CENTERS, 

FLEET INSPECTION STATIONS AND MOTOR VEHICLE DEALER TEST FACILITIES

I.A. Emissions Site Requirements for the Licensing of Emissions Inspection and 

Readjustment Stations, Inspection-Only Stations, Inspection-Only Facilities, Fleet 

Inspection Stations and Motor Vehicle Dealer Test Facilities:

I.A.1. Applicability

All emissions inspection and readjustment stations, inspection-only stations, inspectiononly facilities, fleet inspection stations, and motor vehicle dealer test facilities are required 

to meet all applicable standards pursuant to this Part D and the Department of Revenue's 

adopted regulations in order to qualify for licensing for operation in Colorado's AIR 

Program.

To achieve the uniformity and security needed in test site locations; in order to meet 

federal EPA regulations contained in Federal Register vol. 57, Number 215, of the 

Federal Register and meet the statutory requirements contained in Sections 42-4-301 

through 42-4-316, C.R.S.; the Air Quality Control Commission adopts this standard for 

emissions site requirements.

I.A.2. Standards for emissions inspection sites:

I.A.2.a. All facilities shall be a permanent type of structure.

I.A.2.b. All sites must be capable of receiving mail.

I.A.2.c. All test facilities shall have a minimum of two off-street parking spaces 

for staging to accommodate additional vehicles.

I.A.2.d. All test site facilities shall have a customer waiting area that provides for 

observation of the entire emissions inspection process. Observation can 

be, direct observation, observation by electronic equipment, or other 

methods that prove to be as effective with prior approval of the 

Department of Revenue. 

I.A.2.e. All test sites shall be capable of conducting all aspects of the inspection 

process within the confines of a building or structure, and maintaining 

ambient air temperatures between 41 degrees and 110 degrees 

Fahrenheit in the inspection area as defined in Section I. C. 1. of Part C 

of this regulation. Inspections are not required to be performed within the 
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confines of a structure or building provided ambient temperatures are 

within such parameters.

I.A.2.f. All test site facilities shall have an adequate exhaust removal system 

which shall be designed so as to not alter the inspection results and to 

assure safe ambient air quality of the inspection area as established by 

the Occupational Safety and Health Administration pursuant to 29 CFR, 

Part 1910, Subpart Z.

I.A.3. Pursuant to Sections 42-4-306(4)(a) and 42-4-307 (8)(a), C.R.S. as amended, the 

Division shall develop or contract for the development of a training program for 

emissions mechanics and emissions inspectors. The training program shall be 

comprehensive in nature and address all aspects of vehicle inspection 

procedures specified for this regulation.

I.A.3.a. Participation by emissions inspectors intending to operate in the 

enhanced program area shall be required.

I.A.3.b. Participation by emissions mechanics intending to operate in the basic 

program area shall be voluntary.

I.A.3.c. Training classes shall be funded by tuition charged to the participants.

I.A.3.d. The following tuition rates and fees shall apply

I.A.3.d.(1) The training class fee shall be no greater than $150 per 

participant.

I.A.3.d.(2) The instructor's fee for presenting a class shall not exceed 

$400.

I.A.3.d.(3) The training manual for those emissions mechanics who 

choose not to participate in a training class shall be no greater 

than $25.

I.A.3.e. These same training provisions shall be applicable to the requalification 

provisions of Section II.B. of this Part D.

I.B. The following tools, reference manuals and diagnostic equipment shall be available for 

performance of inspections; and within the basic program, emissions related adjustments 

and repairs.

I.B.1. Division approved calibrated and spanned Test Analyzer System (TAS) or OnBoard Diagnostic Test Analyzer System (OBD TAS).

I.B.1.a. As a provision of continued license to perform AIR Program inspections, 

the TAS must be updated as required, pursuant to this regulation.

I.B.1.b. The station or facility owner or operator shall maintain a full 

service/maintenance contract with the equipment manufacturer or 

equipment manufacturer's designee valid for the duration of the program 

but renewable on an annual basis
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I.B.2. Rules for the operation of AIR Program inspection stations provided by the

Colorado Department of Revenue.

I.B.3. Tachometer capable of reading 4,6 and 8 cylinders, 0-6,000 RPM minimum at no 

greater than 10 RPM of actual speed.

I.B.4. Emissions control systems applications guide as incorporated into the TAS, and 

oxygen sensor/check engine light, systems maintenance guide in either printed 

or electronic medium.

I.B.5. Dwell meter.

I.B.6. Ignition timing light.

I.B.7. Propane enrichment kit for idle mixture adjustment and diagnostics.

I.B.8. Commercially available reference manuals giving idle speed, idle mixture, 

mixture control dwell or fuel injection duration, timing, dwell, fast idle speed 

specification, high altitude specifications and information covering the emissions 

control systems description, diagnostic and repair procedures for the year 

models of vehicles involved in the AIR Program. In either printed or electronic 

medium.

I.B.9. Sufficient hand tools including but not limited to suitable computer scanner 

diagnostic link, digital volt/ohm meter, vacuum pump and other automotive 

diagnostic equipment for proper performance of the inspections, adjustments and 

emissions related repairs as applicable to the licensed entity.

I.B.10. Division approved span gas and equipment for performing gas span checks and 

calibrations.

I.B.11. Suitable non-reactive tail pipe extenders or probe adapter for inspecting vehicles 

with screened or baffled exhaust systems, or exhaust systems with multiple tail 

pipes.

I.B.12. The analyzer manufacturer's maintenance and calibration manual must be 

retained in the inspection area.

I.B.13. (Reserved)

I.B.14. Items #5, 6, 7, 8 and 9 above are not required for licensing as an inspection-only 

station or inspection-only facility.

I.B.15. Items #3 through 11 above are not required for a vehicle fleet self inspection 

station pursuant to 42-4-309 C.R.S.

I.C. A licensed emissions mechanic or emissions inspector who has successfully completed a 

hands-on proficiency check administered by the Department of Revenue in accord with 

the Commission regulations and those of the Department of Revenue, and the criteria 

specified in Part D of this regulation is or will be available to make a proper inspection. 

Enhanced inspection centers shall be open 8:30 am - 7:30 p.m. weekdays, and Saturday 

8:00 a.m. -1:00 p.m.
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Adopted: November 21, 2013 Page 33

I.D. An emissions inspection-only station and inspection-only facility, must so indicate same 

by posting a sign in a readily visible location, and that no emissions related adjustments 

or repair services are available should the vehicle fail the inspection procedure.

I.E. A person to whom there are twenty (20) or more vehicles registered, or to whom said 

number of vehicles are leased for not less than six continuous months, or are consigned 

for sale, may be licensed as a “fleet inspection station” or as a dealer licensed under 

Article 6 of Title 12, C.R.S., a motor vehicle dealers test facility and conduct inspections 

of that fleet or those vehicles inventoried or consigned for retail sale. As a fleet inspection 

station or motor vehicle dealer test facility, no inspections may be conducted for the 

employees or general public, but only on vehicles owned, leased by the business, or 

consigned or held in inventory for sale. A Certificate of Emissions Control issued by a 

fleet emissions inspection station will be valid for 12 months, one vehicle registration 

cycle.

I.E.1. Under the self-inspection provisions of Section 42-4-309, C.R.S. for fleets of 

twenty (20) or more vehicles, the retail sale of a fleet vehicle within the enhanced 

program area requires full compliance with applicable inspection procedures as 

performed by an enhanced inspection center or an (enhanced) inspection-only 

facility.

I.E.2. At the time of initial licensing and annually thereafter, the vehicle fleet shall be 

declared by completing a listing of all eligible vehicles by make, model year, lightheavy duty classification, vehicle identification number, license plate number, and 

if applicable unit number and state of registration on forms provided by the 

Division.

I.F. All AIR Program inspection stations, facilities and centers are required to post in a 

conspicuous location in a clearly legible fashion a sign indicating the fees charged for 

inspections and in the basic program area, and maximum fees for emissions related 

adjustments and repairs required for the issuance of a Certificate of Emissions Control.

I.G. All AIR Program inspection stations, facilities and centers are required to be linked via 

dedicated service line to the program data/communications network.

I.G.1. Basic program inspection services providers and independent inspection-only 

facilities in the enhanced area shall be linked to the data network via dedicated 

voice quality telephone lines with a dial-up back-up telephone line.

I.G.2. Enhanced inspection centers shall be linked via dedicated data quality lines with 

dedicated voice quality lines as dial-up back-up.

I.H. All sites must provide for reasonable access in order for Departments of Revenue (or if 

applicable, Health) staff to conduct periodic quality control and audit functions as 

necessary.

I.I. Upon request for a license as an emissions inspection and readjustment station, 

inspection-only station, fleet inspection station, motor vehicle dealer test facility, or 

inspection-only facility, applicants shall complete forms approved by the Department of 

Revenue which shall include but not be limited to a declaration of any past violations of 

AIR Program statute Section 42-4-301 through 42-4-316, C.R.S. as amended or any rule 

or regulation pursuant to such law.
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Adopted: November 21, 2013 Page 34

II. QUALIFICATION AND LICENSING OF EMISSIONS MECHANICS AND EMISSIONS 

INSPECTORS

II.A. Qualification of Emissions Mechanics and Emissions Inspectors

II.A.1. Application for qualification as an emissions mechanic and emissions inspector 

shall be filed with the Air Pollution Control Division. The Division shall administer 

issuance of letters of qualification. Applications for such letters of qualification 

shall be completed on forms provided by the Division. Before an applicant may 

be given a letter of qualification, he must comply with the requirements of this 

Section II. The Division will notify applicants of the evaluation requirements prior 

to testing.

II.A.2. An applicant must demonstrate knowledge, skill, and competence concerning the 

conduct of emissions inspections, and within the basic program area the 

adjustment and repair of vehicles to manufacturers' specifications. Such 

knowledge, skill and competence will be shown by passing a written and skills 

proficiency qualification test including, but not limited to, knowledge of the 

following:

II.A.2.a. Operation and purpose of emissions control systems.

II.A.2.b. Relationship of exhaust and evaporative HC and CO to timing and 

air/fuel ratio control.

II.A.2.c. Adjustment and repair to manufacturers' and applicable high altitude 

specifications.

II.A.2.d. Rules and regulations of AIR Program and proper inspection procedures.

II.A.2.e. Contemporary diagnostic and engine tune-up procedures.

II.A.2.f. The provisions of the Emissions Control Systems Performance Warranty 

pursuant to Section 207 (A) and (b) of the federal Clean Air Act as it 

applies to the AIR Program.

II.A.2.g. Visual inspection of the required emissions control equipment for 1975 

and newer vehicles.

II.A.2.h. Operation of and proper use, care maintenance, calibration and gas 

span checking of the Division-approved inspection equipment.

II.A.2.i. Proper use of, security, and distribution of inspection forms, Certificates 

of Emissions Control, and supplemental inspection documents.

II.A.2.j. Emissions related adjustment and repair requirements for all vehicles 

failing the initial emissions inspection.

II.A.2.k. Inspecting for visible smoke emissions.

II.A.2.l. (Reserved)
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Adopted: November 21, 2013 Page 35

II.A.2.m. Cause and effect of air pollution.

II.A.2.n. Purpose, goal and function of the AIR Program.

II.A.2.o. Exhaust and evaporative emissions inspection procedures and rationale 

for use.

II.A.2.p. Public relations and motorist assistance.

II.A.2.q. Safety procedures in the inspection lane or bay.

II.B. Requalification Requirements for all Emissions Mechanics and Emissions Inspectors

II.B.1. Upon the determination by the Commission of the necessity of technically 

updating the qualifications for emissions mechanics or emissions inspectors and, 

upon development or approval of retraining courses and retesting requirements

for emissions mechanics to demonstrate said qualification, emissions mechanics, 

or holders of certificates of qualification, shall be required to requalify biennially.

II.B.2. Emissions mechanics and emissions inspectors shall be required to requalify 

within ninety days from the date of written notification by the Department of 

Revenue. Said notice shall be mailed to the address of record in the office of the 

Department of Revenue charged with licensing of emissions mechanics and 

inspectors, which notice shall inform the person of the necessity of requalification 

and the nature of such skills, systems, and procedures requiring the retraining for 

the continued performance of the emissions inspection. The notice shall give the 

name and location of training sources approved or accredited for purposes of 

retraining, the necessity of requalification by a certain date, and the nature and 

evidence of documentation to be filed with the Department of Revenue 

evidencing such requalification, and state that failure to requalify within said 

period of time shall result in suspension or revocation of the emissions 

mechanic's or emissions inspector's license or certification as described in the 

Department of Revenue rules and regulations.

II.B.3. The Division shall issue a letter of requalification to any person who has 

requalified to the satisfaction of the Division and according to the requalification 

regulation of the Department of Revenue.

II.C. Transmittal of Letters of Qualification and Issuance of Emissions Mechanic's and 

Emissions Inspector's Licenses

The Division shall provide a listing of all letters of qualification or letters of requalification for 

emissions mechanics or emissions inspectors to the Department of Revenue, and, upon 

application by any person qualified, the Department of Revenue shall issue an emissions 

mechanic's or emissions inspector's license or renewal license in accord with the regulations of 

that department.

II.D. Lapse of Certificate of Qualification for Emission Mechanic.

A person to whom the Division has issued a letter of qualification, who has not been issued an 

emissions mechanic's or emissions inspector's license within six (6) months from the date of 
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Adopted: November 21, 2013 Page 36

issuance of the most recently issued letter of qualification shall be deemed to have forfeited said 

qualification and shall be required to reapply if a new letter of qualification is requested.

II.E. Program License Application Performance Review Criteria

II.E.1. Applicability

Pursuant to Sections 42-4-306(4)(c) and 42-4-308(1 )(b), C.R.S. the Commission is 

authorized to establish minimum performance criteria for licensed emissions inspectors, 

mechanics, and stations. Based on these performance criteria, Section 42-4-312, C.R.S. 

grants authority to the Executive Director of the Department of Revenue to suspend or 

revoke a license on a finding of a pattern of violations.

In order to meet federal act requirements and to provide consistent criteria for the 

Department of Revenue's review of performance based evaluations that may result in a 

denial of the license application, the Executive Director of the Department of Revenue or 

the designee shall apply criteria contained in this Section E.

II.E.2. Standards

The following criteria shall be used by the Department of Revenue's Executive Director or 

his designee in the review of any emissions license application for a mechanic, inspector, 

inspection and readjustment station, inspection-only station, inspection-only facility, fleet 

station, or motor vehicle dealer test facility.

Performance

Based on violations and penalties provided in Section 42-4-313(4)(b)(1), C.R.S. the 

following criteria will be used for the review of any emissions license application listed in 

this section:

II.E.2.a. Any substantiated violation of intentional passing of a failing vehicle.

II.E.2.b. Any substantiated violation of performance of emissions tests by an 

unlicensed mechanic, inspector, or station.

II.E.2.c. Any substantiated violation of performance of an emissions test on 

falsified emissions test equipment.

II.E.2.d. Any substantiated violation of failing of passing vehicles.

II.E.2.e. Any substantiated violation of flagrant misuse of emissions program 

control documents.

II.E.2.f. Any substantiated pattern of non-compliance with AIR Program 

regulations.

II.E.2.g. Any substantiated violation of false statements on any emissions license 

application in an attempt to conceal problems such as: administrative 

hearings held for program violations, any probation of any emissions 

license held previously or currently held, any suspension or revocation of 

any emissions license held previously or currently.
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Adopted: November 21, 2013 Page 37

For the purposes of emissions license application review, past performance may 

entail complete program history review of any person, persons, or officers of a 

corporation, or partners of any partnership that hold or held a license with the 

AIR Program.

II.E.2.h. As a prerequisite to licensing of an emissions mechanic or emissions 

inspector, a hands-on proficiency check to address the criteria described 

in Section II. A. 2. of this Part D will be administered by the Department 

of Revenue in accord with the regulations of the Commission. This 

evaluation will be conducted at the emissions mechanic's or emissions 

inspector's place of employment and on an exhaust gas analyzer or test 

analyzer system that would be used to conduct inspections.

In order to provide for continuity and consistency with training, testing and 

licensing activities conducted per this Part D, the development and maintenance 

of the hand-on proficiency check will be coordinated between the Department of 

Revenue and the Division.

III. REGISTRATION OF EMISSIONS RELATED REPAIR FACILITIES

III.A. Automotive Emissions Related Repair Facilities May Voluntarily Register with the 

Division.

III.A.1. The repair facility/technicians agree to have the effectiveness of their emissions 

related repairs and repair costs monitored by the Division on an on-going basis.

III.A.2. Repair facility/technicians agree to have repair effectiveness listing provided to 

those motorists whose vehicles fail any element of the inspection procedures 

specified in Part C of this regulation.

III.A.3. The facility shall complete and process AIR Program repair report forms as 

approved by the Division. Repair report form processing equipment may 

incorporate PC based bar code technology such that one-dimensional “3 of 9"

and two dimensional “PDF 417” symbology can be read and written. The system 

must be capable of supporting form generation software provided by the state. 

The printer shall be an ink jet printer or equivalent capable of printing the bar 

code symbology stated. Refer to Section 2.14 of the TAS specifications attached 

as Appendix A of this regulation for microcomputers specifications. The Division 

shall determine performance equivalence.

III.B. As an aid to motorists seeking emissions related repair assistance, a means will be 

established whereby a listing of registered repair facilities whose repair effectiveness 

would be made available and presented to the motorist at the time of inspection failure. 

Repair effectiveness shall include but may not be limited to:

a. Number of vehicles repaired and retested

b. Percent passing on first retest

c. Percent requiring additional repairs and retests

d. Percent issued waivers
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Adopted: November 21, 2013 Page 38

The listing shall document any recognized professional automotive accreditation or memberships 

that may include but not be limited to the National Institute for Automotive Service Excellence, or 

Automotive Service Association. The listing may also indicate the vehicle make(s) or vehicle 

classification that the repair facility specializes in.

III.C. Repair facilities may request removal from the listing or temporary placement on an 

inactive listing while measures are being taken to improve repair effectiveness.

III.D. It is further suggested that:

III.D.1. The repair facility/technicians will seek out appropriate training when repair 

effectiveness deficiencies are identified.

III.D.2. Repair facilities will hire and retain technicians certified under “Automotive 

Service Excellence” tests number A-1, A-6, A-8, and L-1 and that technicians will 

maintain these levels of certifications.

Ill.D.3. That the repair facility be adequately equipped and maintain a level of diagnostic 

and repair equipment necessary to perform emissions related repairs based 

upon the criteria set forth by the Automotive Service Association of Colorado, 

Incorporated.

III.D.4. The Department of Revenue performs a site evaluation of facilities that apply to 

assess compliance and confirm qualifications.

III.D.5. The facility has or could comply with the provisions established in Part D of this 

regulation and have not been subject to the penalties prescribed by Section 42-9-

111, C.R.S.

III.E. The Division will monitor and periodically report to individual repair facilities their repair

effectiveness and average costs as compared to other registered repair facilities.

III.F. The Division shall make repair effectiveness data available to the general public upon 

request as well as periodically to the Department of Revenue.

III.G. The Division may request a site evaluation of any registered repair facility by the 

Department of Revenue for reasons of diminished repair effectiveness or noted 

consumer complaints.

III.H. The Division shall identify the level(s) of repair effectiveness that would result in 

inadequate emission(s) reductions and negatively impact consumer protection.

IV. REQUIREMENTS FOR CLEAN SCREEN/REMOTE SENSING SITES

IV.A. Applicability

Clean Screen Inspection Sites must meet all applicable standards pursuant to this Part D and the 

Department of Revenue's regulations in order to qualify for operating in Colorado's Clean Screen 

Program.

IV.B. Standards for emissions inspection sites
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Adopted: November 21, 2013 Page 39

All sites shall comply with all applicable state and local codes/ordinances and maintain 

appropriate permits for that specific municipality and location.

IV.C. All Clean Screen Sites must provide reasonable access in order for Department of 

Revenue (and if applicable, Division) staff to conduct periodic quality control and audit 

functions as necessary.

IV.D. Applicants for a license as a Clean Screen Emissions Inspector shall complete forms 

approved by the Department of Revenue which shall include, but not be limited to, a 

declaration of any past violations of AIR Program statute Sections 42-4-301 through 42-

4-316, C.R.S., as amended or any rule or regulation pursuant to such law.

V. QUALIFICATION OF CLEAN SCREEN EMISSIONS INSPECTORS

V.A. Clean Screen Emissions Inspector applicants shall apply for letters of qualification on 

forms provided by the Division. The Division shall issue letters of qualification to 

applicants who comply with the requirements of this Section V. The Division will notify 

applicants of the evaluation requirements specified in Part D, Section V.B. prior to testing.

V.B. An applicant for a letter of qualification or requalification must demonstrate knowledge, 

skill, and competence concerning the operation of Clean Screen emissions inspections. 

Such knowledge, skill and competence will be demonstrated on actual Clean Screen 

equipment and by passing a skills proficiency qualification test including, but not limited 

to, knowledge of the following:

V.B.1. Operation of and proper use, care, maintenance, calibration and gas span 

checking of the Division-approved Clean Screen Test Analyzer System.

V.B.2. Safety procedures for the Clean Screen Inspection Site.

V.B.3. Proper setup and breakdown of the Clean Screen equipment

VI. REQUALIFICATION REQUIREMENTS FOR ALL CLEAN SCREEN EMISSIONS INSPECTORS

VI.A. Upon the determination by the Division of the necessity of updating the technical 

qualifications for Clean Screen Emissions Inspectors, holders of certificates of 

qualification shall be required to requalify biannually. The Division may waive this 

requirement should it be unnecessary.

VI.B. Clean Screen Emissions Inspectors shall be required to requalify within ninety days from 

the date of electronic notification by the Department of Revenue.

VI.C. The Division shall issue a letter of requalification to any licensed Clean Screen Emissions 

Inspector who meets the requirements of Section Part D, Section V.B.

VII. TRANSMITTAL OF LETTERS OF QUALIFICATION AND ISSUANCE OF CLEAN SCREEN 

INSPECTOR LICENSES

The Division shall provide a listing of all letters of qualification or letters of requalification for Clean Screen 

Inspectors to the Department of Revenue, and upon application by any person qualified, the Department 

of Revenue may issue a Clean Screen Inspector's license or renewal license in accordance with the 

regulations of that department.
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Adopted: November 21, 2013 Page 40

VIII. LAPSE OF CERTIFICATE OF QUALIFICATION FOR CLEAN SCREEN INSPECTOR

A person to whom the Division has issued a letter of qualification, who has not been issued a Clean 

Screen Inspector license within six (6) months from the date of issuance of the most recently issued letter 

of qualification shall be deemed to have forfeited said qualification and shall be required to reapply if a 

new letter of qualification is requested.

IX. PROGRAM LICENSE APPLICATION PERFORMANCE REVIEW CRITERIA

IX.A. Applicability

Pursuant to Sections 42-4-306(4)(c) and 42-4-308(1 )(b), C.R.S., the Commission is authorized to 

establish minimum performance criteria for licensed Clean Screen Inspectors and Data 

Management Contractor(s). Based on these performance criteria, Section 42-4-312, C.R.S., 

grants authority to the executive director of the Department of Revenue to suspend or revoke a 

license.

In order to provide consistent criteria for the Department of Revenue's review of performance 

based evaluations that may result in a denial of a license application, or revocation of a license, 

the executive director of the Department of Revenue or the designee shall apply criteria 

contained in Sections IV through VII of this Part D.

IX.B. Requirements

The Department of Revenue’s executive director or his designee in the review of any emissions 

license application shall use the following criteria for a Clean Screen Inspector, or Clean Screen 

Data Manager.

Performance

Based on violations and penalties provided in Section 42-4-313(4)(b)(1), C.R.S., the following 

criteria will be used for the review of any license application listed in the section:

IX.B.1. Any violation of intentional passing of a failing vehicle.

IX.B.2. Any violation of performance of Clean Screen inspections by an unlicensed 

inspector, or at an unapproved/unlicensed site.

IX.B.3. Any violation of performance of a Clean Screen inspection on a falsified Clean 

Screened Test Analyzer System.

IX.B.4. Any violation of flagrant misuse of Clean Screen inspection data, control 

documents, vehicle owner information, or vehicle registration data.

IX.B.5. Any pattern of non-compliance with AIR Program regulations, including Clean 

Screen provisions.

IX.B.6. Any violation of false statements on any license application.

IX.B.7. As a prerequisite to licensing of a Clean Screen Inspector, a hands-on 

proficiency check to address the criteria described in Section V of this Part D will 

be administered by the Department of Revenue in accord with the regulations of 
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Adopted: November 21, 2013 Page 41

the Commission. This evaluation will be conducted at a mutually agreed upon 

location and on an approved Clean Screen Test Analyzer System that would be 

used to conduct inspections.

In order to provide for continuity and consistency with qualifying and licensing activities 

conducted per this Part D, the development and maintenance of the hands-on proficiency 

check will be coordinated between the Department of Revenue and the Division.

PART E Prohibited Acts and Penalties to Ensure Proper Inspection Procedures, Adherence 

to Prescribed Procedures and Effective Emissions Related Repairs

I. THIS PART E DESCRIBES THE GROUNDS UPON WHICH THE LICENSE OF AN EMISSIONS 

MECHANIC, EMISSIONS INSPECTOR OR ANY TYPE OF AIR PROGRAM INSPECTION 

BUSINESS MAY BE SUSPENDED, FOR A PERIOD OF TIME NOT LESS THAN Six MONTHS, 

OR REVOKED.

I.A. Pattern of Violations

The license of an emissions mechanic, emissions inspector, inspections and readjustment 

station, inspection-only station, inspection-only facility, fleet inspection facility, motor vehicle 

dealer test facility, or contractor's contract may be revoked or suspended, as appropriate 

pursuant to Sections 42-4-312 and, 42-4-313, C.R.S., if such mechanic, inspector or facility has 

engaged in a pattern of violations of the provisions of this Regulation Number 11, or other 

applicable statutes or regulations, including, but not limited to:

I.A.1. AIR Program inspection business, and/or emissions inspector or emissions 

mechanic is involved in any unauthorized entry into the analyzer or inspection 

system that result in a fraudulent inspection report and/or emissions certificate 

being issued.

I.A.2. AIR Program inspection business, and/or emissions inspector or emissions 

mechanic caused an inspection report and/or emissions certificate to be issued 

to a vehicle that did not at the time of issue comply with the laws, rules or 

regulations.

I.A.3. AIR Program inspection business, and/or emissions inspector or emissions 

mechanic makes, issues, or knowingly uses any imitation or deceptively similar 

or counterfeit inspection report and/or emissions certificate.

I.A.4. AIR Program inspection business, and/or emissions inspector or emissions 

mechanic possesses an inspection report and/or emissions certificate which is 

known to be fictitious, or was issued for another vehicle, or was issued without an 

emissions inspection test having been performed when required.

I.A.5. Exercising licensing privilege other than those granted by the Department of 

Revenue and the Commission.

I.A.6. AIR Program inspection(s) have not or are not being made in accordance with 

applicable laws and the rules and regulations of the Department or the 

Commission.
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Adopted: November 21, 2013 Page 42

I.A.7. Vehicles have not or are not being repaired in accordance with applicable laws 

and the rules and regulations of the Department or the Commission.

I.A.8. Emissions mechanic or emissions inspector failed to a post-valid license.

I.A.9. AIR Program inspection business, and/or emissions inspector or emissions 

mechanic failed to post AIR Program license(s) in a location available and 

conspicuous to the public.

I.A.10. AIR Program inspection business, and/or emission inspector or emissions 

mechanic failed to use the correct inspection report form issued by the 

Department.

I.A.11. AIR Program inspection business, and/or emissions inspector or emissions 

mechanic used an inspection report form for a purpose other than permitted by 

the Department.

I.A.12. AIR Program inspection business, and/or emissions inspector or emissions 

mechanic failed to complete the correct inspection report form or.

I.A.13. AIR Program inspection business, and/or emissions inspector or emissions 

mechanic loaned, sold, gave or transferred inspection report forms to another 

AIR Program inspection business or mechanic.

I.A.14. Repealed.

I.A.15. AIR Program inspection business, and/or emissions inspector or emissions 

mechanic performed air tests with an analyzer or test system that was not 

certified.

I.A.16. AIR Program inspection business, and/or emissions inspector or emissions 

mechanic used span gas that was not approved.

I.A.17. AIR Program inspection business, and/or emissions inspector or emissions 

mechanic, failed to have tools, supplies and records available for inspection by 

the Department of Revenue.

I.A.18. AIR Program inspection business, and/or emissions inspector or emissions 

mechanic used “escape” mode in analyzer without valid reason.

I.A.19. AIR Program inspection business, and/or emissions inspector or emissions 

mechanic failed to properly identify and record a vehicle that fails the air test.

I.A.20. AIR Program inspection business, and/or emissions inspector or emissions 

mechanic failed to properly identify and record a vehicle that passes the 

emissions inspection.

I.A.21. AIR Program inspection business, emissions inspector or emissions mechanic 

falsely reports an (incorrect) vehicle identification number or vehicle information 

on a DR2411 form supplied by the Department of Revenue.
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Adopted: November 21, 2013 Page 43

I.A.22. AIR Program inspection business, and/or emissions inspector or emissions 

mechanic performed inspections while under suspension or administrative hold.

I.A.23. AIR Program inspection business, and/or emissions inspector or emissions 

mechanic continued using an analyzer knowing it was malfunctioning.

I.A.24. AIR Program inspection business, emissions inspector or emissions mechanic 

charged more than posted fee for service.

I.A.25. AIR Program inspection business, through its agent denied the issue of a vehicle 

inspection report and/or Certificate of Emissions Compliance when at the time of 

inspection the vehicle did comply with the laws, rules and regulations for the 

issuance of such a certificate.

I.A.26. AIR Program inspection business was not open and available to perform 

inspection services during normal business hours.

I.A.27. AIR Program inspection business, through its agent, failed to issue a Certificate 

of Waiver to a vehicle that met all the requirements.

I.A.28. AIR Program inspection business, through its agent, issued a Certificate of 

Waiver to a vehicle that was eligible pursuant to Section 207(b) of the federal 

Clean Air Act

I.A.29. AIR Program inspection business, through its agent, performed repairs to the 

emissions control systems of a vehicle that are eligible for any manufacturer's 

warranties without informing the owner of said warranties.

I.A.30. AIR inspection business failed to display all required signs and post fees for 

inspection services.

I.A.31. Electrical supply fails to meet voltage and frequency requirements of 110V (±) 

10% 60HZ, or is not publicly supplied as appropriate to that area.

I.A.32. AIR Program inspection business, through its agent, performed an inspection 

when the temperature of the inspection area was not between 41 degrees and 

110 degrees Fahrenheit.

I.A.33. AIR Program inspection business could not account for controlled documents.

I.A.34. Emissions mechanic or emissions inspector failed to keep their access code 

secure which resulted in an inspection conducted by an unlicensed person.

I.A.35. Emissions mechanic or emissions inspector failed to keep his current mailing 

address on file with the Department of Revenue.

I.A.36. A licensed emissions mechanic or emissions inspector is not employed at the 

facility.

I.B. Conditions Under Which a Station, Facility or Center License may be Denied, Suspended 

or Revoked.
Regulation Number 11

Adopted: November 21, 2013 Page 44

In addition to the grounds listed in Section A, the license of any inspection and readjustment 

station, inspection-only station, inspection-only facility, fleet inspection facility, motor vehicle 

dealer test facility or the Contractor, may be suspended or revoked as appropriate pursuant to 

Sections 42-4-312 and, 42-4-313, C.R.S. for any of the following violations:

I.B.1. AIR Program inspection business, and/or its agent have engaged in a pattern of 

violation of any provision of the applicable laws, rules or regulations.

I.B.2. AIR Program inspection business, through its agent issued a vehicle inspection 

report and/or Certificate of Emissions Waiver when at the time of issue the 

vehicle did not comply with the laws, rules and regulations for the issuance of 

such a certificate.

I.B.3. AIR Program inspection business, through its agent issued a vehicle inspection 

report and/or Certificate of Emissions Control without an air test having been 

performed.

I.B.4. Adjustments or repairs were performed when such adjustments or repairs were 

not authorized or required.

I.B.5. AIR Program inspection business is not equipped as required.

I.B.6. AIR Program inspection business was not operating from the location for which 

the license was issued.

I.B.7. Emissions mechanic or emissions inspector made false statements on official 

forms.

I.B.8. Facilities of applicant for an AIR Program license are not properly equipped for 

the type of license applied for.

I.B.9. The AIR Program inspection business flagrantly misuses control documents by 

committing any of the violations described in Part E, Sections I.A.10through

I.A.14.

I.B.10. An unlicensed person performed all or any part of an inspection procedure.

I.B.11. Within the enhanced program area, Motor Vehicle Dealer Test Facility 

inspections are limited to one per vehicle (consecutively) such that no vehicle 

shall be inspected twice consecutively. Following an inspection at a Motor 

Vehicle Dealer Test Facility that vehicle's inspection for the next cycle must be 

performed in the inspection-only network of enhanced inspection centers or 

decentralized inspection-only facilities; as applicable to the model year of the 

vehicle.

I.C. Conditions Under Which an Emissions Mechanic or Emissions Inspector License may be 

Denied, Suspended or Revoked.

I.C.1. Emissions mechanic or emissions inspector caused a passing Certificate of 

Emissions Compliance to be issued to a failing vehicle.
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Adopted: November 21, 2013 Page 45

I.C.2. Emissions mechanic or emissions inspector made false statements on official 

forms.

I.C.3. The emissions inspector or emissions mechanic performed two or more 

emissions inspections using a test analyzer system that was not updated as 

required by Part B or Appendix A of this regulation.

I.D. Any action to suspend or revoke the license for any enhanced emissions center, or to 

revoke the contractor's agreement pursuant to this Part E, shall be subject to the terms of 

the agreement entered into pursuant to Section 42-4-304(5), C.R.S.

PART F Maximum Allowable Emissions Limits for Motor Vehicle Exhaust, Evaporative and 

Visible Emissions for Light-Duty and Heavy-Duty Vehicles

In order for a vehicle (owner) to obtain a Certificate of Emissions Compliance, the exhaust and 

evaporative emissions from the motor vehicle subject to an EPA approved emissions test as specified in 

Part C of this regulation may not exceed the applicable maximum concentrations or if applicable, 

maximum mass for exhaust carbon monoxide (CO), hydrocarbons (HC) and oxides of nitrogen (NOx); 

and the integrity requirements specified for fuel evaporation control and visible smoke.

I. LIGHT-DUTY VEHICLES (INCLUDING LIGHT-DUTY TRUCKS) SUBJECT TO IDLE SHORT 

TEST(S) FOR ALL VEHICLES OF MODEL YEAR 1981 AND NEWER SUBJECT TO IDLE 

SHORT TEST(S), THE EMISSIONS CONCENTRATION LIMITS OF THIS SECTION I SHALL 

ALSO APPLY AT RAISED IDLE SPEEDS AS SPECIFIED IN SECTION II OF PART C OF THIS 

REGULATION.

I.A. Maximum Concentration Limits for Light-Duty Vehicles (Includes Light-Duty Trucks)

Model Year Percent Carbon Monoxide Parts/million Hydrocarbon

1970 and earlier 3.5 1000

1971 3.0 1000

1972 3.0 1000

1973 3.0 1000

1974 3.0 1000

1975 2.0 600

1976 2.0 600

1977 1.5 400

1978 1.5 400

1979 1.5 400
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Adopted: November 21, 2013 Page 46

Model Year Percent Carbon Monoxide Parts/million Hydrocarbon

1980 1.5 400

1981 and newer 1.2 220

II. HEAVY-DUTY VEHICLES (1978 AND EARLIER GREATER THAN 6000 LBS. GVWR) SUBJECT 

TO IDLE SHORT TEST(S) FOR ALL VEHICLES OF MODEL YEAR 1981 AND NEWER 

SUBJECT TO IDLE SHORT TEST(S), THE EMISSIONS CONCENTRATION LIMITS OF THIS 

SECTION II SHALL ALSO APPLY AT RAISED IDLE SPEEDS AS SPECIFIED IN SECTION II 

OF PART C OF THIS REGULATION.

II.A. Maximum Concentration Limits for Heavy-Duty Vehicles

Model Year Percent Carbon Monoxide Parts/million Hydrocarbon

1967 and earlier 7.0 1500

1968 6.5 1200

1969 6.5 1200

1970 5.5 1000

1971 5.5 1000

1972 5.5 1000

1973 5.5 1000

1974 5.5 1000

1975 5.5 1000

1976 5.5 1000

1977 5.5 1000

1978 5.5 1000

Heavy-Duty Vehicles (1979 and Newer Greater Than 8500 lbs. GVWR) Subject to Idle Short 

Test(s)

1979 4.0 800

1980 3.5 800
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Adopted: November 21, 2013 Page 47

Model Year Percent Carbon Monoxide Parts/million Hydrocarbon

1981 3.0 600

1982 3.0 600

1983 3.0 600

1984 3.0 600

1985 3.0 600

1986 and newer 2.0 300

III. TRANSIENT TEST MASS EMISSIONS LIMITS IN GRAMS/MILE (GPM)

III.A. Light-Duty vehicles (Excluding Light-Duty Trucks)

MODEL YEAR HC CO NOx

1982 3.5 45.0 5.0

1983 3.5 30.0 4.5

1984 3.0 30.0 4.5

1985 2.5 20.0 4.5

1986 2.5 20.0 4.5

1987 2.5 20.0 4.0

1988 2.0 20.0 4.0

1989 2.0 20.0 4.0

1990 2.0 20.0 3.5

1991 1.5 20.0 3.5

1992 1.5 15.0 3.5

1993 1.5 15.0 3.5

1994 1.2 15.0 3.0

1995 1.2 15.0 2.5
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Adopted: November 21, 2013 Page 48

MODEL YEAR HC CO NOx

1996 1.2 15.0 2.0

1997 1.2 15.0 2.0

1998 1.2 15.0 1.5

1999 and newer 1.2 15.0 1.5

III.B. Light-Duty Trucks (equal to or less than 8,500 lbs. G.V.W.R.)

MODEL YEAR HC CO NOx

1982 6.0 65.0 6.0

1983 6.0 65.0 6.0

1984 5.0 55.0 6.0

1985 4.5 45.0 6.0

1986 4.0 40.0 6.0

1987 3.5 30.0 5.5

1988 3.0 25.0 5.0

1989 3.0 25.0 5.0

1990 3.0 25.0 5.0

1991 2.5 25.0 4.5

1992 2.5 25.0 4.5

1993 2.5 25.0 4.5

1994 2.0 20.0 4.0

1995 2.0 20.0 4.0

1996 1.2 15.0 3.5

1997 1.2 15.0 3.0

1998 1.2 15.0 2.5
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Adopted: November 21, 2013 Page 49

MODEL YEAR HC CO NOx

1999 and newer 1.2 15.0 2.0

IV. EVAPORATIVE EMISSIONS CONTROL STANDARDS

System Integrity - A gas cap integrity check to assess the degree of leakage between the fuel filler neck 

sealing surface and the gasoline cap sealing surface shall be performed on all model year 1975 and 

newer vehicles.

IV.A. Pressure decay of the gasoline cap to filler neck sealing surfaces shall not exceed six (6) 

inches of water over a ten (10) second period, or

IV.B. The gasoline cap flow rate shall be compared to an orifice with a National Institute of 

Standards and Technology (NIST) traceable flow rate that will result in a pass/fail flow 

rate threshold of 60 cc/minute of air at 30 inches of water (column).

V. VISIBLE SMOKE

Vehicles shall not exhibit any continuous gray, blue, blue-black, or black smoke of greater than 5% 

opacity from the engine crankcase and/or tailpipe(s) during any engine operating condition of applicable 

inspection procedures.

VI. CLEAN SCREEN PROGRAM MAXIMUM ALLOWABLE EMISSIONS LIMITS

VI.A. In order to obtain a Certificate of Emissions Control through the Clean Screen Program, 

vehicles must not exceed maximum emissions concentrations of 0.50 percent carbon 

monoxide (CO), 1,000 parts per million nitrogen oxides (NOx), and 200 parts per million 

hydrocarbon (HC) as reflected in remote sensing emissions readings.

VI.B. Vehicle owners who participate in the Clean Screen Program shall not be subject to the 

provisions of this Part F other than this Section VI.

VI.B.1. On or before July 1st of each year the Air Pollution Control Division shall develop 

a low emitting vehicle index based on a tabulation of the previous calendar year’s 

IM 240 inspection program results for specified make, model and model year of 

vehicles.

VI.B.2. A 98% passing rate for exhaust emissions shall be set as the minimum allowable 

passing criteria for the low emitting vehicle index.

VI.B.3. In developing the low emitting vehicle index, the Division may use passing 

criteria greater than 98% if necessary to ensure that the use of the low emitting 

vehicle index is equivalent to or better than the use of a second remote sensing 

measurement in terms of air quality benefits.

VII. ON-BOARD DIAGNOSTIC INSPECTION PASSING CRITERIA

In order for a vehicle (owner) to obtain a certificate of emissions compliance, the results of the OBD 

inspection as specified in Part C, Section II.C. of this regulation must meet the following requirements:
Regulation Number 11

Adopted: November 21, 2013 Page 50

VII.A. The data link connector (DLC) is not missing, has not been tampered with, and is 

operational

VII.B. The malfunction indicator light (MIL) illuminates when the ignition key is turned to the key 

on, engine off (KOEO) position.

VII.C. The MIL extinguishes and remains off once the vehicle’s engine is started (KOER).

VII.D. The MIL status, as indicated by the on-board diagnostic test analyzer system is 

commanded off.

VII.E. Only one readiness monitor may be set to “not ready” status.

VII.F. Upon a retest, all monitors except the evaporative monitor must be set to “ready”.

PART G Reserved 

PART H Statements of Basis, Specific Statutory Authority and Purpose

I. AMENDMENTS TO PART A - E

ADOPTED MARCH 21, 1996

The amendments to Regulation Number 11 were adopted by the Air Quality Control Commission 

(Commission) of the State of Colorado. This Statement of Basis, Specific Statutory Authority and Purpose 

is required by Sections 24-4-103(4), C.R.S. The specific statutory authority for these changes is Sections 

42-4-301 through 42-4-316, C.R.S. (1995 Supplement).

The revisions to Regulation Number 11 address the effects of recodifying Title 42 of Colorado's Revised 

Statutes. This regulatory action is necessary to correct statutory references within the regulation in order 

to be consistent with the renumbered statute. The only other change to the rule is to clarify that “licensed 

emissions inspectors” are eligible to perform an emissions inspection pursuant to Part C, Section I.A. The 

previous rule referred only to “authorized emissions inspectors”. The purpose of this change is to avoid 

confusion between emissions inspectors authorized to perform an inspection at an enhanced inspection 

center and emissions inspectors licensed to do so at an inspection-only facility, fleet inspection station, or

motor vehicle dealer test facility. This rule amendment does not change the rights or obligations of any 

person because the term “authorized emissions inspector” has been applied to include “licensed 

emissions inspectors” for purposes of Part C Section I. A. The specific statutory authority for this rule 

amendment is set out at Section 42-4-304 (7), C.R.S.

For the reasons noted, the Commission has adopted amendments to Regulation Number 11, Parts A-E. 

These rule revisions are administrative in nature; do not apply to stationary sources; and will have no 

regulatory impact on any person, facility or activity. Furthermore, the Commission has no discretion not to 

adopt the changes to the numbering scheme for the statutory provisions, and these revisions will have no 

significant fiscal impact. These revisions are not more stringent than the relevant federal requirements.

II. AMENDMENTS TO PARTS A, B, C, F, G, AND APPENDICES A AND B

ADOPTED JULY 17, 1997

The amendments to Regulation Number 11 were adopted by the Air Quality Control Commission 

(Commission) of the State of Colorado. This Statement of Basis, Specific Statutory Authority and Purpose 
Regulation Number 11

Adopted: November 21, 2013 Page 51

is required by Sections 24-4-103(4), C.R.S. The specific statutory authority for these changes is Sections 

42-4-301 through 42-4-316, C.R.S. (1995 Supplement).

1. Changes to Part A(l) (C) (9) and (11) address statutory amendments to Section 42-4-309 

(6) enacted by the 1996 session of the General Assembly which make provision for an 

inspection voucher system for retail sale of used motor vehicles into the enhanced 

emissions inspection program area by licensed dealers. The rule revisions ensure that 

such dealers are not required to have the vehicle inspected prior to the sale provided 

they comply with the requirements of Section 42-4-309 (6). Furthermore, the revisions 

allow sellers to have a vehicle inspected up to one hundred twenty days prior to the sale. 

The specific authority for these changes is set out in Sections 42-4-309 (6) and 42-4-306 

(7). This provision is necessary to implement state law, but is not required by federal law. 

The rule specifically provides that the provisions of 42-4-309 (6) are not federally 

enforceable, and are not included in the SIP. The Department of Revenue, may however, 

enforce such requirements, subject to the adoption of any regulations that may be 

necessary. Such administrative enforcement is necessary to ensure compliance with the 

statutory requirements. The revisions to Regulation Number 11, Part A(I)(C)(13) make it 

clear that a vehicle will fail the inspection for purposes of 42-4-309 (6) if the vehicle has 

any defect that makes it impractical or unsafe to test the vehicle.

2. The revisions to Part A(I)(B) clarify motorist compliance requirements For those persons 

that live in the basic program area yet commute into and have complied with enhanced 

program requirements. The specific statutory authority for these changes is set out in 

Sections 42-4-306 (7) and 42-4-310 (1) (c) (V). This provision is consistent with, and 

does not exceed, federal requirements.

3. The revisions to Part C (II)(G)(4) make it clear that vehicles with excessively long or short 

wheelbases, and specially designed vehicles equipped with hand controls or similar 

apparatus, are exempt from testing on the IM 240 dynamometer. The IM 240 

dynamometer system is not designed to handle such vehicles, and the population of such 

vehicles is so small that this exemption will have no effect on emissions reductions. This 

provision is consistent with, and does not exceed, federal requirements. The specific 

statutory authority for this exemption is set out in Section 42-4-306 (6) (d).

4. The revisions to Part C (III) (D) eliminate the previous requirement to repair or replace the 

catalytic converter and exhaust gas oxygen sensor if the fuel inlet restrictor has become 

enlarged. Leaded fuels, which damaged these components, have not been available for 

several years and this rule is no longer necessary. This provision is consistent with, and 

does not exceed, federal requirements. The specific statutory authority for this exemption 

is set out at Section 42-4-306 (6) (a).

5. The revisions to Part C (XI) allow inspection stations to use vehicle identification numbers 

(VINs) issued by kit car manufacturers and by other states. The rule previously required 

inspection stations to use a VIN assigned by Colorado for kit cars, custom cars and 

home-built vehicles. Under the previous rule, such specialized vehicles were often 

required to comply with inspection criteria applicable to later model vehicles. As a result 

the inspection criteria were unreasonably stringent. This change will ensure that vehicles 

are inspected pursuant to the appropriate procedure, This provision is consistent with, 

and does not exceed, federal requirements. The specific statutory authority for this 

provision is set out at Section 42-4-306 (6).
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Adopted: November 21, 2013 Page 52

6. The revisions to Parts C (IV) and F (IV) provide a pressure integrity or leak check for gas 

caps in order to reduce emissions of volatile organic compounds, an ozone precursor. 

The gas cap pressure check requirements is based on established demonstrated 

methodologies, and will provide an estimated 40% reduction in VOC, an ozone precursor, 

to escape into the atmosphere. Such evidence supports the finding that the rule will result 

in a demonstrable reduction in air pollution. Because the Denver area is in the inspection 

and maintenance program due to carbon monoxide, rather than ozone problems, federal 

law does not require such a pressure check. The state did not take credit for such a 

pressure check in the maintenance plan for ozone, and associated redesignation request, 

recently adopted by the AQCC. Therefore, this provision is not required by federal law, 

and will not be incorporated into the State implementation Plan. An evaporative 

emissions inspection procedure is required pursuant to Sections 42-4-310 (2) (a) and 42-

4-306 (6) (a), C.R.S. for those vehicles inspected in the metro Denver enhanced program 

area.

7. The revisions to Part B (IV)(B&C), (VI)(C&D) and Appendix B propose standards and 

specifications consistent with EPA and recognized industry standards for the 

manufacturer and “naming” of precision calibration gases for use in test analyzer 

systems. Consistent protocol reduces the burden to the gas manufacturer, those 

regulated parties that are end users of the calibration gases, and improve overall quality 

control. Additionally, revisions to Appendix B address specific program administrative 

needs such as the bar code tracking system necessary for tracking certified test analyzer 

system gases which have been placed into service. The revisions to Appendix B are 

consistent with guidance documents issued by EPA. Federal law requires span gases to 

be accurate within a tolerance of 2%, but federal law does not specifically require the 

state to establish requirements for manufacturers. Therefore, the requirements set out in 

Appendix B shall not be included in the SIP, and shall not be federally enforceable. The 

specific statutory authority for this action is Section 42-4-306 (3)(a)(l).

8. The revisions to Appendix A, attachment III establish equipment design and performance 

specifications for a “Motor Vehicle Dealer Transient Mode Test Analyzer System (IG

240)” to be used at Motor Vehicle Dealer Test Facilities (MVDTFs). Equipment that meets 

these specifications will allow MVDTFs to conduct emissions inspections on their used 

vehicle inventory prior to its retail sale. This provision provides increased convenience 

and reduced costs for affected automobile dealers that currently utilize the contractor 

operated IM 240 system in the enhanced program area. Use of this system is not 

mandated. Federal law does not require specifications for an IG 240, and the state did 

not take credit for inspections conducted at the time of sale or transfer of used vehicles 

sold by motor vehicle dealers. Therefore, the specifications applicable to MVDTFs and 

the IG 240 are not included in the SIP. The specific statutory authority for this revision is 

Sections 42-4-304 (19) and 42-4-306 (3)(a)(l)(A-C).

9. Revisions to Part A(l)(9) delete the present exemption that vehicles sold as “tow-away” by 

licensed dealers are not required to comply with applicable emissions inspection 

requirements at the time of sale. The proposal would eliminate present confusion within 

the regulated community. Part A (l)(9) is now consistent with Section 42-4-309(3)(a). The 

Commission is not required to create a specific exemption for tow-away vehicles and 

therefore has the authority to remove the existing exemption. Additional statutory 

authority is set out at Sections 42-4-306 (1) and 42-4-309 (3)(A).

The Department of Revenue is the state agency charged with the regulation of motor vehicle 

dealers, and for the titling and registration of motor vehicles. The tow-away exemption has 
Regulation Number 11

Adopted: November 21, 2013 Page 53

hampered the Department of Revenue's enforcement actions. Therefore, the Commission is 

repealing this exemption and deferring this issue to the Department of Revenue. The Department 

of Revenue should handle this issue through rule making or otherwise, as appropriate.

10. Revisions to Part A (V) amends the notice to interested parties that materials 

incorporated into the rule by reference may be examined at any state publications 

depository library, as required by Section42-4-103 (12.5)(d). The revision expands the 

text of the existing notice of availability to be consistent with prescriptive state 

requirements.

For the reason noted, the Commission has adopted amendments to Regulation Number 11, Parts 

A, B, C, F, G and Appendices A and B. Revisions implement and/or clarify statutory provisions for 

the vehicle emissions inspection program pursuant to Sections 42-4-301 through 42-4-316, 

C.R.S. Rule revisions amend existing inspection procedures consistent with State Implementation 

Plan commitments.

III. REVISIONS TO PART C (VIII) AND PART F (III)

ADOPTED NOVEMBER 19, 1998

The November 19, 1998 revisions to regulations Part C (VIII) (b.4) (b.5) and (c.-g.) reinstate, with some 

minor clarifications, text addressing compliance waivers and related inspection provisions regarding 

specific circumstances involving certain participating motorists and the repair of vehicles that had failed 

one or more emissions inspections. This text was inadvertently omitted during the last publication of the 

regulation, August 1997. The omitted text was initially adopted by the Commission immediately prior to 

implementing the improved basic program and enhanced inspection and maintenance program January 

1995, pursuant to Sections 42-4-301 through 42-4-316, C.R.S. (1998). Reinstating this text results in the 

regulation being consistent with state statute and the federal program. The November 19,1998 revisions 

to regulations Part F (III) reconcile the emissions limits used by enhanced inspection centers for motor 

vehicle emissions inspections with the emissions limits that were used for purposes of demonstrating 

attainment of the National Ambient Air Quality Standards (NAAQS) for carbon monoxide (CO) and for 

particulate matter less than ten microns in diameter (PM10). The rule change only applies to the 

enhanced emissions program and only affects the standards used for testing 1982 and newer vehicles.

Basis and Purpose

The emissions limits adopted by the Commission are more stringent than the emissions limits that were 

being implemented prior to the hearing, but are less stringent than the emissions limits that were 

scheduled to take effect on January 1, 1999 under the previous version of Regulation Number 11.

The emissions limits adopted by the Commission must go into effect by the end of December 1998 in 

order to comply with the minimum federal requirement to show attainment of the NAAQS for CO by 

December 31, 2000.

The emissions limits contained in the previous rule for 1999 and beyond were more stringent than 

necessary to comply with federal law and were so stringent that many vehicles would not be able to 

comply with the standards even when repaired. Such emissions limits were based on EPA guidance 

issued in 1993. Experience with the program since then has demonstrated that such standards are 

unreasonable.

Federal Requirements
Regulation Number 11

Adopted: November 21, 2013 Page 54

There are several federal requirements that are relevant to the emissions limits used in the AIR Program. 

40 CFR Part 51 establishes specific emissions limits for the AIR Program. In addition, the AIR Program 

was used to demonstrate attainment of the NAAQS for CO and PM10. Therefore, the emissions limits 

must be included as enforceable control measures in the State Implementation Plan.

For purposes of CO, 40 CFR Section 51.351 requires the AIR Program to achieve at least as much 

reduction in fleet emissions, measured in grams per mile, as the model federal program. The modeling 

results that were used to demonstrate compliance with the requirements of 40 CFR Part 51 were also 

used to demonstrate attainment of the NAAQS for CO in the Denver CO SIP. The emissions limits for CO 

and hydrocarbons implement the assumptions that were made in the modeling to show compliance with 

40 CFR 51.351 and to show attainment of the CO NAAQS. The emissions limits for hydrocarbons are a 

necessary component of an effective CO control program and, therefore, are being included in the State 

Implementation Plan.

The emissions limits for NOx for the years 1999 through 2014 established in the rule are necessary to 

achieve the NOx reductions that were assumed for the AIR Program in the Denver PM10 SIP. Thus, such 

emissions limits are necessary to implement the control measures contained in the Denver PM10 SIP as 

required by federal law.

For the foregoing reasons, the Commission concludes that the emissions limits in Regulation Number 11 

for the years 1999 through 2014 are necessary to comply with federal law and do not otherwise exceed 

the minimum federal requirements. However, the rule revision also includes an emissions limit for NOx for 

the year 2015 and beyond that is more stringent than the minimum federal requirements. Such more 

stringent NOx limit is necessary beginning in the year 2015 in order for the Denver Regional Council of 

Governments (DRCOG) to demonstrate that the transportation network for the Denver metropolitan area 

will remain below the emissions budget for NOx in the State Implementation Plan. Pursuant to federal 

law, the Commission must adopt such a control measure before DRCOG makes its conformity 

determination. 40 CFR 93.122(a)(3)(l). However, federal law does not require the more stringent 

emissions limit for NOx to be included in the State Implementation Plan. Therefore, the emissions limit for 

NOx established in Part F, Sections III.A.2 and III.B.2 shall not be included in the State Implementation 

Plan.

The specific statutory authority for the adoption of emissions limits for carbon monoxide, hydrocarbons 

and oxides of nitrogen is set out at Section 42-4-306(6), C.R.S. (1998).

Statutory Authority

Pursuant to Section 24-4-103(5), C.R.S. (1998), the standards or cut-points established by the 

Commission on November 19,1998 shall take effect on December 30, 1998; provided the rule revisions 

are published in the Code of Colorado Regulations on December 10, 1998. Such an effective date is 

consistent with the relevant SIP demonstrations. For purposes of Section 42-4-306(6)(b)(ii), C.R.S. 

(1998), the standards established by this rule revision were established on November 19,1998 even 

though such standards shall not become effective until December 30,1998.

Effective date of rule changes

Findings pursuant to Section 25-7-110.8. C.R.S. (1998)

The revisions to Regulation Number 11 are based on reasonably available, validated, reviewed and 

sound scientific methodologies. The Commission has considered all scientific and other information made 

available by interested parties.

.
Regulation Number 11

Adopted: November 21, 2013 Page 55

Evidence in the record supports the finding that the revised emissions limits will result in a demonstrable 

reduction in air pollution when compared to the emissions limits that were in effect prior to the rule 

change.

 The rule adopted by the Commission is the most cost-effective alternative, and will maximize the air 

quality benefits of the regulation in the most cost-effective manner.

IV. REVISIONS TO PARTS A, B, C, D, AND F

ADOPTED FEBRUARY 19, 1999

The February 19, 1999 revisions implement Sections 42-4-304 through 42-4-307 and 42-4-310, C.R.S. as 

amended, pursuant to S.B. 98-182. Additionally, the revisions codify the provisions of Sections 42-4-304 

and 42-4-310, C.R.S. as amended, pursuant to S.B. 98-182.

Basis and Purpose

The revisions implement a “Clean Screen Program” as an operating element of Colorado's AIR Program 

as established in Sections 42-4-301 through 42-4-316, C.R.S. The Clean Screen Program is designed 

and intended to improve participating motorist convenience and reduce costs when complying with a 

periodic inspection requirement. Screening clean vehicles out of the vehicle population subject to 

inspection requirements reduces the burden of compliance on vehicle owners. One program premise is 

that these vehicles would have passed a traditional inspection and that air quality would not necessarily 

benefit from using traditional inspection procedures on these vehicles. Clean Screened vehicles would be 

exempt from complying with what would normally be mandatory inspection, for one inspection cycle.

Explanation of the Provisions

Participation by owners of vehicles registered in the program areas specified, i.e., Larimer County and 

metro Greeley, Weld County as well as by owners of vehicles registered elsewhere but required to obtain 

a certification of emissions compliance by Section 42-4-310 (l)(c)(l), C.R.S., is voluntary. Provisions within 

the enabling legislation allow for participation by other program areas or for other areas of the state based 

upon a request by respective lead air quality planning agencies, and approval by the Commission.

As proposed for implementation in the Larimer County and Weld County program areas, Clean Screening 

is an appropriate application of remote emissions sensing technology. Based on the Greeley Pilot Study 

conducted by the Division, implementing this technology as an alternate inspection procedure brings with 

it an estimated maximum 4-7% loss in emissions reduction compared to traditional inspection procedures. 

The Environmental Protection Agency's modeling projects a 1% loss. The Commission concludes that 

this loss of emissions reductions will have no negative impact on compliance with the National Ambient 

Air Quality Standards for the areas included.

Reducing the number of vehicles seeking an inspection each cycle will reduce business for licensed 

inspection providers serving these program areas.

The Division is committed to continuously evaluating the performance of the program especially as it 

pertains to the specific emissions thresholds used in the program, impacts on air quality, and may request 

the Commission to consider revisions to elements of the program. Additionally, the Division has 

committed to evaluating the feasibility of low emission(s) profiling as a supplementary inspection criteria 

to a Clean Screen Program.

Statutory Authority
Regulation Number 11

Adopted: November 21, 2013 Page 56

Sections 42-4-304 through 42-4-307, and Section 42-4-310, C.R.S., as amended, authorize adoption of a 

Clean Screen Program.

There are no specific federal requirements requiring a Clean Screen Program. This program is not a 

federal mandate. The United States Environmental Protection Agency has published general guidance 

that is reflected in the revised regulations. A revision of the SIP for the applicable program areas is 

necessary to reflect the potential emissions reduction impact associated with Clean Screen Program 

procedures.

Federal Requirements

Explanation of Additional Revisions to Regulation for February 19,1999

The revisions to the regulation also implement the provisions of Sections 42-4-304 and 42-4-310, C.R.S., 

as amended, pursuant to SB 98-046 as it pertains to the responsibility of compliance with emissions 

inspection requirements for vehicles in the process of being sold. The provisions require the seller to 

obtain an emission inspection when the vehicle is operable and can be tested. Where the vehicle is 

deemed inoperable or otherwise cannot be tested, the seller must provide written notice to the purchaser 

prior to completion of the sale on specific forms prepared by the Department of Revenue.

.

The specific statutory authority for the provisions discussed above is set out at Sections 42-4-304 and 42-

4-310, C.R.S. as amended. The Department of Revenue adopted and implemented regulations to 

address these provisions. Regulation Number 11 is now consistent with state statute.

Statutory Authority

There are no federal requirements as it pertains to these provisions.

Federal Requirements

The effective date for the revisions to Regulation Number 11 shall be April 30, 1999.

Effective Date of Rule Changes

V. AMENDMENTS TO PARTS A, C AND F (III)

ADOPTED JANUARY 10, 2000

Regulation Number 11 requires periodic emissions tests for vehicles registered or operating within the 

program area, which covers most of the Front Range. The purpose of the program is to reduce the 

amount of carbon monoxide, oxides of nitrogen, and hydrocarbons emitted by automobiles. The purpose 

of the January 2000 revisions to Regulation Number 11 is to make the program more cost-effective and 

more convenient for motorists, and to do so in a manner that protects air quality.

Basis and Purpose

This rule revision makes two changes to the motor vehicle emissions inspection program. First, it extends 

the clean screen program to the Denver metropolitan area. The dean screen program uses remote 

sensing technology to identify vehicles that do not need to be tested at an emissions inspection station. 

Beginning in the year 2002, the revised rule will allow a motorist that passes the requisite remote sensing 

test to obtain a certification of emissions compliance through the mail without taking the vehicle to an 

inspection station for a test.
Regulation Number 11

Adopted: November 21, 2013 Page 57

Second, the rule-revisions amend the emissions standards for 1996 and later motor vehicles, beginning in

the year 2002. The revisions make the standards consistent with the air pollution control technology on 

new vehicles.

The revisions to Regulation Number 11 were developed in conjunction with the redesignation of the 

Denver metropolitan area as an attainment area for carbon monoxide. Section 175 a of the federal Clean 

Air Act requires the State to demonstrate that the region will remain within the national ambient air quality 

standard (NAAQS) for carbon monoxide for ten years after EPA takes action on the maintenance plan. 

EPA may not take action on the maintenance plan until 2002. Thus, federal law requires the maintenance 

plan to show compliance with the NAAQS for carbon monoxide through the year 2013.

Federal Requirements

Air quality analyses performed for the maintenance plan indicate that the region will remain within the 

NAAQS for carbon monoxide through the year 2010, even with the clean screen program. The tools 

currently available for predicting air quality in the future suggest, however, that the clean screen program 

may be inconsistent with maintenance of the NAAQS for carbon monoxide after 2010. The rule revisions 

provide for the expiration of the clean screen program in the year 2010 in order to demonstrate 

maintenance of the NAAQS through 2013.

The rule revisions codify the emissions standards that were used to perform the computer modeling to 

demonstrate maintenance of the NAAQS. In performing the requisite computer modeling, the Air Pollution 

Control Division (APCD) used emissions standards that are more stringent than appeared in Regulation 

Number 11 prior to these amendments. The APCD used the more stringent standards in order to 

maximize the air quality benefits of the program for purposes of the computer model. Although the 

revisions make more stringent the emissions standards in the rule, the changes do not necessarily make 

the program as a whole more stringent. This is because, as a practical matter, more stringent standards 

will automatically apply under pre-existing state and federal law. The federal rules require vehicle 

manufacturers to equip all 1996 and later light-duty vehicles with on-board diagnostic systems that will 

cause vehicles with emissions in excess of the revised standards to display fault codes (40 CFR Section 

86.094-17). Regulation Number 11 already provides that a vehicle will fail the emissions test if the onboard diagnostic system displays such a fault code (Regulation Number 11, Part C, Section III.C.). The 

result is that the federal standards for the on-board diagnostic systems (which are more stringent than 

even the revised standards) already apply as a practical matter. The rule change is necessary to allow 

the APCD to take credit for more stringent standards when performing the computer modeling exercise. 

The revision merely make the standards consistent with improved technology that vehicle manufacturers 

are using to meet the on-board diagnostic requirements and to meet the Tier-1 standards mandated by 

federal law. The revised standards do not exceed the requirements of federal law.

The air quality impacts of the revisions to Regulation Number 11 were analyzed using the computer 

models approved by EPA, as is required by federal rules. Regulation Number 11, as revised, is necessary 

to comply with the requirements of the federal act and is not more stringent than the requirements of the 

federal act.

Specific statutory authority for the extension of the clean screen program to the Denver area is provided 

in Section 42-4-306(23), C.R.S. (1999). Specific statutory authority to establish emissions standards is 

provided in Section 42-4-306(6)(a), C.R.S. (1999).

Statutory Authority

Findings pursuant to Section 25-7-110.8
Regulation Number 11

Adopted: November 21, 2013 Page 58

The primary intent of the January 2000 changes to Regulation Number 11 is to make the motor vehicle 

emissions inspection program more convenient and less costly, rather than achieving further reductions in 

emissions of air pollution. In addition, the rules establish more stringent emissions standards for 

automobiles in order to make the standards consistent with technology mandated by federal law.

The revisions are based on the computer model currently approved by the EPA. The computer model 

used to develop the revised rule overstates the carbon monoxide problem the Denver area will face in the 

future. The EPA is currently updating and improving the computer model but the revised computer model 

has not been approved by EPA and may not be used for federal regulatory purposes. In spite of the 

problems with the computer model used to develop this regulation, the regulation is based on the most 

reasonably available, validated, reviewed, and sound scientific methodologies currently available under 

federal law. All methodologies and information made available by interested parties have been 

considered.

The alternative chosen by the Commission provides the regulated community flexibility and achieves the 

necessary reduction in air pollution. The evidence is insufficient for the Commission to determine that the 

alternative chosen by the Commission is the most cost-effective alternative. The cost analysis developed 

by the Division indicates that it may be more cost-effective to eliminate the oxygenated fuels program 

instead of implementing a clean-screen program, but there is considerable uncertainty in that cost 

estimate. The impact of oxygenates on gasoline prices varies from year to year depending on the cost of 

ethanol and gasoline. Thus, reducing the oxygen content of gasoline does not ensure lower consumer 

gasoline prices. The Commission chose the alternative proposed by the Regional Air Quality Council 

(RAQC) for several reasons. First the RAQC's proposal is a balanced proposal that was developed 

through an inclusive stakeholder process. Second, it will establish a remote-sensing network, which is a 

necessary first step to establish a cost-effective high-emitter program in the future. Finally, the selection of 

a different option could delay the redesignation of the Denver area and would delay any cost-savings 

associated with such alternative.

VI. AMENDMENTS TO PARTS C AND D 

ADOPTED NOVEMBER 16, 2000

This rule revision makes two changes to the motor vehicle emissions inspection program. First, the 

change to Part C, Section XII.E.2 extends the time period for taking valid emissions readings for purposes 

of the clean screen program. This section previously required a reading within 90 days of the registration 

renewal date for the relevant motor vehicle. Since it often takes 90 days just to correlate the data, make 

the necessary communications and receive payment for the motorist, this time period was too restrictive 

and made the clean screen program impractical. The time period was extended by a minimum of 30 days 

to allow more time for emissions readings.

Basis and Purpose

Second, the provision on licensing requirements for clean screen inspectors in Section IX.B.7 erroneously 

required such inspectors to demonstrate proficiency with the criteria in Section II.A.2 (qualifications for 

emissions mechanics and emissions inspectors) rather than Section V (qualifications for dean screen 

inspectors). The rule revision corrects this citation error.

The federal act and EPA regulations do not mention clean screen programs. See, 40 CFR Part 51, 

Subpart S. EPA has, however, developed a draft guidance document that authorizes the use of dean 

screen programs to exempt certain vehicles from the federally-required automobile inspection program. 

Federal Requirements
Regulation Number 11

Adopted: November 21, 2013 Page 59

EPA document 420-P-98-008 (May 1998). The draft guidance document requires two remote-sensing 

readings, but does not require the readings to be any more recent than twelve months prior to the 

vehicle's regularly scheduled emissions test.

The clean screen program is voluntary and is designed to reduce the burden of the federally based 

automobile inspection program described at 40 CFR Part 51, Subpart S. Overall, the dean screen 

program results in an automobile inspection program that is less stringent than the program described in 

the federal regulations. Thus, the amendments will result in a motor vehicle inspection program that is 

less stringent than the program described in the federal regulations, but that requires more recent test 

results than is required by the draft federal guidance. Because EPA does not expressly require such a 

cutoff date, the revised rule will not be part of the federally enforceable SIP.

Although not expressly required by draft federal guidance, the requirement for a recent emission reading 

is necessary and reasonable to ensure that the emission test is representative of vehicle emissions near 

the time of registration. Motor vehicle emissions deteriorate over time. It follows that emission readings 

should be considered valid for a limited period of time. The General Assembly intended for 1982 and 

newer vehicles to be inspected every twenty-four months. Section 42-4-310(1)(b)(II)(C), C.R.S. A vehicle 

that passes a clean screen test based on a reading taken 120 days prior to the registration renewal date 

can go twenty-eight months without inspection (or even twenty-nine months if the motorist takes full 

advantage of the one month grace-period allowed by the Department of Revenue following the 

registration renewal date). The requirement for an emissions reading within 120 days of the registration 

renewal date strikes a reasonable balance between the requirement to implement a clean screen 

program and the legislative intent for emissions tests every two years.

The federal requirements for the licensing or certification of inspectors are set out at 40 CFR 51.367. The 

criteria established in Regulation Number 11, Part D, Section V are not more stringent than the federal 

requirements.

Specific statutory for the authority to promulgate regulations governing the operation of the clean screen 

program is set out at 42-4-306(23), C.R.S.

Statutory Authority

The primary intent of the November 2000 changes to Regulation Number 11 is not to achieve further 

reductions in emissions of air pollution, but rather to make more practical the administration of the clean 

screen program. Thus, the rule revision is administrative in nature.

Findings Pursuant to 25-7-110.8. C.R.S.

The expanded time period allows additional time for taking emission measurements, analyzing the data, 

and communicating with motorist and the Clerk and Recorder. The revision to the time period does not 

change the standards or technology used in the program. The revision is consistent with all relevant, 

reasonably available, validated, reviewed, and sound scientific methodologies. All validated, reviewed, 

and sound scientific methodologies and information made available by interested parties has been 

considered.

The rule revision makes the dean screen program more cost-effective, provides the contractor and 

motorists with greater flexibility, will achieve the necessary reduction in air pollution, and will maximize the 

air quality benefits of the automobile inspection program in the most cost-effective manner.

VII. AMENDMENTS
Regulation Number 11

Adopted: November 21, 2013 Page 60

ADOPTED DECEMBER 20, 2001

The December 2001 revisions to Regulation Number 11 do three things: First, the rule revisions expand 

the clean screen program to include the enhanced emissions program area. However, the Commission 

did not, at this time, establish an implementation schedule pursuant to Section 42-3-134, C.R.S. This rule 

change is necessary to establish the clean screen authority pursuant to Section 42-4-307.5(1), C.R.S. 

The creation of the clean screen authority is necessary so that the Colorado Department of Revenue may 

receive and expend funds pursuant to Sections 42-4-307(10.5)(a) and Section 13 of House Bill 2001 -

1402 (“HB1402”). Thus, this portion of the rule change has no regulatory effect other than the creation of 

the clean screen enterprise. The Commission intends to hold a subsequent rulemaking hearing to 

establish an implementation schedule.

Basis and Purpose

Second, the rule change excludes the El Paso county portion of the basic emissions program area from 

the clean screen program pursuant to Section 42-4-306(23)(a), C.R.S.

Third, the revisions conform Regulation Number 11 to the provisions of HB 1402, which repealed the 

Verification of Emissions Test requirements.

Although federal rules establish minimum performance requirements for the basic and enhanced 

emissions programs, nothing in the federal rules bear directly on the rule changes that were the subject of 

the December 2001 rulemaking hearing. The revised rule does not exceed the minimum requirements of 

federal law.

Federal Requirements

The specific statutory authority to expand the clean screen program to enhanced emissions program area 

is set out at 42-4-306(23)(b), C.R.S. The specific statutory authority to exclude the El Paso county portion 

of the basic emissions program area from the clean screen program is set out at 42-4-306(23)(a), C.R.S. 

The statutory authority to conform the Regulation to the applicable statutory provision is set out at 42-4-

306(1), C.R.S.

Statutory Authority

The requirement for findings set out in Section 25-7-110.8, C.R.S. does not apply to this rulemaking 

hearing. The creation of the clean screen authority is merely an administrative change; it is not intended 

to reduce air pollution. Similarly, the exclusion of El Paso County from the clean screen program is 

exempt from the requirements of 25-7-110.8 because it makes no change to the program applicable in 

that area because El Paso County was already exempt from the clean screen program. This rule change 

merely formalizes the area's status in the wake of HB 1402. Finally, the Commission has no discretion 

concerning the repeal of the provisions related to the verification of emissions tests. For these reasons, 

25-7-110.8 does not apply to this matter.

Findings Pursuant to 25-7-110.8. C.R.S. 

VIII. AMENDMENTS TO PART A

ADOPTED JULY 18, 2002

Basis and Purpose
Regulation Number 11

Adopted: November 21, 2013 Page 61

This rulemaking action removes the Fort Collins area component of the Automobile Inspection and 

Maintenance Program (“AIR Program”) from the State Implementation Plan (SIP), but does not make any 

change in the state laws implementing the program. This means that the AIR Program will remain in full 

force and effect under state laws, but it will not be federally enforceable after January 1, 2004. The 

continuation of the AIR Program as a state-only program will afford the Division and the City of Fort 

Collins an opportunity to work together to identify feasible options to replace the AIR Program in the Fort 

Collins area.

The maintenance plan adopted by the Commission in conjunction with these rule changes includes a 

commitment to begin implementing the AIR Program in the Fort Collins area in the year 2026. Such a 

commitment is necessary to authorize state and local transportation planning agencies to take emissions 

reduction credit for such a program when such agencies make transportation conformity determinations 

40 CFR 93.122(a)(iii). The Commission intends to reevaluate this commitment when it revises the 

maintenance plan, as it is required to do within eight years pursuant to as required by 42 USC 750 a (b), 

and may, in compliance with all applicable state and federal laws, revise the commitment as necessary 

and appropriate.

After January 1, 2004, the basic AIR Program will no longer be necessary to maintain the National 

Ambient Air Quality Standards for carbon monoxide in the Fort Collins area through the year 2015. 

Therefore, the program is no longer a federal requirement for the Fort Collins area. The Commission is 

removing the program from the State Implementation Plan, but is not repealing the program. The basic 

AIR Program will continue to apply in the Fort Collins area. Thus, the provisions of Regulation Number 11 

applicable to motorists registered in the Fort Collins area are not required by federal law and are more 

stringent than the minimum federal requirements.

Federal Requirements

IX. AMENDMENTS TO PARTS A AND C 

ADOPTED AUGUST 15, 2002

The primary purpose of this rulemaking action is to switch Larimer and Weld counties to a pay-uponregistration system for the Clean Screen Program. The purpose of the Clean Screen Program is to make 

the Automobile Inspection and Readjustment Program (“the AIR program”) more convenient, although not 

necessarily less expensive. The intent behind the pay-upon-registration system is to make it easier for 

motorists to pay for dean screen tests. Motorists were previously required to make a separate payment to 

the contractor by mail before a dean screen test could be used to register a motor vehicle. With the 

change adopted by the Commission, motorists will be able to pay for dean screens tests at the time of 

registration. This change should make the Clean Screen Program, and therefore the AIR Program, more 

convenient for motorists. This rule change is intended merely to give motorists an option.

Basis and Purpose

Clean screen motorists will have the choice of paying for the clean screen test and using it to register the 

vehicle, or having the vehicle tested at a conventional inspection and readjustment station and paying for 

such test at the testing station.

The rule amendments include a change to the timing requirements for remote sensing readings to make 

the Clean Screen Program more flexible. As amended, the regulation requires two valid remote sensing 

readings within a twelve-month period in order to clean screen a vehicle. The regulation previously 

required the most recent reading to be within 120 days of the registration renewal date. The 120-day 

requirement exceeded the minimum federal requirement. The rule has been revised rule to reflect EPA 
Regulation Number 11

Adopted: November 21, 2013 Page 62

guidance and to maximize the use of the Clean Screen Program. The contract provides for adequate 

quality assurance by requiring the contractor to return to the same remote sensing locations on a frequent 

basis. Such rotation of the remote sensing units should minimize the number of vehicles that are dean 

screened based solely on readings taken early in the twelve-month period.

In addition, the rule changes include several minor, housekeeping changes such as:

The elimination of a requirement for the agencies to develop the equivalent of a windshield sticker 

for clean screened vehicles. Such a rule was inconsistent with the change in statute eliminating 

the windshield sticker requirements.

The elimination of a provision requiring annual inspections for government vehicles. Such a rule 

was inconsistent with a change in statute establishing biennial inspections for such vehicles.

The repeal of provisions establishing a method to mail payments to the contractor.

There are no federal requirements relevant to the payment mechanism for the Clean Screen Program. As 

indicated above, the purpose of this change is to make the program more convenient and to provide 

motorists with an option. Although the AIR Program may not be federally required in Larimer or Weld 

county after January 1,2004 federal law requires the continued implementation of the AIR program in 

such areas until removed from the SIP through the SIP revision process. In the meantime, motorists must 

pay for emissions tests. Therefore such payment requirements do not exceed minimum federal 

requirements.

Federal Requirements

For clean screen programs, federal guidelines require two remote sensing readings within twelve months. 

The rule change makes the Colorado rule identical to the federal guideline.

For these reasons, this rule change does not exceed minimum federal requirements and is not otherwise 

more stringent than federal law.

The statutory authority to establish the specific dates for county clerks and recorders to begin collecting 

emissions inspection fees is set out at Section 42-3-134(26.5)(a), C.R.S. The Commission expressed the 

start date as the month in which motor vehicle registrations come due in order to effectively coordinate 

the Commission rules with the motorist notification process used by the County Clerks and Recorders.

Statutory Authority

In addition Section 42-4-306(1) grants the Commission the authority to promulgate such regulations as 

may be necessary to implement the Automobile Inspection and Readjustment Program, which authority 

extends to all the relevant rule changes.

The requirements of 25-7-110.8 do not apply to the August 15, 2002 rule revisions because such 

revisions were not adopted for the purpose of reducing air pollution. Section 25-7-110.8 requires the 

Commission to make express findings whenever it imposes new regulatory requirements to improve air 

quality. The changes are administrative in nature and that are designed to implement the Clean Screen 

Program and the pay-upon-registration program in an efficient and cost-effective manner. Therefore, the 

requirements of Section 25-7-110.8 do not apply here.

Findings Pursuant to 25-7-110.8. C.R.S.
Regulation Number 11

Adopted: November 21, 2013 Page 63

X. AMENDMENTS TO PARTS A AND C 

ADOPTED OCTOBER 17, 2002

This rulemaking action implements the Clean Screen Program in the enhanced emissions program area. 

The purpose of the Clean Screen Program is to make the Automobile Inspection and Readjustment 

Program (“the AIR program”) more convenient, although not necessarily less expensive. This rule change 

is intended merely to give motorists the option of using the Clean Screen Program. Clean screened 

motorists will have the choice of paying for the clean screen test and using it to register the vehicle, or 

paying to have the vehicle tested at a conventional inspection and readjustment station and paying for 

such test at the testing station.

Basis and Purpose

The rule was also changed so that the malfunction indicator light (MIL) and on-board diagnostic (“OBD II”) 

fault codes will not be used as the basis for test failures. Data provided by the Division reveals that MIL 

and OBD II requirements are not cost effective test criteria.

There are no relevant federal requirements to the payment mechanism for the Clean Screen Program. As 

indicated above, the purpose of this change is to make the program more convenient and to provide 

motorists with an option.

Federal Requirements

Nothing in federal law requires MIL or OBD tests for pre-1996 vehicles. The rule change eliminates a preexisting state requirement for such vehicles to pass MIL tests. The rule change also eliminates the 

requirement for 1996 and newer vehicles to pass MIL and OBD tests. Although federal law requires OBD 

tests on such newer vehicles registered in certain carbon monoxide and ozone nonattainment areas, 

such federal requirement no longer applies in Colorado because all carbon monoxide and ozone areas 

have been redesignated to attainment.

For these reasons, this rule change does not exceed minimum federal requirements and is not otherwise 

more stringent than federal law.

The statutory authority to establish the specific dates for County Clerks and Recorders to begin collecting 

emissions inspection fees is set out at Section 42-3-134(26.5)(a), C.R.S. The Commission expressed the 

start date as the month in which motor vehicle registrations come due in order to effectively coordinate 

the Commission rules with the motorist notification process used by the County Clerks and Recorders.

Statutory Authority

The authority to revise the OBD and MIL requirements is set out in Section 42-4-306((i)(a).

The requirements of 25-7-110.8 do not apply to the October 2002 rule revisions. Section 25-7-110.8 

requires the Commission to make express findings only when it imposes new or amended regulatory 

requirements intended to reduce air pollution. Essentially, the statute requires the Commission to 

determine that the costs and burdens imposed by the new or more stringent requirements are justified by 

the air quality benefits. The purpose of the October 2002 rule changes is to reduce the burden of 

Automobile Inspection and Readjustment Program. Therefore, the requirements of Section 25-7-110.8 do 

not apply to such revisions.

Findings Pursuant to 25-7-110.8. C.R.S.
Regulation Number 11

Adopted: November 21, 2013 Page 64

XI. AMENDMENTS TO PART C 

ADOPTED NOVEMBER 21, 2002

This rule change requires the Division to make annual adjustments to the minimum expenditure required 

to qualify for a certification of emissions waiver, based on the consumer price index for all urban 

consumers for the Denver-Boulder metropolitan statistical area as authorized by Section 42-4-

310(1)(d)(VI), C.R.S. The rule adopted by the Commission requires the Division to make such annual 

adjustments through the year 2004. The Commission intends to re-evaluate the waiver amount in 2004. 

At such time, the Division shall submit to the Commission an analysis of cost and emission reduction 

benefit, if any, associated with the adjustments to the waiver amount.

In addition, the rule was also modified so that changes adopted by the Commission at their October 17,

2002 hearing, concerning malfunction indicator light (MIL) requirements, will be delayed until April 1,2003 

to provide an opportunity to complete necessary computer software changes.

The federal requirements for an emissions waiver are set out in 40 CFR 51.360(a)(7). The federal rule 

requires a minimum expenditure of $450, which amount is to be adjusted annually, beginning in 1998, 

based on the consumer price index. However, the federal requirement applies only in certain carbon 

monoxide nonattainment areas. The federal requirement no longer applies to the Denver area since it has 

been redesignated as an attainment area for carbon monoxide, provided the waiver rate does not exceed 

3% of the failed vehicles. Arguments can be made both ways on the question of whether the rule change 

exceeds minimum federal requirements. Arguably, it does not because the revised rule is consistent with 

the intent of the federal law to annually adjust the waiver amount based on the consumer price index.

Federal Requirements

The authority to revise the waiver amount is set out in Section 42-4-310(1)(d)(VI), C.R.S.

Statutory Authority

The authority to delay the effective date of the rule change concerning the MIL is set out in Section 24-4-

103(5), C.R.S.

The revision of emissions repair waiver limits brings the waiver limits in line with the customer cost index. 

The rule revision is based on reasonably available, validated, reviewed, and sound scientific 

methodologies. All validated, reviewed, and sound scientific methodologies and information made 

available by interested parties has been considered. Evidence in the record supports the finding that the 

rule shall result in a demonstratable reduction in air pollution. The rule revision is the most cost-effective 

alternative, provides the regulated community flexibility, and achieves the necessary reduction in air 

pollution. The revised rule will maximize the air quality benefits of the regulation in the most cost-effective 

manner.

Findings Pursuant to 25-7-110.8. C.R.S

The requirements of 25-7-110.8 do not apply to the rule revision delaying repeal of the MIL test 

requirement. Section 25-7-110.8 requires the Commission to make express findings only when it imposes 

new or amended regulatory requirements intended to reduce air pollution. Essentially, the statute requires 

the Commission to determine that the costs and burdens imposed by the new or more stringent 

requirements are justified by the air quality benefits. The rule revision concerning delay of the MIL test 

requirement make implementation of the Commission revisions of October 17, 2002 possible, and thus 
Regulation Number 11

Adopted: November 21, 2013 Page 65

reduce the cost and burden of the Automobile Inspection and Readjustment Program. Therefore, the 

requirements of Section 25-7-110.8 do not apply to such revisions.

XII. AMENDMENTS 

ADOPTED DECEMBER 19, 2002

This rulemaking action removes the Greeley component of the Automobile Inspection and Maintenance 

Program (“AIR Program”) from the State Implementation Plan (“SIP”), effective January 1, 2004. The AIR 

Program would remain a state-only program while the lead air quality planning agency for the Greeley 

area evaluates options for discontinuing the program altogether or retaining it as a local program. The 

AIR Program for the Greeley area has been removed from the SIP because it is no longer necessary for 

the Greeley area to meet the ambient air quality standards.

Basis and Purpose

The maintenance plan adopted by the Commission in conjunction with these rule changes includes a 

commitment to begin implementing the AIR Program in the Greeley area anew in the year 2026. Such a 

commitment is necessary to authorize state and local transportation planning agencies to take emissions 

reduction credit for such a program when such agencies make transportation conformity determinations, 

40 CFR 93.122 (a) (iii). The Commission intends to reevaluate this commitment when it revises the 

maintenance plan, as it is required to do within eight years pursuant to as required by 42 USC Section

750 a (b), and may, in compliance with all applicable state and federal laws, revise the commitment as 

necessary and appropriate. The rule resulting from this rule change exceeds minimum federal 

requirements because air quality modeling shows that the AIR Program is not necessary to maintain the 

national ambient air quality standard for carbon monoxide in the Greeley area after 2003.

The application of the Basic AIR Program to the Greeley area is prescribed in state statute, Section 42-4-

304(20)(a)(V). The Commission has the statutory authority to adopt a comprehensive State 

Implementation Plan (SIP) and to decide which control measure should be included in such SIP, Section 

25-7-105, C.R.S. The Commission is required to exclude from the SIP rules that exceed the minimum 

requirements of federal law, and has the authority to adopt regulations exclusively under state authority, 

Section 25-7-105.1(1), C.R.S. Thus, the Commission has the statutory authority to maintain the AIR 

Program as a state-only rule in the Greeley area, but remove the program from the SIP for such area.

Specific Statutory Authority

The December 2002 changes to Regulation Number 11 merely change the federal status of the 

regulation; this rule change does not have any effect on air quality or motor vehicle emission. Thus, the 

rule change is administrative in nature, and is not based on scientific evidence demonstrating that it will 

improve air quality.

Findings Pursuant to 25-7-110.8. C.R.S.

In evaluating the available options, the Commission considered the option of repealing the AIR Program 

for the Greeley area. Such an option would likely comply with the minimum federal requirements in a 

more cost-effective manner.

Notwithstanding the cost effectiveness of the repeal of the program, the Commission has retained the AIR 

Program as a state-only program. This is the same approach the Commission took for the City of Ft. 

Collins in July 2002. The retention of the regulation as a state-only rule will provide an opportunity for the 
Regulation Number 11

Adopted: November 21, 2013 Page 66

North Front Range Transportation and Air Quality Planning Council to explore planning options for the 

region as a whole.

XII. AMENDMENTS 

ADOPTED SEPTEMBER 18, 2003

The purpose of this rulemaking action is to implement House Bill 2003-1016 and House Bill 2003-1357. 

The bills revised Sections 42-4-309 and 42-4-310, C.R.S. to allow the sale and registration of used motor 

vehicles without an emissions inspection if the motor vehicle is less than three years old, and to provide 

that motor vehicle dealers shall not be required to have vehicles inspected more than once a year.

Basis and Purpose

The federal rules do not require an inspection upon vehicle sale or transfer. The relevant federal 

requirement is the general requirement for the state implementation plan to contain the control measures 

necessary to demonstrate maintenance of the national ambient air quality standards. Although the preexisting requirement for an emissions test upon sale or transfer of a vehicle is included in the state 

implementation plan, Colorado did not take any emissions reduction credit for such a requirement. Thus, 

we may revise the state implementation plan to implement HB03-1016 and HB03-1357.

Federal Requirements

The Commission promulgates these regulatory changes pursuant to its authority to promulgate such 

regulations as may be necessary to implement the program set out in Section 42-4-306(1), C.R.S.

Statutory Authority

The requirements of 25-7-110.8 do not apply to the September 2003 rule revisions because these 

revisions do not establish new requirements intended to reduce air pollution. Instead, the rule revisions 

relax pre-existing requirements as provided in HB03-1016 and HB03-1357.

Findings Pursuant to 25-7-110.8. C.R.S.

XIII. AMENDMENTS 

ADOPTED DECEMBER 18, 2003

The purpose of this revision is to postpone the change in emissions standards scheduled to take effect on 

January 1, 2004 for 1996 and newer light-duty vehicles. The standards scheduled to take effect on 

January 1, 2004 were overly stringent, and were likely to result in an unacceptable number of “false 

failures”. A false failure occurs when a vehicle fails the emissions test even though there is nothing wrong 

with the vehicle. The effect of the rule change is to maintain the status quo pending a SIP revision based 

on MOBILE6. The Commission will reconsider the standards appropriate for 1996 and newer light-duty 

vehicles when it revises the carbon monoxide maintenance plan for the Denver metropolitan area.

The specific authority to establish emissions standards is set out at Section 42-4-306(6)(b), C.R.S.

The requirements of Section 25-7-110.8, C.R.S. do not apply to the November 2003 rule revision 

because the revision does not establish new requirements intended to reduce air pollution. Instead, the 

rule revision relaxes the emissions standards for 1996 and newer vehicles.
Regulation Number 11

Adopted: November 21, 2013 Page 67

XV. AMENDMENTS 

ADOPTED DECEMBER 18, 2003

The purpose of this rulemaking action is to remove the El Paso County component of the automobile 

inspection and maintenance program (“AIR Program”) from the federally enforceable state 

implementation plan (SIP). Although the AIR Program will continue to apply in El Paso County as state 

law, the Commission will schedule another hearing to consider terminating the program in El Paso County 

once the Division has evaluated the impact such termination may have on ozone concentrations.

Basis and Purpose

The AIR program is no longer necessary to comply with minimum federal requirements in El Paso 

County. The retention of a state-only program is arguable more stringent than the minimum federal 

requirements, but it is reasonable and appropriate to retain the program while the Division evaluates the 

impacts the program may have on ozone concentrations.

Section 25-7-105, C.R.S. grants the Commission the authority to adopt a comprehensive SIP. In addition,

Section 25-7-105.1(1), C.R.S. authorizes the Commission to adopt rules exclusively under state authority 

that shall not be part of the SIP.

Statutory Authority

The December 2003 changes to Regulation Number 11 merely change the federal status of the 

regulation. This rule change is administrative in nature and will not have any effect on air quality or motor 

vehicle emissions.

Findings Pursuant to 25-7-110.8. C.R.S.

XVI. AMENDMENTS 

ADOPTED MARCH 12, 2004

The revisions to Regulation Number 11 reduce the maximum number of vehicles that may be exempted 

from conventional emissions testing at an inspection station through the use of the Clean Screen 

Program. The Clean Screen Program, beginning February 28, 2005, may evaluate regulation Number 11 

previously provided that up to 80% of the fleet. However, it appeared at the hearing the goal of screening 

80% of the vehicle fleet with the Clean Screen Program was unrealistic; a more realistic goal would be to 

screen 50% of the vehicle fleet. Revising the Regulation and the SIP to reflect this reality will result in an 

emission reduction benefit for purposes of the attainment demonstration.

Basis and Purpose

The Commission also repealed provisions stating that the NOx standards and gas cap test requirements 

were not to be included in the State Implementation Plan. Previously, such requirements were not 

necessary to the SIP because the State took no credit for the measures for SIP modeling purposes. The 

requirements are, however, necessary for the attainment demonstration set out in the Early Action 

Compact Ozone Action Plan for the 8-hour Ozone Control Area. Therefore, these requirements must 

now be incorporated into the SIP.

The statutory authority for the rule change is set out at Section 42-4-306(23)(a), C.R.S. This rule revision 

is based on the recognition that practical and technical hurdles make it unlikely that the clean screen 
Regulation Number 11

Adopted: November 21, 2013 Page 68

program will achieve the 80% level previously authorized by the regulation. The amendment is not 

intended to reduce pollution, rather the change is necessary so that the SIP will reflect the true nature of 

the clean screen program. Since this change is not intended to reduce air pollution, the requirements of 

25-7-110.8 do not apply.

XVII. AMENDMENTS 

ADOPTED FEBRUARY 18, 2005

The purpose of this rulemaking is to specify that the AIR program will no longer apply in El Paso, Larimer, 

and Weld counties. 

Basis and Purpose

Federal law no longer requires the basic program in El Paso, Larimer, and Weld counties because the 

Commission has submitted carbon monoxide maintenance plans for such areas showing maintenance of 

the NAAQS without the AIR program. 

Federal Requirements

The Commission promulgates these regulatory changes pursuant to its authority to promulgate such 

regulations as may be necessary to implement the program set out in Section 42-4-306(1), C.R.S. 

Specific statutory authority to specify that the AIR program no longer apply in El Paso, Larimer, and Weld 

counties is set out in Section 42-4-316(1), C.R.S.

Statutory Authority

The requirements of 25-7-110.8 do not apply to the February 2004 rule revisions because these revisions 

do not establish new requirements intended to reduce air pollution. Instead, these revisions terminate the 

program in El Paso, Larimer, and Weld counties.

Findings Pursuant to 25-7-110.8, C.R.S.

XVIII. AMENDMENTS 

ADOPTED NOVEMBER 17, 2005

The purposed of this rulemaking is to implement provisions contained in HB05-1214 that eliminate the 

inspection requirement for vehicles that have not yet reached their fourth model year registering in the I/M

Program area for the first time. Another purpose of this revision is to prevent a change in emissions 

standards scheduled to take effect on January 1, 2006 for 1996 and newer light-duty vehicles. The 

standards scheduled to take effect on January 1, 2006 were overly stringent, and were likely to result in 

an unacceptable number of “false failures”. A false failure occurs when a vehicle fails the emissions test 

even thought there is nothing wrong with the vehicle. The effect of the rule change is to maintain the 

status quo. The provisions amended in this rule change are not more stringent than federal 

requirements.

The Commission promulgates these regulatory changes pursuant to its authority to promulgate such 

regulations as may be necessary to implement the program set out in Section 42-4-306(1), C.R.S. and 

the authority to set emissions standards provided by Section 42-4-306(6)(b).

Statutory Authority
Regulation Number 11

Adopted: November 21, 2013 Page 69

The requirements of 25-7-110.8 do not apply to the November 2005 rule revisions because these 

revisions do not establish new requirements intended to reduce air pollution. Instead, these revisions 

implement state statute and lessen the cost and burden of the automobile inspection and readjustment 

program.

Findings Pursuant to 25-7-110.8, C.R.S.

XIX. AMENDMENTS 

ADOPTED JUNE 21, 2007

The purpose of this rulemaking is to allow the option of using a low emitting vehicle index in place of a 

second remote sensing clean screen measurement for clean screen program eligibility.

Federal requirements allow substitution of program elements or criteria contained in a State 

Implementation Plan when such new program element or criteria gives equal or greater air quality 

benefits than the program element or criteria replaced. Rule modifications adopted at this rule making 

are intended to produce similar air quality benefits as the old rule. 

Federal Requirements

The Commission promulgates these regulatory changes pursuant to its authority to promulgate such 

regulations as may be necessary to implement the clean screen and high emitter programs set out in 

Sections 42-4-306(23), 42-4-307(12), and 42-4-310(5) C.R.S. Specific statutory authority for this rule 

change is set out in Section 42-4-306(23), C.R.S. General authority for this regulation is contained in the 

Colorado Air Pollution and Control Act (Colorado Act) Sections 25-7-105, and 25-7-109, C.R.S., which 

authorize the Commission to promulgate air emission control regulations to control air pollutants and to 

implement a State Implementation Plan (SIP) for maintenance of air quality.

Statutory Authority

This rule modification is intended to make the Clean Screen Program more convenient to the public and 

increase the cost effectiveness of the program. It is administrative in nature, and is not intended to be 

more stringent than existing rule. Therefore requirements of 25-7-110.8 do not apply to the April 2007 

rule revisions because these revisions do not establish new requirements intended to reduce air pollution. 

Findings Pursuant to 25-7-110.8, C.R.S.

The requested rulemaking action is designed as a step to implement HB1302 requirements to increase 

the use of remote sensing to clean screen vehicles in the I/M Program. The requested rulemaking is not 

anticipated to raise any significant factual, policy or legal issues, but rather to improve the efficiency of the 

I/M Program, to reduce its regulatory burden, and to help facilitate the eventual implementation of a highemitter program as required by statute. 

Factual and Policy issues For Commission To Decide

The proposed rule is designed to implement the requirements in HB06-1302 for increasing the use of 

remote sensing in the I/M Program and for building a framework for a high-emitter program. The scientific 

and technical basis for the specific revisions in this rulemaking are generally accepted results found in 

reports developed under the direction of the Colorado Air Quality Control Commission and the Air 

Scientific/Technical Rationale
Regulation Number 11

Adopted: November 21, 2013 Page 70

Pollution Control Division, including reports conducted by the state contractor, Envirotest, for the State of 

Colorado, such as the Greeley Study Report which EPA relied upon in developing its guidance for remote 

sensing programs.

Rule Portions Not Specifically Required by the Federal Act

The Federal Act does not specifically require this rule, nor is it more stringent than requirements of the 

federal act. Rather, it provides a means to more efficiently meet current requirements of the state 

implementation plan as now required under the federal act. In addition, as addressed above, this rule 

meets requirements under state law to improve the clean screen program.

Further, these revisions will include any typographical and grammatical errors throughout the regulation.

XX. AMENDMENTS 

ADOPTED OCTOBER 18, 2007

This Statement of Basis, Specific Statutory Authority and Purpose complies with the requirements of the 

Colorado Administrative Procedure Act Sections 24-4-103(4), C.R.S. for new and revised regulations.

The Air Quality Control Commission has adopted these state-only provisions as a means of implementing 

the legislative direction set forth in HB06-1302. The specific purpose of the amendments is to establish 

the regulatory requirements for a mandatory remote sensing based High Emitting Vehicle Identification 

Program on a limited pilot scale basis as an add-on to the existing vehicle inspection and maintenance 

program and to continue the Clean Screen Program as contemplated by HB06-1302. These revisions 

reflect the Commission’s determination that the goals of HB06-1302 can be achieved in the most cost 

effective way by first enacting a High Emitting Vehicle Identification Pilot Project, that can be used to test 

the effectiveness of using remote sensing technology to identify high emitting vehicles prior to 

establishing a full scale High Emitting Vehicle Identification Program. In the establishing the pilot 

Program the Commission has concluded that while the program should be independent of the existing 

inspection and maintenance programs, the testing procedures and requirements should, for the most 

part, mirror the procedures and requirements applicable to the existing I/M programs. Additional 

requirements have been added, however, to make the Pilot Project more useful in studying the 

effectiveness of remote sensing technology in identifying high emitting vehicles without unduly burdening 

the motoring public, while still enacting the specific legislative directives set forth in HB06-1302. 

Basis and Purpose

These revisions are not specifically required by the Federal Clean Air Act and are not intended to be 

included in any State Implementation Plan

The specific statutory authority for these revisions is set forth in Sections 42-4-307, 42-4-307.7, and 42-4-

313 C.R.S, which direct the Commission to develop and implement a remote sensing based high emitting 

vehicle identification program, and to expand the existing Clean Screen Program.

Specific Statutory Authority

The proposed rule is designed to implement the requirements in HB06-1302 for increasing the use of 

remote sensing in the I/M Program and for building a framework for a high-emitter program. The scientific 

and technical basis for the specific revisions in this rulemaking are generally accepted results found in 

Scientific/Technical Rationale
Regulation Number 11

Adopted: November 21, 2013 Page 71

reports developed under the direction of the Colorado Air Quality Control Commission and the Air 

Pollution Control Division, including reports conducted by the state contractor, Envirotest, for the State of 

Colorado, such as the Greeley Study Report which EPA relied upon in developing its guidance for remote 

sensing programs. Evidence in the record supports the finding that the High Emitter Pilot Project will 

result in a reduction of air emissions though the identification and repair of high emitting vehicles.

XXI. AMENDMENTS 

ADOPTED MARCH 20, 2008

The purpose of this rulemaking is to implement revised, more stringent, model year emissions standards. 

It is expected that this revision will result in increased air quality benefits generated by the inspection and 

maintenance program. Another purpose of this revision is to delete obsolete language and correct minor 

typographic errors.

Basis and Purpose

The effect of the rule change is to identify more high emitting motor vehicles. Emissions reductions 

generated by the repair of these vehicles are expected to assist in reducing summertime ozone 

concentrations. The state this summer violated the national ambient air quality standards for ozone, 

making necessary these modifications. The provisions amended in this rule change are not more 

stringent than federal requirements.

The Commission promulgates these regulatory changes pursuant to its authority to authority to set 

emissions standards as provided by Section 42-4-306(6)(b)(I), C.R.S. Additional authority is set forth in 

Section 42-4-306(1), C.R.S., which gives the Commission the authority to adopt regulations as may be 

necessary to implement the emissions testing program. 

Specific Statutory Authority

The rule is based on reasonably available, validated, reviewed, and sound scientific methodologies 

including analysis of existing emission testing data and EPA approved mobile source emissions 

modeling. It will result in demonstratable reductions in ozone precursor emissions, and should help 

reduce the risk to human health or the environment from high ozone levels in the Denver Metro Area. 

Among the options considered, the regulatory option chosen will maximize the air quality benefits in the 

most cost-effective manner.

Scientific/Technical Rationale

XXII. AMENDMENTS 

ADOPTED OCTOBER 16, 2008

The purpose of this rulemaking is to implement revised visual inspection procedures and methodology for 

1996 and newer model year vehicles. It is expected that this rule revision will result in improved 

inspection throughput, resulting in shorter vehicle wait times and improved motorist convenience. 

Another purpose of this revision is to delete obsolete language and correct minor typographic errors.

Basis and Purpose

The effect of the rule change is to shorten the amount of time it takes to inspect vehicles for exhaust and 

gas cap evaporative emissions. 
Regulation Number 11

Adopted: November 21, 2013 Page 72

Currently the state receives no sip credit from visual inspecting 1996 and newer vehicles. Therefore, this 

rule change will result in no sip credit loss. Vehicles that would be expected to fail the visual component 

of the I/M inspection will continue to be detected through interrogation of the MIL command and OBD 

system.

Another purpose of this rulemaking is to eliminate certain no longer relevant components of the 

regulation, concerning chlorofluorocarbons and motor vehicle filler-neck inspections. These inspections 

have become obsolete, and no longer serve a purpose. Chlorofluorocarbons have been outlawed for a 

number of years now. The filler-neck restriction was to prevent the use of leaded gasoline in unleaded 

fueled vehicles. Leaded gasoline use in on-highway motor vehicles has been banned since 1993.

The Commission promulgates these regulatory changes pursuant to its authority to authority to set 

emissions inspection requirements and procedures as provided by Section 42-4-306(a), C.R.S. 

Additional authority is set forth in Section 42-4-306(1), C.R.S., which gives the Commission the authority 

to adopt regulations as may be necessary to implement the emissions testing program. 

Specific Statutory Authority

The rule is based on reasonably available, validated, reviewed, and sound scientific methodologies. This 

rule change will bring the visual inspection component in line with current EPA guidance and 

requirements and the practices of other states. The regulatory change will maximize the air quality 

benefits from the AIR Program, while improving motorist convenience in a cost-effective manner.

Scientific/Technical Rationale

XXIII. AMENDMENTS 

ADOPTED DECEMBER 12, 2008

In November 2007, USEPA designated the Denver Metro Area (DMA) and North Front Range (NFR) as 

out of attainment with the then current eight-hour ozone standard of 0.84 ppm. Since that time, USEPA 

has promulgated a new, stricter standard of 0.75 ppm. 

Basis and Purpose

High ozone concentrations are of concern since breathing ozone can trigger a variety of health problems 

including chest pain, coughing, throat irritation, and congestion. It can worsen bronchitis, emphysema, 

and asthma. Ground-level ozone also can reduce lung function and inflame the linings of the lungs. 

Emissions from motor vehicles are one of the prime contributors to ozone pollution in the DMA and NFR.

The purpose of this rulemaking is to expand the existing enhanced emissions inspection program 

currently applicable in the seven County Denver Metro Areas to the AIR Program area of Larimer and 

Weld counties. It is important to re-establish an inspection and maintenance program in this area as part 

of the state’s efforts to reduce ozone precursor emissions in the Denver Metro and North Front Range 

Area.

The Commission promulgates these regulatory changes pursuant to 42-4-306(9)(A)(II), C.R.S., which 

allows the Commission to expand the existing enhanced emissions inspection program to the AIR 

Program Area portions of Larimer and Weld counties. Additional authority is set forth in Section 42-4-

Specific Statutory Authority
Regulation Number 11

Adopted: November 21, 2013 Page 73

306(1), C.R.S., which gives the Commission the authority to adopt regulations as may be necessary to 

implement an emissions testing program. 

The rule is based on reasonably available, validated, reviewed, and sound scientific methodologies. 

Analysis of existing motor vehicle emissions inspection programs and their benefits, both in state, as well 

as from other states, were analyzed in developing this rule. Emissions benefits were derived using EPA 

approved mobile source emissions modeling.

Scientific/Technical Rationale

Comprehensive analysis of this rule shows that it will result in demonstratable reductions in ozone 

precursor emissions, and should help reduce the risk to human health or the environment from high 

ozone levels in the Area. Among the options considered, the regulatory option chosen will maximize the 

air quality benefits in the most cost-effective manner.

XXIV. AMENDMENTS 

ADOPTED MARCH 18, 2010

The purpose of this rulemaking is to provide agreement with statute regarding program boundaries, 

update certain technical specifications, and provide for some limited flexibility for the startup of the 

enhanced vehicle inspection and maintenance program in the North Front Range area. This rule revision 

will result in:

Basis and Purpose

1) Boundaries for the inspection and maintenance program in Larimer and Weld Counties that are 

consistent with the boundaries established in SB09-003. While the Commission interprets that the 

boundaries that the legislature adopted in Section 42-4-304(20) as part of SB09-003 are selfimplementing, this regulatory action will provide clarity for the motoring public and the county clerks in 

understanding which geographic areas in Larimer and Weld Counties are included and excluded from 

emissions testing requirements, 

2) Specifications for an up-to-date test analyzer system for vehicle fleets and independent inspection 

shops (for 1981 and older vehicles) to provide a voluntary alternative to centralized emissions testing, 

3) A set of interim phase-in emissions cut-points (pass/fail standards) that better reflect the condition of 

vehicles in the North Front Range vehicle fleet and the capabilities of the North Front Range automobile 

repair industry, and 

4) Flexibility of program start date that reflect the realities of starting up a major contractor-operated public 

program in the North Front Range,

5) A demonstrable reduction in tailpipe and evaporative emissions of ozone precursor pollutants that will 

help Colorado achieve compliance with the 8 hour ozone standard in the Denver Metropolitan Area and 

North Front Range.

The enhanced emissions program startup in the North Front Range is a state-only emissions reduction 

strategy and is not included in any State Implementation Program (SIP) with the US EPA. 

The Commission has extended the timeline for implementation of the program for the Estes Park area 

and intends for the Division to return to the Commission to discuss an analysis of the applicable science 
Regulation Number 11

Adopted: November 21, 2013 Page 74

and the effects of the program on the population living in the region. The Commission also intends for the 

Division to provide a review of other vehicle emission testing programs that could be implemented in the 

area.

The Commission promulgates these regulatory changes pursuant to its authority to: 1) establish 

regulations for program areas under 42-4-306(1); 2) review and change emissions program area 

boundaries under 42-4-304 (20) (d); 3) establish technical specifications for Test Analyzer Systems under 

42-4-306 (3)(a); and 4) to establish interim emissions cut-points (standards) under 42-4-306 (6). Statute 

also provides flexibility for startup of the North Front Range enhanced I/M Program in 42-4-304 (20)(c) as 

amended by SB 09-003.

Specific Statutory Authority

The proposed rule is based on reasonably available, validated, reviewed, and sound scientific 

methodologies. All validated, reviewed and sound scientific methodologies and information made 

available by interested parties has been considered by the Commission in the adoption of this revision. 

Further, the Commission finds, based on the evidence in the record, that this revision will bring about 

reductions in risks to human health and the environment associated with ground-level ozone, as well as 

its precursor pollutants, and that these benefits justify the costs to government and the public. This 

revision maximizes air quality benefits in the most cost-effective manner of all alternatives available to the 

Commission. This proposed rule change will provide clarity for citizens, county clerks, and vehicle fleet 

operators in the North Front Range. It will also ensure that the vehicle emissions failure rate of this new 

program is reasonable, manageable and that those vehicles that fail emissions are repairable within the 

capabilities of local repair businesses. Finally, the proposed rule will allow administrative flexibility to 

begin the program when the testing network is complete and the public has been properly informed of 

program requirements. The record demonstrates that this change will result in demonstrable reductions 

in tailpipe and evaporative ozone precursor emissions from vehicles in the Front Range ozone nonattainment area.

Scientific/Technical Rationale

XXV. AMENDMENTS

ADOPTED AUGUST19, 2010

The purpose of this rulemaking is to revise the provisions of Regulation Number 11 to add a Nitrogen 

Oxides (NOx) cut-point to the selection criteria used in the Clean Screen Program. This change will 

enhance the environmental effectiveness of the Automobile Inspection and Readjustment (AIR) Program 

as a whole by helping to ensure that vehicles with high NOx emissions are not exempted from testing 

through the Clean Screen Program. This change will also address one of the key recommendations by 

the State Auditor’s Office during the 2009 performance audit of the AIR Program.

Basis and Purpose

The Commission promulgates these regulatory changes pursuant to its authority to establish rules 

governing the Clean Screen Program including clean screen emission levels pursuant to Sections 42-4-

306 (23)(a) and 42-4-306 (6)(a), C.R.S.

Specific Statutory Authority

Scientific/Technical Rationale
Regulation Number 11

Adopted: November 21, 2013 Page 75

The rule is based on reasonably available, validated, reviewed, and sound scientific methodologies 

including analysis of existing emission testing data, clean screen data and EPA approved mobile source 

emissions modeling. It will result in demonstrable reductions in ozone precursor emissions as well as 

mobile source air toxics, and should help reduce the risk to human health or the environment from vehicle 

emissions in the program area. Among the options considered, the regulatory option chosen will 

maximize the air quality benefits in the most cost-effective manner.

XXVI. AMENDMENTS

ADOPTED OCTOBER 21, 2010

Basis and Purpose

The purpose of this rulemaking is to correct 12 clerical errors for the implementation of the enhanced 

vehicle inspection and maintenance program in Colorado’s North Front Range. 

This rule revision will result in a set of interim phase-in emissions cut-points (pass/fail standards) that 

better reflect the condition of vehicles in the North Front Range vehicle fleet and the capabilities of the 

North Front Range automobile repair industry. 

The Commission’s intent to implement phase-in cutpoints is evident in the Statement of Basis and 

Purpose for the March 18, 2010 rulemaking hearing; however 12 of the 108 numerical values in the tables 

adopted at that time were incorrect. This rulemaking is intended to correct those 12 values and 

implement the Commission’s original intent from its March 18, 2010 public hearing. 

The enhanced emissions program startup in the North Front Range is a state-only emissions reduction 

strategy and is not included in any State Implementation Program (SIP) with the US EPA. 

The Commission promulgates these regulatory changes pursuant to its authority to establish interim 

emissions cut-points (standards) under 42-4-306 (6) C.R.S.

Specific Statutory Authority

The proposed rule is based on reasonably available, validated, reviewed, and sound scientific 

methodologies. All validated, reviewed and sound scientific methodologies and information made 

available by interested parties has been considered by the Commission in the adoption of this revision. 

This proposed rule change will ensure that the vehicle emissions failure rate of this new program is 

reasonable, manageable and that those vehicles that fail emissions are repairable within the capabilities 

of local repair businesses.

Scientific/Technical Rationale

XXVII. AMENDMENTS

ADOPTED JANUARY 20, 2011

Basis and Purpose

The purpose of this rulemaking is to correct 12 clerical errors for the implementation of the enhanced 

vehicle inspection and maintenance program in Colorado’s North Front Range. 
Regulation Number 11

Adopted: November 21, 2013 Page 76

This rule revision will result in a set of interim phase-in emissions cut-points (pass/fail standards) that 

better reflect the condition of vehicles in the North Front Range vehicle fleet and the capabilities of the 

North Front Range automobile repair industry. 

The Commission’s intent to implement phase-in cutpoints is evident in the Statement of Basis and 

Purpose for the March 18, 2010 rulemaking hearing; however 12 of the 108 numerical values in the tables 

adopted at that time were incorrect. This rulemaking is intended to correct those 12 values and 

implement the Commission’s original intent from its March 18, 2010 public hearing. 

The enhanced emissions program startup in the North Front Range is a state-only emissions reduction 

strategy and is not included in any State Implementation Program (SIP) with the US EPA. 

The Commission promulgates these regulatory changes pursuant to its authority to establish interim 

emissions cut-points (standards) under 42-4-306 (6) C.R.S.

Specific Statutory Authority

The proposed rule is based on reasonably available, validated, reviewed, and sound scientific 

methodologies. All validated, reviewed and sound scientific methodologies and information made 

available by interested parties has been considered by the Commission in the adoption of this revision. 

This proposed rule change will ensure that the vehicle emissions failure rate of this new program is 

reasonable, manageable and that those vehicles that fail emissions are repairable within the capabilities 

of local repair businesses.

Scientific/Technical Rationale

XXVIII. AMENDMENTS

ADOPTED SEPTEMBER 15, 2011

The purpose of this rulemaking is to revise the provisions of Regulation Number 11 to exclude the Estes 

Park area from the North Front Range Enhanced IM Program. Previous rulemaking had scheduled the 

Estes Park area to be included in the program on December 31, 2011.

Basis and Purpose

The Commission promulgates these regulatory changes pursuant to its authority to establish rules 

governing program adoption and implementation pursuant to Sections 42-4-304(20)(d) and 42-4-306(1) 

and 42-4-306 (6)(a) and Section 42-4-306 (7)(a) and Section 42-4-306 (9)(a)(II), C.R.S.

Specific Statutory Authority

As compared with the Denver Metro North Front Range region, the Estes Park area is unique because 

most summertime vehicle emissions are from tourist vehicles, the areas older residents would experience 

a hardship driving to remote testing stations, the increased vehicle miles travelled to the test stations is 

counter-productive, and the cost of emission reductions is proportionally higher in Estes Park.

Scientific/Technical Rationale

In developing this rule, the Division met with Estes Park and Larimer County officials on April 13, 2011 to 

discuss the upcoming rulemaking proceedings and the Division’s proposal. Those officials obtained party 

status and presented an alternative proposed rule to exclude Estes Park from the emissions program.
Regulation Number 11

Adopted: November 21, 2013 Page 77

XXIX. AMENDMENTS

ADOPTED MAY 17, 2012

The purpose of this rulemaking is to:

Basis and Purpose

- Remove the regulatory prohibition that disallows government fleet-owned vehicles from being clean 

screened by roadside emissions monitors,

- Clarify the language for criteria to issue an economic hardship waiver for a vehicle that cannot pass 

emissions,

- Add clarifying language to the body of the regulation that clearly designates the North Front Range I/M 

Program as a state-only program and that it is not part of any State Implementation Plan with US EPA,

- Remove obsolete provisions for less-stringent phase-in emissions standards (cutpoints) for the North 

Front Range enhanced program startup, and remove the repealed Part G, which established regulatory 

authority to operate the roadside remote sensing high emitter pilot project through July 1, 2010.

- Replace language that was inadvertently deleted in Part F that provides for specific pass/fail criteria for 

1981 and newer vehicles receiving a two-speed idle emissions test. 

The Automobile Inspection and Readjustment (AIR) Program is designed to reduce motor vehicle 

emissions through the detection and repair of high emitting gasoline-powered motor vehicles. To 

accomplish this goal vehicles within the program area are required to undergo a periodic inspection at an 

emissions testing station. Vehicles that fail the inspection must undergo repairs and pass a retest in 

order to register their vehicle. To reduce the inconvenience for motorists, the AIR Program also uses 

roadside remote sensing devices to screen out clean vehicles and exempt them from their periodic test 

(Clean Screen Program). Clean screened vehicle owners still pay the $25 inspection fee. 

Government-owned fleet vehicles (City, County, State, School district and special district vehicles) are 

required to undergo emissions testing just like privately-owned vehicles. Since government-owned 

vehicles renew their registration information every year in a completely different manner than privately 

owned vehicles, and government vehicles do not pay an annual registration fee, there was never a 

mechanism for notification of “Passing Roadside Emissions” or payment for clean screen of government 

vehicles. Therefore, government vehicles were prohibited by Regulation from participation in Clean 

Screen.

At the request of several local governments, and in an effort to comply with directives from the Governor’s 

office, the Division, Department of Revenue and the emissions inspection contractor have agreed to 

develop procedures to provide for clean screen notification and payment mechanisms to allow 

government fleet vehicles to be clean screened, at the option of the government agency. The proposed 

rule in this request for hearing removes the regulatory prohibition against clean screening Government 

vehicles in Part C, Section XII.A.4.c. 

The Commission is revising rules on hardship waivers in Part C, Section VIII.D. to ensure that the 

Commission’s rules are consistent with its statutory authority. The Commission is revising rules to clarify 

that the North Front Range program is a state-only program to address an objection from the US EPA in 

Part A, Section II.40. and Part A, Section V.A. The Commission is removing provisions already noted in 

the regulation as repealed or obsolete (North Front Range phase-in cutpoints in Part F, Section III.C. and 
Regulation Number 11

Adopted: November 21, 2013 Page 78

Part F, Section III.D. and the High emitter pilot project), and replacing language that was inadvertently 

rescinded in 2006 (pass/fail criteria for 1981 and newer vehicles receiving a two-speed idle emissions 

test).

The Commission is revising the language for criteria to issue an economic hardship waiver for a vehicle 

that cannot pass emissions after receiving comment that Regulation Number 11 should, but does not, 

establish those criteria. The Commission adds clarifying language that clearly designates the North Front 

Range I/M Program as a state-only program because, under the previous version of the rules governing 

the North Front Range I/M program, it is not clear whether the program is in the State Implementation 

Plan approved by the Environmental Protection Agency. When originally adopted, the Commission 

intended for the program to be state-only. EPA sought clarification, so the rules now explicitly state that 

the program is state-only.

Finally, the Commission is removing expired cutpoints and addressing the inadvertent deletion of pass/fail 

criteria for older vehicles.

This rule revision will result in:

1) Improved convenience and reduced costs for state and local government fleet operators, by making 

emissions compliance easier and faster, 

2) Legal and regulatory clarity in the rule language, while not affecting procedures and operation of the 

program or its customers,

3) A lean and streamlined regulation by removing repealed and obsolete provisions.

The Commission has the authority to promulgate rules governing the operation of the clean screen 

program pursuant to Section 42-4-306(23). The Commission has the authority to promulgate rules 

governing the issuance of economic hardship waivers pursuant to Section 42-4-306 (7) (a) (II) (C), C.R.S. 

; the labeling of the North Front Range as state-only falls under the general authority of the Commission 

to promulgate rules pursuant to Section 42-4-306 (1) C.R.S.; establishing cutpoints and pass-fail criteria 

in Section 42-4-306 (6)(a) C.R.S.; operating the remote sensing high emitter project in Section 42-4-307.7 

C.R.S.

Specific Statutory Authority

None of the revisions in this rulemaking exceed federal requirements. With the exception of the revision 

addressing the two-speed idle emissions test, these rules are not federally mandated, nor are there any 

counterpart federal rules. The rule is based upon reasonably available, validated, reviewed, and sound 

scientific methodologies, and the Commission has considered all information submitted by interested 

parties. This revision will result in cost savings and efficiencies to state and local government vehicle 

fleets with minimal impact on air quality and emissions, and that the cost savings to government and the 

public justify the slight air quality impact. This proposed rule change will provide clarity for citizens, 

government vehicle fleet operators, and the automotive repair industry and achieve any necessary 

reduction in air pollution. These rules will maximize the air quality benefits of the regulation in the most 

cost-effective manner.

Additional findings under Sections 25-7-110.5(5) and 25-7-110.8, C.R.S

XXX. AMENDMENTS

ADOPTED DECEMBER 20, 2012
Regulation Number 11

Adopted: November 21, 2013 Page 79

This revision to Regulation Number 11, Parts A, B, C, D, E, F and H – is to amend language that would 

extend model-year exemptions; require on-board diagnostic inspections; no longer require visual 

inspections of emission control systems on 1996 model-year and newer vehicles; require retesting after 

failing gas cap integrity test; delete obsolete language; and revise typographical, grammatical, and 

formatting errors. 

This Statement of Basis, Specific Statutory Authority, and Purpose complies with the requirements of the 

Colorado Administrative Procedures Act, Section 24-4-103, C.R.S., and the statutory authority provided in 

Sections 42-4-301 through 42-4-316, C.R.S.

Basis and Purpose

The Commission’s December 2012 amendments are intended to assure that emission reduction benefits 

are maintained while at the same time increasing the flexibility and convenience of motor vehicle 

emission inspections. The amendments increase new vehicle model-year exemptions from emissions 

testing from four to seven years. The amendments provide for OBD inspections of 1996 year-model and 

newer motor vehicles for the first two testing cycles (four model years) after the seven year new vehicle 

exemption runs out. Procedures are included to default to the use of OBD testing on vehicles that are not 

readily testable using IM 240; and to default to IM 240 testing on vehicles that are not readily testable with 

OBD. Visual inspections of emission control equipment are eliminated on 1996 year-model and newer 

motor vehicles. To clarify and assure compliance with the federal requirements at Title 40, Part 51, 

Subpart S, 51.357, the already current practice of requiring a full retest after a gas cap failure is being 

specified as part of the evaporative fuel control inspection procedures.

Federal Requirements

The current inspection and maintenance program, except in the North Front Range is contained in 

Colorado’s ozone State Implementation Plan (SIP). Any revision to the program requires that air quality 

credits achieved from the program are not lost.

In general, EPA rules require certain nonattainment areas implement Inspection and Maintenance 

programs as part of a SIP. Under the Clean Air Amendments of 1990, the Denver metropolitan area was 

required to implement an “Enhanced” IM Program, specifically for carbon monoxide. Since that time, the 

state has come into attainment with carbon monoxide, but the program remains a necessary element of 

Colorado’s ozone SIP. The North Front Range area of the program operates as a state-only program

Specific Statutory Authority

Sections 42-4-306 and 42-4-310, C.R.S. authorize the Air Quality Control Commission (“Commission”) to 

promulgate rules for inspection of motor vehicle emissions. Section 42-4-306(8) authorizes the 

Commission to exempt motor vehicles from emission inspections. Section 42-4-306(3)(b)(V)(B) 

authorizes the Commission to promulgate rules for alternative motor vehicle emission inspections, 

including on-board diagnostics (OBD) inspections. 42-4-306(6)(a) authorizes the Commission to 

promulgate rules on inspection procedures, including those related to OBD and evaporative gases. 

Findings Pursuant to 25-7-110.8, C.R.S.

The revision of the rule is to lessen the regulatory burden on the motoring public through expanding the 

new vehicle exemption period to seven years and the introduction of OBD inspection to select vehicles, 

among other measures, while maintaining the current air quality benefits received from the program, in a 

cost effective manner, at similar or reduced costs to the current program.
Regulation Number 11

Adopted: November 21, 2013 Page 80

The rule revision is based on reasonably available, validated, reviewed, and sound scientific 

methodologies. All validated, reviewed, and sound scientific methodologies and information made 

available by interested parties has been considered. Evidence in the record supports the finding that the 

rule shall result in a continued demonstrable reduction in air pollution. The rule revision is the most costeffective alternative, provides the regulated community flexibility, and achieves the necessary reduction in 

air pollution. The revised rule will maximize the air quality benefits of the regulation in the most costeffective manner.

XXXI. AMENDMENTS

ADOPTED NOVEMBER 21, 2013

This revision to Regulation Number 11 is to amend language that will clarify provisions contained in the 

existing regulation concerning model year exemptions and program implementation dates, updating the 

listed repair waiver cost limit from $450 to the currently used $715 limit, modifying qualification criteria 

used to grant an economic hardship waiver, and incorporating a new Test Analyzer Specification for Onboard Diagnostics in Appendix A. Obsolete technical specifications and procedures are being deleted 

and formatting, grammatical and typographical corrections are being made.

This Statement of Basis, Specific Statutory Authority, and Purpose complies with the requirements of the 

Colorado Administrative Procedures Act, Section 24-4-103, C.R.S., and the statutory authority provided in 

Sections 42-4-301 through 42-4-316, C.R.S.

Basis and Purpose

The Commission’s November 2013 amendments are intended to clarify, amplify, and streamline the rule 

in support of previous recent changes to the Automobile Inspection and Readjustment Program. The 

proposed modifications are considered minor and will not result in any significant change in program 

costs or air quality benefits.

The basis of these modifications is to address any ambiguities that may exist in the interpretation of new 

program changes, as well as add a new Test Analyzer Specification for On-board Diagnostics as required 

by Regulation Number 11, Part B, Section X.

Federal Requirements

The current inspection and maintenance program is contained in Colorado’s ozone State Implementation 

Plan (SIP), with the exception of Larimer and Weld Counties in the North Front Range. Any revision to 

the program requires that air quality credits achieved from the program are not lost.

In general, EPA rules require certain nonattainment areas implement Inspection and Maintenance 

programs as part of a SIP. Under the Clean Air Amendments of 1990, the Denver metropolitan area was 

required to implement an “Enhanced” IM Program, specifically for carbon monoxide. Since that time, the 

state has come into attainment with carbon monoxide, but the program remains a necessary element of 

Colorado’s ozone SIP. The North Front Range area of the program operates as a state-only program

Specific Statutory Authority

Sections 42-4-306 and 42-4-310, C.R.S. authorize the Air Quality Control Commission (“Commission”) to 

promulgate rules for inspection of motor vehicle emissions. Section 42-4-306(8) authorizes the 

Commission to exempt motor vehicles from emission inspections. Section 42-4-306(3)(b)(V)(B) 

authorizes the Commission to promulgate rules for alternative motor vehicle emission inspections, 
Regulation Number 11

Adopted: November 21, 2013 Page 81

including on-board diagnostics (OBD) inspections. 42-4-306(6)(a) authorizes the Commission to 

promulgate rules on inspection procedures, including those related to OBD and evaporative gases. 

Findings Pursuant to 25-7-110.8, C.R.S.

The revision of the rule is to clarify provisions contained in rule or that are administrative in nature. These 

changes do not increase the regulatory burden on the motoring public, while maintaining the current air 

quality benefits received from the program, in a cost effective manner, at similar or minimally reduced 

costs to the current program.

The rule revision is based on reasonably available, validated, reviewed, and sound scientific 

methodologies. All validated, reviewed, and sound scientific methodologies and information made 

available by interested parties has been considered. Evidence in the record supports the finding that the 

rule shall result in a continued demonstrable reduction in air pollution. The rule revision is the most costeffective alternative, provides the regulated community flexibility, and achieves the necessary reduction in 

air pollution. The revised rule will maximize the air quality benefits of the regulation in the most costeffective manner.

APPENDIX A Technical Specifications

(Technical Specifications)

COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT

SPECIFICATIONS FOR COLORADO 94 ANALYZER

HARDWARE SPECIFICATIONS

Revised Sept 09, 1994

INTRODUCTION

The Colorado AIR Program is in the process of modifying its current automotive inspection and 

maintenance program to comply with the Clean Air Amendments of 1990. Colorado's current program is 

based upon BAR 84 inspection technology utilizing a decentralized program format encompassing nine 

fFront rRange counties. In order to achieve compliance with the Clean Air Amendments of 1990, 

Colorado will change to a program format that will have a contractor based operation conducting the IM

240 emissions test and a population of independent inspectors conducting inspections utilizing a new 

Colorado 94 emissions analyzer. The contractor is based in the “enhanced” program area, basically the 

Denver metropolitan area and will inspect 1982 and newer vehicles. Independent inspection facilities will 

inspect vehicles of all years within the “basic” program area as well as being able to inspect 1981 and 

older vehicles within the “enhanced” area.

The demands for more accurate analytical information as well as a more automated inspection process 

with real-time data transfer has superseded the capabilities of BAR 84 technology. Current BAR 90 

analytical technology is acceptable, but other system enhancements are necessary to meet Colorado’s 

inspection needs. These enhancements and other technical details are described in the remainder of this 

document.

1.0 GENERAL

1.1 Design Goals
Regulation Number 11

Adopted: November 21, 2013 Page 82

The specifications that have been developed are designed utilizing a personal computer system. 

The analyzer system must be capable of performing uniform and consistent emission tests for 

Colorado's Automotive Inspection and Readjustment (AIR) Program. Features of the analyzer 

include: vehicle emissions measurements of hydrocarbon (HC), carbon monoxide (CO), carbon 

dioxide (CO2)and oxygen(O2); engine RPM measurements, exhaust dilution determinations, 

pressure test system for EVAP; data entry; data retrieval tables; a dedicated printer (for vehicle 

inspection certificates) and an additional printer for diagnostics and general purpose printouts; 

data recording on double sided high density 1.44 megabyte (Mb) 3.5” floppy diskette and a 

120Mb (or greater) hard drive; modem for “on-line real time” data transmission; CRT information 

display to the inspector; bar code (2D) reader and printing capabilities; and fully menu driven, 

interactive simple microprocessor controlled operation.

Additional, automatic features required include: gas calibrations, zero and span checks, pressure 

calibrations, gas auditing procedure; leak checks, HC hang-up checks, audit menus (i.e., data 

read system), test sequencing, and low-flow checks. The analyzer shall be designed and 

constructed to provide reliable and accurate service in the automotive environment. The software 

used in the analyzer shall consist of a process control system as well as data look-up files. 

Security shall be provided to prevent unauthorized modifications to the software or test data and 

recording unauthorized entry (tampering) and locking out of the inspection process when 

detected.

The emissions analyzer software shall be designed for maximum operational simplicity.

It shall also be capable of providing emission-reading characteristics, independent of the 

inspection function, which can be used for vehicle diagnostic.

1.2 Useful Life

The useful life of the analyzer shall be a minimum of five years.

1.3 Nameplate Data

A nameplate including the following information shall be permanently affixed to the housing of the 

analyzer:

Name and Address of Manufacturer

Model Description

Serial Number

Date of Assembly

The manufacturer shall affix a stick-on type label to the analyzer that contains a toll-free 

telephone number for customer service. This number can also be included in a service software 

message.

1.4 Manuals

Each analyzer shall be delivered with the following manuals:

A. Reference Operating Instructions
Regulation Number 11

Adopted: November 21, 2013 Page 83

B. Operation Instruction Manual

C. Maintenance Instruction Manual (limited)

D. Initial Start-up Instructions

Colorado 94 Analyzer manufacturers may consolidate manuals. The manuals shall be 

constructed of durable materials and shall not deteriorate as a result of normal use over a 

five-year period. The analyzer housing shall provide convenient storage for each manual 

in a manner that will:

E. Allow easy use.

F. Prevent accidental loss or destruction.

1.5 Certification Documentation

The analyzer software shall be fully documented. Two copies of the documentation listed below 

shall be submitted to the Colorado Department of Public Health and Environment as part of the 

certification application.

A. Complete program listings. Program listings may be on diskette. They are not 

required to be submitted with the application for certification.

B. Functional specifications.

C. Functional flowcharts of the software.

D. Example inputs and outputs from all processes.

E. Detailed interface information on system components including the identification 

of protocol and output specifications.

F. All DOS file layouts with file names, file types, file security, field names, field 

types, field sizes, and field editing criteria.

Documentation provided by the vendor to meet this requirement will be treated as 

proprietary information by the Colorado Department of Public Health and Environment.

Prior to certification of any Colorado 94 emissions analyzer for sale in Colorado, the 

manufacturer of such analyzer shall provide the Division with software source codes and 

all other technical information (including, but not limited to all working codes, schematics 

and drawings) necessary to operate, maintain, calibrate and repair such analyzer in the 

event that the manufacturer or its agent ceases providing adequate maintenance, 

calibration and repair services in Colorado. The manufacturer shall keep such information 

current, and will provide the Division with copies of any and all changes. So long as such 

maintenance, calibration and repair, services are available from the manufacturer or its 

agent, the Division shall protect such information as confidential commercial data if it is 

clearly marked as such. In the event that the manufacturer becomes insolvent or stops 

providing adequate maintenance, repair or calibration services in Colorado all such 

information shall be the property of the Division and may be released to a third party as 

necessary to repair, calibrate and maintain the analyzers.
Regulation Number 11

Adopted: November 21, 2013 Page 84

1.6 Warranty Coverage/Mandatory Service Contract

A written warranty coverage agreement, signed by an authorized representative of the equipment 

manufacturer and the vehicle inspection station owner, which provides a complete description of 

coverage for all systems and components and all manufacturer provided services listed in Section 

1.8, must accompany the sale or lease of each Colorado 94 emissions analyzer.

An extended service contract must be available upon the expiration of the manufacturers original 

warranty period. Original manufacturer’s warranty shall be a minimum of one year from the date 

of purchase. The “service contract” shall be offered in one-year increments and is a mandatory 

condition of inspection station operation. The “service contract” agreement shall include the 

inspection station owner's name, inspection station address, telephone number, inspection 

station identification number, analyzer serial number and detailed terms of the agreement. The 

agreement must extend for at least one year with the expiration date entered to software file and 

monitored by the system clock. Approaching expiration messages must be displayed at daily 

system start-up beginning thirty days prior to expiration and massaging “30 days until expiration, 

29 days etc.” Failure to renew the “service contract agreement” will cause the analyzer to 

automatically “lock-out” from any official inspection process. Renewals shall be offered at the 

inspection station owner’s request and governed by “good business” practices between the 

parties involved. Service contract agreements must be available by the manufacturer for the 

mandated life of the Colorado AIR Program. Cost disclosures and detailed descriptions of 

coverage’s must be available in printed form and distributed to all Colorado 94 users. Cost 

disclosure shall also be made for “consumable” inventory items 1.8B. This information would 

most appropriately be presented with the original manufactures warranty.

1.7 Tampering Resistance

Controlled access design shall be the responsibility of the manufacturer and is subject to approval 

by the Colorado Department of Public Health and Environment. Analyzer service personnel, 

inspectors or others shall be prohibited, to the Colorado Department of Public Health and 

Environment satisfaction, from creating or changing any test results, programs or data files 

contained in the analyzer. Manufacturers shall utilize special BIOS partitions, or other appropriate 

software and hardware provisions, deemed necessary to protect the I/M files and programs. The 

protection features shall prevent access to the secured floppy disk drive and those portions of the 

hard disk containing I/M programs and test data or files.

The emission analyzer and the sampling system shall be made tamper-resistant to the Colorado 

Department of Public Health and Environment satisfaction. At a minimum, the manufacturer shall 

develop tamper-resistant features to prevent unauthorized access though the cabinet. 

Microswitches, keyed locks, or software algorithms requiring the use of a password, which can be 

changed by the Colorado Department of Public Health and Environment would all be acceptable 

provided the physical or logical design effectively prevents unauthorized access.

Manufacturers may offer analyzers with additional floppy disk drives that can run optional 

software application programs.

If tampering occurs, a software lockout algorithm shall be activated which aborts any existing test 

sequence and prevents further inspections until an authorized AIR Program official clears the 

lockout.

The lockout system shall be designed so that an AIR Program official from the audit menu can 

activate it. Only AIR Program Auditors may remove lockouts put in place from the audit menu. 
Regulation Number 11

Adopted: November 21, 2013 Page 85

Manufacturers shall develop a system by which their service technicians shall be prevented from 

clearing “tamper” lockouts.

Optional software packages shall not interfere with the normal operation of the I/M inspection and 

testing software, and shall not compromise the tamper-resistant features of the analyzer.

Manufacturer field service representatives will not have access to DOS, unless assurances 

acceptable to the Colorado Department of Public Health and Environment have been provided 

that insure, integrity of the system will not be jeopardized.

1.8 Manufacturer Provided Services

The manufacturer shall agree to provide the following services to the inspection station as part of 

the manufacturer’s original warranty and thereafter as a portion of the service contract 

agreement. The cost of a service agreement is to be listed on a year-by-year basis. Future 

charges cannot exceed the amount published.

A. Delivery, installation, calibration, and verification of the proper operating condition 

of a Colorado 94 emissions analyzer.

B. Quarterly (90 days) examination, calibration, and routine maintenance of the 

analyzer and sampling systems. Full systems support and repair, including 

loaner units. Upon initial sale or loan, provide “extra” printer medium (1 ea.) 

sample filter(s)(2), sample hose (1) and sample probes (1). Maintain the “extra” 

consumable inventory upon examination and provide a software history file for 

the replacement of consumables accessible to AIR Program officials. 

Consumables and the cost(s) thereof must be disclosed in the service 

agreement.

C. Instruct all certified inspectors employed by the inspection station at the time of 

installation in the proper use, maintenance, and operation of the analyzer. The 

analyzer shall contain a feature that will allow an inspector to go through the 

complete inspection procedure without generating an official inspection record. 

This function will be used for evaluating inspector performance, by AIR Program 

officials, or by the manufacturer for demonstration purposes. The “training mode” 

shall not require the use of an inspector’s access code or allow access to 

secured areas of hardware or software. The display shall show a message 

throughout the inspection that this is not an official inspection. Vehicle inspection 

reports shall indicate to the satisfaction of the Colorado Department of Public 

Health and Environment that they are for training only. No official Certificate of 

Compliance will be generated during the training exercise.

D. On-site service response by a qualified repair technician within two (2) business 

days, (48 hours) excluding Sundays and national holidays, of a request from the 

inspection station. The names, toll-free telephone numbers, and service facility 

addresses of all manufacturer representatives responsible for equipment service 

shall be provided to the inspection station. A service representative shall be 

available at all times during normal working hours. Sundays and national 

holidays are not included. All system repairs, component replacements, and/or 

analyzer adjustments, shall be accomplished on-site within 48 hours after a 

service request has been initiated. If the completion of this work is not possible 

within this time period, a Colorado 94 loaner unit shall be provided until the 
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malfunctioning unit is properly repaired and returned to service. Service 

representatives shall have a software driven menu option that allows the transfer 

of inspection station, inspector information and other applicable data files from 

one analyzer to another without manual inputs and without transfer of previous 

test files.

E. Updates of the “Functional” software will be limited to once per year at no cost.

Updates of operational software i.e., file based information will be on an “as required” 

basis. All forms of software updating will utilize modem technology for the updating 

process. File updates are at no cost and every effort will be made to minimize them.

F. The analyzer software shall be designed so that AIR Program officials can insert 

a floppy disk, prepared by the manufacturer, into the Program system host, and 

update the existing software version, via modem. A system of manual updating 

by program officials utilizing the auditor’s menu shall also be available. Look-up 

up tables and message screens shall be designed sufficiently separate from the 

main operations software so that it is not possible, to interfere in any way with the 

operations of the analyzer.

The Colorado Department of Public Health and Environment will require the manufacturer 

to render updates as necessary in the first year of the program to ensure the program 

meets all design criteria. Thereafter software updates will be limited to once per year at 

no cost. Since modem software updating will be utilized, there are no costs to the 

analyzer owner. A software version number, consisting of a four character alpha-numeric 

code made up of the last two digits of the year followed by a two character version 

number, shall be recorded in the analyzer and included on each vehicle test record. The 

analyzer manufacturer shall not modify any existing software version without obtaining 

written approval from the Colorado Department of Public Health and Environment.

The Colorado Department of Public Health and Environment may require the 

manufacturers to conduct on-site or laboratory testing of in-use analyzers in order to 

document continued compliance. When an analyzer is removed from the field, for repair 

or testing, manufacturers shall supply the inspection station from which it was removed 

with a temporary replacement unit meeting all program requirements. Manufacturers shall 

pay for all necessary shipping and transfer costs for the replacement of the analyzer 

selected for compliance testing. Manufacturers shall also pay for any required testing 

performed by their personnel or by an independent company.

The manufacturers shall provide training to AIR Program officials on all operational, 

maintenance, and quality control features of the analyzers, including full access to and 

use of inspection menus, audit menus and calibration menus, as well as optional 

programs offered to inspectors. Such training shall be conducted at the manufacturer's 

expense as a condition of certification and thereafter at reasonable intervals upon written 

request by the Colorado Department of Public Health and Environment

1.9 Certification Requirements

The manufacturer shall submit a formal certificate to the Colorado Department, of Public Health 

and Environment that states that any analyzer sold or leased by the manufacturer or its 

authorized representatives for use in the Colorado AIR Program will satisfy all design and 

performance criteria described in these specifications. The manufacturer shall also provide 
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sufficient documentation to demonstrate conformance with these criteria including a complete 

description of all hardware components, the results of appropriate performance testing, and a 

point-by-point response to specific requirements. Previous certification by the California Bureau of 

Automotive Repair (BAR) is necessary for the analytical bench.

In addition, a full description of the company's service procedures and policies, as well as sample 

contracts, warranties, and extended service agreements, shall be provided as part of the 

certification application to ensure proper maintenance of all analyzers throughout their useful life. 

One fully functional analyzer shall be presented for evaluation and one additional fully functional 

analyzer for the certification process. If certified these units will remain in AIR Program 

possession for continued in-use evaluation for the life of the AIR Program. In the event that 1 % 

of overall unit sales exceed this two-unit base, in-use evaluation will require 1 % of overall unit 

sales for in use evaluation.

2.0 CONSTRUCTION DESIGN

2.1 Materials

All materials used in the fabrication of the analyzer and the appropriate housing assembly shall 

be new and of industrial quality and durability. Contact between non-ferrous and ferrous metals 

shall be avoided where possible. Suitable protective coatings shall be applied where galvanic 

action is likely. All mechanical fasteners shall have appropriate locking features. Use of selftapping screws shall be limited. All parts subject to adjustment or removal and reinstallation shall 

not be permanently deformed by the adjustment or removal-reinstallation process and this 

process shall not cause deformations to adjoining parts. Only materials that are not susceptible to 

deterioration when in contact with automobile exhaust gases shall be used.

2.2 Construction

The analyzer shall be complete and all necessary parts and equipment required for satisfactory 

operation shall be furnished. A suitable means of storing the probes and sample hose shall be 

provided. A means of storing the “spares” inventory shall be included. All parts shall be 

manufactured and assembled to permit the replacement and/or adjustment of components and 

parts without requiring the modification of any parts or the basic equipment design. Where 

practical, components and/or subassemblies shall be modularized. The analyzer cabinet finish 

shall be baked enamel or another durable finish.

2.3 Mobility

The analyzer unit shall be designed for easy and safe movement over rough surfaces and/or 

graded surfaces (15° incline). The center of gravity and wheel design shall be such that the 

analyzer can negotiate a vertical grade separation of one-half inch (1/2") without overturning 

when being moved in a prescribed manner. Industrial grade, swivel casters shall be used to 

permit 360° rotation of the unit. The caster wheels shall be equipped with oil resistant tires and 

foot operated brakes capable of preventing movement on a 15° incline.

2.4 Electrical Materials/Construction

Unless otherwise specified, all electrical components and wiring shall conform to standards 

established by the Underwriters Laboratories, Standard for Electrical and Electronic Measuring 

and Testing Equipment (U.L-1244).
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The analyzer shall operate from an 115VAC, 60 hertz (Hz) supply. An input voltage variation of 

±12 volts shall not change analyzer performance more than 1 % of full scale. The analyzer must 

operate on a 15 AMP breaker. The power cable shall be equipped with a standard three-prong 

connector at the inlet, and shall have a National Electrical Code rating of SO, SJO or better with 

an overall length not to exceed 25 feet. Each emissions analyzer shall incorporate safety devices 

to prevent conditions hazardous to personnel or detrimental to equipment. The system shall be 

grounded to prevent electrical shock, and adequate circuit overload protection shall be provided. 

The analyzer shall incorporate an internal surge protector.

2.5 Sampling System

The sampling system consists of two subsystems: (1) external sampling system; and (2) internal 

sampling system. The external system shall include a sample probe, sample hose twenty-five feet 

(25') in length, a water trap, and a filtration system. The internal subsystem shall include but not 

necessarily be limited to, a sample pump and bypass pump, or an equivalent system approved by 

the Colorado Department of Public Health and Environment.

The sample probe shall incorporate a positive means of retention to prevent it from slipping out of 

the tailpipe when in use. A thermally insulated, securely attached handgrip shall be provided on 

the probe in such a manner that easy probe insertion using one hand is ensured.

The probe shall also have a smooth surface near the probe tip before the flexible portion of the 

probe to be used for sealing of the span gas adaptor necessary for field or on-board leak 

checking (vacuum or gas) or response time checking equipment. For standardization, it is 

recommended that the sealing surface be one-half inch (1/2") in outside diameter and one-half to 

one inch (1/2” to 1”) long. A probe tip cap shall be provided for the sample system leak check. A 

probe tip adapter or assembly shall be included for use with spark arrester type tail pipes.

The interconnecting hose shall be of such design and weight that the inspector can easily handle 

it. The hose shall be of non-kinking construction and fabricated of materials that will not be 

affected by or react with the exhaust gases. Molecular HC hang-up shall be minimized. The hose 

connection to the analyzer shall be reinforced at the point of maximum bending. The system shall 

be designed with a water trap in the bypass sample stream. The water trap shall be continually 

self-draining. The trap bowl shall be constructed of a durable transparent material. The water trap 

should be located as low as possible on the analyzer so that condensed water in the sample hose 

will drain into them. However, the trap must be placed in a position readily visible to the inspector. 

The sample for the analyzer shall be obtained from the top of the water trap. The sampling 

system shall be equipped with a suitable particulate filter upstream of the optical bench. There 

may be a secondary filter located in the sample hose, serviceable by the inspector. This filter 

must have sufficient capacity to filter the samples obtained during the routine testing of vehicles in 

the inspection station. Threaded connections must be used to attach the filter to the sample hose. 

A prompt shall be provided to the inspector indicating when the filter should be changed based on 

an indication of low flow (automatic lock-out) or other criteria approved by the Colorado 

Department of Public Health and Environment

The pumps shall contain corrosion resistant internal surfaces. The pumps shall have a minimum 

operational life of 2,000 hours without failure.

The sample pump system may be a single pump, multiple pumps, or a multiple stage pump or an 

equivalent system approved by the Colorado Department of Public Health and Environment. The 

sample pump shall have integral motor overload protection and be permanently lubricated. The 
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bypass system shall be connected in the sample system so that any water condensed in the 

water trap is removed and dumped outside the system.

2.6 Storage Temperature

While in storage, the analyzer and all components thereof shall be undamaged from ambient air 

temperatures ranging from 0° F to 120° F.

2.7 Operating Temperature

The analyzer and all components shall operate within calibration limits in ambient air 

temperatures ranging from 41° F to 110° F.

2.8 Humidity Conditions

The analyzer shall be designed for use inside a building that is vented or open to outside ambient 

humidity. The analyzer, including all components of the analytical, sampling, and computer 

systems, shall operate within the required performance specifications at ambient conditions of up 

to 80% percent non-condensing relative humidity throughout the required temperature range, 

assuming the components are reasonably protected by the inspector from direct contact with 

water, or other condensing moisture. Failure of any component due to exposure to temperature 

and humidity extremes within this limits specified during actual use shall be corrected at the 

manufacturer's expense.

2.8.1 Temperature Control

Analyzer components that affect sensitivity and calibration shall have their internal 

temperatures controlled to maintain design temperature when exposed to prevailing 

ambient conditions. If internal operating temperatures are exceeded the analyzer will 

automatically lockout from any official inspection process.

2.9 Barometric Pressure Compensation

Barometric pressure compensation shall be provided. Compensation shall be made for elevations 

up to 6,000 feet (mean sea level). At any given altitude and temperature, errors due to barometric 

pressure changes of ±two inches (2") of mercury shall not exceed the accuracy limits specified in 

this specification. Manufacturers shall describe in writing how compensation will be 

accomplished. The method used shall be acceptable if approved by the Colorado Department of 

Public Health and Environment.

2.10 Operational Design

A. Analytical System

These analyzers shall utilize non-dispersive infrared systems for measuring 

hydrocarbons (HC), carbon monoxide (CO), and carbon dioxide (CO2). Oxygen (O2) 

shall also be measured and ambient air will be used for calibration purposes.

B. Readout Display/CRT Screen
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The screen shall contain numerical HC (as hexane), CO, CO2 and O2 displays and a 

pass/fail indication at the completion of the inspection process. Pressure purge shall be a 

pass/fail indication, with pressure/time values recorded to file.

The numerical display shall be of a digital format. The resolution of the emissions display 

shall be as follows:

HC: XXXX ppm (as hexane)

CO: XX.XX%

CO2: XX.X%

O2: XX.X%

The MINIMUM display increments shall be 1 ppm HC, 0.01 % CO, 0.1% CO2, and 0.1% 

O2. The displays shall be capable of full-scale readings of 2000 ppm HC (as hexane), 

9.99% CC, 16.0% CO2 and 25.0% O2.

CRT display is to be employed for an exhaust sample validity (sample dilution). This 

indication will signal excess dilution in the exhaust system based upon measurement of 

CO + CO2 emissions.

The analyzer shall be capable of selecting the pass/fail values (limits) based on vehicle 

model year, vehicle type, or other criteria. The system shall be designed in such a 

manner that the standards and vehicle groups may be readily revised by a modem 

software update.

Specific emissions limits and vehicle model year groupings are available in this 

Regulation Number 11, Part F: maximum allowable emissions limits for motor vehicle 

exhaust, evaporative and visible emissions for Light-Duty and Heavy-Duty vehicles.

2.11 Automatic Calibrations

The analyzer shall be designed to require an automatic two-point gas calibration for HC, CO, and 

CO2, and an automatic electrical zero and span check. (O2 shall be measured by ambient air.) 

The automatic gas calibration shall be conducted every 24 or 72 hours, activated by the internal 

clock. The option of 24 HOUR calibration will be software selectable, with the default @ 72 hours. 

Electrical zero and span check (automatic) shall be required prior to each test sequence. Userfriendly prompts shall be provided to the inspector to indicate every step needed to properly 

perform the required gas calibration (including when it is necessary to turn the gas cylinder valve 

on and off).

If the system is not calibrated, or the system fails the calibration or the zero and span check, an 

error message or fault indication shall be displayed and the analyzer shall be locked out to 

prevent the performance of an emissions inspection. Lockout will remain until the system is 

property calibrated and passes a calibration check and zero and span check.

The calibration record will contain before and after calibration readings. The gas calibration shall 

ensure that accuracy specifications are satisfied and that linearity is correct at the required span 

points. The gas calibration and leak check procedures shall require no more than five (5) minutes 
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to complete. The analyzer shall provide adequate prompts on the display to guide the inspector 

through the calibration procedure in a manner that minimizes the amount of calibration gas used.

The system shall have the capability of printing historical calibration data for specified date 

ranges by the AIR Program Auditor. (Audit menu, calibration history)

For HC, CO and CO2, analyzer manufacturers shall limit gas usage during the gas calibration 

procedure to two liters per point. The analyzer shall also be designed to keep the loss of 

calibration gas to an absolute minimum (less than 0.5 liters in 24 hours) if the calibration gas 

valve(s) is/are not shut off. Manufacturers shall provide an evaluation of this capability, consisting 

of at least four (4) analyzers, with their certification application materials and shall demonstrate

this feature during certification.

The analyzer shall be equipped with a gas calibration port for the purpose of performing a probe 

to calibration port comparison for audit purposes. Gas auditing shall be accomplished by 

introducing standard gases into the analyzer either through the calibration port or through the 

probe. Span gases utilized for calibration shall be within two percent (2%) of the following points: 

Ambient air may be used to calibrate the O2 sensor.

(HC) 300 ppm propane

1.0 % carbon monoxide (CO)

6.0 % carbon monoxide (CO2)

Bal. Nitrogen (N2)

(HC) 1200 ppm propane

4.0 % carbon monoxide (CO)

12.0 % carbon monoxide (CO2)

Bal. Nitrogen (N2)

The standard gases used to calibrate, and audit the analyzers shall satisfy the criteria included in 

the Federal Clean Air Act, Section 207 (b) and described in Subpart W of Part 85 of Chapter I, 

Title 40 of the Code of Federal Regulations. In order to ensure that the quality of the standard 

gases used in the program meet these specifications, all standard gases purchased by the 

inspection facility for use in the analyzer must conform to the requirements established in 1990 by 

the California BAR for Test Analyzer System Calibration Gases. Calibration gases must be 

purchased from a vendor that has Colorado gas blender certification, REF. Colorado Regulation 

Number 11, Appendix B. These requirements include the testing and certification of the 

concentration, accuracy, precision, and purity of the standard gases to within the referenced limits 

and the labeling of individual gas canisters describing these and other specified parameters.

Automatic EVAP Pressure Calibration

The pressure test system is to be calibrated every 24 or 72 hours and zero/span checked before 

each inspection. Pressure calibration checks should be performed simultaneously with the gas 
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calibration procedure. Calibration and/or zero span checks must pass or the analyzer must 

lockout from further testing until the discrepancies are corrected. All calibrations will be stored to 

the Cal.Dat file. Pressure system calibrations shall be performed in a maximum time period of 5 

minutes, calculated independently from the gas calibration and leak check. The optional 24-hour 

option shall be selectable and defaulted to 72 hours.

A. Automatic Leak Check

An automatic leak checking system shall be provided that will allow the vacuum side of 

the system to be checked for leakage. Appropriate valves lines, and switches shall be 

installed to permit this operation. Minimal activity by the inspector, such as setting the 

probe in a holder or capping the probe, is permitted, provided errors resulting from 

improper inspector action would be identified by the computer and would require 

corrective actions. Improper action would cause the system to fail a leak check, and 

automatically lockout. User-friendly prompts shall be provided to the inspector to indicate 

every step needed to properly perform the required leak check (including when it is 

necessary to turn the gas cylinder valve on and off).

A system leak check shall be accomplished every 4 or 24 hours and in conjunction with 

the gas calibration performed every 24/72 hours, activated by the internal clock. The 4-

hour option shall be software selectable with the 24 hours as the default value. Four-hour 

leak checks are required only for those facilities performing more than 4000 inspections 

per year. The analyzer shall not allow an error of more than ±3% of reading using midrange Colorado certified span gas to perform the leak check. Fittings and connectors 

used on the sample hose and probe shall be constructed to inhibit the bypass of the leak 

check. A maximum of two liters of calibration gas may be used to perform the leak check. 

If the system is not leak checked, or the system fails a leak check, an error message or 

fault indication shall be displayed, and the analyzer will be locked out to prevent the 

performance of an emission inspection, until the system is properly leak checked and 

passes.

B. Automatic HC Hang-Up Check

The analyzer shall be designed for using ambient air induced through the sample probe, 

prior to each test sequence. The analyzer shall have a CRT prompt/indicator. “Hang-up” 

activation shall cause the analyzer to automatically sample ambient air through the 

sample line and probe. The system shall continue to sample room air for a maximum of 

150 seconds or until the HC response is below 20-ppm hexane.

If the HC hang-up does not drop below 20 ppm within 150 seconds, a message shall be 

displayed indicating possible dirty filters or sample line. If after 150 seconds HC levels 

are not below specified values, the test shall be discontinued until HC hang-up is 

corrected. When the level stabilizes below this value, an indication that testing may begin 

shall be displayed. The analyzer shall be locked out from operating until the HC level is 

met.

C. Vehicle Diagnostics

During analyzer warm-up, emissions diagnostics and other gas reading functions shall be 

prohibited. After successful warm-up and for the purpose of vehicle diagnosis or repairs, 

the analyzer shall have a menu selection that will allow the analyzer to continuously 

monitor the vehicle exhaust.
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The automatic data collection system shall be prevented from operating anytime the 

analyzer is not being used in the official emissions inspection mode.

D. Dilution

The analyzer manufacturer shall document to the satisfaction of the Colorado 

Department of Public health and Environment that the flow rate on the analyzer shall not 

cause more than 10% dilution during sampling of the exhaust at normal idle (10% dilution 

defined as sample of 90% exhaust and 10% ambient air). Manufacturers shall utilize the 

procedures specified by the BAR for demonstrating this dilution criterion. The analyzer 

shall be equipped with a feature to identify vehicle exhaust system leaks and sample 

dilution. The preferred method for identifying leaks is monitoring the CO & CO2 levels in 

the exhaust. Other additional techniques that can demonstrate improved sensitivity to 

leaks may also be used.

DILUTION VALUES:

All light duty vehicles: 6%

All heavy-duty vehicles: 5%

If the CO + CO2 reading is less than the limit, the inspector shall be prompted to check 

the exhaust system for leaks and to make sure that the sample probe is all the way into 

the tailpipe. If the excessive dilution is detected after the initiation of the test sequence, 

the analyzer output shall display “SAMPLE DILUTION”. If dilution continues the inspector 

shall be required to “Abort Test”. The system shall store the “Abort Test” indication.

E. Engine Tachometer

A digital display tachometer shall be CRT displayed for the purpose of measuring engine 

speed. The tachometer operation shall be by two means; (1) radio frequencies “RF” type 

transmitter/receiver that requires no direct vehicle connection and can detect engine 

RPM on vehicles utilizing “DIS” systems. (2) a cable type connection capable of detecting 

engine RPM from all forms of current O.E.M. ignition technology. Tachometer 

performance shall be no less than; RPM with a 0.5 second response time and an 

accuracy of ±3.0% of actual RPM. During an official inspection process, the software will 

prompt the inspector to shut the engine off while connecting the RPM probe (only if a 

cable connection is being made). A software “HELP” screen will be available to assist the 

inspector in locating an RPM signal. This information may be supplied or reviewed by the 

Colorado Department of Public Health and Environment. Based on the vehicle 

identification information available to the inspector, the analyzer will prompt the inspector 

as to which vehicles require a specific type or method of connection of the tachometer 

pick-up. Analyzers shall be provided with all the software and hardware that is necessary 

to make them capable of reading engine RPM from all O.E.M. ignition technologies in use 

at the time of certification, Possible updates may be required to enable future ignition 

systems to be monitored for engine RPM.

F. Analytical Bench Accuracy

Each analyzer shall meet the following analytical accuracy requirement:
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Channel Range Accuracy

HC ppm 0-400 ±12 ppm

401-1000 ±30 ppm

1001- ±80 ppm

2000

CO% 0-2.00 ±0.15 %

2.01-5.00 2.040%

CO2% 04.0% ±0.6

4.1-14.0 ±0.5%

14.1-16.0 ±0.6%

O2% 0-10.0 ±0.5%

0-10 ±1.3%

The analyzer display resolution electronics shall have sufficient resolution and accuracy 

to achieve the following:

HC 1 ppm HC

CO 0.01 % CO

CO2 0.1% CO2

O2 0.1% O2

G. Drift

If zero and/or calibration drift cause the infrared signal levels to move beyond the 

adjustment range of the analyzer, the inspector shall be locked out from testing and 

instructed to call for service.

H. Warm-Up

The analyzer shall reach stabilized operation in an inspection station environment within 

15 minutes at ° 41 degrees Fahrenheit from “power on”. The instrument shall be 

considered “warmed-up” when the zero and span readings for HC, CO, and CO2 have 

stabilized, within ± 3% of full range of low scale, for five minutes without adjustment.
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Functional operation of the gas-sampling unit shall remain disabled through a system 

lockout until the instrument meets stability and warm-up requirements. If the analyzer 

does not achieve stability with 15 minutes, from “power-on”, it shall be locked out from 

I/M testing and a message shall be displayed instructing the inspector to call for service.

During the warm-up, the Main Menu shall be displayed unless an optional functional 

menu or menus are offered. The analyzer system shall lock out all bench related 

functions during warm-up. During warm-up, a message under the main menu shall be 

prominently displayed as follows: “Warm-up in progress - checking for stability”. During 

the initial entry into the “warm-up” period, and before any other menu can be selected, 

the software will automatically enter a “bulletin display” function and display any 

messages or bulletins forwarded from the AIR Program host system via modem transfer 

in the past 72 hours. This screen will reference the inspector.dat file and require each 

inspector to enter their access code as verification of receipt, before allowing that 

inspector to Proceed with an inspection. No inspector can enter into an official inspection 

without having “logged on” as having seen the Bulletin screen. When stability is achieved 

and the warm-up requirements are satisfied, access to gas bench functions shall be 

permitted.

I. System Response Time Requirements

The response time from the probe to the display shall not exceed eight (8) seconds to 

90% of a step change in input, nor will it exceed 12 seconds to 95% of a step change in 

input. For the O2 sensor, the response time shall be no more than fifteen (15) seconds to 

90% of full scale.

J. Optical Correction Factors

The hexane/propane equivalency factor (PEF) shall be limited to values between 0.49 

and 0.52. If an optical bench is used that can demonstrate accuracy of propane/hexane 

identification within specification, using a range greater or lesser than indicated, it will be 

considered. Factor confirmation shall be made on each analyzer assembly by measuring 

both N-hexane and propane on assembly line quality checks. The PEF shall be 

permanently stored in non-volatile memory. The PEF shall be displayed on the monitor 

on request by inquiry through the menu system. The optical bench shall he marked with a 

permanent “stamped” type tag identifying its PEF.

The signal strength from the source to the detector for all channels shall be monitored 

such that when the signal degrades beyond the adjustment range of the analyzer, the 

analyzer shall be locked out from operation, i.e. fail calibration.

K. Interference Effects

The effect of extraneous gas interference on the HC, CO, and CO2 analyzers shall not 

exceed ±10 ppm HC, ± 0.05% CO, and ±0.20% for CO2.

The instrument design shall insure that readings do not vary as a result of 

electromagnetic radiation and induction devices normally found in the inspection 

environment (including high energy vehicle ignition systems, RF transmission radiation 

sources, and building electrical systems). In addition, the manufacturer shall ensure that 

the analyzer processor and memory components are sufficiently protected to prevent the 

loss of programs and test records.
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2.12 Gas Calibration File

At the conclusion of each gas calibration the required data shall be placed in the CAL.DAT file.

2.13 Microcomputer Specifications

A. A standard microcomputer must be included in the analyzer and is to be used to 

control all analyzer functions. Each vendor is to develop DOS executable 

programs for each required function. These programs shall:

1. control each of the analyzer functions and time of function;

2. examine and obtain values from all of the analyzer sensors;

3. read and write information to diskette in standard DOS format; and

4. copy the analyzer, inspection station identification information from the 

hard disk onto each new floppy diskette when formatted.

The Colorado Department of Public Health and Environment reserves the right to 

add additional programs and functional performance requirements, up to the 

technical limits of the hardware, to improve the I/M program.

Sufficient flexibility shall be provided in the design of the microcomputer system 

to allow expansion of the analyzer to include, but not be limited to, the following 

additional capabilities:

1. connect and recover data from vehicle on-board diagnostic 

systems (OBD) meeting SAE specifications when they become 

available;

2. monitor vehicle recall data; identify, record and process data as 

required when an official EPA/SAE format is identified.

3. accommodate additional input channels in both analog and 

digital form. Two free slots, 16 bit capability.

The manufacturer may offer additional features that utilize the 

microcomputer as a stand-alone personal computer by providing optional 

software to perform various non-l/M functions. Such offerings must not 

interfere with the inspection requirements, or in any manner affect or 

allow the inspector to tamper with the inspection-related computer 

programming or data files.

The analyzer shall be equipped with an internal clock that operates 

independently from the power source and will provide accurate and 

automatic date and time information for the following functions:

a. each test performed;

b. automatic gas calibration and pressure test check (72 

hours); (24 hour) optional
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c. automatic leak check (4 or 24 hours and every 24/72 

hours for automatic gas calibration), and leak check 

combination.

d. audit sequence:

All equipment and software submitted for Colorado certification 

must be the full and current configuration proposed for sale. 

Partial, dated, or incomplete models are not acceptable.

Acceptance of the microcomputer portion of the Colorado 94 

Analyzer system will be dependent upon the satisfactory 

performance of the full-proposed configuration meeting all the 

requirements of this specification.

The proposed hardware configuration must be fully supported by 

all software and/or operating systems listed in the acceptance 

requirements or elsewhere in these specifications. Performance 

tests to prove compatibility will be conducted. The vendor will 

bear all shipping and equipment preparation charges for the 

certification testing.

2.14 Standard Hardware: Minimum Required Configuration

1. Operating System

DOS Version 6.2 or most current

2. Processor

The microprocessor must be fully compatible with the Intel 80486 microprocessor. 

Upgradable to Pentium technology.

3. RAM Memory

The system must contain at least 2 MB of user available RAM. (expandable to 16 MB)

4. Power Up Sequence

The system must include a power up sequence that provides a self-diagnostic routine to 

check the on-line presence of critical PC components (including, at a minimum, the 

processor, firmware ROM, hard disk controller, keyboard, clock, modem, printers, bar 

code reader I/O ports, setup RAM and memory).

5. Video

The CRT display must be at least 12” in diagonal measure and operate in a VGA mode.

The software shall automatically blank the screen or use a screen saver mode, if no 

keyboard entry is made for 10 minutes. The display shall return when the inspector 

strikes any key.
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6. Floppy Disk

Each unit must come with an IBM compatible floppy disk drive that will permit full usage 

of 2sHD 1.44 Mb 3.5” removable media. The drive must be located in a secured area 

accessible only to authorized AIR Program Service representatives. That secured drive 

must also include an approved method to limit logical access. Colorado Department of 

Public Health and Environment will test the system for drive security and it should not 

provide access to the secured floppy except through the approved security procedure. 

The secured floppy drive shall be designated the “A” drive.

7. Hard Disk

Each unit must come with at least 120 megabytes of hard disk storage. The vendor may 

use up to 40 megabytes for their programs and data provided at least a full 80 megabytes 

of usable storage is available for Colorado Department o1 Public Health and Environment 

and user information. The hard disk is to be self-parking (where applicable), shock 

mounted, and able to operate reliably in the inspection environment. The hard disk must 

also include a Colorado Department of Public Health and Environment approved method 

of limiting access to data and programs. The hard disk containing programs and data files 

shall be designated the “C” drive.

8. I/O Ports

The unit must include sufficient I/O ports of proper configuration to allow the connection 

of all required options and the capability to add additional I/O boards.

9. Keyboard

The Colorado 94 Analyzer keyboard must be fully interfaced with the microcomputer and 

have all of the necessary normal, numeric, cursor, control, shift, alternate, and function 

keys needed to operate a standard IBM PC compatible microcomputer, preferably 101 

keys should be provided.

10. Bar Code Scanner

The bar code scanner shall be equivalent to the PDF 1000 “HV” (High Visibility) Scanner 

from Symbol Technologies. Performance specifications are included in Technical 

Specification Appendix A. The PDF 1000 “HV” is a scanner capable of reading both 1 -D 

and PDF-417(2-D) bar codes.

11. Hard Disk Expansion

System must include a hard disk interface that will fully support a second internal disk 

drive of the same type as the original type drive or a functional equivalent approved by 

the Colorado Department of Public Health and Environment that does not compromise 

tamper-resistance.

12. Additional Storage

3.5” 1.44 Mb Floppy Disk Drive IBM Optical disk drive, floptical, CD ROM reader etc., 

these options would be for manufacturer offered look up tables, service information or 

other options requiring additional storage capability.
Regulation Number 11

Adopted: November 21, 2013 Page 99

13. Communications

Hayes compatible modem at 14,400B, M.N.P. Level 5. Error correction: Microcom 

networking protocol (M.N.P.) levels 1-4 and V.42 data compression: M.N.P. level 5 and 

V.32BIS/V.42BIS. Protocol will be provided within the operational software package. 

Modem communications will be necessary during the inspection process for V.I.N. 

verification, multiple “I” Test Control, vehicle recall etc., from the Network System Host 

Computer.

2.15 Required Printers

A. Diagnostic printer:

A 24 pin impact printer shall be supplied which is dedicated to the task of printing 

designated information on a VEHICLE DIAGNOSTIC FORM, or other repair type 

information. Continuous, fanfold, preprinted (ghost printed certificates) will be used. The 

printer shall print information on the certificate using 12 characters per inch and 80 

characters per line.

B. Certificate Printer:

The certificate printer is to be a “thermal transfer” technology printer, capable of 

producing PDF 417, two dimensional bar code and Code 39, one-dimensional bar code. 

As of date, Standard Register produces a model of printer that meets or exceeds all 

requirements necessary to print upon the required certificate. This model is a PT650 

Thermal/Thermal Transfer Printer. Specifications of the certificate printer shall be 

Standard Register FT650 or equivalent. With equivalency being defined as successful 

completion of printing, security, storing and dispensing of the required certificate. Final 

acceptance of alternative printers lies with written State approval.

Standard Register PT650 technical specifications are included in the Technical 

Specification Appendix B.

PHYSICAL SPECIFICATIONS OF CERTIFICATE:

Physical specifications of the certificate, to include print fields, physical design, materials 

and sizing are to be determined by the Department of Revenue.

C. Certificate Security:

The inspection certificate printer and certificate storage area shall be located in a secured 

area. Access to the area securing the printer and certificates shall be available only to the 

licensed inspector at the station. The certificate storage area shall have a redundant 

security system utilizing both a hardware lock and a software lock that meets Colorado 

Department of Public Health and Environment approval. Certificates will be prevented 

from being “pulled” through the printer. A form of printer locking must be utilized. The 

secured area containing certificates and the certificate printer, shall be designed so that 

the same key can be used to open any access doors that secure any optional storage 

media. If any of these doors are opened, a microswitch (or equivalent) shall be used 

which prevents the printing of certificates and records each event with time and date to 

an entry.dat file.
Regulation Number 11

Adopted: November 21, 2013 Page 100

The purpose of the software lock is to restrict access to the printer with the following 

exceptions: loading and aligning certificates prior to printing, clearing paper misfeed or 

jam problems, etc., and to provide a record of the personnel performing those functions.

The area containing the certificates shall be located so that proper routing is maintained 

on the certificates as they are fed through the printer.

If tampering occurs, a software lockout algorithm shall be activated which aborts any 

existing test sequence and prevents further emission testing until an AIR Program official 

clears the lockout.

There shall be easy access to the vehicle diagnostic report printer so that the inspector 

can easily replace paper, clear paper jams and change ribbons.

2.16 Clock/Calendar

The analyzer unit shall have a real time clock/calendar which shall make available the current 

date and time. Date will be in month, day, year format and time will be in 24-hour format. The AIR

Program system host computer shall update both time and date during each transfer of data via 

the system modem.

The date/time, along with the time the test started and when it ended, is to be included on the test 

record. The start time is when the inspector’s access code is entered and the end time is when 

the analyzer data is written to the test file.

If the clock/calendar fails or becomes unstable (as referenced to the program host system during 

modem data transfer), the analyzer unit shall be locked out from I/M testing and a message shall 

be displayed indicating that service is required.

Resetting of the clock, independent of the host updating, shall require controlled access.

2.17 Lockout Notification

The analyzer shall alert the inspector of any lockout situation by prominently displaying a 

message on the CRT. Any lockout condition will be stored to file.

2.18 Vehicle Diagnosis

The analyzer shall be capable of menu selection that will allow the analyzer to be used as an 

ordinary garage type emissions analyzer for general automotive repair work and diagnostics.

2.19 Software Loading

The inspector shall not have to load the microcomputer's operating or applications software to 

operate the analyzer. On each POWER ON of the analyzer, the analyzer shall automatically do 

all microcomputer component self-diagnostics, memory checking, and loading of all necessary 

operating software without inspector intervention. Upon satisfactory computer component check 

out, the applications software is to present a menu of available analyzer operations. All offered 

features are to be menu-driven. For each feature, a context sensitive, on-line help facility is to be 

provided which can be accessed preferably with a single keystroke.

3.0 DISPLAY PROMPTS AND PROGRAMMING CRITERIA REQUIREMENTS
Regulation Number 11

Adopted: November 21, 2013 Page 101

Operational software requirements will be available from the Division upon request.

ATTACHMENT I PDF 1000 Scanner TO THE TECHNICAL SPECIFICATION APPENDIX A

This document is contained in the Air Pollution Control Division’s Emissions Technical Center Procedures 

Manual and is incorporated by reference.

PDF 1000 SCANNER

PERFORMANCE CHARACTERISTICS

Type: Raster scanning, retro-collective

Scan Element Low mass, single mirror, resonant

Light Source: 675 nm. Laser diode

Pattern Size: At 9 in. (22.8 cm) from the nose of the scanner, the pattern is 7 in. (17.8 

cm) horizontally and 2.6 in. (6.6 cm) vertically

Scan Rate: 560 scans/sec. 280 Hz + 10 Hz (horizontal)

Frame Rate: 22 frames/sec. 11 Hz + 1 Hz (vertical)

Optical Resolution Can decode a 6.6 mil X-dimension symbol (PDF417); Y-dimension must 

be 3X

Haz Size of PDF 417: 5.9 in. (15cm) wide x 2.3 in. (5.8 cm) high (928 code words, at security 

level 0-8)

PHYSICAL CHARACTERISTICS

Pitch Tolerance: + 30” (“front and back”)

Skew: + 15” plane parallel to symbol (“side to side”)

Rotational Tolerance: + 3” (assuming 3:1 codeword module aspect ratio)

Dead Zone/Optical Throw Print: + 2” (1 D symbologies) or + 9” (PDF417) from beam direction

Print Contrast Resolution (min): 25% (1-D symbologies) or 35% (PDF417) absolute dark/light 

reflectance differential, measured at 675 nm

Ambient Light Immunity: 8000 ft-candles (86100 LUX) of sunlight

Humidity: 5 to 95% relative humidity (non-condensing)

Shock: Unit functions normally after 4ft (1.2m) drop to concrete

Environmental Scaling: MIL-STD-810d windblown dust and rain
Regulation Number 11

Adopted: November 21, 2013 Page 102

Operating Temperature: 14° to 104° F (-10° to 40°C)

Storage Temperature: -40° to 140° F (-40° to 60°C)

Coil Cable Length: 6 ft. (183cm)

Weight 10.4 oz (295gm) without cable

Dimensions: 7.2 in. (18.2 cm) H x 4.2 in. (10.7cm) Lx L7 in. (4.3 cm) W

Laser Class: CDRH Class II, IEC 825 Class II

PL 140 Decoder/Interface

Decode Capabilities: 2-D symbologyPDF417 (up to 928 code words at security level 0-8). 1-

D Symbologies: UPC-A, UPC-E, EAN-8, EAN-13, Code 39, Code 39 

Full ASCII, Code 128, Interleaved 2 of 5, Codabar.

Memory: 64K x 32-bit PROM; 32K x32-bit RAM (128K ram OPTION); 256 X 16 

bits EEPROM for system parameters

Humidity: 5-95% relative humidity (non-condensing)

Shock: 4-ft. (1.2m) drop to concrete

Environmental Sealing: Environmentally sealed against dust and rain (with battery pack 

attached)

Operating Temperature: 14° to 104° F (-10° to 40° C)

Storage Temperature: -40° to 140° F (-40° to 60°C)

Weight: 11.2 oz. (318 gm) With batter pack 27.8 oz. (788.13 gm)

Dimensions: 4.0 in. (10.2 cm) high x 4.0 in. (10.2cm) long x 1.4 in. 13.6 cm wide (2.8 

in (7.1 cm wide with batter pack)

Agency Approvals: FCC Class A, UL, CSA, VDE

Power Requirements: DC Power: 11 VDC from wall transformer or 6 VDC from Battery Pack. 

Wall transformer power requirements: 115 VAC @ .15A, 220/240 VAC 

@ .075A, 100V @ .15A. Pack will support several thousand scans per 

8-hour shift. Actual number depends on PDF417 symbol size and mix 

of 1D bar codes scanned.

ATTACHMENT II Thermal Transfer Printer TO THE TECHNICAL SPECIFICATION APPENDIX 

A

This document is contained in the Air Pollution Control Division’s Emissions Technical Center Procedures 

Manual and is incorporated by reference.
Regulation Number 11

Adopted: November 21, 2013 Page 103

THERMAL TRANSFER PRINTER

STANDARD FEATURES

● On line/Off line Operation

● Thermal/Thermal Transfer

● Extremely High doc density (203 dots/inch. 8 dots/mm

● Print speed 6 inches plus per second

● Media width 5.25

● Print width 5.10"

● Large maximum media size 5.25-W X 60 L

● User-selectable bar code ratios

● Internal take-up mechanism

● External rewind mechanism

● Print material. Label and lag stock

● Label presentation

● Print head temperatures software selectable

● Easy - load ribbon

● Alpha-numeric keypad

● LCD Display 2X20

● 512K of on board Ram Expandable to 8 MB

● Rotation of text and bar codes 90. 18O and 270 including human readable

● Date and Time Clock

● Label back feed for cutting and dispensing modes

● Intelligent Formats

PRINT MODES

Three print modes are standard

● Batch - printing one or more labels with or without backing paper
Regulation Number 11

Adopted: November 21, 2013 Page 104

● Rewind - printing a batch of labels and rewinding

● Present Mode - Present sensor stops each label for presentation before delivering the next label

BAR CODES

● Code 39

● Interleave 2 of 5

● Codabar

● Code 128 A. B, and C subsets

● UPC-A and E

● UPC addendum codes 2 and 5 digit

● UPC random weight

● EAN 13 and 8

● Code93

● Universal shipping contained symbology (with fixed or random weight codes) code 39 variations to 

produce all industry standards such as LOGMARS. HIBCC. and AIAG

● Bar code modulus (“x” dimensions): 5 mil to 10 mil in picket or ladder orientation

● Bar codes printed with or without human readable interpretation

FONT STYLES

● 12 Scalable Fonts On-Board

● Downloadable font support

● Downloadable graphics

● Inverse text support

● International language support different language character sets

● Inverse image support

MEDIA SPECIFICATIONS

● Media type: Roll-fed, die-cut continuous or fan-fold labels, tags or tickets

● Material: plain paper thermal transfer or thermal sensitive paper
Regulation Number 11

Adopted: November 21, 2013 Page 105

● Sensing: adjustable transmissive sensor for die cut labels or tags.

● Reflective sensor for use with black marks

● Programmable top of form

● Maximum media width: 5.25

● Minimum media width: 0. 50”

● Maximum media length: 60.0”

● Minimum media length: 0.50”

● Thickness: 0.0023” to 0.012” (including liner)

● Supply roll capacity. 8"(203mm)

● Internal rewind capacity: 6"( 152mm)

● External rewind capacity: 8"(203mm)

● Fanfold stock internal and external capabilities

PRINT HEADS

● Standard width: 5.1"( 128mm) 8 dot/mm (203 dots/inch. 8 dots/M)

● Optional widths available

● Optional Dot Densities available

PRINT SPEED

● Standard speed :6"(152mm) plus per second

● Programmable print speeds of 1.5" (38 mm) 3"(72mm) up to 6"(1.52mm) plus per second

COMMUNICATION INTERFACE

● RS-232C.RS-422. RS-185

● Centronics parallel interface

● Robust XON/XOFF. CTS, DTR handshake

● Programmable 7 or 8 bit length

● Multidrop protocol

● Bidirectional Printer to Host
Regulation Number 11

Adopted: November 21, 2013 Page 106

OPTIONS

● Ribbon Saver

● Cutter mechanism and Tray

● Font Data Cards (up to 1MB)

● Application Cards (up to 1 MB)

● Graphics Display

● Full Alphanumeric keyboard

● Scanner Support

● User Data Support Cards (up to 1MB)

● Twinax & Coax IBM Inter faces

MECHANICAL

● Height: 10"(254mm)

● Width: 11"(279mm)

● Depth: 16"(406mm)

● Weight: 35 lbs. (16 kg)

ELECTRICAL

● Power 110/220 VAC + or - 10% 5O/60 Hz at 2 amps maximum 100 VAC on request

● Built to ULCSA and TUV-GS safety standards and VDE Class B and FCC Class A emissions standard

ENVIRONMENTAL

● Operating Temperature: 32° F to 100° F (0° to40° C)

● Storage Temperature:-40F to 140° F (-40° Cto60° C)

● Humidity. 10% to 90% non-condensing

● Ventilation: Free air movement

● Dust: non-conducting, non-corrosive

ATTACHMENT III Colorado Automobile Dealers Transient Mode Test Analyzer System

TO TECHNICAL SPECIFICATION, APPENDIX A
Regulation Number 11

Adopted: November 21, 2013 Page 107

This document is contained in the Air Pollution Control Division’s Emissions Technical Center Procedures 

Manual and is incorporated by reference.

COLORADO AUTOMOBILE DEALERS TRANSIENT MODE TEST ANALYZER SYSTEM

TRANSIENT MODE TEST SYSTEM TECHNICAL AND HARDWARE SPECIFICATIONS

COLORADO AUTOMOBILE DEALERS TRANSIENT MODE TEST ANALYZER SYSTEM

(IG 240)

TEST SYSTEM TECHNICAL AND HARDWARE SPECIFICATIONS

JANUARY 27, 1997

INTRODUCTION

This document contains technical specifications for a Colorado Automobile Dealers Transient Mode IG

240 Test Analyzer System. The technical specifications of the system are based upon the Environmental 

Protection Agency High-Tech I/M Test Procedures dated June 1996, Emission Standards, Quality Control 

Requirements and Equipment Specifications: IM 240 and Functional Evaporative System Tests technical 

guidance document EPA-AA-RSPD-IM-96-1, dated June 1996. The technical concept allows for the use 

of technologies of similar application but of a lower monetary cost. Utilizing lower cost technologies and 

identifying equipment required to directly address the requirements of the Colorado Enhanced Inspection 

Program, the system can perform transient loaded mode testing in the Motor Vehicle Dealer Test Facility 

pursuant to Section 42-4-309 (3)(B), C.R.S.

In review of these specifications, sections may indicate that they are not applicable. Not applicable 

indicates that the content of that section does not apply to the Colorado system. Not applicable sections 

remain within this specification, as they provide insight into the systems total capability with hardware 

often sharing functionality with another test process. This specification is intended to act as a guide to 

hardware requirements, provides insight into the application of the hardware, and provides testing and 

quality control requirements and to provide a general overview of the operating system software 

requirements. Numerical references to methodology or procedures refer to sections so indicated within 

the code of federal regulations (40 CFR 85.2 July 1996) (EPA).

This attachment III establishes equipment specifications, test procedures and test standards. In order to 

qualify for the Colorado Automobile Dealers Transient Mode IG 240 Test Analyzer System must comply 

with the equipment specifications, must be capable of performing all applicable elements of the test 

procedure, and must be capable of measuring, calculating, displaying and recording each test standard.

Table of Contents

Introduction

Test Standards

(a) Transient Mode Emissions Limits

(b) Transient Test Score Calculations

(c) Evaporative System Pressure Test Standards
Regulation Number 11

Adopted: November 21, 2013 Page 108

Transient Mode and Evaporative System Purge Test Procedures

(a) General Requirements

(b) Pre-inspection and Preparation

(c) Equipment Positioning and Settings

(d) Vehicle Conditioning

(e) Vehicle Emission Test Sequence

(f) Emission Measurements

Evaporative System Pressure Test Procedures

(a) General Requirements

(b) Pre-inspection and Preparation

(c) Canister-End Pressure Test - NOT APPLICABLE

(d) Fuel Inlet Pressure Test -- NOT APPLICABLE

(e) Fuel Cap Leak Test - Pressure Decay Method

(f) Fuel Cap Leak Test - Flow Rate Method.

Colorado Automobile Dealers Transient Mode Equipment Specifications

(a) Dynamometer Specifications

(b) Constant Volume Sampler

(c) Analytical Instruments

(d) Colorado Specific Hardware

Evaporative System Inspection Equipment

(a) General Requirements

(b) Evaporative Purge System - NOT APPLICABLE

(c) Evaporative System Pressure Test Equipment

Transient Mode Test Quality Control Requirements and Acceptance

Testing Procedures

(a) General Requirements
Regulation Number 11

Adopted: November 21, 2013 Page 109

(b) Dynamometer

(c) Constant Volume Sampler

(d) Analysis System

(e) Gases Calibration, Working and Span Gases Shall Conform to Regulation Number 11, Appendix

(f) Quality Control Data Files

Test Report

(a) Acceptance Test Reporting for Transient Mode Evaluation

Terms

(a) Definitions

(b) Abbreviations

Test Standards

(a) Transient Mode Emissions Limits - Regulation Number 11, Part F “Maximum Allowable 

Emissions Limits”

EMISSIONS LIMITS

M/Y CO HC NOx

LDV:

1982

1983-84

1985

1986-90

1991-94

1995 & newer

65

50

25

25

20

20

5

5

5

4

4

4

8

8

8

6

6

4
Regulation Number 11

Adopted: November 21, 2013 Page 110

M/Y CO HC NOx

LDT 1-2:

1982-83

1984-85

1986-90

1991 & newer

107

80

67

53

8

8

6

6

12

12

9

9

Emissions limits are subject to periodic revision and as such provisions must be made for ease of 

adjustments

(b) Transient Test Score Calculations

(1) Composite Scores. The composite scores for the test shall be determined by dividing the 

sum of the mass of each exhaust component obtained in each second of the test by the 

number of miles driven in the test. The first data point is the sample taken from t=0 to t=l. 

The composite test value shall be calculated by the equation in (b)(l)(i):

(i)

Transient Test Score Calculations - Composite Scores

(2) Second-by-Second Mass Calculations. The mass of each exhaust component shall be 

calculated to five significant digits for each second of the test using the following 

equations:

(i) Hydrocarbon mass: HCMASS = VMIX * DENSITYHC * HCconc

 -----------------

 1000000

(ii) Carbon Monoxide mass: COMASS = VMIX * DENSITYco *COconc
Regulation Number 11

Adopted: November 21, 2013 Page 111

 -----------------

 1000000

(iii) Oxides of Nitrogen mass: NOxMASS = VMIX * DENSITYNO2* KH NOxconc

 -----------------

 1000000

(iv) Carbon Dioxide mass: CO2MASS = VMIX *DENSITYCO2 *CO2conc

 -----------------

100

(3) Meaning of Terms.

(i) HCmass = Hydrocarbon emissions in grams per second.

(ii) DensityHC = Density of hydrocarbons is 16.33 grams per cubic foot assuming an 

average carbon to hydrogen ratio of 1:1.85 at 68° F and 760 mm Hg pressure.

(iii) HCconc = Average hydrocarbon concentration per second of the dilute exhaust 

sample measured as described in Section 85.2226(c)(4), and corrected for 

background, in ppm carbon equivalent, i.e., equivalent propane * 3.

(A) HCconc = HCe-HCd(1-) Where:

(B) HCe = Hydrocarbon concentration of the dilute exhaust sample as 

measured in ppm carbon equivalent.

(C) HCd = Background hydrocarbon concentration of the dilution air, sampled 

as described in Section 85.2221(b)(5), as measured in ppm carbon 

equivalent.

(D) 13.4

DF = -------------------------- calculated on a second-by-second basis

CO2e + (HCe + COe)*10-4

(iv) Vmix = The CVS flow rate in cubic feet per second corrected to standard 

temperature and pressure.

(v) COmass = Carbon monoxide emissions in grams per second.

(vi) DensityCO = Density of carbon monoxide is 32.97 grams per cubic foot at 68 °F 

and 760 mm Hg pressure.

(vii) COconc = Average carbon monoxide concentration per second of the dilute 

exhaust sample measured as in Section 85.2226(c)(4), and corrected for 

background, water vapor, and CO2 extraction, in ppm.

(A)

 1

COconc = COe - COd (1- ----- )

 DF
Regulation Number 11

Adopted: November 21, 2013 Page 112

(B) COe = Carbon monoxide concentration of the dilute exhaust in ppm.

(C) COd = Background carbon monoxide concentration of the dilution air, 

sampled as described in Section 85.12221(b)(5), in ppm.

(viii) NOxmass = Oxides of nitrogen emissions in grams per second.

(ix) DensityN02 = Density of oxides of nitrogen is 54.16 grams per cubic foot assuming 

they are in the form of nitrogen dioxide at 68 °F and 760 mm Hg pressure.

(x) NOxconc = Average concentration of oxides of nitrogen per second of the dilute 

exhaust sample measured as described in Section 85.2226(c)(4), and corrected 

for background in ppm.

(A)

 1

NOxconc = NOxe - NOxd (1- ----- )

 DF

(B) NOxe = Oxides of nitrogen concentration of the dilute exhaust sample as 

measure in ppm.

(C) NOxd = Background oxides of nitrogen concentration of the dilution air, 

sampled as described in Section 85.2221(b)(5), measured in ppm.

(xi) KH = humidity correction factor.

(A)

 1

KH ----------------------

 1 - 0.0047 (H - 75)

(B) H = Absolute humidity in grains of water per pound of dry air.

(C)

(43.478)Ra * Pd

H = ------------------------

 Ra

PB - (Pd * --------)

 100

(D) Ra = Relative humidity of the ambient air, percent.

(E) Pd = Saturated vapor pressure, mm Hg at the ambient dry bulb 

temperature. If the temperature is above 86° F, then it shall be used in 

lieu of the higher temperature, until EPA supplies final correction factors.

(F) PB = Barometric pressure, mm Hg.

(xii) CO2mass = Carbon dioxide emissions in grams per second.
Regulation Number 11

Adopted: November 21, 2013 Page 113

(xiii) DensityCO2 = Density of carbon dioxide is 51.81 grams per cubic foot at 68°F and 

760 mm Hg.

(xiv) CO2conc = Average carbon dioxide concentration per second of the dilute exhaust 

sample measured as described in Section 85.2226(c), and corrected for 

background in percent.

(A)

 1

CO2conc = CO2e - CO2d (1- ---- )

 DF

(B) CO2d = Background carbon dioxide concentration of the dilution air, 

sampled as described in Section 85.2221(b)(5), measured in percent.

(C)(d) Evaporative System Pressure Test Standards

(1) Visual Check. The vehicle shall fail the evaporative system visual check if any part of the 

system is missing, damaged, improperly connected, or disconnected as described in 

Section 85.2222(b).

(2) Canister End Pressure Test Standards. NOT APPLICABLE The vehicle shall fail the 

pressure test if the system cannot maintain a pressure above eight inches of water for up 

to two minutes after being pressurized to 14 ± 0.5 inches of water. The vehicle shall also 

fail if it does not possess a check valve, as identified in the Look-up Table, and if no 

pressure drop is detected when the fuel cap is loosened as described in Section

85.2222(c)(4).

(3) Fuel Inlet Pressure Test. NOT APPLICABLE

(i) Pass/Fail Determination. Flow rate, fill pressure, and decay pressure shall be 

measured at 2 Hz, averaged over 1 second intervals, and curve fitted using a 

least squares technique. If the volume compensated pressure drop is more than 

the pressure loss determined from starting and ending pressures in the Pressure 

Decay Reference Equation in Section 85.22C5(c)(3)(ii), the vehicle shall fail. 

Otherwise the vehicle shall pass. If not using volume compensation, the vehicle 

shall fail if the loss in pressure exceeds 6 inches of water.

(ii) Pressure Decay Reference Equation. This equation provides pressure loss 

values equivalent to a loss of pressure from 14 to 8 inches of water when the 

starting pressure is other than 14 inches of water.

P = 40 * ( 0.9967 - 2.7 * 10-6 * t )t

Where:

P = Starting or ending pressure, in inches of water,

t = Time, in seconds.

(iii) Fast-Pass. Fast-pass determinations may be made anytime during the pressure 

decay between 20 and 120 seconds if the measured pressure exceeds the 
Regulation Number 11

Adopted: November 21, 2013 Page 114

corresponding Pressure Test Reference Equation cut point, from Section

85.2205 (c)(3)(ii), by 1 inch of water pressure. The cut point is determined by 

adding 1 inch of water to the pressure value at a. time t. The pressure at time t 

corresponds to the pressure at the equivalent “start time” plus the time in 

seconds between 20 and 120 when the fast pass determination is made. The 

State may propose and the Division may approve other fast pass algorithms 

provided they minimize false results.

(iv) Pressure Drop. For vehicles without vapor control valves (burp valves), the 

clamp(s) shall be removed from the hose(s) and the system shall be monitored 

for a gradual pressure drop. If no pressure drop is detected, the vehicle shall fail 

the test. If the Pressure Test Look-up Table identifies the vehicle as possessing a 

vapor control valve, the system shall not be monitored for a loss of pressure.

(4) Fuel Cap Test. (Part F, Subpart IV of Regulation Number 11)

(i) Pressure Decay Method. If pressure decays by 6 inches of water or more during 

the 10-second period, the vehicle shall fail the fuel cap integrity test.

(ii) Flow Rate Method. The fuel cap leak rate shall be compared 1:0 an orifice with a 

National Institute of Standards and Technology traceable flow rate which will 

result in a pass/fail flow rate threshold of 60 cubic centimeters per minute of air at 

30 inches of water column. If the leak rate exceeds 60 cubic centimeters per 

minute at a pressure of 30 inches of water column, the cap shall fail the test.

Transient Mode and Evaporative System Purge Test Procedures

(a) General Requirements

(1) Data Collection. The following information shall be determined for the vehicle being 

tested and used to automatically select the dynamometer inertia and power absorption 

settings:

(i) Vehicle type: LDGV, LDGT1, LDGT2, and others as needed,

(ii) Chassis model year,

(iii) Make,

(iv) Model,

(v) Number of cylinders, or cubic inch displacement of the engine

(vi) Transmission type.

(2) Ambient Conditions. The ambient temperature, absolute humidity, and barometric 

pressure shall be recorded continuously during the transient or as a single set of readings 

up to 4 minutes before the start of the transient driving cycle.

(3) Restart. If shut off, the vehicle shall be restarted as soon as possible before the test and 

shall be running at least 30 seconds prior to the transient driving cycle.
Regulation Number 11

Adopted: November 21, 2013 Page 115

(b) Pre-inspection and Preparation

(1) Accessories. All accessories (air conditioning, heat, defogger, radio, automatic traction 

control if switchable, etc.) shall be turned off (if necessary, by the inspector).

(2) Leaks. The vehicle shall be inspected for exhaust leaks. Gas measurement of carbon 

dioxide or other gases shall be acceptable. Vehicles with leaking exhaust systems shall 

be rejected from testing.

(3) Operating Temperature. The vehicle temperature gauge, if equipped and operating, shall 

be checked to assess temperature. If the temperature gauge indicates that the engine is 

not at normal operating temperature, the vehicle shall be inspected and shall get a 

second-chance emission test if it fails the initial test for any criteria exhaust component. 

Vehicles in overheated condition shall be rejected from testing.

(4) Tire Condition. Vehicles shall be rejected from testing if the tire cords, bubbles, cuts, or 

other damage are visible. Vehicles shall be rejected that have space-saver spare tires on 

the drive axle. Vehicles may be rejected that do not have reasonably sized tires. Vehicle 

tires shall be visually checked for adequate pressure level. Drive wheel tires that appear 

low shall be inflated to approximately 30 psi, or to tire sidewall pressure, or 

manufacturer's recommendation.

(5) Ambient Background. Background concentrations of hydrocarbons, carbon monoxide, 

oxides of nitrogen, and carbon dioxide (HC, CO, NOx, and CO2, respectively) shall be 

sampled as specified in Section 85.2226(b)(2)(iv) to determine background concentration 

of constant volume sampler dilution air. The sample shall be taken for a minimum of 15 

seconds within 120 seconds of the start of the transient driving cycle, using the same 

analyzers used to measure tailpipe emissions except as provided in Section

85.2221(f)(3). Average readings over the 15 seconds for each gas shall be recorded in 

the test record. Testing shall be prevented until the average ambient background levels 

are less than 20 ppm HC, 30 ppm CO, and 2 ppm NOx, or outside ambient air levels (not 

influenced by station exhaust), which ever are greater.

(6) Sample System Purge. While a system is in operation, the CVS shall continuously purge 

the CVS hose between tests, and the sample system shall be continuously purged when 

not taking measurements.

(7) Negative Values. Negative gram per second readings shall be integrated as zero and 

recorded as such.

(c) Equipment Positioning and Settings

(1) Purge Equipment. NOT APPLICABLE If an evaporative system purge test is to be 

performed:

(i) The evaporative canister shall be checked unless the canister is inaccessible. A 

missing or obviously damaged canister shall result in failure of the visual 

evaporative system check.

(ii) The evaporative system shall be visually inspected for the appearance of proper 

hose routing and connection of hoses, unless the canister is inaccessible. If any 

evaporative system hose is disconnected, then the vehicle shall fail the visual 
Regulation Number 11

Adopted: November 21, 2013 Page 116

evaporative system check. All hoses disconnected for the test shall be 

reconnected after a purge flow test is performed.

(iii) The purge flow measurement equipment shall be connected in series between 

the evaporative canister and the engine, preferably on the canister end of the 

hose. For vehicles equipped with a service port for evaporative functional testing, 

the measurement equipment shall be connected to the port.

(2) Roll Rotation. The vehicle shall be maneuvered onto the dynamometer with the drive 

wheels positioned on the dynamometer rolls. Prior to test initiation, the rolls shall be 

rotated until the vehicle laterally stabilizes on the dynamometer. Drive wheel tires shall be 

dried if necessary to prevent slippage during the initial acceleration.

(3) Cooling System. Testing shall not begin until the test-cell cooling system is positioned 

and activated. The cooling system shall be positioned to direct air to the vehicle cooling 

system, but shall not be directed at the catalytic converter.

(4) Vehicle Restraint. Testing shall not begin until the vehicle is restrained. Any restraint 

system shall meet the requirements of Section 85.2226(a)(5)(ii). In addition, the parking 

brake shall be set for front wheel drive vehicles prior to the start of the test.

(5) Dynamometer Settings. Dynamometer power absorption and inertia weight settings shall 

be automatically chosen from a Division supplied electronic look-up table that will be 

referenced based upon the vehicle identification information obtained in (a)(l). Vehicles 

not listed shall be tested using default power absorption and inertia settings as follows:

DYNAMOMETER DEFAULT SETTINGS

vehicle type number of cylinders track road load 

horsepower

test inertia weight

All 3 12:1 2000

All 4 12.8 2500

All 5 14.5 3000

All 6 14.5 3000

LDGV 8 16.2 3500

LDGT 8 17.7 4000

LDGV 10 16.2 3500

LDGT 10 19.2 4500

LDGV 12 17.7 4000

LDGT 12 20.7 5000
Regulation Number 11

Adopted: November 21, 2013 Page 117

(6) Exhaust Collection System. The exhaust collection system shall be positioned to insure 

complete capture of the entire exhaust stream from the tailpipe during the transient 

driving cycle. The system shall meet the requirements of Section 85.2226(b)(2).

(d) Vehicle Conditioning

(1) Second-chance Retest. A vehicle shall get a second-chance emission test if it fails the 

initial test and all criteria exhaust components are at or below 2.0 times the applicable 

standards.

(2) Program Evaluation. NOT APPLICABLE Vehicles being tested for the purpose of 

program evaluation under Section 51.353(c) shall receive two full transient emission tests 

(i.e., a full 240 seconds each). Results from both tests and the test order shall be 

separately recorded in the test record. Emission scores and results provided to the 

motorist may be from either test.

(3) Discretionary Preconditioning. Any vehicle may be preconditioned using any of the 

following methods:

(i) Non-loaded Preconditioning. Increase engine speed to approximately 2500 rpm, 

for up to 4 minutes, with a tachometer.

(ii) Loaded Preconditioning. Drive the vehicle on the dynamometer at 30 miles per 

hour for up to 240 seconds at road-load.

(iii) Transient Preconditioning. After maneuver the vehicle onto the dyno, drive a 

transient cycle consisting of speed, time, acceleration, and relative load as 

determined by the Division.

(e) Vehicle Emission Test Sequence

(1) Transient Driving Cycle. The vehicle shall be driven over the following cycle:

Time Speed Time Speed Time Speed Time Speed Time Speed

0 0 48 25.7 96 0 144 24.6 192 54.6

1 0 49 26.1 97 0 145 24.6 193 54.8

2 0 50 26.7 98 3.3 146 25.1 194 55.1

3 0 51 27.5 99 6.6 147 25.6 195 55.5

4 0 52 28.6 100 9.9 148 25.7 196 55.7

5 3 53 29.3 101 13.2 149 25.4 197 56.1

6 5.9 54 29.8 102 16.5 150 24.9 198 56.3
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Adopted: November 21, 2013 Page 118

Time Speed Time Speed Time Speed Time Speed Time Speed

7 8.6 55 30.1 103 19.8 151 25 199 56.6

8 11.5 56 30.4 104 22.2 152 25.4 200 56.7

9 14.3 57 30.7 105 24.3 153 26 201 56.7

10 16.9 58 30.7 106 25.8 154 26 202 56.3

11 17.3 59 30.5 107 26.4 155 25.7 203 56

12 18.1 60 30.4 108 25.7 156 26.1 204 55

13 20.7 61 30.3 109 25.1 157 26.7 205 53.4

14 21.7 62 30.4 110 24.7 158" 27.3 206 51.6

15 22.4 63 30.8 111 25.2 159 30.5 207 51.8

16 22.5 64 30.4 112 25.4 160 33.5 208 52.1

17 22.1 65 29.9 113 27.2 161 36.2 209 52.5

18 21.5 66 29.5 114 26.5 162 37.3 210 53

19 20.9 67 29.8 115 24 163 39.3 211 53.5

20 20.4 68 30.3 116 22.7 164 40.5 212 54

21 19.8 69 30.7 117 19.4 165 42.1 213 54.9

22 17 70 30.9 118 17.7 166 43.5 214 55.4

23 14.9 71 31 119 17.2 167 45.1 215 55.6

24 14.9 72 30.9 120 18.1 168 46 216 56

25 15.2 73 30.4 121 18.6 169 46.8 217 56

26 15.5 74 29.8 122 20 170 47.5 218 55.8

27 16 75 29.9 123 20.7 171 47.5 219 55.2

28 17.1 76 30.2 124 21.7 172 47.3 220 54.5
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Adopted: November 21, 2013 Page 119

Time Speed Time Speed Time Speed Time Speed Time Speed

29 19.1 77 30.7 125 22.4 173 47.2 221 53.6

30 21.1 78 31.2 126 22.5 174 47.2 222 52.5

31 22.7 79 31.8 127 22.1 175 47.4 223 51.5

32 22.9 80 32.2 128 21.5 176 47.9 224 50.5

33 22.7 81 32.4 129 20.9 177 48.5 225 48

34 22.6 82 32.2 130 20.4 178 49.1 226 44.5

35 21.3 83 31.7 131 19.8 179 49.5 227 41

36 19 84 28.6 132 17 180 50 228 37.5

37 17.1 85 25.1 133 17.1 181 50.6 229 34

38 15.8 86 21.6 134 15.8 182 51 230 30.5

39 15.8 87 18.1 135 15.8 183 51.5 231 27

40 17.7 88 14.6 136 17.7 184 52.2 232 23.5

41 19.8 89 11.1 137 19.8 185 53.2 233 20

42 21.6 90 7.6 138 21.6 186 54.1 234 16.5

43 23.2 91 4.1 139 22.2 187 54.6 235 13

44 24.2 92 0.6 140 24.5 188 54.9 236 9.5

45 24.6 93 0 141 24.7 189 55 237 6

46 24.9 94 0 142 24.8 190 54.9 238 2.5

47 25 95 0 143 24.7 191 54.6 239 0

(2) Driving Trace. The inspector shall follow an electronic, visual depiction of the 

time/speed relationship of the transient driving cycle (hereinafter, the trace). The visual 

depiction of the trace shall be of sufficient magnification and adequate detail to allow 

accurate tracking by the driver and shall permit the driver to anticipate upcoming speed 

changes. The trace shall also clearly indicate gearshifts as specified in Section

85.2221(e)(3).
Regulation Number 11

Adopted: November 21, 2013 Page 120

(3) Shift Schedule. For vehicles with manual transmissions, inspectors shall shift gears 

according to the following shift schedule:

Shift Sequence gear Speed miles per hour Nominal Cycle Time 

seconds

1- 2 15 9.3

2-3 25 47.0

De-clutch 15 87.9

1-2 15 101.6

2-3 25 105.5

3-2 17 119.0

2-3 25 145.8

3-4 40 163.6

4-5 45 167.0

5-6 50 180.0

De-clutch 15 234.5

Gearshifts shall occur at the points in the driving cycle where the specified speeds are obtained. 

For vehicles with fewer than six forward gears the same schedule shall be followed with shifts 

above the highest gear disregarded.

(4) Speed Excursion Limits.Speed excursion limits shall apply as follows:

(i) The upper limit is 2 mph higher than the highest point on the trace within 1 

second of the given time.

(ii) The lower limit is 2 mph lower than the lowest point on the trace within 1 second 

of the given time.

(iii) Speed variations greater than the tolerances (such as may occur luring gear 

changes) are acceptable provided they occur for no more than 2 seconds on any 

occasion.

(iv) Speeds lower than those prescribed during accelerations are acceptable 

provided the vehicle is operated at maximum available power during such 

accelerations until the vehicle speed is within the excursion limits.
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Adopted: November 21, 2013 Page 121

(v) Exceedances of the limits in Section 85.2221(i) through Section 85.2221(iii) shall 

automatically result in a void test. Tests shall be aborted if the upper excursion 

limits are exceeded. Tests may be aborted if the lower limits are exceeded.

(5) Speed Variation Limits.

(i) A linear regression of feedback value on reference value shall be performed on 

each transient driving cycle for each speed using the method of least squares, 

with the best fit equation having the form: y = mx + b, where:

(A) y = The feedback (actual) value of speed;

(B) m = The slope of the regression line;

(C) x = The reference value; and

(D) b = The y-intercept of the regression line.

(ii) The standard error of estimate (SE) of y on x shall be calculated for each 

regression line. A transient driving cycle lasting the full 240 seconds that exceeds 

the following criteria shall be void and the test shall be repeated:

(A) SE = 2.0 mph maximum.

(B) m = 0.96-1.01.

(C) r

2 = 0.97 minimum.

(D) b = ± 2.0 mph.

(iii) A transient driving cycle that ends before the full 240 seconds that exceeds the 

following criteria shall be void and the test shall be repeated:

(A) SE = (NOT APPLICABLE)

(B) m = (NOT APPLICABLE)

(C) r

2 = (NOT APPLICABLE)

(D) b = (NOT APPLICABLE)

(6) Distance Criteria. The actual distance traveled for the transient driving cycle and the 

equivalent vehicle speed (i.e., roll speed) shall be measured. If the absolute difference 

between the measured distance and the theoretical distance for the actual test exceeds 

0.05 miles, the test shall be void.

(7) Vehicle Stalls. Vehicle stalls during the test shall result in a void and a new test. More 

than 3 stalls shall result in test failure.

(8) Dynamometer Controller Check. For each test, the measured horsepower, and inertia if 

electric simulation is used, shall be integrated from 55 seconds to 81 seconds (divided by 

26 seconds), and compared with the theoretical road-load horsepower (for the vehicle 
Regulation Number 11

Adopted: November 21, 2013 Page 122

selected) integrated over the same portion of the cycle. The same procedure shall be 

used to integrate the horsepower between 189 seconds to 201 seconds (divided by 12 

seconds). The theoretical horsepower shall be calculated based on the observed speed 

during the integration interval. If the absolute difference between the theoretical 

horsepower and the measured horsepower exceeds 0.5 hp, the test shall be void. 

Alternate error checking methods may be used if shown to be equivalent and approved 

by the Division.

(9) Inertia Weight Selection. Operation of the inertia weight selected for the vehicle shall be 

verified as specified in Section 85.2226(a)(4)(iii). For systems employing electrical inertia 

simulation, an algorithm identifying the actual inertia force applied during the transient 

driving cycle shall be used to determine proper inertia simulation. For all dynamometers, 

if the observed inertia is more than 1 % different from the required inertia, the test shall 

be void.

(10) CVS Operation. The CVS operation shall be verified for each test for a CFV-type CVS by 

measuring either the absolute pressure difference across the venturi or measuring the 

blower vacuum behind the venturi for minimum levels needed to maintain choke flow for 

the venturi design. The operation of an SSV-type CVS shall be verified throughout the 

test by monitoring the difference in pressure between upstream and throat pressure. The 

minimum values shall be determined from system calibrations. Monitored pressure 

differences below the minimum values shall void the test.

(11) Fuel Economy. For each test, the health of the overall analysis system shall be evaluated 

by checking a test vehicle's fuel economy for reasonableness, relative to upper and lower 

limits, representing the range of fuel economy values normally encountered for the test 

inertia and horsepower selected. For each inertia selection, the upper fuel economy limit 

shall be determined using the lowest horsepower setting typically selected for the inertia 

weight, along with statistical data, test experience, and engineering judgment. A similar 

process for the lower fuel economy limit shall be used with the highest horsepower 

setting typically selected for the inertia weight. For test inertia selections where the range 

of horsepower settings is greater than 5 horsepower, at least two sets of upper and lower 

fuel economy limits shall be determined and appropriately used for the selected test 

inertia. Tests with fuel economy results in excess of 1.5 times the upper limit shall result 

in a void test.

(f) Emission Measurements

(1) Exhaust Measurement. The emission analysis system shall sample and record dilute 

exhaust HC, CO, CO2, and NOx during the transient driving cycle as described in 

Section 85.2226(c).

(2) Purge Measurement. NOT APPLICABLE The analysis system shall sample and record 

the purge flow in standard liters per second and total volume of flow in standard liters 

over the course of the actual driving cycle as described in - Section 85.2227(b).

(3) Integrity Measurement. The analysis system shall measure and record the integrity of the 

fuel cap as described in Section 85.2227(c).

Evaporative System Pressure Test Procedures NOT APPLICABLE

(a) General Requirements
Regulation Number 11

Adopted: November 21, 2013 Page 123

(1) The on-vehicle pressure tests described in Section 85.2222(c) and (d) shall be performed 

after any tailpipe emission test to be performed on a vehicle. Fuel cap tests described in 

Section 85.2222(e).and (f) may be performed before or after the tailpipe emission test.

(2) The pressure test shall be conducted in a manner that minimizes changes in 

temperature, since pressure measurements are affected by changes in the vapor space 

temperature.

(3) The Look-up Table identifies which cm-vehicle pressure test to perform on a given 

vehicle. Vehicles receiving the canister end pressure test specified in Section 85.2222(c) 

do not need to receive any other pressure tests. Vehicles receiving the feel inlet pressure 

test specified in Section 85.2222(d) should also be given one of the fuel cap pressure 

tests specified in Sections 85.2222(e) and (f).

(4) Alternative procedures may be used if they are shown to be equivalent or better to the 

satisfaction of the Division. Any damage done to the evaporative emission control system 

during this test shall be repaired.

(b) Pre-inspection and Preparation

(1) The evaporative canister(s) shall be visually checked to the degree practical. A missing 

or obviously damaged canister(s) shall fail the visual evaporative system check.

(2) The evaporative system hoses shall be visually inspected for the appearance of proper 

routing, connection, and condition, to the degree practical. If any evaporative system 

hose is misrouted, disconnected, or damaged, the vehicle shall fail the visual evaporative 

system check.

(3) If the fuel cap is missing, obviously defective or the wrong style cap for the vehicle, the 

vehicle shall fail the visual evaporative system check.

(c) Canister-End Pressure Test NOT APPLICABLE

(1) Equipment Set-up. Test equipment shall be connected to the fuel tank canister hose at 

the canister end. The fuel cap shall be checked to ensure that it is properly, but not 

excessively tightened, and shall be tightened if necessary.

(2) Pressure Value. The system shall be pressurized to 14 ± 0.5 inches of water without 

exceeding 26 inches of water system pressure.

(3) Stability. Close off the pressure source, seal the evaporative system and monitor 

pressure decay for up to two minutes.

(4) Depressurization. Loosen the fuel cap after a maximum of two minutes and monitor for a 

sudden pressure drop, indicating that the fuel tank was pressurized.

(5) Reconnection. The inspector shall carefully ensure that all items disconnected or 

loosened in the course of the test are properly reconnected at the conclusion of the test.

(d) Fuel Inlet Pressure Test NOT APPLICABLE
Regulation Number 11

Adopted: November 21, 2013 Page 124

(1) Equipment Set-up. The vapor vent line(s) from the fuel tank to the canister(s) shall be 

clamped off as close to the canister(s) as practical without damaging evaporative system 

hardware. If the line(s) cannot be clamped (for example a rigid line), they shall be 

removed at the canister(s) and capped or plugged. Dual fuel tanks shall be checked 

individually if pressurizing from the fill pipe interface of only one fuel tank cannot access 

the complete vapor control system. A fuel inlet adapter, as specified in Section

85.2227(c), appropriate to the style of fuel inlet on the vehicle (not the fuel cap on the 

vehicle) shall be selected based on a software prompt and shall be installed on the 

vehicle's fuel inlet.

(2) Pressure Value. The fuel tank shall be pressurized to a value at or slightly above the 

minimum test pressure specified in the Look-up Table.

(3) Stability. Pressure stability shall be maintained for a period of 10 seconds prior to the 

start of the pressure decay measurement. Pressure shall not increase by more than 0.5 

inches of water during the first 20 seconds of the decay measurement. Alternate 

definitions of stability may be proposed by the state and approved by the Administrator 

provided they minimize the risk of false results.

(4) Volume Compensation. (Optional) Pressure decay measurements are affected by the 

vapor volume (fuel tank level) in the fuel tank. Volume-compensated pressure decay 

measurements will increase test repeatability, and are therefore recommended. Measure 

the volume-compensated pressure decay for up to 120 seconds after stability is 

achieved, using the equation in Section 85.2222(d)(5) This equation is based on 

normalizing the pressure decay measurements to a vapor volume of 50 liters. The 

Division may approve other methods of compensation for differences in fuel tank vapor 

volume.

(5)

V

P = P0 * K ( t * ------ )

VS

Where:

P = Pressure, in inches of water at time t, compensated for 

differences in fuel tank vapor space volume.

P0 = The stabilized pressure at the start of the decay portion of the 

pressure test, in niches of water.

k = A constant derived from curve fitting the pressure/time data from 

the decay portion of the pressure test, using the equation:

P = P0 * kt

t = Time measured from the start of the decay portion of the 

pressure test, in seconds.

Vs = Reference volume of the fuel vapor space, 50 liters.
Regulation Number 11

Adopted: November 21, 2013 Page 125

V = Volume of the fuel vapor space, in liters, calculated using the 

following equation:

 ÆP ÆV

V = ( Pb * 13.6 + ------ ) * -------------------

 2 (ÆP + ÆPI)

Where:

Pb = Barometric pressure, in inches of Hg.

ÆP = Pressure increase during the fill period, in inches of water.

ÆV = The flow meter measured volume of gas which pressurizes the 

vapor space, in liters at 20 C and 1 atmosphere.

ÆPL = The loss in pressure due to the presence of a leak during the fill 

process, in inches of water.

Evaporative System Pressure Test Procedures – Fuel Inlet Pressure Test Equation

Where:

_ = Summation of the second-by-second pressure loss during the fill 

period.

P0 = The stabilized pressure at the start of the decay portion of the 

pressure test, in inches of water.

k = A constant derived from curve fitting the pressure/time data from 

the decay portion of the pressure test, using the equation:

P = P0 * kt

Pt = Pressure values reported in one second intervals during the fill

period, in inches of water.

(e) Fuel Cap Leak Test - Pressure Decay Method

(1) The fuel cap shall be removed from the fuel Met and installed on a test rig with a nominal 

1 liter head space and be pressurized to 28+1.0 inch of water.

(2) The pressure decay shall be monitored as specified in this Regulation Number 11, Part F,

Subpart IV.
Regulation Number 11

Adopted: November 21, 2013 Page 126

(3) The fuel cap shall be replaced on the fuel inlet and tightened appropriately.

(f) Fuel Cap Leak Test - Flow Rate Method

(1) The fuel cap shall be removed from the fuel inlet and installed on the flow test device 

using the adapter appropriate for the fuel cap, as specified in Section 85.2227(c).

(2) The fuel cap flow rate shall be monitored as specified in this Regulation Number 11, Part 

F, Subpart IV.

(3) The fuel cap shall be replaced on the fuel inlet and tightened appropriately.

Colorado Automobile Dealers Transient Mode Test Analyzer System Equipment Specifications

(a) Dynamometer Specifications

(1) General Requirements.

(i) The dynamometer structure (e.g., bearings, rollers, pit plates, etc.) shall 

accommodate all light-duty vehicles and light-duty trucks up to 8500 pounds 

GVWR.

(ii) Road load horsepower and inertia simulation shall be automatically selected 

based on the vehicle parameters in the test record.

(iii) Alternative dynamometer specifications or designs may be proposed to the state 

and approved based upon a determination that, for the purpose of properly 

conducting an approved Transient Mode inspection, the evidence supporting 

such deviations will not cause improper vehicle loading.

(2) Power Absorption.

(i) Coefficients. The coefficients AV, BV, and CV, from vehicle track coast down 

testing, and referenced in the equations in this section are those specified during 

new car certification, or as specified by a vehicle class designator determined by 

the Division. Coefficients shall be calculated to a minimum of five (5) significant 

digits by the equations specified in Section 85.2226(a)(2)(i)(A) through Section

85.2226(a)(2)(i)(C). Power fractions determined from track coast-down data shall 

be calculated to a minimum of two (2) significant digits as specified in Section

85.2226(a)(2)(i). In the absence of new car certification coefficients information or 

a vehicle class designator identifying a power fraction, the default power fractions 

in Section 85.2226(a)(2)(i)(J) shall be used.

(A) Av = * (TRLHP@ 50 mph) hp/mph

(B) Bv = * (TRLHP@ 50 mph) hp/mph2

(C) Cv = * (TRLHP@ 50 mph) hp/mph3

(D) Where AVPF, BvPF, and CvPF are power fractions (PF), and indicate the 

fraction of the total power reflected by each coefficient Av, Bv, and Cv.
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Adopted: November 21, 2013 Page 127

(E) AvPF + BvPF + CvPF = 1

(F) Derivation of AVPF, BVPF, and CVPF from known track coast-down 

curves shall be computed as follows:

(1)

AV (50)

AVPF = ------------------------------------------------

 {AV (50) + BV (2500) + CV (125,000)}

(2)

BV (2500)

BVPF = ------------------------------------------------

 {AV (50) + BV (2500) + CV (125,000)}

(3)

CV (125,000)

CVPF = ------------------------------------------------

 {AV (50) + BV (2500) + CV (125,000)}

(4) Default values:

AVPF = 0.35

BVPF = 0.10

CVPF = 0.55

(ii) Vehicle Loading. The true vehicle loading used during the transient driving cycle 

shall follow the equation in Section 85.2226(a)(2)(iii) between 10 and 60 mph. 

The dynamometer

controls shall set the dynamometer loading to achieve the coast-down target time 

(± 1 second) with the vehicle on the dynamometer using the vehicle-specific 

inertia test weights. A conversion equation or table of target time versus 

horsepower for the dynamometer design shall be used. Target time shall be 

converted to horsepower by the equation Section 85.2226(a)(2)(iv) or pre-defined 

horsepower values may be used.

(iii) TRLHP@ Obmph = {Av * Obmph} + {Bv * Obmph2} + {Cv * Obmph3}

Av, Bv, Cv = Coefficients specified in Section 85.2226(a)(2)(i) for vehicle 

track coast down curves.

Obmph = Observed mph

TRLHP = Track Road Load Horsepower, which includes loading 

contributions from the power absorber, parasitic losses, and tire/roll 

interface losses.

(iv)
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Adopted: November 21, 2013 Page 128

Colorado Automobile Dealers Transient Mode Equipment Specifications – Dynamometer Specifications

ET = Elapsed time for the vehicle on the road to coast down from 55 to 

45 mph, and from 22 to 18 mph

ETW = Inertia weight in pounds

V1 = Initial velocity in feet/second (i.e., velocity at either 55 or 22 mph)

V2 = Final velocity in feet/second (i.e., velocity at either 45 or 18 mph)

(v) In practice, the true vehicle loading is derived from equations of “force” (i.e., 

F=MA). In determining vehicle load on a dynamometer, applied loads in units of 

force tangential to the roll surface are not dependent on the roll diameter used, 

whereas applied loads in units of torque of horsepower are dependent on the roll 

diameter. The equation in Section 85.2226(a)(2)(vi) may be used to convert track

road-load horsepower values in Section 85.2226(a)(2)(iii) to units of force.

(vi) TRLF@ Obmph = {Af} + {Bf * Obmph} + (Cf * Obmph2}

TRLF = Track Road-Load Force (in units of pounds)

Af = 375 * AV (AV in HP/mph2 units)

Bf = 375 * BV (BV in HP/mph3 units)

Cf = 375 * CV (CV in HP/mph units)

Af, Bf, Cf = Equivalent force coefficients to the coefficients specified in 

Section 85.2226(a)(2)(i) for vehicle track coast down curves.

(vii) Range and Curve of Power Absorber. The range of power absorber at 50 mph 

shall be sufficient to cover track road-load horsepower (TRLHP) values between 

4 and 35 horsepower. The absorption shall be adjustable across the required 

horsepower range at 50 mph in 0.1 horsepower increments. The accuracy of the 

power absorber shall be ± 0.25 horsepower or ± 2% of point whichever is 

greater.

(viii) Parasitic Losses (General Requirements). The parasitic losses in each 

dynamometer system (such as windage, bearing friction, and system drive 

friction) shall be characterized between 10 and 60 mph upon initial acceptance. 

There shall be no sudden discontinuities in parasitic losses below 10 mph. 

Further, when added to the lowest possible loading of the power absorber 

(dynamometer motoring is considered a negative load), the parasitic losses must 
Regulation Number 11

Adopted: November 21, 2013 Page 129

be sufficiently small such that proper loading will occur between 10 and 60 mph 

for a vehicle with a 50 mph track road-load horsepower value of 4 horsepower. 

The parasitic horsepower losses shall be characterized either digitally in five mph 

increments and linearly interpolated in-between, or the data at 10 mph 

increments shall fit the equation in Section 85.2226(a)(2)(ix) to within 2 percent of 

point.

(ix) PLHP = {Ap * (Obmph)} + {(Bp) * (Obmph)2} + {(Cp) * (Obmph)3}

PLHP = Dynamometer parasitic losses.

Ap, Bp, and Cp are curve coefficients necessary to properly characterize 

the dynamometer parasitic losses for the inertia weight(s) used.

(x) Parasitic Losses (Low Speed Requirements). The coast down time of the 

dynamometer between 8 and 12 mph shall be greater than or equal to the value 

calculated by the equation in Section 85.2226(a)(2)(xi) when the dynamometer is 

set for a 2000-pound vehicle with a track road-load horsepower of 4 horsepower 

at 50 mph.

(xi) Low Speed Loading. The following procedure is used to determine if a 

dynamometer system is correctly loading a vehicle with an ETW of 2000 pounds 

and a TRLHP of 6.0 horsepower at low speeds. Use “default” coefficients from 

Section 85.2226(a)(2)(i)(F)(4). Dynamometer must be warmed up prior to this 

procedure.

(A) Select vehicle with a driven axle weight between 1200 and 1300 pounds 

(sandbags or other ballast may be used to achieve this weight). Record 

vehicles driven axle weight to the nearest pound.

(B) Calculate the actual tire/roll interface losses (ATRL) using the following 

sub procedure.

(1) Determine PLHP for dynamometer system being tested.

(2) Calculate GTRL using equations from Sections

85.2226(a)(2)(xiii) and (xv) or (xvi).

(3) Calculate IHP using the following formula:

IHP = TRLHP-PLHP-GTRL

(4) Set dynamometer based on IHP calculated is step C above.

(5) Perform dynamometer coast down with vehicle selected in step 1 

correctly positioned on rolls. Record coast down time from 12 

mph to 8 mph.

(6) Calculate new TRLHP based on 12 mph to 8 mph coast

(7) Calculate actual tire/roll interface losses (ATRL) using the 

following equation.
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ATRL = TRLHP-PLHP-IHP

(C) Using calculated ATRL determine new IHP using the following formula:

IHP = TRLHP-PLHP-ATRL

(D) Set dynamometer based on IHP calculated is step 3 above.

(E) Perform dynamometer coast down with vehicle selected in step 1 

correctly positioned on rolls. Record coast down tune from 12 mph to 8 

mph.

(F) The maximum, average, and minimum time limits for the ondynamometer coast-down window at 10 mph shall be calculated by the 

following equations.

Colorado Automobile Dealers Transient Mode Equipment Specifications – Dynamometer Specifications

(xii) Tire/Roll Interface Losses. Generic tire/roll interface losses shall be determined 

for each dynamometer design used, and applied to obtain proper vehicle loading. 

A means to select or determine the appropriate generic tire/roll interface loss for 

each test vehicle shall be employed. Dynamometer design parameters include 

roll diameter, roll spacing, and roll surface finish. Generic tire/roll interface losses 

may be determined by the acceptance procedures in Section 85.2234(b)(4). 

Alternatively, generic values determined by the Division, or by a procedure 

accepted by the Division, may be used. The equation in Section

85.2226(a)(2)(xiii) may be used to quantify tire/roll interface losses. Coefficients 

for equation in Section 85.2226(a)(2)(xiii) shall be calculated to a minimum of five 

(5) significant digits by the equations specified in Section 85.2226(a)(2)(xiii)(A) 

through Section 85.2226(a)(2)(xiii)(I). Tire loss power fractions determined from 

track coast-down data shall be calculated to a minimum of two (2) significant 

digits as specified in Section 85.2226(a)(2)(xiii)(J). In the absence of new car 
Regulation Number 11

Adopted: November 21, 2013 Page 131

certification information or a vehicle class designator identifying a tire loss power 

fraction, the default tire loss power fractions indicated equations Section

85.2226(a)(2)(xiii)(E) through Section 85.2226(a)(2)(xiii)(I) shall be used as 

specified in Section 85.2226(a)(2)(xiii)(J).

(xiii) GTRL@ Obmph = {At * (Obmph)} + {Bt * (Obmph)2} + {Ct * (Obmph)3}

GTRL@ Obmph = Generic Tire/Roll Interface losses at the observed mph

Where: At, Bt, and Ct are curve coefficients necessary to properly 

characterize the tire/roll interface losses.

(A) At = * (GTRL@ 50 mph) hp/mph

(B) Bt = * (GTRL@ 50 mph) hp/mph2

(C) Ct = * (GTRL@ 50 mph) hp/mph3

(D) At8= * (GTRL@ 50 mph) hp/mph

(E) Bt8= * (GTRL@ 50 mph) hp/mph2

(F) Ct8= * (GTRL@ 50 mph) hp/mph3

(G) At20= * (GTRL@ 50 mph) hp/mph

(H) Bt20= * (GTRL@ 50 mph) hp/mph2

(I) Ct20= * (GTRL@ 50 mph) hp/mph3

(J) Where:

(1) At, Bt, and Ct are curve coefficients necessary to properly 

characterize the tire/roll interface losses.

(2) At8, Bt8, and Ct8 are curve coefficients when using twin 8.625 inch 

diameter rolls.

(3) At20, Bt20, and Ct20 are curve coefficients when using twin 20.0 

inch diameter rolls.

(4) AtPF, BtPF, and CtPF indicate the fraction of the total tire loss 

power fraction reflected by each coefficient At, Bt, and Ct.

(5) AtPF + BtPF + CtPF = 1

(6) Derivation of AtPF, BtPF, and CtPF from known track or 

dynamometer data shall be computed as follows:

Colorado Automobile Dealers Transient Mode Equipment Specifications – Dynamometer Specifications
Regulation Number 11

Adopted: November 21, 2013 Page 132

(xiv) In the absence of new car certification GTRL@ 50 mph or a vehicle class designator, 

the GTRL@ 50 mph shall be calculated

(A) by the equation in Section 85.2226(a)(2)(xv) when using twin 8.625-inch 

diameter rolls

(B) by the equation in Section 85.2226(a)(2)(xvi) when using twin 20.0-inch 

diameter rolls

(xv) For 8.625” dynamometers:

GTRL@ 50 mph = (-0.378193) + {(0.0033207) * (DAXWT)}

Where: DAXWT = Axle weight on the drive tires

GTRL@ 50 mph = Losses for 8.625 inch diameter roll

(xvi) For 20” dynamometers:

GTRL@ 50 mph = (0.241645) + {(0.0020844) * (DAXWT)}

Where: DAXWT = Axle weight on the drive tires

GTRL@ 50 mph = Losses for 20.0 inch diameter roll

(xvii) Indicated Horsepower. The power absorption for each test shall be selected at 50 

mph. The indicated power absorption (IHP) at 5C mph after accounting for 

parasitic and generic tire losses shall be determined by the equation in Section

85.2226(a)(2)(xv).

(xviii) IHP@ 50 mph = TRLHP@ 50 mph - PLHP@ 50 mph - GTRL@ 50 mph

(xix) In systems where the power absorption is actively controlled, the indicated 

horsepower at each speed between 0 and 60 mph shall conform 1:0 the equation 

in Section 85.2226(a)(2)(xvii). Approximations for a smooth curve with no 

discontinuities may be used between 0 and 10 mph.

(xx) IHP@ Obmph = TRLHP@ Obmph - PLHP@ Obmph - GTRL@ Obmph
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(3) Rolls.

(i) Size and Type. The dynamometer shall be equipped with twin rolls. The rolls 

shall be coupled side to side. In addition, the front and rear rolls shall be coupled. 

The dynamometer roll diameter shall be between 8.5 and 21.0 inches. The 

spacing between the roll centers shall comply with the equation in Section

85.2226(a)(3)(ii) to within +0.5 inches and -0.25 inches. The parasitic and generic 

tire/roll interface losses for the specific roll diameter, spacing, and surface finish 

used shall be determined as indicated in Section 85.2226(a)(2)(viii), (a)(2)(ix), 

and Section 85.2226(a)(2)(xii) as necessary to properly load vehicles as defined 

in Section 85.2226(a)(2)(ii) and Section 85.2226(a)(2)(iii). The dynamometer rolls 

shall accommodate an inside track width of 30 inches and an outside track width 

of at least 100 inches.

(ii) Roll Spacing = (24.375 + D) * SIN 31.5153_

D = dynamometer roll diameter.

Roll spacing and dynamometer roll diameter are expressed in inches.

(iii) Design. The roll size, surface finish, and hardness shall be such that tire slippage 

on the first acceleration of the transient driving cycle is minimized under all 

weather conditions; that the specified accuracy of the distance measurement is 

maintained; and that tire wear and noise are minimized.

(4) Inertia.

(i) Mechanical Inertia Simulation. NOT APPLICABLE The dynamometer shall be 

equipped with mechanical flywheels providing test inertia weights between at 

least 2000 to 5500 pounds, in increments of no greater than 500 pounds. The 

tolerance on the base inertia weight and the flywheels shall be within 1 % of the 

specified test weights. The proper inertia weight for any test vehicle shall be 

selectable.

(ii) Electric Inertia Simulation. Electric inertia simulation, or a combination of electric 

and mechanical simulation may be used in lieu of mechanical flywheels, provided 

that the performance of the electrically simulated inertia complies with the 

following specifications. Exceptions to these specifications may be allowed upon 

a determination by the Division that such exceptions would not significantly 

increase vehicle loading or emissions for the purpose of properly conducting an 

approved IG 240 test.

(A) System Response. The torque response to a step change shall be at 

least 90% of the requested change within 100 milliseconds after a step 

change is commanded by the dynamometer control system, and shall be 

within 2 percent of the commanded torque by 300 milliseconds after the 

command is issued. Any overshoot of the commanded torque value shall 

not exceed 25 percent of the torque value.

(B) Simulation Error. An inertia simulation error (ISE) shall be continuously 

calculated any time the actual dynamometer speed is above 10 MPH 

and below 60 MPH. The ISE shall be calculated by the equation in 
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Adopted: November 21, 2013 Page 134

Section 85.2226(a)(4)(ii)(C), and shall not exceed 1 percent of the inertia 

weight selected (IWS) for the vehicle under test.

(C) ISE = (IWS - It) / (IWS) * 100

(D) It = Im +

Where:

It = Total inertia being simulated by the dynamometer (kg)

It (lb force) = It (kg) * 2.2046

Im = Base (mechanical inertia of the dynamometer (kg)

V = Measured roll speed (m/s)

Fm = Force measured by the load cell (translated to the roll surface) (N)

Frl = Road load force (N) required by IHP at the measured roll speed (V)

t = Time (sec)

(iii) Inertia Weight Selection. NOT APPLICABLE For dynamometer systems 

employing mechanical inertia flywheels, the test system shall be equipped with a 

method, independent from the flywheel selection system that identifies which 

inertia weight flywheels are actually rotating during the transient driving cycle.

(5) Other Requirements.

(i) Test Distance and Vehicle Speed. The total number of dynamometer roll 

revolutions shall be used to calculate the distance traveled. Pulse counters may 

be used to calculate the distance directly if there are at least 16 pulses per 

revolution. The measurement of the actual roll distance for the composite and 

each phase of the transient driving cycle shall be accurate to within ±0.01 mile. 

The measurement of the roll speed shall be accurate to within ±0.1 mph. Roll 

speed measurement systems shall be capable of accurately measuring a 3.3 

mph per second acceleration rate over a one second period with a starting speed 

of 10 mph.

(ii) Vehicle Restraint. The vehicle shall be restrained during the transient driving 

cycle. The restraint system shall be designed to minimize vertical and horizontal 

force on the drive wheels such that emission levels are not significantly affected.

(iii) Vehicle Cooling. The test system shall provide for a method to prevent 

overheating of the vehicle. The cooling method shall direct air to the cooling 

system of the test vehicle. The cooling system capacity shall be 5400 ±300 

SCFM within 12 inches (30.5 cm) of the intake to the vehicle's cooling system. 

The cooling system design shall avoid improper cooling of the catalytic converter.

(iv) Four-Wheel Drive. OPTIONAL If used, four-wheel drive dynamometers shall 

insure the application of correct vehicle loading as defined in Section
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Adopted: November 21, 2013 Page 135

85.2226(a)(2) and shall not damage the four-wheel drive system of the vehicle. 

Front and rear wheel rolls shall maintain speed synchronization within 0.2 mph.

(v) Augmented Braking. NOT APPLICABLE Fully automatic augmented braking 

shall be used from seconds 85 through 95 and after second 223 of the driving 

cycle. Fully automatic augmented braking may be used in other deceleration 

periods of the driving cycle with the approval of the Division. During the periods 

of augmented braking the operator shall be made aware that augmented braking 

is occurring and shall be trained not to use the vehicle accelerator during these 

periods. It shall be automatically interlocked such that it can be actuated only 

while the vehicle brakes are applied. Simultaneous engine acceleration is 

systematically prevented through periodic quality assurance.

(b) Constant Volume Sampler

(1) General Design Requirements.

(i) Venturi Type. A constant volume sampling (CVS) system of the critical flow 

venturi (CFV), sub-sonic venturi (SSV), or square edged orifice (SEO) type shall 

be used to collect vehicle exhaust samples. The CVS system and components 

shall generally conform to the specifications in Section 86.109-90.

(ii) CVS Flow Size. The CVS system shall be sized in a manner that prevents 

condensation in the dilute sample over the range of ambient conditions to be 

encountered during testing. A minimum 325 SCFM CVS system and heated lines 

or sample conditioning system (dryer) may be used to eliminate condensation 

and to increase measured concentrations for better resolution. Should the heated 

sample lines be used, the sample line and components (e.g., filters, etc.) shall be 

heated to a minimum of 120° F and a maximum of 250°F, which shall be 

monitored during the transient driving cycle.

(iii) CVS Compressor. The CVS compressor flow capacity shall be sufficient to 

maintain proper flow in the main CVS venturi with an adequate margin. For CFV 

CVSs the margin shall be sufficient to maintain choke flow. The capacity of the 

blower relative to the CFV flow capacity shall not be so large as to create a 

limited surge margin.

(iv) Materials. All materials in contact with exhaust gas shall be unaffected by and 

shall not affect the sample (i.e., the materials shall not react with the sample, and 

neither shall they taint the sample as a result of out gassing). Acceptable 

materials include stainless steel, Teflon, silicon rubber, and Tedlar.

(v) Alternative Approaches. Alternative CVS specifications, materials, or designs 

may be allowed upon a determination by the Division, that for the purpose of 

properly conducting an approved short test, the evidence supporting such 

deviations will not significantly affect the proper measurement of emissions.

(2) Sample System.

(i) Sample Probe. The sample probe within the CVS shall be designed such that a 

continuous and adequate volume of sample is collected for analysis. The system 

shall have a method for determining if the sample collection system has 
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Adopted: November 21, 2013 Page 136

deteriorated or malfunctioned such that an adequate sample is not being 

collected, or that the response tune has deteriorated such that the tune 

correlation for each emission constituent is no longer valid.

(ii) CVS Mixing Tee.

(A) Design and Effect. The mixing tee for diluting the vehicle exhaust with 

ambient air shall be at the vehicle tailpipe exit as in Section 86.109-

90(a)(2)(iv). The dilution-mixing tee shall be capable of collecting 

exhaust from all light-duty vehicle and light-duty truck exhaust systems. 

The design used shall not cause static pressure in the tailpipe to change 

such that the emission levels are significantly affected. A change of ±1.0 

inch of water, or less, shall be acceptable.

(B) Locating Device. The mixing tee shall have a device for positively 

locating the tee relative to the tailpipe with respect to distance from the 

tailpipe, and with respect to positioning the exhaust stream from the 

tailpipe(s) in the center of the mixing tee flow area. The locating device, 

or the size of the entrance to the tee shall be such that if a vehicle moves 

laterally from one extreme position on the dynamometer to the other 

extreme, that mixing tee will collect all of the exhaust sample.

(iii) Dual Exhaust. For dual exhaust systems, the design used shall insure that each 

leg of the sample collection system maintains equal flow. Equal flow will be 

assumed if the design of the “Tee” intersection for the dual CVS hoses is a “Y” 

that minimizes the flow loss from each leg of the “Y,” if each leg of the dual 

exhaust collection system is approximately equal in length (± 1 foot), and if the 

dilution area at the end of each leg is approximately equal. In addition, the CVS 

flow capacity shall be such that the entrance flow velocity for each leg of the dual 

exhaust system is sufficient to entrain all of the vehicle's exhaust from each 

tailpipe.

(iv) Background Sample. The mixing tee shall be used to collect the background 

sample. The position of the mixing tee for taking the background sample shall be 

within 12 lateral and 12 longitudinal feet of the position during the transient 

driving cycle, and approximately 4 vertical feet from the floor.

(v) Integrated Sample. A continuous dilute sample shall be provided for integration 

by the analytical instruments in a manner similar to the method for collecting bag 

samples as described in Section 86.109.

(c) Analytical Instruments

(1) General Requirements.

(i) The emission analysis system shall automatically sample, integrate, and record 

the specified emission values for HC, CO, CO2, and NOx. Performance of the 

analytical instruments with respect to accuracy and precision, drift, interferences, 

noise, etc. shall be similar to instruments used for testing under Section 86 

Subparts B, D, and N. Analytical instruments shall perform in this manner in the 

full range of operating conditions in the system environment.
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(ii) Alternative analytic equipment specifications, materials, designs, or detection 

methods may be allowed upon a determination by the Division, that for the 

purpose of properly conducting an approved short test, the evidence supporting 

such deviations will not significantly affect the proper measurement of emissions.

(2) Detection Methods and Instrument Ranges.

(i) Total Hydrocarbon Analysis. A flame ionization detector shall determine total 

hydrocarbon analysis. If a 325 SCFM CVS is used, the analyzer calibration curve 

shall cover at least the range of 0 ppmC to 4,000 ppmC. Use of a different CVS 

flow capacity shall require an adjustment to these ranges. Appropriate 

documentation supporting any adjustment in ranges shall be available. Such 

documentation shall also address the ability of any altered ranges to accurately 

measure all cutpoints, including cutpoints for vehicles older than those specified 

in Section 85.2205(a) that may be used in the specific I/M program for which the 

altered ranges are proposed to be used. The calibration curve must comply with 

the quality control specifications in Section 85.2234(d).

(ii) Carbon Monoxide Analysis. CO analysis shall be determined using a nondispersive infrared analyzer. If a 325 SCFM CVS is used, CO analysis shall 

cover at least the range of 0 ppm to 20,000 ppm (2%). ppm. Use of a different 

CVS flow capacity shall require an adjustment to these ranges. Appropriate 

documentation supporting any adjustment in ranges shall be available. Such 

documentation shall also address the ability of any altered ranges to accurately 

measure all cutpoints, including cutpoints for vehicles older than those specified 

in Section 85.2205(a) that may be used in the specific I/M program for which the 

altered ranges are proposed to be used. The calibration curve must comply with 

the quality control specifications in Section 85.2234(d).

(iii) Carbon Dioxide Analysis. CO2 analysis shall be determined using an NDIR 

analyzer. If a 325 SCFM CVS is used, CO2 analysis shall cover at least the 

range of 0 ppm to 80,000 ppm (8%). Use of a different CVS flow capacity shall 

require an adjustment to these ranges. Appropriate documentation supporting 

any adjustment in ranges shall be available. Such documentation shall also 

address the ability of any altered ranges to accurately measure all cutpoints, 

including cutpoints for vehicles older than those specified in Section 85.2205(a) 

that may be used in the specific I/M program for which the altered ranges are

proposed to be used. The calibration curve must comply with the quality control 

specifications in Section 85.2234(d).

(iv) Oxides of Nitrogen Analysis. NOx analysis shall be determined using 

chemiluminescence. The NOx measurement shall be the sum of nitrogen oxide 

and nitrogen dioxide. If a 325 SCFM CVS is used, the NOx analysis shall cover 

at least the range of 0 ppm to 1000 ppm. Use of a different CVS flow capacity 

shall require an adjustment to these ranges. Appropriate documentation 

supporting any adjustment in ranges : shall be available. Such documentation 

shall also address the ability of any altered ranges to accurately measure all 

cutpoints, including cutpoints for vehicles older than those specified in this 

Regulation Number 11, Part F, that may be used for which the altered ranges are 

proposed to be used. The calibration curve must comply with the quality control 

specifications in Section 85.2234(d).
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Adopted: November 21, 2013 Page 138

(3) System Response Requirements. The governing requirement for system response is the 

ability of the integration system to measure vehicle emissions to within ±5 % of that 

measured from a bag sample simultaneously collected over the same integration period, 

on both clean and dirty vehicles. Historically, continuously integrated emission analyzers 

have been required to have a response time of 1.5 seconds or less to 90% of a step 

change, where a step change was 60% of full scale or better. System response tunes 

between a step change at the probe and reading 90% of the change have generally been 

less than 4-10 seconds. Systems proposed that exceed these historical values shall 

provide an engineering explanation as to why the slower system response of the 

integrated system will compare to the bag reading within the specified 5 %.

(4) Integration Requirements.

(i) The analyzer voltage responses, CVS pressure(s), CVS temperature(s), 

dynamometer speed, and dynamometer power shall be sampled as a frequency 

of no less than 5 Hertz, and the voltage levels shall be averaged over 1 second 

intervals.

(ii) The system shall properly tune correlate each analyzer signal, CVS signals and 

dynamometer signals to the driving trace (test time). The driving trace update 

rate from the computer shall be at a rate to produce a smooth transition from one 

data point to another.

(iii) The one-second average analyzer voltage levels shall be converted to 

concentrations by the analyzer calibration curves. Corrected concentrations for 

each gas shall be derived by subtracting the pre-test background concentrations 

from the measured concentrations, according to the method in Section

85.2205(b). The corrected concentrations shall be converted to grams for each 

second using the equations specified in Section 85.2205(b) to combine the 

concentrations with the CVS flow over the same interval. The grams of emissions 

per test phase shall be determined using the equations in Section 85.2205(b).

(iv) When multiple analyzers are used for any constituent, the integration system 

shall simultaneously integrate both analyzers. The integrated values for the

lowest analyzer in range shall be used for each second.

(v) For all constituents, the background concentration levels from the lowest range 

analyzer shall be used, including the case where multiple analyzers may have 

been used.

(5) Analytical System Design.

(i) Materials. All materials in contact with exhaust gas prior to and throughout the 

measurement portion of the system shall be unaffected by and shall not affect 

the sample (i.e., the materials shall not react with the sample, and neither shall 

they taint the sample as a result of out gassing). Acceptable materials include 

stainless steel, Teflon, silicon rubber, and Tedlar.

(ii) Bag Ports. All analysis systems shall have provisions for reading a sample bag. 

A portable pump for sampling such bags is permitted.
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(iii) System Filters. The sample system shall have an easily replaceable filter 

element to prevent particulate matter from reducing the reliability of the analytical 

system. The filter element shall provide for reliable sealing after filter element

changes. If the sample line is heated, the filter system shall also be heated.

(iv) Availability of Intermediate Calculation Variables. Upon request prior to a test, all 

intermediate calculation variables shall be available to be downloaded to 

electronic files or hard copy. These variables shall include those that calculate 

the vehicle emission test results, perform emission analyzer and dynamometer 

function checks, and perform quality assurance and quality control 

measurements.

(d) Colorado Automobile Dealers Transient Mode Test Analyzer System Specific Hardware

General Design Requirements.

(i) Computer System. Minimum CPU system to include; 90MHZ Pentium processor, 

Memory 16MB, Secondary Cache 256 KB, Video Type SVGA, Video Card 2 MB 

memory, 15” Color Monitor (drivers aid), Diskette drive A 1.44 MB, Hard-disk 

drive C 1.6 GB, Parallel Port (1), Serial Port (1), Mouse Port (1), 104 Key 

Keyboard, Expansion Slots (4). Port configurations noted may not reflect the 

necessary number or type to support subsystem requirements or options.

(ii) Modem. Minimum requirement. Hayes compatible able to operate at 14.400B 

M.N.P. level 5. Error correction, Microcom networking protocol (M.N.P.) levels 1-

4 with V.42 data compression. M.N.P. level 5 - V.32BIS/V.42BIS.

(iii) Printer. Vehicle Inspection Report. 24 pin impact printer operating at 12 

characters per inch and 80 characters per line.

(iv) Printer. Diagnostic Report, (customer option) 24-pin impact printer operating at 

12 characters per inch and 80 characters per line.

(v) Printer. Certificate/Sticker. A Standard Register PT-640, thermal transfer printer.

(vi) Barcode Scanner. Symbol Technologies PDF 1000 HV or equivalent.

(1) Fuel cap Tester. An internal or external unit capable of performing either the pressure 

decay method or flow rate method of fuel cap testing as defined in Evaporative System 

Test Procedures, Sections (e) and (f).

(2) System Security. Access to the analytical system, computer system, official state 

documents shall be prevented by locked enclosure and monitored by micro switches or 

other similar means to assure that unauthorized access is denied. Detection of 

unauthorized access shall result in automatic inspection system lock out.

(3) Manufacturer Options installed to operate independent of an official inspection processes 

may be utilized and configured into the hardware as necessary. An example would be a 

CD-ROM for vehicle diagnostics or software supported programs.

Evaporative System Inspection Equipment
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(a) General Requirements

(1) Equipment Design. Automated and computerized test systems shall be used for the 

evaporative system tests. Pass/fail decisions shall be made automatically. The systems 

shall be tamper resistant and designed to avoid damage to the vehicle during installation, 

testing, and removal.

(2) Alternative Systems. Alternative purge or pressure test equipment, specifications, 

materials, or designs, may be proposed and approved upon a determination by the 

Division that, for the purpose of properly conducting an approved Transient Mode test, 

the evidence supporting such deviations will not appreciably or adversely affect the 

proper determination of system integrity, the proper measurement of purge, or the proper 

operation of the vehicle.

(b) Evaporative Purge System NOT APPLICABLE

(1) General Requirements. The evaporative purge analysis system shall measure the 

instantaneous purge flow in standard liters/minute, and shall compute the total volume of 

the flow in standard liters over the transient driving cycle.

(2) Specifications. The purge flow measuring system shall comply with the following 

requirements.

(i) Flow Capacity. A minimum of 50 liters per minute.

(ii) Pressure Drop. Maximum of 16 inches of water at 50 liters per minute for the 

complete system including hoses necessary to connect the system to the vehicle.

(iii) Totaled Flow. 0 to 100 liters of volume

(iv) Response Time. 410 milliseconds maximum to 90% of a step change between 

approximately 2 and 10 liters per minute measured with air.

(v) Accuracy.

(A) ±2.0 liters per minute between 10 and 50 liters per minute (rate)

(B) ±0.15 liters per minute between 0 and 10 liters per minute (rate)

(C) ±4% of 50 standard liters total flow volume between 10 and 50 liters total 

flow volume over one minute.

(D) ±1.5% of 10 standard liters between 0 and 10 liters total volume flow 

over one minute.

(vi) Noise. The maximum noise shall be less than 0.001 liters per second

(vii) Calibration Gas. Air

(3) Automatic Operation. Vehicle purge flow shall be monitored with a computerized system 

at a minimum sample rate of 1 Hz, shall automatically capture average (if sampled faster 

than 1 Hz) second-by-second readings, and shall automatically derive a pass/fail 
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decision. In determining the total volume of flow, the monitoring system shall not count 

signal noise as flow volume. The test sequence shall be automatically initiated when the 

transient driving cycle test is initiated.

(4) Adaptability. The purge flow system shall have sufficient adapters to connect in a leaktight manner with the variety of evaporative systems and hose deterioration conditions in 

the vehicle fleet. The purge measurement system shall not substantially interfere with 

purge flow.

(c) Evaporative System Pressure Test Equipment ITEMS 1-4 NOT APPLICABLE

(1) General Requirements.

(i) Pressure Gas. Nitrogen (N2), or equivalent non-toxic, non-greenhouse, inert gas, 

shall be used for pressurizing the evaporative system.

(ii) Automatic Operation. The process for filling the evaporative system, monitoring 

compliance, recording data, and making a pass/fail decision shall be automatic. 

After the determination that the evaporative system has been filled to the specific 

pressure level, and upon initiation of the test, the pressure level in the 

evaporative system shall be recorded at a frequency of no less than 1 Hertz until 

the conclusion of the test.

(iii) Test Abort. The system shall be equipped with an abort system that positively 

shuts off and relieves pressure. The abort system shall be capable of being 

activated quickly and conveniently by the inspector should the need arise.

(2) Adapters and Clamps.

(i) Canister Hose Adapters. The system shall have sufficient adapters to connect in 

a leak-tight manner with the variety of evaporative systems and hose 

deterioration conditions in the vehicle fleet.

(ii) Fuel Inlet Adapters. Fuel inlet adapters that fit on the vehicles fuel inlet in a 

manner similar to the fuel cap and designed to admit a pressurized source of gas 

into the fuel tank shall be used for the fuel inlet pressure test specified in 

85.222(d). Inlet specific adapters shall be available for at least 95 percent of the 

fuel inlets that are used on U.S. light duty vehicles and light duty trucks for the 

model years Specified in Part F of this Regulation. Varying internal volumes of 

the adapter assemblies shall not affect the accuracy of the test results. Adapters 

shall be made available within two years of the introduction of new model year 

vehicles.

(iii) Hose Clamp. The hose clamp used for the fuel inlet pressure test shall be 

designed to apply only enough pressure to close the hose without damaging it. 

The nose of the clamp shall be smooth-surfaced or otherwise designed to avoid 

abrasion of the vehicle hose.

(3) Pressure Gauge. The device for measuring pressure in the vehicle's evaporative system 

shall have a minimum range of 0 to 50 inches of water and an accuracy of +-0.3 inches of 

water (2 % of 15) or better.
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(4) Flow Meter. A flow meter with a range of at least 0 to 10 liters per minute and +-5% 

accuracy shall be used for the measurement of flow.

(5) Fuel Cap Tester. The tester shall provide a visual or digital signal that the required air 

supply pressure is within the acceptable range and the flow comparison test is ready to 

be conducted. The tester shall incorporate an upstream maintainable filter. If the tester is 

battery powered, it must be equipped with an automatic shutoff and a low-battery 

indicator. A NIST traceable reference passing fuel cap of nominal 52-56 cubic 

centimeters per minute, and a NIST traceable reference failing fuel cap of nominal 64-68 

cubic centimeters per minute shall be supplied with the tester for daily test verification. 

Leak rate measurements shall be accurate to ±3 cubic centimeters per minute.

(6) Flow Standard. The flow standard shall be a square edged circular orifice with a NIST 

traceable flow rate that in combination with the comparison circuitry will produce a 

pass/fail threshold of 60 cubic centimeters at 30 inches of water column. Transducers 

used in the comparison circuitry shall have accuracy traceable to NIST. The supply 

pressure may be obtained using room air and any convenient low-pressure source. The 

tester shall control the supply pressure and prevent over pressurization.

Quality Control Requirements and Acceptance Testing Procedures

(a) General Requirements

(1) Minimums. The frequency and standards for quality control specified here are minimum 

requirements, unless modified as specified in Section 85.2234(2). Greater frequency or 

tighter standards may be used as determined by the Division.

(2) Statistical Process Control. Reducing the frequency of the quality control checks, 

modifying the procedure or specifications, or eliminating the quality control checks 

altogether may be allowed if the Division determines, for the purpose of properly 

conducting an approved short test, that sufficient Statistical Process Control (SPC) data 

exist to make a determination, that the SPC data support such action, and that taking 

such action will not significantly reduce the quality of the emission measurements. Should 

emission measurement performance or quality deteriorate as a result of allowing such 

actions, the approval shall be suspended, and the frequencies, procedures, 

specifications, or checks specified here or otherwise approved shall be reinstated, 

pending further determination by the Division.

(3) Modifications. The Division may modify the frequency and standards contained in this 

section if found to be impractical.

(b) Dynamometer

(1) Coast Down Check.

(i) The calibration of each dynamometer shall be checked on a weekly basis by a 

dynamometer coast-down equivalent that in Section 86.118-78 (for reference see 

EOD Test Procedures TP-302A and TP-202) between the speeds of 55 to 45 

mph, and between 22 to 18 mph. All rotating dynamometer components shall be 

included in the coast-down check for the inertia weight selected.
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(ii) The base dynamometer and the base plus each prime inertia weight flywheel, if 

any, shall be checked with at least two horsepower settings within the normal 

range of the inertia weight. For dynamometers that use electrical inertia 

simulation and have a base inertia outside of the range of 3000 pounds to 4500 

pounds, the coast-down check shall be conducted with at least two horsepower 

settings at the base inertia, and two settings at either 2500 pounds or 4500 

pounds, whichever is furthest from the base inertia weight. For both mechanical 

flywheel dynamometers and electrical inertia simulation dynamometers, the 

horsepower settings selected shall correspond to a vehicle/engine category that 

matches the inertia weight selected for the coast-down test. Where the base 

inertia, or the base inertia plus the smallest flywheel results in a coast-down 

inertia of less than 2250 pounds, only one horsepower setting is required for the 

check.

(iii) The coast-down procedure shall be of a self-motoring method. If the difference 

between the measured coast-down tune and the theoretical coast-down time is 

greater than ±1 second on the 55 to 45 mph coast-down as calculated by Section

85.2234(b)(l)(iii)(A) or (B), official testing shall automatically be prevented, and 

corrective action shall be taken to bring the dynamometer into calibration. Official 

testing shall also automatically be prevented, and corrective action shall be taken 

to bring the dynamometer into calibration, if the difference between the measured 

coast-down time and the theoretical coast-down time for 22 to 18 mph is outside 

of the time window calculated by Section 85.2234(b)(l)(iii)(C) or (D). For tests 

using inertia weights of 8500 lbs. and above, if the difference between the 

measured coast-down time and the theoretical coast-down time is outside of the 

time window calculated by Section 85.2234(b)(l)(iii)(O) or (D) for the 22 mph to 

the 18 mph coast-down when substituting 0.27 HP for the allowable force-error 

(equivalent to 5.0 pounds-force at 20 mph), official testing shall automatically be 

prevented, and corrective action shall be taken to bring the dynamometer into 

calibration.

(A) The off-dynamometer target coast-down time at 50 mph (DBT@50 mph.g) 

for dynamometers with 8.265-inch rolls shall be calculated as follows.

Transient Mode Test Quality Control Requirements and Acceptance Testing Procedures

(B) The off-dynamometer target coast-down time at 50 mph (DBT@50 mph-2o) 

for dynamometers with 20.0-inch rolls shall be calculated as follows.

Transient Mode Test Quality Control Requirements and Acceptance Testing Procedures
Regulation Number 11

Adopted: November 21, 2013 Page 144

(C) The maximum and minimum time limits for the off-dynamometer coastdown window at 20 mph (DTMax@20 mph-8, DTMin@20 mph-8) for 

dynamometers with 8.265-inch rolls shall be calculated by the following 

equations. The TRLHP and GTRL used in these calculations shall be 

determined from the same vehicle/engine category used to determine 

the 50 mph off-dynamometer target coast-down time. If the calculated 

maximum value (DTMax@20 mph-8) exceeds twice the target value 

calculated for a specific vehicle/engine category (DT Ave@20 mph-8),or if 

the maximum value is a negative number, a value equal to twice the

target value shall be substituted for the maximum time limit.

Transient Mode Test Quality Control Requirements and Acceptance Testing Procedures

(D) The maximum and minimum time limits for the off-dynamometer coastdown window at 20 mph (DTMax@20mph-20, DTMin@20 mph-20) for 

dynamometers with 20.0-inch rolls shall be calculated by the following 

equations. The TRLHP and GTRL used in these calculations shall be 
Regulation Number 11

Adopted: November 21, 2013 Page 145

determined from the same vehicle/engine category used to determine 

the 50 mph off-dynamometer target coast-down time.

Transient Mode Test Quality Control Requirements and Acceptance Testing Procedures

(E) Where:

DET@ 50 mph-dd = Off-dynamometer target coast-down time (seconds) at 

50 mph for a dynamometer with a roll diameter corresponding to the 

designator “dd”

DTMax@20 mph-dd = Upper off-dynamometer target coast-down time limit 

(seconds) at 20 mph for a dynamometer with a roll diameter 

corresponding to the designator “dd”

DTAve @20 mph-dd = Off-dynamometer target coast-down time (seconds) at 

20 mph for a dynamometer with a roll diameter corresponding to the 

designator “dd”

DTMin @ 20 mph-dd = Lower off-dynamometer target coast-down time limit 

(seconds) at 20 mph for a dynamometer with a roll diameter 

corresponding to the designator “dd”

TRLHP@ 50 mph = Track Road Load Horsepower at 50 mph for a specific 

vehicle engine category selected for the coast down check.

TRLHP@ 20 mph = Track Road Load Horsepower at 20 mph for the 

corresponding specific vehicle engine category selected for the 50 mph 

coast down check.
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GTRL@ 50 mph-dd = Generic Tire/Roll Horsepower loss at 50 mph for a 

dynamometer with “dd” roll size, and corresponding to the specific 

vehicle engine category selected for the 50 mph coast down check.

GTRL@ 20 mph-dd = Generic Tire/Roll Horsepower loss at 20 mph for a 

dynamometer with “dd” roll size, and corresponding to the specific 

vehicle engine category selected for the 50 mph coast down check.

ETW = Equivalent Test Weight (i.e., inertia weight) in pounds 

corresponding to the specific vehicle engine category selected for the 50 

mph coast down check.

Vxx2 = Velocity in feet per second corresponding to the mph value “xx”

0.17 HP = Horsepower representation of an allowable force-error of 3.3 

pounds-force at 20 mph. This allowable force-error is approximately 

equivalent to a ± 2-second tolerance in the off-dynamometer target 

coast-down time at 50 mph for a dynamometer with 8.625” rolls when 

using a TRLHP computed from the EPA on-dynamometer target coastdown time. This force-error is approximately equivalent 1:0 a ± 1.25-

second tolerance in the off-dynamometer target coast-down time at 50 

mph for a dynamometer with 20.0' rolls.

(iv) The clock used to check the coast-down time shall be accurate to 0.1 percent of 

reading between 10 and 1000 seconds with a resolution of 0.01 seconds.

(v) The results of each dynamometer coast-down check performed shall be 

automatically computed and recorded on electronic media with a date and time 

stamp.

(2) Roll Speed. Roll speed and roll counts shall be checked each operating day by an 

independent means (e.g., photo tachometer). Deviations of greater than ±0.2 mph or a 

comparable tolerance in roll counts shall require corrective action. Alternatively, a 

redundant roll speed transducer independent of the primary transducer may be used in 

lieu of the daily comparison. Accuracy of redundant systems shall be checked monthly.

(3) Warm-Up. Dynamometers shall be in a warmed up condition for use in official testing. 

Warm-up is defined as sufficient operation that allows the dynamometer to meet the 

coast down time (within 3 seconds) identified for the specific dynamometer during 

calibration. The reference coast-down time shall be the value for 55 to 45 mph with the 

lightest inertia weight and lowest horsepower for that weight used during weekly 

calibrations. Alternatively, the reference coast-down time shall be the value for 22 to 18 

mph with the lightest inertia weight and lowest horsepower for that weight used during 

weekly calibration, with a time standard of +20%. Comparing the measured parasitic 

losses at least 25 mph to reference values established during calibration may check 

warm-up.

(4) Acceptance Testing. Upon initial installation and prior to beginning official testing, the 

performance of each dynamometer and dynamometer design shall be verified for 

compliance with the requirements in Section 85.2226(a). Specific acceptance verification 

requirements are described in Section 85.2234(b)(4)(i) through Section 85.2234(b)(4)(v).
Regulation Number 11

Adopted: November 21, 2013 Page 147

(i) Coast Down/Vehicle Loading Check Following Installation. The coast down 

performance of each dynamometer shall be checked to verify the ability of the 

dynamometer and dynamometer load setting system to meet dynamometer 

target coast down times prior to beginning official testing. The performance shall 

be checked by the procedure defined in Section 85.2234(b)(4)(i)(A) through 

Section 85.2234(b)(4)(i)(J), or by a comparable procedure approved by the 

Division.

(A) The dynamometer shall be warmed-up by the dynamometer 

manufacturer's procedure.

(B) At least three vehicle/engine categories shall be selected from the LookUp table for vehicle loading. The vehicle/engine categories should cover 

the range of expected test vehicles.

(C) The dynamometer shall be set for the first vehicle/engine category 

selected based on the variables used to uniquely index the vehicle 

engine category (e.g., model year, manufacturer, model, number of 

cylinders, engine size, and transmission type).

(D) The dynamometer shall be coasted down from 65 mph to 5 mph with the 

settings pre-selected in Section 85.2234(b)(4)(i)(C).

(E) The 55 mph to 45 mph, and the 22 mph to 18 mph coast down tunes 

shall be recorded for the data collected in Section 85.2234(b)(4)(i)(D).

(F) The dynamometer shall be coasted down from 65 mph to 5 mph after 

having been adjusted for each of the other two vehicle engine 

categories, and the 55 mph to 45 mph, and the 22 mph to 1 mph coast 

down times shall be recorded for each coast-down.

(G) The coast-downs specified in Section 85.2234(b)(4)(i)(C) through 

Section 85.2234 (b)(4)(i)(F) shall be replicated for a total of three coastdown tests for each vehicle inertia category. The replications of the 

coast-downs for each vehicle engine category shall be run in random 

sequence.

(H) The off-dynamometer target coast-down tune at 50 mph (DET@ 50 mph-dd) 

for each vehicle/engine category shall be calculated as specified in 

Section 85.2234(b)(l)(iii)(A) or (B) for the applicable dynamometer roll 

size.

(I) The upper and lower off-dynamometer coast-down time limits at 20 mph 

(DTMax @ 20 mph-dd, DTMin @ 20 mph-dd) for each vehicle/engine category shall 

be calculated as specified in Section 85.2234(b)(l)(iii)(C) or (D) for the 

applicable dynamometer roll size.

(J) The dynamometer vehicle loading is considered acceptable if each 

measured 55 mph to 45 mph coast-down tune for each vehicle/engine 

category tested is within ±1 second of the off-dynamometer target coastdown time determined in (b)(4)(i)(H) above, and if each measured 22 

mph to 18 mph coast-down tune for each vehicle/engine category tested 
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is within the off-dynamometer target coast-down time limits determined in 

(b)(4)(i)(I) above.

(ii) Vehicle Loading Check of Dynamometer Design. For each dynamometer design 

used, the Division shall obtain and maintain a report verifying the ability of the 

dynamometer design to properly load vehicles as specified in Section

85.2226(a). The dynamometer manufacturer may prepare the report. The report 

shall identify how each requirement in Section 85.2226(a) is performed by the 

specific dynamometer design used. In addition, where specific performance 

levels or characterizations are specified {e.g., Section 85.2226 (a)(2)(viii), 

Section 85.2226(2)(x), Section 85.2226(4)(ii) and Section 85.2226(a)(5)}, test 

data with supporting analysis verifying compliance shall be included. At a 

minimum, the test data shall include a comparison and analysis of the expected 

coast-down times versus the actual vehicle on-dynamometer coast-down times 

for at least three vehicles spanning the range of drive axle weights and 

horsepower. Actual track coast-down data and curves shall be available for the 

makes and models of vehicles selected from which the expected coast-down 

times shall be derived. The analysis shall also graphically compare the track 

horsepower curves to curves generated from the on-dynamometer coast-down 

testing. Reasons for variations in time, equivalent to one horsepower, between 

the expected coast-down times and the actual vehicle on-dynamometer coastdown times, or variations between the curves of more than one horsepower shall 

be explained in the report.

(iii) Alternative Coast Down/Vehicle Loading Check. This procedure may be used in 

lieu of the procedures in Section 85.2234(b)(4)(i). The coast down performance 

of each dynamometer shall be checked with at least two categories of vehicles to 

verify the ability of the dynamometer and dynamometer load setting system to 

meet dynamometer target coast down times. The coast down performance of 

each dynamometer design used shall be checked with at least 6 categories of 

vehicles to determine the ability of the dynamometer design to properly load the 

vehicle over the required speed range as defined in Section 85.2226(a)(2). The 

performance of the design shall be checked by the procedure defined Section

85.2234(b)(4)(ii)(A) through Section 85.2234(b)(4)(ii)(L), or by a comparable 

procedure proposed by the Division.

(A) The dynamometer shall be warmed-up by the dynamometer 

manufacturer's procedure, and the tires and drive train on the test car 

shall be warmed-up by operating the vehicle at 50 mph for 20 minutes. 

The tire pressure in the test vehicles shall be at 45 psi.

(B) The dynamometer indicated power (IHP) and inertia weight for the 

vehicle should be selected for the test vehicle.

(C) The test vehicle shall be coasted down from 65 mph to 5 mph on the 

dynamometer with the settings pre-selected in 

Section85.2234(b)(4)(i)(B).

(D) The 55 mph to 45 mph, and the 22 mph to 18 mph coast down times 

shall be recorded for the data collected in Section 85.2234(b)(4)(i)(C).
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(E) The test vehicle shall again be coasted down from 65 mph to 5 mph on 

the dynamometer with the dynamometer power absorber reset to a load 

of zero.

(F) A speed versus horsepower equation of the form in Section

85.2226(a)(2)(iii) shall be determined for the data collected in Section

85.2234(b)(4)(i)(E).

(G) The test vehicle shall be removed from the dynamometer, and the 

dynamometer shall be coasted down from 65 mph to 5 mph with the 

dynamometer power absorber set to a load of zero.

(H) A speed versus horsepower equation of the form in Section

85.2226(a)(2)(ix) for parasitic losses (PLHP) shall be determined for the 

data collected in Section 85.2234(b)(4)(i)(G).

(I) The tire/roll interface losses shall be determined by subtracting the 

horsepower curve determined in Section 85.2234(b)(4)(i)(H) from the 

horsepower curve determined in Section 85.2234(b)(4)(i)(F). The tire 

loss curve (GTRL) shall be in the form specified in Section

85.2226(a)(2)(xiii).

(J) Repeat the steps in Section 85.2234(b)(4)(i)(B) through Section

85.2234(b)(4)(i)(I) to obtain a total of three sets of data for each test 

vehicle. The dynamometer and vehicle may be warmed-up as needed to 

meet the requirements in Section 85.2234(b)(4)(i)(A).

(K) For each test vehicle, compute the average 55 mph to 45 mph coast 

down tune, the average 22 mph to 18 mph coast down time, and the 

average tire/roll interface loss curve as measured in Section

85.2234(b)(4)(i)(B) through Section 85.2234(b)(4)(i)(J).

(L) The dynamometer vehicle loading is considered acceptable if, for each 

test vehicle, the average values determined in Section

85.2234(b)(4)(i)(K) are within ±1 second of the 55 mph to 45 mph for the 

target time specified in Section 85.2226(a)(2)(ii), are within ±7 percent of 

the 22 mph to 18 mph that is calculated from Section 85.2226(a)(2)(iii) 

and Section 85.2226(a)(2)(iv), and within ±15 percent of a generic tire/roll 

loss curve for the category of vehicle.

(iv) Load Measuring Device Check. The load measuring device on each 

dynamometer shall be checked by a dead-weight method (or equivalent) at least 

six points across the range of loads used for vehicle testing. Physical checking 

weights shall be traceable to NIST standards to within ±0.5 percent. Equivalent 

methods shall document the method used to verify equivalent accuracy. The 

accuracy of the interpreted value used for calculation or control shall be within ±1 

percent of full scale.

(v) Vehicle Inertia Loading. The actual inertia applied to the vehicle by each inertia 

weight, in combination with the base inertia, shall be verified for each 

dynamometer to insure compliance with the requirements in Section

85.2226(a)(4)(i) or Section 85.2226(a)(4)(ii) as applicable.
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Adopted: November 21, 2013 Page 150

(vi) Parasitic loss check between 8 and 12 mph. The coast down tune of each 

dynamometer between 8 and 12 mph shall be verified for compliance with the 

requirements of Section 85.2226(a)(2)(x).

(vii) Speed and Distance Check. The performance of the speed and distance 

measuring system of each dynamometer shall be verified for compliance with the 

requirements of Section 85.2226(a)(5)(i). The ability to resolve acceleration as 

specified in Section 85.2226(a)(5)(i) need only be generically verified for the 

design used. If more than one design is used, each design shall be verified.

(viii) Warm-up System Check. The dynamometer warm-up system shall be checked 

for compliance with the requirements in Section 85.2234(b)(3) by conducting a 

coast down check immediately following completion of the warm-up specified by 

the dynamometer manufacturer or the system. The design of the warm-up 

system should be checked across the range of temperatures experience in-use, 

and particularly at the lower speeds.

(5) Coast-down Times. Following acceptance, 55 to 45 mph, and 22 to 18 mph coast-down 

times shall be determined for quality control purposes with the vehicle off the 

dynamometer for each inertia weight and for at least 2 horsepower settings within the 

normal range of the inertia weight as required in Section 85.2234(b)(l)(ii). These quality 

control values shall be determined when the dynamometer has been set to meet either 

the coast-down target times with the vehicle on the dynamometer (i.e., 55 to 45 mph and 

22 to 18 mph), or the equation coefficients. The Division, may however, select different 

vehicle/engine categories to check coast-down times as in Section 85.2234(b)(4)(i) for 

audit purposes.

(c) Constant Volume Sampler

(1) Flow Calibration. The flow of the CVS shall be calibrated at six flow rates upon initial 

installation, 6 months following installation, and every 12 months thereafter. The flow 

rates shall include the nominal rated flow-rate and a rate below the rated flow-rate for 

both critical flow Venturis and subsonic Venturis, and a flow-rate above the rated flow for 

sub-sonic Venturis. The flow calibration points shall cover the range of variation in flow 

that typically occurs when testing. A complete calibration shall be performed following 

repairs to the CVS that could affect flow.

(2) System Check. CVS flow calibration at the nominal CVS design flow shall be checked 

once per operating day using a procedure that identifies deviations in flow from the true 

value. A procedure equivalent to that in Section 86.119(c) shall be used. Deviations 

greater than ±4% shall result in automatic lockout of official testing until corrected.

(3) Cleaning Flow Passages. The sample probe shall be checked at least once per month 

and cleaned if necessary to maintain proper sample flow. CVS venturi passages shall be 

checked once per year and cleaned if necessary.

(4) Probe Flow. The indicator identifying the presence of proper probe flow for the system 

design (e.g., proportional flow for CFV systems, minimum flow for time correlation of 

different analyzers) shall be checked on a daily basis. Lack of proper flow shall require 

corrective action.
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(5) Leak Check. The vacuum portion of the sample system shall be checked for leaks on a 

daily basis and each time the system integrity is violated (e.g., changing a filter).

(6) Bag Sample Check. On a quarterly basis, vehicle exhaust shall be collected in sample 

bags with simultaneous integrated measurement of the sample. At least one bag each for 

Phase 1 and for Phase 2 of the transient test cycle shall be conducted. Differences 

between the two measurement systems greater than 10% shall result in system lockout 

until corrective action is taken. For the purposes of acceptance testing, the differences 

shall be no greater than 5 %.

(7) Response Time Check. The response time of each analyzer shall be checked upon initial 

installation, during each check for compliance with Section 85.2234(c)(6), after each 

repair or modification to the flow system that would reasonably be expected to affect the 

response time, and as determined by the Division. The check shall include the complete 

sample system from the sample probe to the analyzer. Statistical process control shall be 

used to monitor compliance and establish fit for use limits based on the requirements in 

Section 85.2226(c). At a minimum, response time measurements that deviate 

significantly from the average response time for all CVS systems designed to the same 

specification in the program shall require corrective action before testing may resume.

(8) Mixing Tee Acceptance Test.

(i) The design of the mixing tee shall be evaluated by running the transient driving 

cycle on at least two vehicles, representing the high and low ends of engine 

displacement and inertia. Changes in the static tailpipe pressure with and without 

CVS, measured on a second-by-second basis within 3 inches of the end of the 

tailpipe, shall not exceed ±1.0 inch of water.

(ii) The ability of the mixing tee design to capture all of the exhaust as a vehicle 

moves laterally from one extreme position on the dynamometer to the other 

extreme shall be evaluated with back-to-back testing of three vehicles, 

representing the high and low ends of engine displacement and inertia. The 

back-to-back testing shall be done with the mixing tee at the tailpipe and with an 

airtight connection to the tailpipe (i.e., the mixing tee will be effectively moved 

downstream, as in typical FTP testing). The difference in carbon-balance fuel 

economy between the mixing tee located at the vehicle and the positive 

connection shall be no greater than 6%.

(iii) The design of the dual exhaust system shall be evaluated with back-to-back 

testing of three vehicles, representing the high and low ends of engine 

displacement and inertia, with an airtight connection to the tailpipe (i.e., the 

mixing tee will be effectively moved downstream, as in typical FTP testing, for 

these qualification tests). The difference in carbon-balance fuel economy 

between the two methods shall be no greater than 5%.

(d) Analysis System

(1) Calibration Curve Generation.

(i) Upon initial installation, calibration curves shall be generated for each analyzer. If 

an analyzer has more than one measurement transducer, each transducer shall 
Regulation Number 11

Adopted: November 21, 2013 Page 152

be considered as a separate analyzer in the analysis system for the purposes of 

curve generation and analysis system checks.

(ii) The calibration curve shall consider the entire range of the analyzer as one 

curve.

(iii) A ten (10)-point equal distribution calibration curve is required of each analyzer. 

The calibration zero gas shall be used to set the analyzer to zero.

(iv) Gas dividers may be used to obtain the intermediate points for the general range 

classifications specified.

(v) The calibration curves generated shall be a polynomial of the best fit and no 

greater than 4th order, and shall fit the data within 2.0% at each calibration point 

as specified in Section 86.121-90, Section 86.122-78, Section 86.123-78, and 

Section 86.124-78.

(vi) Each curve shall be verified for each analyzer with a confirming calibration 

standard between 40-80% of full scale that is not used for curve generation. 

Each confirming standard shall be measured by the curve within 2.5%.

(2) Spanning Frequency. The zero and up-scale span points shall be checked at 2 hour 

intervals following the daily mid-scale curve check specified in Section 85.2234(d)(4) and 

adjusted if necessary. If the up-scale span point drifts by more than 2.0% from the 

previous check or, for the first check performed after the daily calibration check described 

in Section 85.2234(d)(4), from the daily check official testing shall be prevented and 

corrective action shall be taken to bring the system into compliance. If the zero point drifts 

by more than 2 ppm HC, 1 ppm NOx, 10 ppm CO, or 40 ppm CO2, official testing shall 

be prevented and corrective action shall be taken to bring the system into compliance. 

Or, the unit may be zeroed prior to each test.

(3) Limit Check. The tolerance on the adjustment of the up-scale span point shall be 0.4% of 

point. A software algorithm to perform the zero and span adjustment and subsequent 

calibration curve adjustment shall be used. Cumulative software up-scale zero and span 

adjustments greater than ±10% from the latest calibration curve shall cause official 

testing to be prevented and corrective action shall be taken to bring the system into 

compliance.

(4) Daily Calibration Checks. The curve for each analyzer shall be checked and adjusted to 

correctly read zero using a working zero gas, and an up-scale span gas within the 

tolerance in Section 85.2234(d)(3), and then by reading a mid-scale span gas within 

2.5% of point, on each operating day prior to vehicle testing. If the analyzer does not read 

the mid-scale span point within 2.5% of point, the analyzer shall automatically be 

prevented from official testing. The up-scale span gas concentration for each analyzer 

shall correspond to approximately 80% of full scale, and the mid-point concentration shall 

correspond to approximately 15% of full scale.

(5) Weekly NOx Converter Checks. The converter efficiency of the NO2 to NO converter 

shall be checked on a weekly basis or as determined by the Division. The check shall be 

equivalent to Section 86.123-78 (for reference see EOD Form 305-01) except that the 

concentration of the NO gas shall be in the range of 100-300 ppm. Alternative methods 

may be used if approved by the Division.
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(6) Weekly NO/NOx Flow Balance. The flow balance between the NO and NOx test modes 

shall be checked weekly or as determined by the Division. The check may be combined 

with the NOx converter check as illustrated in EPA NVFEL Form 305-01.

(7) Monthly Calibration Checks. The basic calibration curve shall be verified monthly by the 

same procedure used to generate the curve in Section 85.2234(d)(l), and to the same 

tolerances.

(8) FID Check.

(i) Upon initial operation, and after maintenance to the detector, each FID shall be 

checked, and adjusted if necessary, for proper peaking and characterization 

using the procedures described in SAE Paper Number 70141 or by analyzer 

manufacturer recommended procedures.

(ii) The response of each FID to a methane concentration of approximately 50 ppm 

CH4 shall be checked once per month. If the response is outside of the range of 

1.00 to 1.30, corrective action shall be taken to bring the FID response within this 

range. The response shall be computed by the equation in Section

85.2234(d)(9)(iii).

(iii) Ratio of Methane Response =

(9) Integrator Checks. Upon initial operation, emissions from a vehicle with transient cycle 

test values between 60% and 400% of the 1984 LDGV standard shall be simultaneously 

sampled by the normal integration method and by the bag method in each system. The 

data from each method shall be put into a historical database for determining normal and 

deviant performance for each test system. Specific deviations between the integrator and 

bag readings exceeding ±10% shall require corrective action.

(10) Cross-Checks. NOT APPLICABLE On a quarterly basis, and whenever gas bottles are 

changed, each analyzer in a given facility shall analyze a sample of a test gas. The test 

gas shall be independent of the gas used for the daily calibration check in Section

85.2234(d)(4), in independent bottles. The same test gas, or gas mixture shall be used 

for all analyzers. The concentration of the gas shall be one of three values corresponding 

to approximately 0.5 to 3 times the cut point (in gpm) for 1984 and later model year 

vehicles for the constituent. One of the three values shall be at the lower end of the 

range, another shall be at the higher end of the range, and the other shall be near the 

middle of the range. The values selected shall be rotated in a random manner for each 

crosscheck. A gas divider may determine the value of the checking sample. The 

deviation in analysis from the concentration of the checking sample for each analyzer 

shall be recorded and compared to the historical mean and standard deviation for the 

analyzers at the network and at all facilities. Any reading exceeding 3 sigma shall cause 

the analyzer to be placed out of service.

(11) Interference, Laboratory Testing. The design of each CO, CO2, and NOx analyzer shall 

be checked for water vapor interference prior to initial service. The interference limits in 

this paragraph shall apply to analyzers used with a CVS of 700 SCFM or greater. For 

analyzers used with lower flow rate CVS units, the allowable interference response shall 

be proportionately adjusted downward.
Regulation Number 11

Adopted: November 21, 2013 Page 154

(i) CO Analyzer. A gas mixture of 4% CO2 in N2 bubbled through water with a 

saturated-mixture temperature of 40°C shall produce a response on the CO 

analyzer of no greater than 15 ppm at 40°C. Also, a gas mixture of 4 percent 

CO2 in N2 shall produce a response on the CO analyzer of no greater than 10 

ppm at 40°C.

(ii) CO2 Analyzer. A calibration zero gas bubbled through water with a saturatedmixture temperature of 40°C shall produce a response on the CO2 analyzer of no 

greater than 60 ppm.

(iii) NOx Analyzer. A calibration zero gas bubbled through water with a saturatedmixture temperature of 40°C shall produce a response on the NOx analyzer of no 

greater than 1 ppm. Also, a gas mixture of 4 percent CO2 in either N2 or air shall 

produce a response on the NOx analyzer of no greater than 1.0 ppm at 40°C.

(12) Interference — Field Testing. Each CO, CO2, and NOx analyzers shall be checked for 

water vapor interference prior to initial service, and on a yearly basis thereafter. The infield check prior to initial service and the yearly checks shall be performed on a high 

ambient temperature summer day (or simulated conditions). For analyzers used with 

lower flow rate CVS units, the allowable interference response shall be proportionately 

adjusted downward. The allowable interference level shall be adjusted to coincide with 

the saturated-mixture temperature used. For the CO analyzer, a rejection ratio of 9,000 to 

1 shall be used for this calculation. A ratio of 2000 to 1 shall be used for CO2 analyzers. 

A ratio of 90,000 to 1 shall be used for NOx analyzers.

(e) Gases

Calibration, Working and Span Gases Shall Conform to Regulation Number 11, Appendix B

(f) Quality Control Data Files for Individual Test Systems. In general, quality files control for 

individual test systems shall include parameters that will allow the cause for abnormal 

performance of a test system to be pinpointed to individual systems or components. Test system 

control charts shall include at a minimum:

(i) Overall number of voided tests

(ii) Number of voided tests by type

(iii) Level of difference between theoretical and measured coast-down times

(iv) Level of difference between theoretical and measured CVS flow

(v) Level of up-scale span change from last up-scale span (not required if software 

corrections are tracked)

(vi) Level of mathematical or software correction to the calibration curve as a result of an upscale span change (if used)

(vii) Level of difference between the analyzer response to the daily crosscheck, and the test 

gas concentration

(viii) Level of difference between the integrated measurements 2nd the bag measurements
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(ix) The system response time

(x) Level of the FID CH4 response ratio

(xi) Level of the ambient background concentrations

(xii) The average, median, 10th percentile and 90th percentile of the composite emissions (HC, 

CO, CO2, and NOx) measured over the defined periodic basis

(xiii) Average number of passing vehicles, and average number of failing vehicles over the 

defined periodic basis

(xiv) Level of difference between theoretical or measured values for other parameters 

measured during quality assurance procedures

Test Report

(a) Acceptance Test Reporting for System Evaluation

(1) Test Types and Standards. The test report shall indicate the types of tests performed on 

the vehicle and the test standards for each. Test standards shall be displayed to the 

appropriate number of significant digits as in Section 85.2205(a). The reported standards 

shall be the composite test standards.

(2) Test Scores. The test report shall show the scores for each test performed. Test scores 

shall be displayed to the same number of significant digits as the standards.

(3) Transient Mode Test Scores. The reported score for the Transient Mode shall be in units 

of grams per mile and shall be selected based upon the following:

(i) If the emissions of any exhaust component of the composite Transient Test are 

below the applicable standard in Pan F of this regulation, then the vehicle shall 

pass for that constituent and the composite score shall be reported.

(ii) If the emissions of any exhaust component on the composite Transient Test 

exceed the applicable standard in Part F of this regulation, but are below the 

Phase 2 standard, then the vehicle shall pass for that component and the Phase 

2 score shall be reported.

Terms

(a) Definitions

(1) Track coast-down target time: The new vehicle certification track coast-down time 

between 55 and 45 mph.

(2) Road load horsepower: The power required for a vehicle to maintain a given constant 

speed taking into account power losses due to such things as wind resistance, tire 

losses, bearing friction, etc.

(3) Tier 1: New gaseous and particulate tailpipe emission standards for use in certifying new 

light duty vehicles and light duty trucks phased in beginning with the 1994 model year.
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(1) CVS hose: The hose, connecting to the tailpipe of the vehicle that carries exhaust and 

dilution air to the stationary portion of the CVS system.

(1) The Division: Colorado Department of Public Health and Environment, Air Pollution 

Control Division.

(5)(b) Abbreviations

(1) CFV: Critical flow venturi

(2) CH4: Methane

(3) CO2: Carbon dioxide

(4) CO: Carbon monoxide

(5) CRM: Certified reference material

(6) CVS: constant volume sampler

(7) FID: Flame ionization detector

(8) gpm: Grams per mile

(9) GVWR: Gross Vehicle Weight Rating

(10) HC: Hydrocarbons

(11) HDGT: Heavy-Duty Gasoline-powered Truck greater than 8500 pounds GVWR

(12) hp: horsepower

(13) Hz: cycles per second (Hertz)

(14) I/M: Inspection and Maintenance

(15) IW: Inertia weight

(16) LDGT1: Light-Duty Gasoline-powered Truck from 0 to 6000 pounds GVWR

(17) LDGT2: Light-Duty Gasoline-powered Truck from 6001 to 8500 pounds GVWR

(18) LDGV: Light-Duty Gasoline-powered Vehicle

(19) LVW Loaded Vehicle Weight

(20) mph: Miles per hour

(21) NDIR: non-dispersive infrared

(22) NIST: National Institute for Standards and Technology
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(23) NO2: Nitrogen dioxide

(24) NO: Nitrogen oxide

(25) NOx: Oxides of nitrogen

(26) NVFEL: National Vehicle and Fuel Emissions Laboratory

(27) Obmph: Observed dynamometer speed in mph of the loading roller, if rolls are not 

coupled

(28) PLHP: Parasitic horsepower loss at the observed dynamometer speed in mph

(29) ppm: parts per million by volume

(30) ppmC: parts per million, carbon

(31) psi: Pounds per square inch

(32) RFP: Request for Proposal

(33) RLHP Road Load Horsepower

(34) rpm: revolutions per minute

(1) SCFM: standard cubic feet per minute

(1) SEO: square edged orifice

(37) SPC: Statistical process control

(38) SRM: Standard reference material

(39) SSV: Subsonic venturi

(40) TRLHP: Track road-load horsepower

ATTACHMENT IV Specifications for Colorado 97 Analyzer TO THE TECHNICAL 

SPECIFICATION APPENDIX A

COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT

SPECIFICATIONS FOR COLORADO 97 ANALYZER

INTRODUCTION

Colorado's current enhanced I/M program contains a two-speed idle (TSI) emissions testing component, 

the Colorado 94 Test Analyzer System that is based upon BAR 90 technology. The TSI program utilizes a 

decentralized, independent inspection only format encompassing the seven nineDenver Metro Area 

(DMA) Front Range counties. The DMA program is expanding to the North Front Range counties of Weld 
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and Larimer in 2010. This inspection only population of independent inspectors will conduct inspections 

utilizing a new Colorado 97 emissions analyzer. 

The demands for more accurate analytical information as well as a more automated inspection process 

with real-time data transfer has superseded the capabilities of BAR 90 (Colorado 94) technology. System 

enhancements are necessary to meet Colorado’s inspection needs. These enhancements and other 

technical details are described in this document.

1.0 GENERAL

It is expected that the Colorado 97 software will be Colorado 94 software upgraded to BAR 97 and SAE 

J1978 and J1979 compliance. 

1.1 Design Goals 

The specifications that have been developed are designed utilizing a personal computer system. 

The analyzer system must be capable of performing uniform and consistent emission tests for 

Colorado's Automotive Inspection and Readjustment (AIR) Program. Features of the analyzer 

include: vehicle emissions measurements of hydrocarbon (HC), carbon monoxide (CO), carbon 

dioxide (CO2)and oxygen(O2); engine RPM measurements, exhaust dilution determinations, 

pressure test system for EVAP; OBD II monitor readiness and diagnostic trouble code retrieval; 

data entry; data retrieval tables; a dedicated printer (for vehicle inspection certificates; data 

recording on hard drive or removable media ; modem for “on-line real time” data transmission; 

monitor information display to the inspector; bar code reader and printing capabilities; and fully 

menu driven, interactive simple microprocessor controlled operation. 

Additional, automatic features required include: gas calibrations, zero and span checks, pressure 

calibrations, gas auditing procedure; leak checks, HC hang-up checks, audit menus (i.e., data 

read system), test sequencing, and low-flow checks. The analyzer shall be designed and

constructed to provide reliable and accurate service in the automotive environment. The software 

used in the analyzer shall consist of a process control system as well as data look-up files. 

Security shall be provided to prevent unauthorized modifications to the software or test data and 

recording unauthorized entry (tampering) and locking out of the inspection process when 

detected. 

The emissions analyzer software shall be designed for maximum operational simplicity. 

It shall also be capable of providing emission-reading characteristics, independent of the 

inspection function, which can be used for vehicle diagnostic. 

1.2 Useful Life 

The useful life of the analyzer shall be a minimum of five years. 

1.3 Nameplate Data 

A nameplate including the following information shall be permanently affixed to the housing of the 

analyzer: 

Name and Address of Manufacturer 

Model Description 
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Serial Number 

Date of Assembly 

The manufacturer shall affix a stick-on type label to the analyzer that contains a toll-free 

telephone number for customer service. This number can also be included in a service software 

message. 

1.4 Manuals 

Each analyzer shall be delivered with the following manuals: 

A. Reference Operating Instructions 

B. Operation Instruction Manual 

C. Maintenance Instruction Manual (limited) 

D. Initial Start-up Instructions 

Colorado 97 Analyzer manufacturers may consolidate manuals. The manuals shall be 

constructed of durable materials and shall not deteriorate as a result of normal use over a fiveyear period. The analyzer housing shall provide convenient storage for each manual in a manner 

that will: 

E. Allow easy use. 

F. Prevent accidental loss or destruction. 

1.5 Certification Documentation 

The analyzer software shall be fully documented. Two copies of the documentation listed below 

shall be submitted to Colorado Department of Public Health and Environment as part of the 

certification application. 

A. Complete program listings. Program listings may be on disk. They are not 

required to be submitted with the application for certification. 

B. Functional specifications. 

C. Functional flowcharts of the software. 

D. Example inputs and outputs from all processes. 

E. Detailed interface information on system components including the identification 

of protocol and output specifications. 

F. All file layouts with file names, file types, file security, field names, field types, 

field sizes, and field editing criteria. 
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Documentation provided by the vendor to meet this requirement will be treated as proprietary 

information by Colorado Department of Public Health and Environment. 

Prior to certification of any Colorado 97 emissions analyzer for sale in Colorado, the manufacturer 

of such analyzer shall provide the Division with software source codes and all other technical 

information (including, but not limited to all working codes, schematics and drawings) necessary 

to operate, maintain, calibrate and repair such analyzer in the event that the manufacturer or its 

agent ceases providing adequate maintenance, calibration and repair services in Colorado. The 

manufacturer shall keep such information current, and will provide the Division with copies of any 

and all changes. So long as such maintenance, calibration and repair, services are available from 

the manufacturer or its agent, the Division shall protect such information as confidential 

commercial data if it is clearly marked as such. In the event that the manufacturer becomes 

insolvent or stops providing adequate maintenance, repair or calibration services in Colorado all 

such information shall be the property of the Division and may be released to a third party as 

necessary to repair, calibrate and maintain the analyzers. 

1.6 Warranty Coverage/Service Contract 

A written warranty coverage agreement, signed by an authorized representative of the equipment 

manufacturer and the vehicle inspection station owner, which provides a complete description of 

coverage for all systems and components and all manufacturer provided services listed in Section 

1.8, must accompany the sale or lease of each Colorado 97 emissions analyzer. 

An extended service contract shall be available upon the expiration of the manufacturers original 

warranty period. Original manufacturer’s warranty shall be a minimum of one year from the date 

of purchase. The “service contract” shall be offered in one-year increments. The “service 

contract” agreement shall include the inspection station owner's name, inspection station 

address, telephone number, inspection station identification number, analyzer serial number and 

detailed terms of the agreement. The agreement must extend for at least one year and if 

purchased, the expiration date must be entered to software file and monitored by the system 

clock. Approaching expiration messages must be displayed at daily system start-up beginning 

thirty days prior to expiration and messaging “30 days until expiration, 29 days etc.” Renewals 

shall be offered at the inspection station owner’s request and governed by “good business” 

practices between the parties involved. Service contract agreements must be available by the 

manufacturer for the mandated life of Colorado AIR Program. Cost disclosures and detailed 

descriptions of coverage’s must be available in printed form and distributed to all Colorado 97 

users. Cost disclosure shall also be made for “consumable” inventory items 1.8B. This 

information would most appropriately be presented with the original manufactures warranty. 

1.7 Tampering Resistance 

Controlled access design shall be the responsibility of the manufacturer and is subject to approval 

by Colorado Department of Public Health and Environment. Analyzer service personnel, 

inspectors or others shall be prohibited, to Colorado Department of Public Health and 

Environment satisfaction, from creating or changing any test results, programs or data files 

contained in the analyzer. Manufacturers shall utilize special BIOS partitions, or other appropriate 

software and hardware provisions, deemed necessary to protect the I/M files and programs. The 

protection features shall prevent access to the secured floppy disk drive and those portions of the 

hard disk containing I/M programs and test data or files. 

The emission analyzer and the sampling system shall be made tamper-resistant to the Colorado 

Department of Public Health and Environment satisfaction. At a minimum, the manufacturer shall 
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develop tamper-resistant features to prevent unauthorized access through the cabinet. 

Microswitches, keyed locks, or software algorithms requiring the use of a password which can be

changed by the Colorado Department of Public Health and Environment would all be acceptable 

provided the physical or logical design effectively prevents unauthorized access. 

Manufacturers may offer analyzers with additional disk drives that can run optional software 

application programs. 

If tampering occurs, a software lockout algorithm shall be activated which aborts any existing test 

sequence and prevents further inspections until an authorized AIR Program official clears the 

lockout. 

The lockout system shall be designed so that an AIR Program official from the audit menu can 

activate it. Only AIR Program Auditors may remove lockouts put in place from the audit menu. 

Manufacturers shall develop a system by which their service technicians shall be prevented from 

clearing “tamper” lockouts. 

Optional software packages shall not interfere with the normal operation of the I/M inspection and 

testing software, and shall not compromise the tamper-resistant features of the analyzer. 

Manufacturer field service representatives will not have access to DOS, unless assurances 

acceptable to Colorado Department of Public Health and Environment have been provided that 

insure, integrity of the system will not be jeopardized. 

1.8 Manufacturer Provided Services 

The manufacturer shall agree to provide the following services to the inspection station as part of 

the manufacturer’s original warranty and thereafter as a portion of the service contract 

agreement. The cost of a service agreement is to be listed on a year-by-year basis. Future 

charges cannot exceed the amount published. 

A. Delivery, installation, calibration, and verification of the proper operating condition 

of a Colorado 97 emissions analyzer. 

B. Quarterly (90 days) examination, calibration, and routine maintenance of the 

analyzer and sampling systems. Full systems support and repair, including 

loaner units. Upon initial sale or loan, provide “extra” printer medium (1 ea.) 

sample filter(s) (2), sample hose (1) and sample probes (1). Maintain the “extra” 

consumable inventory upon examination and provide a software history file for 

the replacement of consumables accessible to AIR Program officials. 

Consumables and the cost(s) thereof must be disclosed in the service 

agreement. 

C. Instruct all certified inspectors employed by the inspection station at the time of 

installation in the proper use, maintenance, and operation of the analyzer. The 

analyzer shall contain a feature that will allow an inspector to go through the 

complete inspection procedure without generating an official inspection record. 

This function will be used for evaluating inspector performance, by AIR Program 

officials, or by the manufacturer for demonstration purposes. The “training mode” 

shall not require the use of an inspector’s access code or allow access to 

secured areas of hardware or software. The display shall show a message 

throughout the inspection that this is not an official inspection. Vehicle inspection 
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reports shall indicate to the satisfaction of Colorado Department of Public Health 

and Environment that they are for training only. No official Certificate of 

Compliance will be generated during the training exercise. 

D. On-site service response by a qualified repair technician within two (2) business 

days, (48 hours) excluding Sundays and national holidays, of a request from the 

inspection station. The names, toll-free telephone numbers, and service facility 

addresses of all manufacturer representatives responsible for equipment service 

shall be provided to the inspection station. A service representative shall be 

available at all times during normal working hours. Sundays and national 

holidays are not included. All system repairs, component replacements, and/or 

analyzer adjustments, shall be accomplished on-site within 48 hours after a 

service request has been initiated. If the completion of this work is not possible 

within this time period, a Colorado 97 loaner unit shall be provided until the 

malfunctioning unit is properly repaired and returned to service. Service 

representatives shall have a software driven menu option that allows the transfer 

of inspection station, inspector information and other applicable data files from 

one analyzer to another without manual inputs and without transfer of previous 

test files. 

E. Updates of the “Functional” software will be limited to once per year at no cost. 

Updates of operational software, i.e., file based information will be on an “as required” 

basis. All forms of software updating will utilize modem technology for the updating 

process. File updates are at no cost and every effort will be made to minimize them. 

F. The analyzer software shall be designed so that AIR Program officials can insert 

a disk, prepared by the manufacturer, into the Program system host, and update 

the existing software version, via modem. A system of manual updating by 

program officials utilizing the auditor’s menu shall also be available. Look-up up 

tables and message screens shall be designed sufficiently separate from the 

main operations software so that it is not possible, to interfere in any way with the 

operations of the analyzer. 

Colorado Department of Public Health and Environment will require the manufacturer to 

render updates as necessary in the first year of the program to ensure the program 

meets all design criteria. Thereafter software updates will be limited to once per year at 

no cost. Since modem software updating will be utilized, there are no costs to the 

analyzer owner. A software version number, consisting of a four character alpha-numeric 

code made up of the last two digits of the year followed by a two character version 

number, shall be recorded in the analyzer and included on each vehicle test record. The 

analyzer manufacturer shall not modify any existing software version without obtaining 

written approval from Colorado Department of Public Health and Environment. 

Colorado Department of Public Health and Environment may require the manufacturers 

to conduct on-site or laboratory testing of in-use analyzers in order to document 

continued compliance. When an analyzer is removed from the field, for repair or testing, 

manufacturers shall supply the inspection station from which it was removed with a 

temporary replacement unit meeting all program requirements. Manufacturers shall pay 

for all necessary shipping and transfer costs for the replacement of the analyzer selected 

for compliance testing. Manufacturers shall also pay for any required testing performed 

by their personnel or by an independent company. 
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The manufacturers shall provide training to AIR Program officials on all operational, 

maintenance, and quality control features of the analyzers, including full access to and 

use of inspection menus, audit menus and calibration menus, as well as optional 

programs offered to inspectors. Such training shall be conducted at the manufacturer's 

expense as a condition of certification and thereafter at reasonable intervals upon written 

request by Colorado Department of Public Health and Environment 

1.9 Certification Requirements 

The manufacturer shall submit a formal certificate to Colorado Department, of Public 

Health and Environment that states that any analyzer sold or leased by the manufacturer 

or its authorized representatives for use in Colorado AIR Program will satisfy all design 

and performance criteria described in these specifications. The manufacturer shall also 

provide sufficient documentation to demonstrate conformance with these criteria 

including a complete description of all hardware components, the results of appropriate 

performance testing, and a point-by-point response to specific requirements. Previous 

certification by the California Bureau of Automotive Repair (BAR) is necessary for the 

analytical bench. 

In addition, a full description of the company's service procedures and policies, as well as 

sample contracts, warranties, and extended service agreements, shall be provided as 

part of the certification application to ensure proper maintenance of all analyzers 

throughout their useful life. One fully functional analyzer shall be presented for evaluation 

and one additional fully functional analyzer for the certification process. If certified these 

units will remain in AIR Program possession for continued in-use evaluation for the life of 

the AIR Program. In the event that 1 % of overall unit sales exceed this two-unit base, inuse evaluation will require 1 % of overall unit sales for in use evaluation. 

2.0 HARDWARE SPECIFICATIONS

2.1 General

Colorado 97 hardware shall be compliant with the BAR 97 Section 2 specification, the August 

2008 revision available at: 

http://www.smogcheck.ca.gov/70_siteWideInfo/Library/09_IndustryResources.html

And/or current SAE on-board diagnostic “J” standards including but not limited to J1978 and 

J1979 available from SAE.

NOTE: The Colorado 97 is not an ASM system. ASM hardware, i.e. the dynamometer and NOx 

sensor, are not needed. By extension, ASM software is also unnecessary.

2.2 Span Gases

The Colorado 97 shall use the same span gases utilized for calibration of the Colorado 94 TAS 

namely:

AIR 94 Low Range:

300 ppm propane

1.0% carbon monoxide
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6.0% carbon monoxide

Balance: oxygen-free nitrogen

AIR 94 Mid Range:

1200 ppm propane

4.0% carbon monoxide

12.0% carbon monoxide

Balance: oxygen-free nitrogen

2.3 Audit Gases

Audit gases shall be those described in Colorado Air Quality Control Commission Regulation 

Number 11.

3.0 SOFTWARE COMPONENTS

3.1 Communication and Data Field Specification

Operational software requirements at a minimum must support the existing Colorado 94 

Communication Protocol and Data Field Specification. See Appendix A.For inquiries referencing 

the Communication and Data Field Specification, please contact the Colorado Air Pollution 

Control Division

3.2 Society of Automotive Engineers (SAE) “J” Standards

The Colorado 97 shall be compliant with current SAE on-board diagnostic “J” standards including 

but not limited to J1978 and J1979.

3.3 OBD II

The Colorado 97 must be capable of accessing OBD II readiness monitors and diagnostic trouble 

codes. The operational software requirements will be available from the Division upon request.

3.4 Forms

The Colorado 97 shall be capable of completing the current, pre-printed, continuous form-fedprint 

on demand Vehicle Inspection Report (VIR) form. Examples of the VIR and the Vehicle Repair 

Form (VRF) are in Appendix Bare following this Section 3.0.

3.5 Upgrades

Software shall be updated/upgraded per Section 1.8 aboveof this Attachment IV.

Colorado 94 Communications and Data Fields Specification
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Vehicle Inspection Report – Passing Form-Front
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Vehicle Inspection Report – Failing Form-Back (Vehicle Repair Form)
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Vehicle Inspection Report Form-Completed
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ATTACHMENT V Specifications for Colorado On-Board Diagnostic (OBD) Stand-Alone 

Analyzer
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INTRODUCTION

This document contains specifications for manufacturers to design a Colorado (CO) Onboard Diagnostic 

(OBD) Test Analyzer System (CO-OBD-TAS) for use in the Colorado Automobile Inspection and 

Readjustment (AIR) program. The CO-OBD-TAS certified for use shall be capable of conducting OBD 

emissions inspections, malfunction indicator lamp/check engine light (MIL) visual inspections, gas cap 

visual and pressure tests and a visual opacity check. 

Changes to Regulation 11 allow for OBD Inspections as of January 1st 2015. Light-duty vehicles in their 

eighth through eleventh (8th-11th) model years will receive a mandatory (i.e., pass/fail determination) 

OBD inspection.

The OBD, MIL, gas cap and opacity inspections shall be conducted in accordance with the procedures 

set forth in AQCC Regulation No. 11, 40 C.F.R. Part 51, and EPA guidance document 420-R-01-015, 

Performing Onboard Diagnostic System Checks as Part of a Vehicles Inspection and Maintenance 

Program.

Design Goals

The CO-OBD-TAS must be designed and constructed to provide reliable and accurate service in the 

automotive service environment and have a useful life of at least five years. The software used in the COOBD-TAS must consist of a process control system capable of using reference data. The software also 

must be designed for maximum operational simplicity and be capable of providing testing information that 

can be used for vehicle diagnostics. In addition, the CO-OBD-TAS must include security measures that 

will prevent unauthorized modifications to the software or inspection data, record unauthorized entry, also 

known as tampering, and prevent subsequent inspections when tampering is detected.

The CO-OBD-TAS specifications contain the minimum requirements for CO-OBD-TAS used to perform 

emissions inspections in the AIR Program. Manufacturers may include additional items with approval from 

the Colorado Department of Public Health and Environment (CDPHE).

It is expected that the CO-OBD-TAS software will be SAE 1978 and J1979 compliant. The OBD 

inspection will include a visual and functional (bulb) check of the Malfunction Indicator Light (MIL) and an 

electronic examination of the vehicle’s OBD computer. As outlined in the EPA guidance document, there 

are seven steps in this OBD inspection:

• Initiate the inspection by collecting and entering the vehicle identification information;

• Perform a visual inspection of the MIL and perform a key-on, engine-off inspection;

• Locate the vehicle’s data link connector (DLC) and connect the OBD test equipment;

• Start and run the vehicle;

• With the OBD test equipment connected, determine the following:

o The status of the vehicle's non-continuous readiness monitors;

o The status of the MIL (commanded on or off);

o The Diagnostic Trouble Codes (DTCs);
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• Electronically record the results of the OBD inspection; and

• Turn off the vehicle and disconnect the scan tool.

Pass/Fail Requirement

The CO-OBD-TAS shall fail vehicles for the following reasons:

o Gas Cap visual fails; or 

o Gas Cap integrity does not meet the standards; or

o Visual opacity greater than 5%; or

o The MIL does not illuminate at all during the Bulb check (Fail); or

o The MIL stays illuminated when the vehicle is running (Fail); or

o MIL status is commanded on; regardless of whether or not the MIL is actually illuminated (Fail).

The CO-OBD-TAS shall pass vehicles for the following reasons:

o Gas Cap visual inspection passes; 

o Gas Cap integrity is within standards; 

o Visual opacity less than 5%; 

o The readiness requirements in Section 4 are met; 

o The MIL visual bulb check passes; 

o The MIL is not commanded on; and

o No Fraud is detected, as per Section 7.

Readiness Monitors

As part of the OBD inspection, the status of the vehicle’s non-continuous readiness monitors is to be 

queried. The OBD TAS Manufacturer will implement EPA’s listing of “Manufacturers Known to Have OBD 

Readiness Issues” and apply corrections to the readiness monitor requirements for those vehicles. 

Otherwise the following readiness monitors requirements apply:

o The oxygen sensor and/or heated oxygen sensor monitor(s) shall be ready if supported;

o The catalyst monitor shall be ready if supported; and 

o A 2001 or newer model year shall have no more than one (1) supported readiness monitor not 

ready; or 
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o A 2000 or older model year shall have no more than two (2) supported readiness monitors not 

ready

If the readiness monitor requirements are not met and the MIL is not commanded on then the inspection 

shall be automatically aborted with the reason printed out the vehicle Inspection Report (VIR). 

If a vehicle is unable to receive an OBD inspection (i.e. unable to communicate, DLC or readiness 

monitor issues), then the inspection will be aborted and the reason printed out the vehicle Inspection 

Report (VIR). 

Keyless Ignitions

If a vehicle has a keyless ignition, then the OBD TAS software shall bypass the MIL bulb check. The 

software shall determine keyless ignition systems electronically, by way of an OBD test information lookup table. The software shall provide for an override (changes the default, from the table, for the keyless 

ignition data field) in case the keyless ignition vehicle is not listed in the table. 

OBD Retest Requirements

The same readiness monitor requirements in Section 4 shall apply to OBD re-tests. 

OBD Fraud Prevention 

The contractor will build an OBD inspection fraud detection module as approved by the CDPHE in the 

CO-OBD-TAS software. 

OBD Equipment Requirements

The CO-OBD-TAS must include hardware and software necessary to access the on-board computer 

systems on all model-year 1996 and newer vehicles. The equipment design and operation of the COOBD-TAS must meet the federal requirements contained in Title 40 of the Code of Federal Regulations 

(CFR), Chapters 85.2207-2231 and the recommended practices regarding OBD inspections contained in 

the J1962, J1978 and J1979 published by the Society of Automotive Engineers (SAE). The CO-OBD-TAS 

must be able to connect to the vehicle’s OBD connector and access, at a minimum, the following OBD 

data:

o The engine revolutions per minute (RPM);

o The readiness monitor status;

o The malfunction indicator light (MIL) status;

o The OBD communications protocol;

o The electronic VIN; and

o The diagnostic trouble codes (DTCs).

At a minimum, the CO-OBD-TAS must also be capable of communicating with all OBD vehicles that use 

the following communications protocols:

o International Organization for Standardization (ISO) 9141;
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o Variable pulse width (VPW) as defined in the SAE’s J1850;

o Pulse width modulation (PWM) as defined in the SAE’s J1850;

o Keyword protocol 2000 (KWP); and

o Controller area network (CAN) as defined in the ISO 15765-4.3:2001.

The OBD interrogation process must be fully integrated into the CO-OBD-TAS, automated, and require 

no inspector intervention to collect and record the OBD data retrieved via the OBD connector link. No 

separate interface may be used.

The CO-OBD-TAS shall meet the design and performance specifications in the Air Quality Control 

Commission’s (AQCC) Regulation Number 11. 

Gas Cap Tester

The gas cap tester must be able to supply air pressure significant enough to produce and measure a leak 

rate of 60 cubic centimeters per min (cc/min) of air at 30 inches of water pressure. The tester must be 

tamper resistant; control the air supply pressure and prevent over pressurization; provide a visual or 

digital signal that the required air supply pressure is within the acceptable range and a flow comparison 

test is ready to be conducted; be supplied with a reference passing gas cap, or equivalent, with a nominal 

52-56 cc/min leak rate; and be supplied with a reference failing gas cap, or equivalent, with a nominal 64-

68 cc/min leak rate.

The tester may use: a squared edged circular orifice to generate the required leak rate; and ambient air or 

any convenient low pressure source.

The gas cap tester connector must be a minimum length of 20 feet so that it can reach gas caps that are 

attached to vehicles.

The CO-OBD-TAS must prevent all inspections if the gas cap tester calibration has not passed in the last 

24 hours.

Gas Cap adapters must be available for at least 95 percent of the gas caps used for the most recent 12 

model-year light-duty vehicles and trucks. Varying internal volumes of the gas caps and adapter 

assemblies must not affect the accuracy of the inspection results. Adapters must be made available the 

first day of each year upon the introduction of new model-year vehicles.

Opacity

The CO-OBD-TAS software shall require an entry for a visual opacity inspection. 

Recording of Test Results/Documentation

The CO-OBD-TAS shall automatically record the date, start time, station, and inspector ID for each test. 

Required data for each element of the inspection shall be collected and entered into the CO-CO-OBDTAS. A data specification is available from CDPHE upon request. Due to possible systems changes or 

new requirements, the required data list may be changed.

The CO-OBD-TAS shall print the test results in the form of a state-approved Vehicle Inspection Report 

(VIR, Form DR2071). The CO-OBD-TAS shall print these forms from plain security paper or some other 
Regulation Number 11

Adopted: November 21, 2013 Page 175

paper as approved by CDPHE. The VIR shall contain at a minimum the OBD test results. VIRs for 

vehicles with a passing OBD test shall include a Certificate of Emissions Compliance (CEC) printed on 

the VIR. 

Computers and Peripheral Requirements

The CO-OBD-TAS functions must be controlled by a personal computer (PC), or functional equivalent, 

and include the hardware and software needed to perform the functions required by this specification. 

The CDPHE reserves the right to add additional programs and performance requirements, up to the 

technical limits of the hardware, to improve the AIR program. 

The manufacturer may offer a CO-OBD-TAS with additional disk drives that can run optional software 

hardware application programs, however, the computer must not be bootable from any additional drive, 

nor must any program run from one of these drives have access to the computer’s operating system. 

Additional drives must be located in a limited access secured area within the CO-OBD-TAS cabinet. The 

peripheral equipment, such as bar code readers, OBD scanners, and keyboards may use wireless 

communication to interact with the CO-OBD-TAS.

VID Communications Overview

A required component of the AIR program is the electronic transmission of inspection data. The 

Centralized Emissions Testing Contractor for the Colorado AIR program has an electronic network that 

enables the CO-OBD-TAS to automatically connect to a centralized vehicle identification database (VID). 

The CO-OBD-TAS must demonstrate the ability to receive, install, use, and transmit data to and receive 

data from the VID using the communications protocol. The communications protocol will be provided by 

the CDPHE.

Each inspection station must obtain and maintain VID communication services. The CO-OBD-TAS must 

use the communications protocol to access the features of the VID communications services in order to 

conduct vehicle inspections. 

Printer

A laser printer or a CDPHE approved equivalent printer must be supplied with each CO-OBD-TAS 

purchased, leased, or upgraded. The CO-OBD-TAS’s printer must be interchangeable with a locally 

purchased off-the-shelf laser printer. 

Power and Telephone Cord

The modem must be, at a minimum, designed to connect to the CO-OBD-TAS with a modular telephone 

connector that has a standard wiring configuration. The connector must be located on the back of the COOBD-TAS cabinet. Alternatives to this requirement may be proposed to the CDPHE for evaluation.

The telephone and power cords must be at least 25 feet long and enclosed in a protective cable meeting 

the Underwriter’s Laboratory approval. Alternative methods to protect the telephone and power cords may 

be submitted to the CDPHE for approval. The manufacturer shall design the cabinet so that convenient 

storage is provided for the excess telephone and power cords.

Power Requirements
Regulation Number 11

Adopted: November 21, 2013 Page 176

The CO-OBD-TAS must operate on an alternating current (AC) and must not be powered by a portable 

AC generating unit. Input power must be 115 volts of alternating current (VAC) with 60 hertz. The 

instruments must meet the specified requirements over an input voltage variation of at least +/- 12 volts. 

Construction

The CO-OBD-TAS must be designed and constructed to provide reliable and accurate service in the 

automotive service environment. The CO-OBD-TAS must be supplied with a cabinet that is equipped with 

a storage area large enough to secure all accessories and operating manuals.

Materials 

The materials used in construction of the CO-OBD-TAS must be resistant to corrosive substances found 

in the automotive service environment and be designed to last for at least five years. The exterior and 

interior finish of the entire cabinet and console must be sufficiently durable to withstand the chemicals and 

environmental conditions normally encountered in the automotive service environment for the period of 

the warranty.

Mobility 

The CO-OBD-TAS may be permanently mounted or mobile with the use of wheels. Wheels must be at 

least five inches in diameter and have a locking mechanism capable of preventing movement on a 15 

degree incline.

The CO-OBD-TAS must be designed to move over rough surfaces, through three-inch deep holes, and 

on 15 degree inclines without tipping over. The CO-OBD-TAS must not tip over when placed at the center 

of an inclined plane and rotated 360 degrees stopping in the position where it is most likely to tip over. 

The incline plane must make an angle of 10 degrees with the horizontal floor. In addition, the CO-OBDTAS must not become unstable or tip over when rolled straight off the edge of a two-inch high platform or 

when one wheel is rolled over a drain, two inches below the surface, or inside an 18-inch diameter 

depression.

Electrical Design 

Fuses or circuit breakers must be used to protect individual electrical circuits in the CO-OBD-TAS. The 

main circuit breaker and fuses must be readily accessible from the exterior of the cabinet. CO-OBD-TAS 

operation must be unaffected by electrical line noise and voltage surges. The CO-OBD-TAS must be 

protected from voltage surges to prevent damage to the internal components from a simultaneous start 

up of a 220 volt compressor, an arc welder, hydraulic controls, and other equipment commonly found in 

the typical automotive service environment.

Bar Code Scanner

The bar code scanner must be able to read a one-dimensional (1-D) and a two-dimensional (2-D) bar 

code through a windshield and use visible laser diode technology or an equivalent approved by the 

CDPHE. The bar code scanner must not be able to read Universal Product Code (UPC) 1-D bar codes. 

The bar code scanner must be able to withstand multiple drops to concrete covering a distance of at least 

4 feet and be environmentally sealed to withstand the normal operating conditions of an automotive 

service environment.

Additional Specifications
Regulation Number 11

Adopted: November 21, 2013 Page 177

The useful life of the CO-OBD-TAS shall be a minimum of five years.

A nameplate including the following information shall be permanently affixed to the housing of the COOBD-TAS: Name and Address of Manufacturer, Model Description, Serial Number, and Date of 

Assembly.

Each CO-OBD-TAS shall be delivered with the following manuals: Reference Operating Instructions, 

Operation Instruction Manual, Maintenance Instruction Manual (limited), and Initial Start-up Instructions

CO-OBD-TAS manufacturers may consolidate manuals. The manuals shall be constructed of durable 

materials and shall not deteriorate as a result of normal use over a five-year period. The CO-OBD-TAS 

housing shall provide convenient storage for each manual in a manner that will allow easy use and 

prevent accidental loss or destruction.

The CO-OBD-TAS software shall be fully documented. Two copies of the documentation listed below 

shall be submitted to CDPHE as part of the Certification application. 

Functional Specifications

CO-OBD-TAS manufacturers shall provide for use during the Acceptance Testing Process: 

o Functional flowcharts of the software; 

o Example inputs and outputs from all processes; 

o Detailed interface information on system components including the identification of protocol and 

output specifications; and 

o All file layouts with file names, file types, file security, field names, field types, field sizes, and field 

editing criteria.

Documentation provided by the vendor to meet this requirement will be treated as proprietary information 

by Colorado Department of Public Health and Environment.

Prior to certification of any CO-OBD-TAS for sale in Colorado, the manufacturer shall provide the CDPHE 

technical information (including, but not limited to all working codes, schematics and drawings) necessary 

to operate, maintain and repair such CO-OBD-TAS in the invent that the manufacturer ceases providing 

adequate maintenance, and repair services in Colorado. 

The CO-OBD-TAS manufacturer shall keep such information current, and will provide CDPHE with copies 

of any and all changes. So long as such maintenance and repair services are available from the 

manufacturer or its agent, the CDPHE shall protect such information as confidential commercial data if it 

is clearly marked as such. In the event that the manufacturer becomes insolvent or stops providing 

adequate maintenance or repair services in Colorado all such information shall be the property of the 

CDPHE and may be released to a third party as necessary to repair and maintain the CO-OBD-TAS.

Warranty Coverage

A written warranty coverage agreement, signed by an authorized representative of the equipment 

manufacturer and the vehicle inspection station owner, which provides a complete description of 

coverage for all systems and components and all manufacturer provided services must accompany the 
Regulation Number 11

Adopted: November 21, 2013 Page 178

sale or lease of each CO-OBD-TAS. Original manufacturer’s warranty shall be a minimum of one year 

from the date of purchase. An extended service contract shall be available upon the expiration of the 

manufacturers original warranty period.

Tampering Resistance

Controlled access design shall be the responsibility of the manufacturer and is subject to approval by 

CDPHE. CO-OBD-TAS service personnel, inspectors or others shall be prohibited, to satisfaction of 

CDPHE, from creating or changing any test results, programs or data files contained in the CO-OBD-TAS. 

The CO-OBD-TAS shall be made tamper-resistant to the satisfaction of CDPHE and DOR. 

If tampering occurs, a software lockout algorithm shall be activated which aborts any existing test 

sequence and prevents further inspections until an authorized AIR Program official clears the lockout.

Auditing Requirements 

Title 42, Article 4, Part 3, C.R.S. establishes the I/M Program-based authority of the Colorado Department 

of Revenue (DOR). As such, DOR is responsible for emissions inspector and station licensing as 

prescribed by C.R.S., AQCC Regulation 11, and DOR Regulation 1. In order to maintain the integrity of 

the I/M Program, DOR conducts various quality assurance audits of the CO-CO-OBD-TAS units. The 

specification for this audit will be provided by CDPHE and DOR. 

Manufacturer Provided Services

The CO-OBD-TAS manufacturer shall agree to provide the following services to the inspection station as 

part of the manufacturer’s original warranty:

The delivery, installation, calibration, and verification of the proper operating condition of a CO-OBD-TAS. 

Instruction of all certified inspectors employed by the inspection station, at the time of installation, in the 

proper use, maintenance, and operation of the CO-OBD-TAS. 

On-site service response by a qualified repair technician within two (2) business days, (48 hours) 

excluding Sundays and national holidays, of a request from the inspection station. 

CDPHE will require the manufacturer to render updates as necessary in the first year of the program to 

ensure the program meets all design criteria. Thereafter software updates will be limited to once per year 

at no cost. Since modem software updating will be utilized, there are no costs to the CO-OBD-TAS owner. 

A software version number, consisting of a four character alpha-numeric code made up of the last two 

digits of the year followed by a two character version number, shall be recorded in the CO-OBD-TAS and 

included on each vehicle test record. The CO-OBD-TAS manufacturer shall not modify any existing 

software version without obtaining written approval from CDPHE.

CO-OBD-TAS manufacturers shall provide training to AIR Program officials on all operational, 

maintenance, and quality control features of the CO-OBD-TAS units, including full access to and use of 

inspection menus and audit menus. Such training shall be conducted at the manufacturer's expense as a 

condition of certification. 

Certification Requirements

The CO-OBD-TAS manufacturer shall submit a formal certificate to CDPHE that states that any CO-OBD 

TAS sold or leased by the manufacturer or its authorized representatives for use in Colorado AIR 
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Adopted: November 21, 2013 Page 179

Program will satisfy all design and performance criteria described in these specifications. The 

manufacturer shall also provide sufficient documentation to demonstrate conformance with these criteria 

including a complete description of all hardware components, the results of appropriate performance 

testing, and a point-by-point response to specific requirements.

In addition, a full description of the company's service procedures and policies, as well as sample 

contracts, warranties, and extended service agreements, shall be provided as part of the certification 

application to ensure proper maintenance of all CO-OBD-TAS throughout their useful life. One fully 

functional CO-CO-OBD-TAS shall be presented for evaluation and certification process.

The Acceptance Testing Procedure (ATP) for CO-OBD-TAS will include a verification that the unit meets 

all requirements in this specification and federal requirements contained in 40 CFR §§85.2207 - 85.2231 

and the recommended practices contained in the J1962, J1978, and J1979 published by the SAE. The 

ATP procedures and acceptance criteria are contained in the EPA’s guidance document, “Performing 

Onboard Diagnostic System Checks as Part of a Vehicle Inspection and Maintenance Program” (EPA, 

2001) or EPA’s applicable update to this document.

ver. 9-16-13

APPENDIX B Standards and Specifications for Calibration/Span Gas Suppliers

STATE OF COLORADO

DEPARTMENT OF PUBLIC HEALTH & ENVIRONMENT

COLORADO AIR PROGRAM

STANDARDS AND SPECIFICATIONS FOR CALIBRATION/SPAN GAS SUPPLIERS

INCLUDING

GAS REQUIREMENTS FOR THE BASIC AND ENHANCED INSPECTION

TEST PROGRAMS

1997

INTRODUCTION

This Appendix B describes the standards and specifications for the suppliers of span and calibration 

gases to the Colorado AIR Program, including facility requirements and documentation required of 

potential suppliers.

CONTENTS

SECTION 1: Definitions

BASIC AND ENHANCED IDLE AIR PROGRAM

SECTION 2: Basic and Enhanced Idle Air Program - Technical rRequirements

SECTION 3: Calibration/sSpan gGas aApproval & lLabeling
Regulation Number 11

Adopted: November 21, 2013 Page 180

SECTION 4: Cylinder tTracking and rRecall

ENHANCED IM & IG 240 AIR PROGRAM

SECTION 5: Enhanced IM & IG 240 Air Program - Technical rRequirements

SECTION 6: Calibration/span gas approval & labelingColorado Approval Process

AIR PROGRAM/BASIC AND ENHANCED

SECTION 7: Blender fFacility rRequirements & dDocumentation

ATTACHMENT I

Program Contact/Addresses/Phone Numbers

ATTACHMENT HII

“Colorado Approved” Label Samples

SECTION 1 DEFINITIONS

AIR: Colorado's “Automotive Inspection & Readjustment” Program.

ANALYTICAL ACCURACY: The relative percent deviation of the stated concentration of the components 

of a gas blend from the “true” value as determined by comparison with Colorado AIR Program standards.

(% DEV = STATED CONC - “TRUE” CONC/“TRUE” CONC X 100)

AUDIT GAS: Reference gas standards with direct traceability to NIST and/or EPA, to be used by AIR 

Program QA/QC personnel.

APCD: Colorado “Air Pollution Control Division”.

AUTHORIZED GAS BLENDER: A blender of precision gas products selected to provide such products 

pursuant to the requirements of 42-4-306(3)(A)(l)(C).

BALANCE GAS: The balance or makeup gas for Colorado AIR Program gases shall be as follows: for 

basic program tri-blend span gases, nitrogen shall be the balance gas. For the enhanced IM 240 program 

standards and span gases, air shall be the balance gas. The balance gas for mixtures containing nitric 

oxide (NO) shall be nitrogen.

BAR: California “Bureau of Automotive Repair”

BLEND TOLERANCE: Deviation between the requested or nominal concentration and the measured or 

certified concentration of a gas mixture.

CALIBRATION STANDARD: A precision blended gas used to generate calibration curves, with an 

analytical accuracy of +/- 1%, traceable to NIST gas standards. (Enhanced Program)
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Adopted: November 21, 2013 Page 181

CALIBRATION/SPAN GAS: A blend of carbon monoxide (CO), carbon dioxide (CO2), and propane, with 

a balance gas of nitrogen (NO2), which is used to calibrate the Colorado 94 test analyzers. (Basic 

program)

CALIBRATION ZERO AIR: The gas used as a diluent for gas dividers or to establish analyzer zero during 

calibration curve generation. Impurities shall not exceed 0.1 ppm carbon response, 0.5 ppm CO, 1 ppm 

CO2, 0.1 ppm NOx, and 1 ppm moisture. Blended air shall have oxygen content between 20.6% and 21%

CALIBRATION ZERO NITROGEN: The gas used as a diluent for gas dividers or to establish analyzer 

zero during calibration curve generation shall have a minimum purity of 99.997% with impurities not to 

exceed 0.1 ppm carbon response, 0.5 ppm CO, 1 ppm CO2, 0.1 ppm NOx, 1 ppm moisture and 0.5 ppm 

O2.

CAPSL: Colorado AIR Program Standards Lab.

CDPHE: Colorado Department of Public Health & Environment.

CERTIFIED GAS BLENDER: A blender of precision gas products, approved by the Colorado AIR 

Program. A certified blender has met or exceeded the requirements set forth by the CDPHE to provide a 

consistently high quality calibration and span gas to both the Basic and Enhanced Air Program.

CGA: Compressed Gas Association

CRM: Certified Reference Material

DOT: Department of Transportation

FID: HC analyzer using a flame ionization detector

FED FUEL: A mixture of 40% hydrogen (+/- 2%) and 60% helium

FID OXIDIZER: Zero grade air with oxygen content between 20.6% And 21 %

GOLD STANDARDS: NIST traceable air program standards named by EPA at the National Vehicle Fuels 

and Emission lab (NVFEL), Ann Arbor, Michigan

NIST: National Institute of Standards and Technology

STATE: The State of Colorado

SRM: Standard reference material. The highest integrity gas standard, prepared by, and only available 

from, NIST.

VETC: Vehicle Emission Technical Center, 15608 East 18th Avenue, Aurora, Colorado 80011.

WORKING SPAN GAS: Gases used in the enhanced IM 240 Air Program for high and mid-scale span 

checks and/or adjustments as well as analyzer cross-checks. These gases shall have an analytical 

accuracy of +/- 2%.

WORKING ZERO GAS: Air or nitrogen used in the daily zeroing of enhanced program analyzers. 

Impurities shall not exceed 1 ppm carbon response, 2 ppm CO, 0.04% C02, 0.3 ppm NOx, and 1% 
Regulation Number 11

Adopted: November 21, 2013 Page 182

moisture. Air shall have oxygen content between 20.6% and 21%. Nitrogen shall contain a maximum of 

0.5% O2.

SECTION 2 BASIC & ENHANCED IDLE AIR PROGRAM/TECHNICAL REQUIREMENTS

2.0 GENERAL

This section describes the calibration/span gas requirements, specifications for these gases, and types of 

cylinders allowed. Such specifications shall be included in any request for bids issued pursuant to 42-4-

306(3)(a)(l)(c).

2.1 GAS REQUIREMENTS

The following identifies the calibration/span gas blends required for the Colorado basic & enhanced idle 

AIR Program:

CALIBRATION/SPAN GASES

AIR94LOW

300 ppm Propane (as THC)

1.0 % Carbon Monoxide

6.0 % Carbon Dioxide

Balance Nitrogen

AIR94MID

1200 ppm Propane (as THC)

4.0 % Carbon Monoxide

12.0 % Carbon Dioxide

Balance Nitrogen

2.2 GAS BLEND ACCURACIES

The combined errors due to blending and naming of the above calibration/span gases shall not exceed 

+/- 2% for each component.

2.3 ANALYTICAL ACCURACY

The analytical accuracies for idle air program gases are:

(A) Calibration/span gas: +/-2% of nominal value

(B) Audit gases: +/- 1% of nominal value
Regulation Number 11

Adopted: November 21, 2013 Page 183

2.4 BLEND TOLERANCE

Zero blend tolerance is required for basic & enhanced idle AIR Program calibration span gases.

2.5 BLENDER REFERENCE STANDARDS

Each authorized gas blender shall present documentation of its own internal standards for approval. The 

state provides two methods for standard documentation:

(I) Blender may prepare a reference cylinder of each gas blend intended for the AIR 

Program to be named vs. Colorado's gold standards. Cylinder(s) shall be sent to the 

state for naming and labeling. This standard will become the blender's reference 

standard for the analysis of production span gases.

NOTE: The associated costs of shipping reference cylinders to and from Colorado will be the 

responsibility of the blender. No shipping costs will be borne by the state.

(II) Blenders certified by the State of California, Bureau of Automotive Repair, may elect to 

submit copies of their current certification including a listing of all SRM's, CRM's, or other 

reference gases accepted by bar, as pertaining to the analysis of I/M span gases. BAR 

acceptance of these standards will be sufficient to obtain approval of same for the AIR 

Program.

2.6 CYLINDERS

The cylinders to be used in the Colorado 94 analyzers in the field shall be low pressure, non refillable, 

disposable canisters.

High pressure, refillable cylinders will be used by AIR Program audit/QC teams and, in some cases, by 

analyzer manufacturers. Approval of span gas in high pressure cylinders will be on an individual basis. 

(See Section 3)

2.7 DISPOSABLE CYLINDERS

(A) Disposable cylinders shall be in accordance with dot specification 39 for non refillable, 

disposable cylinders. (260 PSIG service pressure, 325 PSIG test pressure, 650 PSIG 

minimum burst pressure) [CFR Title 49, Part 178, Section 178.65, Oct 1, 1996]

(B) Nominal size shall not exceed 750 cubic inches +/- 5% (approximately 9 inches inside 

diameter by 16 inches high, providing an equivalent water capacity of 27 lbs.) As a 

minimum, cylinders shall contain 7.5 cubic feet of gas blend at 260 PSIG cylinder 

pressure.

(C) Cylinders shall be designed with an integral stand to facilitate upright storage.

(D) Cylinder outlet shall be CGA 165, 1/4” SAE flare, 45 degree male. Shutoff valves shall be 

of the non refillable type.

(E) Cylinders shall be equipped with a safety relief device in accordance with DOT 

regulations [CFR 49, 173.34,(D), Oct, 1996]. The safety relief device must comply with 

the requirements of the compressed gas association pamphlet S.1.1, 8th Edition, 1994.
Regulation Number 11

Adopted: November 21, 2013 Page 184

(F) Cylinders shall have a built in safety shield to protect the shut off valve.

(G) No material shall be used in cylinder fabrication or assembly, or in cylinder charging 

equipment, which is incompatible with the gas blend as to cause contamination or 

degradation.

(H) Blenders must comply with applicable DOT specifications for the shipment of cylinders. 

[CFR Title 49, Volume 2, Part 173, Subpart B, Oct, 1996].

2.8 HIGH PRESSURE REFILLABLE CYLINDERS

(A) Refillable cylinders must be aluminum and made in accordance with DOT specifications 

3AA or 3AL [CFR Tide 49, Volume 2, Part 178, Subpart C, Oct, 1996], whichever is 

applicable.

(B) All cylinders must comply with applicable DOT Regulations and requirements for safety 

and shipment. [CFR Title 49, Volume 2, Part 173, Subpart B, Oct, 1996]

2.9 LABELING

(A) Caution labels shall be affixed to all cylinders and shall comply with applicable DOT and 

OSHA regulations.

(B) “Colorado Approved” labels will be provided by the Colorado AIR Program (Section 3) 

and shall be affixed to the upper portion of the canisters.

2.10 EXPIRATION

Triblend span gas cylinders containing CO, CO2, and propane in nitrogen, shall have an expiration date 

of 36 months after date of fill.

2.11 QUALITY ASSURANCE

All gas blenders shall have in place a fully documented and implemented quality assurance program as a 

prerequisite to certification. This QA program shall include, but not be limited to:

(A) Regular equipment maintenance and calibration, performed in accordance with 

manufacturer guidelines, as a minimum.

(B) Documentation of the analysis of each batch or lot of gas produced. A copy of the 

certificate of analysis from each batch or lot shall accompany each approval request.

(C) Blender may choose to retain a cylinder from each batch/lot for internal documentation. 

However, one cylinder from each batch/lot must accompany each request for “Colorado 

Approved” labels. This sample cylinder will not be returned.

(D) Documentation of maintenance and calibration of equipment and instrumentation shall be 

made available upon request.

2.12 BREACH OF TERMS
Regulation Number 11

Adopted: November 21, 2013 Page 185

Each contract entered into pursuant to 42-4-306(3)(a)(l)(C), shall authorize the APCD to suspend the 

blender's authority to supply precision gas products to inspection and readjustment stations, inspectiononly facilities, fleet inspection stations, motor vehicle dealer facilities and enhanced inspection centers in 

the event the gas blender violates the terms of the contract and this appendix B. The APCD may 

terminate such a suspension once the blender corrects the problems that led to the violation. An onsite 

inspection of the blender's facility by an APCD representative may be required to ensure that the relevant 

requirements are being observed.

SECTION 3 CALIBRATION/SPAN GAS APPROVAL & LABELING

3.0 GENERAL

Information in this section describes the calibration/span gas approval process as well as the procedure 

for obtaining “Colorado Approved” labels.

3.1 CALIBRATION SPAN GAS APPROVAL PROCEDURE

Batches or lots of span gas will be produced referencing procedures and specifications contained herein. 

Authorized blender shall analyze a representative number of cylinders from each batch or lot. Authorized 

blender shall then request from the CDPHE a number of Colorado approved labels corresponding to the 

number of cylinders in that batch or lot. The request for labels must include:

(I) Analytical report to contain:

(A) Actual analysis of samples in batch

(B) Number of cylinders in batch

(C) Fill date

(D) Number of labels required

(E) Batch or lot number

(II) One representative cylinder from each batch or lot of span gas produced to be verified by 

analysis and retained for future reference.

NOTE: This sample cylinder will not be returned. Cylinder will be archived by the state until the 

expiration date expires (36 months from fill date). This sample may be analyzed as a spot check 

or reference gas in matters concerning potential inquiries into batch integrity.

Upon approval, blender will be sent an appropriate number of “Colorado Approved” labels to be 

affixed to cylinders in that batch or lot.

Samples, along with request for “Colorado Approved” labels, should be sent to: CDPHE

VEHICLE EMISSION TECHNICAL CENTER

15608 E. 18TH AVENUE

AURORA, COLORADO 80011
Regulation Number 11

Adopted: November 21, 2013 Page 186

ATTN: SPAN GAS VERIFICATION PROGRAM

3.2 CALIBRATION/SPAN GAS APPROVAL/HIGH PRESSURE CYLINDERS

Approval of calibration/span gases in high pressure cylinders will be done on an individual basis. Each 

cylinder seeking approval must be submitted for verification against AIR Program standards. A certificate 

of analysis shall accompany each cylinder and shall contain the following information:

(A) Cylinder number

(B) Components contained

(C) Analytical results

(D) Analytical accuracy

(E) Statement of traceability

(F) Analysis date

(G) Fill date

Upon approval, blender will be notified that the cylinder is ready for pickup by the purchaser. Approved 

cylinder, with “Colorado Approved” label attached, may be picked up during normal business hours (8:00 

am - 5:00 pm) Monday through Friday. Cylinders shall be sent to the above address.(See 3.1)

3.3 SHIPPING COSTS

Blenders shall provide for the shipping of all cylinders seeking Colorado approval for use in the AIR 

Program. The pick-up and delivery of individual high pressure cylinders is also the responsibility of the 

blender and/or the purchaser of that cylinder. These cylinders are expected to be picked-up within 30 

days of notification of approval. No costs pertaining to the pick-up or delivery of span gases shall be 

borne by the state.

3.4 LABELING

“Colorado Approved” labels will be provided by the State of Colorado. These labels will include 

information necessary to track span gases throughout the system as well as identify each cylinder as 

Colorado approved. Information contained on the label will include:

(A) Blender name

(B) Blending facility

(C) Batch or lot number

(D) Identify “low” (yellow label) or “mid” (white label) SPAN GAS

(E) Fill date

(F) Expiration date
Regulation Number 11

Adopted: November 21, 2013 Page 187

(G) AIR Program number

(H) Bar code containing cylinder tracking information

(For a sample of the “Colorado Approved” labels, see attachment II)

3.5 AIR PROGRAM NUMBER

“Colorado Approved” labels will contain an AIR Program number. Each certified blender will be assigned 

a letter code that will precede the numbering of batch cylinders. These coded numbers will be generated 

by the state and assigned to each cylinder as batches of span gas are produced. Cylinder numbers will 

be held on file for the life span of the cylinder to assist in tracking, auditing and accounting purposes.

SECTION 4 CYLINDER TRACKING & RECALL

4.0 GENERAL

This section describes the method of tracking calibration/span gas throughout the AIR Program area. This 

system protects the inspection stations and provides for a replacement, in an expedient manner, should a 

non-conforming calibration/span gas be discovered.

4.1 TRACKING CYLINDERS VIA BAR CODE

Each “Colorado Approved” label will contain a bar code to be scanned whenever a cylinder of 

calibration/span gas is put into service on a Colorado 94 analyzer or Motor Vehicle Dealer Transient 

Mode Test Analyzer System. Scanned information will be stored in a file, accessible through a host 

computer linking all inspection stations. AIR Program QA/QC personnel will be able to locate individual 

cylinders, track batches of span gas, etc., throughout the program area.

Label bar codes will be generated at the time of batch or lot approval and will contain information 

necessary to facilitate the tracking process. Blenders are required to continue to track internally, the 

whereabouts of “Colorado Approved” batches of calibration/span gas prior to retail sale. In the event of a 

recall of a batch of non-conforming calibration/span gas, the blender, through procedure described herein 

(see 4.2), will begin recall. In-use calibration/span gas affected will be identified by bar cod; information 

through system host and replacement procedures will begin.

4.2 RECALL PROCEDURE

In the event a non-conforming cylinder of calibration/span gas is discovered at an AIR Program inspection 

station, the following recall procedure will begin:

(A) Suspected non-conforming span gas confiscated by AIR Program Q/C personnel;

(B) Cylinder brought to the Colorado AIR Program Standards Lab (CAPSL) for analysis;

(C) Exposed non-conforming cylinder cross referenced by air number go blender and batch;

(D) Archived sample retrieved and analyzed vs. suspected non-conforming cylinder. Blender 

advised of results;

(E) Through host system, the state identifies whereabouts of any non-conforming cylinders 

on line. Blender provided with a listing of affected inspection stations;
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Adopted: November 21, 2013 Page 188

(F) Blender shall immediately begin recall of all remaining unsold cylinders from batch in 

question and, simultaneously, begin process of supplying known conforming cylinder(s) 

to affected inspection stations by overnight service;

(G) A total recall and replacement of all cylinders in affected batch must be completed within 

10 days. A detailed report of the recall procedure and analysis of cause of the nonconforming product entering the system will be provided to the state within 15 days.

(H) The state may elect to withhold certification of future batches until such time as blender 

shows problems have been corrected.

(I) The state may also suspend the contract with the blender if information obtained 

suggests blending procedures were violated, pending a correction of the problems that 

caused the violation.

SECTION 5 ENHANCED IM & IG 240 AIR PROGRAM / TECHNICAL REQUIREMENTS

5.0 GENERAL

This section addresses the calibration gases, technical requirements, cylinder specifications and 

documentation required for IM & IG 240 testing.

5.1 GASES

Gases used in the calibration and support of IM & IG 240 testing shall conform to the provisions outlined 

in CFR Title 40, Part 86, Subpart B, Section 114, as revised July 1, 1992, for exhaust emission testing. 

Concentrations for IM 240 gases are as follows:

5.2 CALIBRATION GASES/CURVE GENERATION

(I) High tri-blends: (+/-1% analytical accuracy)

CO:9000 ppm

C02:3.6%

Propane:600 ppm

Balance: Air

(II) High NOx: (+/-1%)

NOx:450 ppm

Balance: Nitrogen

5.2.1 MID-SCALE CALIBRATION GASES/CURVE CONFORMATION

(I) Mid tri-blend: (+1-1%)

CO:4500 ppm
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Adopted: November 21, 2013 Page 189

C02:1.8 %

Propane:300 ppm

Balance: Air

(II) Mid NOx tri-blend: (+/-1%)

NOx:225 ppm

Balance: Nitrogen

5.2.2 CALIBRATION ZERO GASES

(I) Calibration zero AIR

HC : < 0.1 ppm

CO : < 0.5 ppm

C02 : < 1.0 ppm

NOx : < 0.1 ppm

Moisture : < 1.0 ppm

02: 20.6 % - 21.0 %

(II) Calibration zero Nitrogen

Purity : 99.997 %

HC : < 0.1 ppm

CO : < 0.5 ppm

CO2 : < 1.0 ppm

NOx : < 0.1 ppm

Moisture : < 1.0 ppm

O2 : < 0.5 ppm

5.3 DAILY SPAN GASES

(I) High tri-blend span (+/-2% analytical accuracy)

CO : 8000 ppm

C02 : 3.2 %
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Adopted: November 21, 2013 Page 190

Propane : 535 ppm

Balance : Air

(II) NOx mid span (+/-2%)

NOx : 75 ppm

Balance : Nitrogen

5.4 WORKING ZERO GASES

(I) Working zero AIR

HC : < 0.1 ppm

CO : < 2.0 ppm

CO2 < 400 ppm

NOx < 0.3 ppm

Moisture < 1.0 ppm

OY2 : 20.6-21.0 %

(II) Working zero Nitrogen

Purity : 99.997%

HC : < 1.0 ppm

CO : < 2.0 ppm

C02 : < 400 ppm

NOx : < 0.3 ppm

Moisture : < 1.0 ppm

02 : < 0.5 ppm

5.5 SUPPORT GASES

A variety of miscellaneous support gases are required for IM & IG 240 testing. Among these are:

GAS USAGE

Propane : 99.5% (min) CVS system flow checks
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Adopted: November 21, 2013 Page 191

GAS USAGE

Methane : 50 ppm/AIR FID check gas

FID Fuel: 40% H2/60% HE FID burner fuel

N02 : 200 ppm/N2 NOx converter efficiency 

test gas

AIR : 18%-21% NOx ozonator gas

5.6 IG 240 GASES

Calibration, span, working and support gases required by IG 240 systems, are among the gases listed 

(5.2 thru 5.5). Additional gases of specific concentrations and blend make-up may be required pending 

final configuration of the IG system.

5.7 CYLINDERS

Calibration and working gas tri or quad-blends used for IM & IG 240 testing, must be supplied in 

aluminum cylinders as well as all no or NOx blends. Other gases may be supplied in steel or aluminum 

cylinders as appropriate.

High pressure refillable cylinders shall be manufactured in accordance with DOT specifications 3AL or 

3AA [CFR Title 49, Volume 2, Part 178, Subpart C, Oct l, 1996], whichever is applicable.

Approved valves and relief devices, appropriate for the intended use, shall be used on all high pressure 

cylinders. [CFR Title 49, Volume 2, Subpart B, Section 173.124, Oct 1, 1996]

All cylinders shall have appropriate labeling to comply with all DOT regulations concerning transportation 

and safety. [CFR 49, Volume 2, Part 173, Subpart B, Oct 1, 1996].

5.8 MISCELLANEOUS

A full line of gas products shall be made available to the enhanced AIR Program contractor(s) to insure 

safe handling and storage of gas cylinders, such as regulators, carts, restraints, and leak detection 

equipment. The contractor(s), as well as state QA/QC personnel, may also request a variety of gas 

blends, tri-blends, and other specialty gas products associated with automotive emission testing. Blender 

must demonstrate the ability to provide the above gases, equipment and associated products, in order to 

be designated as an approved blender to the Colorado enhanced AIR Program.

5.9 CERTIFICATES OF ANALYSIS

Each calibration gas, working span gas, and calibration zero gas shall be documented by a certificate of 

analysis to include; cylinder number, components, analytical results, accuracy, traceability and analysis 

date. A batch analysis certificate stating purity may document zero grade air and nitrogen. (Zero AIR 

certificate must also provide documentation of oxygen content.)

The enhanced program contractor(s) must produce documentation of cylinder contents of the above upon 

request of state QA/QC personnel.
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Adopted: November 21, 2013 Page 192

5.9.1 TRACKING CYLINDERS VIA BAR CODE

Each “Colorado Approved” label will contain a bar code to be scanned whenever a cylinder of 

calibration/span gas is put into service on a Colorado 94 analyzer or Motor Vehicle Dealer Transient 

Mode Test Analyzer System scanned information will be stored in a file, accessible through a host 

computer linking all inspection stations. AIR Program QA/QC personnel will be able to locate individual 

cylinders, track batches of span gas, etc., throughout the program area.

Label bar codes will be generated at the time of batch or lot approval and will contain information 

necessary to facilitate the tracking process. Blenders are required to continue to track internally, the 

whereabouts of “Colorado Approved” batches of calibration/span gas prior to retail sale. In the event of a 

recall of a batch of non-conforming calibration/span gas, the blender, through procedure described herein 

(see 4.2), will begin recall. In-use calibration/span gas affected will be identified by bar code information 

through system host and replacement procedures will begin.

SECTION 6 COLORADO APPROVAL PROCESS

6.0 CALIBRATION STANDARDS AND AUDIT GASES

All calibration standards used in the Colorado Enhanced IM & IG 240 AIR Program must be submitted by 

the contractor to the state for approval and labeling as “Colorado Approved”. In addition, all audit gases 

utilized by AIR Program QA/QC teams will undergo the same verification and/or renaming process that 

will take place at the Colorado AIR Program standards lab (CAPSL) in Broomfield, Colorado. At CAPSL, 

each standard and/or audit gas will be read vs. program gold standards, named by EPA's NVFEL, in an 

effort to tie all primary gases to one source, regardless of manufacturer.

Each calibration standard and audit gas will receive a “Colorado Approved” label displaying the 

concentration of each major component as determined by analysis comparing such calibration standard 

or audit gas to the program gold standards. Labeled values are to be used in curve generation by the 

contractor and by audit teams to verify analyzer accuracy.

6.1 ZERO AIR/OXYGEN CONTENT

On a random basis, cylinders of zero air will be analyzed at CAPSL to verify oxygen content. As 

previously stated, the oxygen content of artificial blended air shall be 20.6 to 21 %. This is necessary to 

insure that an air cylinder used as a backup to a zero air generator (zag), will provide air as close to 

ambient in 02 as possible, should a zag be taken offline. FID response has been shown to be greatly 

affected by the O2 content of oxidizer air. Random analysis will provide verification that O2 content in 

zero air is within specifications.

SECTION 7 BLENDER FACILITY REQUIREMENTS & DOCUMENTATION

7.0 GENERAL

(A) A gas blender who intends to supply calibration/span gas to the Colorado AIR Program 

basic inspection stations and/or enhanced program contractor(s), must be selected by 

the Colorado Department of Public Health & Environment pursuant to 42-4-

306(3)(A)(l)(C).

(B) If a company has more than one facility that will be providing gases to Colorado, each 

must be included in the selection. The selection of one blending facility owned by a 
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Adopted: November 21, 2013 Page 193

company does not imply or impart authority to other facilities within that company to 

supply precision gas products in Colorado.

(C) The CDPHE shall be notified of a pending sale of a blending facility at least 60 days prior 

to change of ownership.

(D) Contracts shall be for a one year period, but may be renewed annually.

7.1 CONTRACT PROPOSAL PACKET

The certification request packet shall contain information described in the following paragraphs. 

Information submitted should be as complete as possible. However, should some information be 

unavailable, so indicate and provide reasons, therefore, for AIR Program consideration.

7.2 CONFIDENTIAL AND COMMERCIAL INFORMATION

To the extent authorized by 24-72-101, C.R.S., the Colorado Department of Public Health & Environment 

shall maintain the confidentiality of any information which is included in the blender's bid and which is 

clearly marked as proprietary or confidential.

7.3 APPLICATION

The following items are to be included in blenders request for air program approved status:

(A) COVER SHEET - An application cover sheet must be signed by the President or Chief 

Financial Officer of the gas blending company.

(B) BLENDING FACILITY DESCRIPTION-Provide a complete description of the blending 

facility to include:

— Facility location

— Physical dimensions of lab and production areas

— Number of employees

— General description of blending facility and procedures

(C) INSTRUMENTATION - Provide description of all instrumentation utilized in the blending 

and analysis of AIR Program calibration/span gases. Provide instrumentation brand, 

model, type (NDIR, FID, GC, etc.). As well as calibration and maintenance schedules and 

personnel responsible.

(D) REFERENCE STANDARDS - Indicate the cylinder numbers, SRM/CRM numbers, 

concentrations and expiration dates for each NIST traceable reference standard to be 

used in the preparation and/or naming of AIR Program gases.

(E) BUSINESS STATUS REPORT - Application for certification shall contain information to 

verify blending facility's status as a bona fide blender of precision gases. Include 

evidence that applicant is a registered corporation in Colorado and/or a registered out-ofstate corporation.
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Adopted: November 21, 2013 Page 194

(F) DISTRIBUTORS AND MARKETING - Applicant shall provide a description of expected 

distribution and marketing plans for providing calibration/span gas to the basic AIR 

program. Include a current listing of the names, addresses and phone numbers of the 

distributors used by the applicant. Such information shall be updated as necessary and 

notification of any change provided to the state in a timely manner. Lists of distributors 

will be made available to AIR Program inspection stations.

(G) RECALL OF NON-CONFORMING GASES/BASIC PROGRAM - Certified blenders shall 

be responsible for the recall and replacement of non-conforming calibration/span gases. 

Blenders will be required to replace suspected non-conforming cylinders by overnight 

service. Should such a discovery extend past a single cylinder to a batch or lot, a total 

recall of all cylinders will take place. (See Section 4).

Applicant shall provide procedures intended for use should such a recall be necessary.

(H) QUALITY ASSURANCE - Applicant shall include information regarding internal quality 

assurance program(s). Provide details of techniques, methodology and documentation 

utilized in QA program. Include calibration and maintenance schedules for all equipment 

and instrumentation used.

(I) SAFETY REGULATIONS - Certification application must include assurance the applicant 

is in compliance with all applicable DOT and OSHA regulations and standards.

(J) LIABILITY - Provide a copy of product liability insurance demonstrating adequate 

protection (minimum $300,000) exists for catastrophic failure situations (e.g., cylinder or 

valve rapture, noxious gas leakage, etc.). Evidence of bonding coverage shall be 

provided upon request.SECTION 1 DEFINITIONS

AIR: Colorado's “Automotive Inspection & Readjustment” Program.

ANALYTICAL ACCURACY: The relative percent deviation of the stated concentration of the components 

of a gas blend from the “true” value as determined by comparison with Colorado AIR Program standards.

(% DEV = STATED CONC - “TRUE” CONC/“TRUE” CONC X 100)

AUDIT GAS: Reference gas standards with direct traceability to NIST and/or EPA, to be used by AIR

Program QA/QC personnel.

APCD: Colorado “Air Pollution Control Division”.

AUTHORIZED GAS BLENDER: A blender of precision gas products selected to provide such products 

pursuant to the requirements of 42-4-306(3)(A)(l)(C).

BALANCE GAS: The balance or makeup gas for Colorado AIR Program gases shall be as follows: for 

basic program tri-blend span gases, nitrogen shall be the balance gas. For the enhanced IM 240 program 

standards and span gases, air shall be the balance gas. The balance gas for mixtures containing nitric 

oxide (NO) shall be nitrogen.

BAR: California “Bureau of Automotive Repair”

BLEND TOLERANCE: Deviation between the requested or nominal concentration and the measured or 

certified concentration of a gas mixture.
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Adopted: November 21, 2013 Page 195

CALIBRATION STANDARD: A precision blended gas used to generate calibration curves, with an 

analytical accuracy of +/- 1%, traceable to NIST gas standards. (Enhanced Program)

CALIBRATION/SPAN GAS: A blend of carbon monoxide (CO), carbon dioxide (CO2), and propane, with 

a balance gas of nitrogen (NO2), which is used to calibrate the Colorado 94 test analyzers. (Basic 

program)

CALIBRATION ZERO AIR: The gas used as a diluent for gas dividers or to establish analyzer zero 

during calibration curve generation. Impurities shall not exceed 0.1 ppm carbon response, 0.5 ppm CO, 1 

ppm CO2, 0.1 ppm NOx, and 1 ppm moisture. Blended air shall have oxygen content between 20.6% and 

21%

CALIBRATION ZERO NITROGEN: The gas used as a diluent for gas dividers or to establish analyzer 

zero during calibration curve generation shall have a minimum purity of 99.997% with impurities not to 

exceed 0.1 ppm carbon response, 0.5 ppm CO, 1 ppm CO2, 0.1 ppm NOx, 1 ppm moisture and 0.5 ppm 

O2.

CAPSL: Colorado AIR Program Standards Lab.

CDPHE: Colorado Department of Public Health & Environment.

CERTIFIED GAS BLENDER: A blender of precision gas products, approved by the Colorado AIR 

Program. A certified blender has met or exceeded the requirements set forth by the CDPHE to provide a 

consistently high quality calibration and span gas to both the Basic and Enhanced Air Program.

CGA: Compressed Gas Association

CRM: Certified Reference Material

DOT: Department of Transportation

FID: HC analyzer using a flame ionization detector

FED FUEL: A mixture of 40% hydrogen (+/- 2%) and 60% helium

FID OXIDIZER: Zero grade air with oxygen content between 20.6% And 21 %

GOLD STANDARDS: NIST traceable air program standards named by EPA at the National Vehicle Fuels 

and Emission lab (NVFEL), Ann Arbor, Michigan

NIST: National Institute of Standards and Technology

STATE: The State of Colorado

SRM: Standard reference material. The highest integrity gas standard, prepared by, and only available 

from, NIST.

VETC: Vehicle Emission Technical Center, 15608 East 18th Avenue, Aurora, Colorado 80011.

WORKING SPAN GAS: Gases used in the enhanced IM 240 Air Program for high and mid-scale span 

checks and/or adjustments as well as analyzer cross-checks. These gases shall have an analytical 

accuracy of +/- 2%.
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Adopted: November 21, 2013 Page 196

WORKING ZERO GAS: Air or nitrogen used in the daily zeroing of enhanced program analyzers. 

Impurities shall not exceed 1 ppm carbon response, 2 ppm CO, 0.04% C02, 0.3 ppm NOx, and 1% 

moisture. Air shall have oxygen content between 20.6% and 21%. Nitrogen shall contain a maximum of 

0.5% O2.

SECTION 2 BASIC & ENHANCED IDLE AIR PROGRAM/TECHNICAL REQUIREMENTS

2.0 GENERAL

This section describes the calibration/span gas requirements, specifications for these gases, and 

types of cylinders allowed. Such specifications shall be included in any request for bids issued 

pursuant to 42-4-306(3)(a)(l)(c).

2.1 GAS REQUIREMENTS

The following identifies the calibration/span gas blends required for the Colorado basic & 

enhanced idle AIR Program:

CALIBRATION/SPAN GASES

AIR94LOW

300 ppm Propane (as THC)

1.0 % Carbon Monoxide

6.0 % Carbon Dioxide

Balance Nitrogen

AIR94MID

1200 ppm Propane (as THC)

4.0 % Carbon Monoxide

12.0 % Carbon Dioxide

Balance Nitrogen

2.2 GAS BLEND ACCURACIES

The combined errors due to blending and naming of the above calibration/span gases shall not 

exceed +/- 2% for each component.

2.3 ANALYTICAL ACCURACY

The analytical accuracies for idle air program gases are:

(A) Calibration/span gas: +/-2% of nominal value
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Adopted: November 21, 2013 Page 197

(B) Audit gases: +/- 1% of nominal value

2.4 BLEND TOLERANCE

Zero blend tolerance is required for basic & enhanced idle AIR Program calibration span gases.

2.5 BLENDER REFERENCE STANDARDS

Each authorized gas blender shall present documentation of its own internal standards for 

approval. The state provides two methods for standard documentation:

(I) Blender may prepare a reference cylinder of each gas blend intended for the AIR 

Program to be named vs. Colorado's gold standards. Cylinder(s) shall be sent to 

the state for naming and labeling. This standard will become the blender's 

reference standard for the analysis of production span gases.

NOTE: The associated costs of shipping reference cylinders to and from Colorado will be 

the responsibility of the blender. No shipping costs will be borne by the state.

(II) Blenders certified by the State of California, Bureau of Automotive Repair, may 

elect to submit copies of their current certification including a listing of all SRM's, 

CRM's, or other reference gases accepted by bar, as pertaining to the analysis of 

I/M span gases. BAR acceptance of these standards will be sufficient to obtain 

approval of same for the AIR Program.

2.6 CYLINDERS

The cylinders to be used in the Colorado 94 analyzers in the field shall be low pressure, non 

refillable, disposable canisters.

High pressure, refillable cylinders will be used by AIR Program audit/QC teams and, in some 

cases, by analyzer manufacturers. Approval of span gas in high pressure cylinders will be on an 

individual basis. (See Section 3)

2.7 DISPOSABLE CYLINDERS

(A) Disposable cylinders shall be in accordance with dot specification 39 for non 

refillable, disposable cylinders. (260 PSIG service pressure, 325 PSIG test 

pressure, 650 PSIG minimum burst pressure) [CFR Title 49, Part 178, Section 

178.65, Oct 1, 1996]

(B) Nominal size shall not exceed 750 cubic inches +/- 5% (approximately 9 inches 

inside diameter by 16 inches high, providing an equivalent water capacity of 27 

lbs.) As a minimum, cylinders shall contain 7.5 cubic feet of gas blend at 260 

PSIG cylinder pressure.

(C) Cylinders shall be designed with an integral stand to facilitate upright storage.

(D) Cylinder outlet shall be CGA 165, 1/4” SAE flare, 45 degree male. Shutoff valves 

shall be of the non refillable type.
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Adopted: November 21, 2013 Page 198

(E) Cylinders shall be equipped with a safety relief device in accordance with DOT 

regulations [CFR 49, 173.34,(D), Oct, 1996]. The safety relief device must 

comply with the requirements of the compressed gas association pamphlet S.1.1, 

8th Edition, 1994.

(F) Cylinders shall have a built in safety shield to protect the shut off valve.

(G) No material shall be used in cylinder fabrication or assembly, or in cylinder 

charging equipment, which is incompatible with the gas blend as to cause 

contamination or degradation.

(H) Blenders must comply with applicable DOT specifications for the shipment of 

cylinders. [CFR Title 49, Volume 2, Part 173, Subpart B, Oct, 1996].

2.8 HIGH PRESSURE REFILLABLE CYLINDERS

(A) Refillable cylinders must be aluminum and made in accordance with DOT 

specifications 3AA or 3AL [CFR Tide 49, Volume 2, Part 178, Subpart C, Oct, 

1996], whichever is applicable.

(B) All cylinders must comply with applicable DOT Regulations and requirements for 

safety and shipment. [CFR Title 49, Volume 2, Part 173, Subpart B, Oct, 1996]

2.9 LABELING

(A) Caution labels shall be affixed to all cylinders and shall comply with applicable 

DOT and OSHA regulations.

(B) “Colorado Approved” labels will be provided by the Colorado AIR Program 

(Section 3) and shall be affixed to the upper portion of the canisters.

2.10 EXPIRATION

Triblend span gas cylinders containing CO, CO2, and propane in nitrogen, shall have an 

expiration date of 36 months after date of fill.

2.11 QUALITY ASSURANCE

All gas blenders shall have in place a fully documented and implemented quality assurance 

program as a prerequisite to certification. This QA program shall include, but not be limited to:

(A) Regular equipment maintenance and calibration, performed in accordance with 

manufacturer guidelines, as a minimum.

(B) Documentation of the analysis of each batch or lot of gas produced. A copy of 

the certificate of analysis from each batch or lot shall accompany each approval 

request.

(C) Blender may choose to retain a cylinder from each batch/lot for internal 

documentation. However, one cylinder from each batch/lot must accompany 

each request for “Colorado Approved” labels. This sample cylinder will not be 

returned.
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Adopted: November 21, 2013 Page 199

(D) Documentation of maintenance and calibration of equipment and instrumentation 

shall be made available upon request.

2.12 BREACH OF TERMS

Each contract entered into pursuant to 42-4-306(3)(a)(l)(C), shall authorize the APCD to suspend 

the blender's authority to supply precision gas products to inspection and readjustment stations, 

inspection-only facilities, fleet inspection stations, motor vehicle dealer facilities and enhanced 

inspection centers in the event the gas blender violates the terms of the contract and this 

appendix B. The APCD may terminate such a suspension once the blender corrects the problems 

that led to the violation. An onsite inspection of the blender's facility by an APCD representative 

may be required to ensure that the relevant requirements are being observed.

SECTION 3 CALIBRATION/SPAN GAS APPROVAL & LABELING

3.0 GENERAL

Information in this section describes the calibration/span gas approval process as well as the 

procedure for obtaining “Colorado Approved” labels.

3.1 CALIBRATION SPAN GAS APPROVAL PROCEDURE

Batches or lots of span gas will be produced referencing procedures and specifications contained 

herein. Authorized blender shall analyze a representative number of cylinders from each batch or 

lot. Authorized blender shall then request from the CDPHE a number of Colorado approved labels 

corresponding to the number of cylinders in that batch or lot. The request for labels must include:

(I) Analytical report to contain:

(A) Actual analysis of samples in batch

(B) Number of cylinders in batch

(C) Fill date

(D) Number of labels required

(E) Batch or lot number

(II) One representative cylinder from each batch or lot of span gas produced to be 

verified by analysis and retained for future reference.

NOTE: This sample cylinder will not be returned. Cylinder will be archived by the state 

until the expiration date expires (36 months from fill date). This sample may be analyzed 

as a spot check or reference gas in matters concerning potential inquiries into batch 

integrity.

Upon approval, blender will be sent an appropriate number of “Colorado Approved” labels 

to be affixed to cylinders in that batch or lot.

Samples, along with request for “Colorado Approved” labels, should be sent to: CDPHE
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Adopted: November 21, 2013 Page 200

VEHICLE EMISSION TECHNICAL CENTER

15608 E. 18TH AVENUE

AURORA, COLORADO 80011

ATTN: SPAN GAS VERIFICATION PROGRAM

3.2 CALIBRATION/SPAN GAS APPROVAL/HIGH PRESSURE CYLINDERS

Approval of calibration/span gases in high pressure cylinders will be done on an individual basis. 

Each cylinder seeking approval must be submitted for verification against AIR Program 

standards. A certificate of analysis shall accompany each cylinder and shall contain the following 

information:

(A) Cylinder number

(B) Components contained

(C) Analytical results

(D) Analytical accuracy

(E) Statement of traceability

(F) Analysis date

(G) Fill date

Upon approval, blender will be notified that the cylinder is ready for pickup by the purchaser. 

Approved cylinder, with “Colorado Approved” label attached, may be picked up during normal 

business hours (8:00 am - 5:00 pm) Monday through Friday. Cylinders shall be sent to the above 

address.(See 3.1)

3.3 SHIPPING COSTS

Blenders shall provide for the shipping of all cylinders seeking Colorado approval for use in the 

AIR Program. The pick-up and delivery of individual high pressure cylinders is also the 

responsibility of the blender and/or the purchaser of that cylinder. These cylinders are expected to 

be picked-up within 30 days of notification of approval. No costs pertaining to the pick-up or 

delivery of span gases shall be borne by the state.

3.4 LABELING

“Colorado Approved” labels will be provided by the State of Colorado. These labels will include 

information necessary to track span gases throughout the system as well as identify each cylinder 

as Colorado approved. Information contained on the label will include:

(A) Blender name

(B) Blending facility
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Adopted: November 21, 2013 Page 201

(C) Batch or lot number

(D) Identify “low” (yellow label) or “mid” (white label) SPAN GAS

(E) Fill date

(F) Expiration date

(G) AIR Program number

(H) Bar code containing cylinder tracking information

(For a sample of the “Colorado Approved” labels, see attachment II)

3.5 AIR PROGRAM NUMBER

“Colorado Approved” labels will contain an AIR Program number. Each certified blender will be 

assigned a letter code that will precede the numbering of batch cylinders. These coded numbers 

will be generated by the state and assigned to each cylinder as batches of span gas are 

produced. Cylinder numbers will be held on file for the life span of the cylinder to assist in 

tracking, auditing and accounting purposes.

SECTION 4 CYLINDER TRACKING & RECALL

4.0 GENERAL

This section describes the method of tracking calibration/span gas throughout the AIR Program 

area. This system protects the inspection stations and provides for a replacement, in an 

expedient manner, should a non-conforming calibration/span gas be discovered.

4.1 TRACKING CYLINDERS VIA BAR CODE

Each “Colorado Approved” label will contain a bar code to be scanned whenever a cylinder of 

calibration/span gas is put into service on a Colorado 94 analyzer or Motor Vehicle Dealer 

Transient Mode Test Analyzer System. Scanned information will be stored in a file, accessible 

through a host computer linking all inspection stations. AIR Program QA/QC personnel will be 

able to locate individual cylinders, track batches of span gas, etc., throughout the program area.

Label bar codes will be generated at the time of batch or lot approval and will contain information 

necessary to facilitate the tracking process. Blenders are required to continue to track internally, 

the whereabouts of “Colorado Approved” batches of calibration/span gas prior to retail sale. In the 

event of a recall of a batch of non-conforming calibration/span gas, the blender, through 

procedure described herein (see 4.2), will begin recall. In-use calibration/span gas affected will be 

identified by bar cod; information through system host and replacement procedures will begin.

4.2 RECALL PROCEDURE

In the event a non-conforming cylinder of calibration/span gas is discovered at an AIR Program 

inspection station, the following recall procedure will begin:

(A) Suspected non-conforming span gas confiscated by AIR Program Q/C 

personnel;
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Adopted: November 21, 2013 Page 202

(B) Cylinder brought to the Colorado AIR Program Standards Lab (CAPSL) for 

analysis;

(C) Exposed non-conforming cylinder cross referenced by air number go blender and 

batch;

(D) Archived sample retrieved and analyzed vs. suspected non-conforming cylinder. 

Blender advised of results;

(E) Through host system, the state identifies whereabouts of any non-conforming 

cylinders on line. Blender provided with a listing of affected inspection stations;

(F) Blender shall immediately begin recall of all remaining unsold cylinders from 

batch in question and, simultaneously, begin process of supplying known 

conforming cylinder(s) to affected inspection stations by overnight service;

(G) A total recall and replacement of all cylinders in affected batch must be

completed within 10 days. A detailed report of the recall procedure and analysis 

of cause of the non-conforming product entering the system will be provided to 

the state within 15 days.

(H) The state may elect to withhold certification of future batches until such time as 

blender shows problems have been corrected.

(I) The state may also suspend the contract with the blender if information obtained 

suggests blending procedures were violated, pending a correction of the 

problems that caused the violation.

SECTION 5 ENHANCED IM & IG 240 AIR PROGRAM / TECHNICAL REQUIREMENTS

5.0 GENERAL

This section addresses the calibration gases, technical requirements, cylinder specifications and 

documentation required for IM & IG 240 testing.

5.1 GASES

Gases used in the calibration and support of IM & IG 240 testing shall conform to the provisions 

outlined in CFR Title 40, Part 86, Subpart B, Section 114, as revised July 1, 1992, for exhaust 

emission testing. Concentrations for IM 240 gases are as follows:

5.2 CALIBRATION GASES/CURVE GENERATION

(I) High tri-blends: (+/-1% analytical accuracy)

CO:9000 ppm

C02:3.6%

Propane:600 ppm

Balance: Air
Regulation Number 11

Adopted: November 21, 2013 Page 203

(II) High NOx: (+/-1%)

NOx:450 ppm

Balance: Nitrogen

5.2.1 MID-SCALE CALIBRATION GASES/CURVE CONFORMATION

(I) Mid tri-blend: (+1-1%)

CO:4500 ppm

C02:1.8 %

Propane:300 ppm

Balance: Air

(II) Mid NOx tri-blend: (+/-1%)

NOx:225 ppm

Balance: Nitrogen

5.2.2 CALIBRATION ZERO GASES

(I) Calibration zero AIR

HC : < 0.1 ppm

CO : < 0.5 ppm

C02 : < 1.0 ppm

NOx : < 0.1 ppm

Moisture : < 1.0 ppm

02: 20.6 % - 21.0 %

(II) Calibration zero Nitrogen

Purity : 99.997 %

HC : < 0.1 ppm

CO : < 0.5 ppm

CO2 : < 1.0 ppm

NOx : < 0.1 ppm
Regulation Number 11

Adopted: November 21, 2013 Page 204

Moisture : < 1.0 ppm

O2 : < 0.5 ppm

5.3 DAILY SPAN GASES

(I) High tri-blend span (+/-2% analytical accuracy)

CO : 8000 ppm

C02 : 3.2 %

Propane : 535 ppm

Balance : Air

(II) NOx mid span (+/-2%)

NOx : 75 ppm

Balance : Nitrogen

5.4 WORKING ZERO GASES

(I) Working zero AIR

HC : < 0.1 ppm

CO : < 2.0 ppm

CO2 < 400 ppm

NOx < 0.3 ppm

Moisture < 1.0 ppm

OY2 : 20.6-21.0 %

(II) Working zero Nitrogen

Purity : 99.997%

HC : < 1.0 ppm

CO : < 2.0 ppm

C02 : < 400 ppm

NOx : < 0.3 ppm

Moisture : < 1.0 ppm
Regulation Number 11

Adopted: November 21, 2013 Page 205

02 : < 0.5 ppm

5.5 SUPPORT GASES

A variety of miscellaneous support gases are required for IM & IG 240 testing. Among these are:

GAS USAGE

Propane : 99.5% (min) CVS system flow checks

Methane : 50 ppm/AIR FID check gas

FID Fuel: 40% H2/60% HE FID burner fuel

N02 : 200 ppm/N2 NOx converter efficiency 

test gas

AIR : 18%-21% NOx ozonator gas

5.6 IG 240 GASES

Calibration, span, working and support gases required by IG 240 systems, are among the gases 

listed (5.2 thru 5.5). Additional gases of specific concentrations and blend make-up may be 

required pending final configuration of the IG system.

5.7 CYLINDERS

Calibration and working gas tri or quad-blends used for IM & IG 240 testing, must be supplied in 

aluminum cylinders as well as all no or NOx blends. Other gases may be supplied in steel or 

aluminum cylinders as appropriate.

High pressure refillable cylinders shall be manufactured in accordance with DOT specifications 

3AL or 3AA [CFR Title 49, Volume 2, Part 178, Subpart C, Oct l, 1996], whichever is applicable.

Approved valves and relief devices, appropriate for the intended use, shall be used on all high 

pressure cylinders. [CFR Title 49, Volume 2, Subpart B, Section 173.124, Oct 1, 1996]

All cylinders shall have appropriate labeling to comply with all DOT regulations concerning 

transportation and safety. [CFR 49, Volume 2, Part 173, Subpart B, Oct 1, 1996].

5.8 MISCELLANEOUS

A full line of gas products shall be made available to the enhanced AIR Program contractor(s) to 

insure safe handling and storage of gas cylinders, such as regulators, carts, restraints, and leak 

detection equipment. The contractor(s), as well as state QA/QC personnel, may also request a 

variety of gas blends, tri-blends, and other specialty gas products associated with automotive 

emission testing. Blender must demonstrate the ability to provide the above gases, equipment 

and associated products, in order to be designated as an approved blender to the Colorado 

enhanced AIR Program.
Regulation Number 11

Adopted: November 21, 2013 Page 206

5.9 CERTIFICATES OF ANALYSIS

Each calibration gas, working span gas, and calibration zero gas shall be documented by a 

certificate of analysis to include; cylinder number, components, analytical results, accuracy, 

traceability and analysis date. A batch analysis certificate stating purity may document zero grade 

air and nitrogen. (Zero AIR certificate must also provide documentation of oxygen content.)

The enhanced program contractor(s) must produce documentation of cylinder contents of the 

above upon request of state QA/QC personnel.

5.9.1 TRACKING CYLINDERS VIA BAR CODE

Each “Colorado Approved” label will contain a bar code to be scanned whenever a 

cylinder of calibration/span gas is put into service on a Colorado 94 analyzer or Motor 

Vehicle Dealer Transient Mode Test Analyzer System scanned information will be stored 

in a file, accessible through a host computer linking all inspection stations. AIR Program 

QA/QC personnel will be able to locate individual cylinders, track batches of span gas, 

etc., throughout the program area.

Label bar codes will be generated at the time of batch or lot approval and will contain 

information necessary to facilitate the tracking process. Blenders are required to continue 

to track internally, the whereabouts of “Colorado Approved” batches of calibration/span 

gas prior to retail sale. In the event of a recall of a batch of non-conforming 

calibration/span gas, the blender, through procedure described herein (see 4.2), will 

begin recall. In-use calibration/span gas affected will be identified by bar code information 

through system host and replacement procedures will begin.

SECTION 6 COLORADO APPROVAL PROCESS

6.0 CALIBRATION STANDARDS AND AUDIT GASES

All calibration standards used in the Colorado Enhanced IM & IG 240 AIR Program must be 

submitted by the contractor to the state for approval and labeling as “Colorado Approved”. In 

addition, all audit gases utilized by AIR Program QA/QC teams will undergo the same verification 

and/or renaming process that will take place at the Colorado AIR Program standards lab (CAPSL) 

in Broomfield, Colorado. At CAPSL, each standard and/or audit gas will be read vs. program gold 

standards, named by EPA's NVFEL, in an effort to tie all primary gases to one source, regardless 

of manufacturer.

Each calibration standard and audit gas will receive a “Colorado Approved” label displaying the 

concentration of each major component as determined by analysis comparing such calibration 

standard or audit gas to the program gold standards. Labeled values are to be used in curve 

generation by the contractor and by audit teams to verify analyzer accuracy.

6.1 ZERO AIR/OXYGEN CONTENT

On a random basis, cylinders of zero air will be analyzed at CAPSL to verify oxygen content. As 

previously stated, the oxygen content of artificial blended air shall be 20.6 to 21 %. This is 

necessary to insure that an air cylinder used as a backup to a zero air generator (zag), will 

provide air as close to ambient in 02 as possible, should a zag be taken offline. FID response has 

been shown to be greatly affected by the O2 content of oxidizer air. Random analysis will provide 

verification that O2 content in zero air is within specifications.
Regulation Number 11

Adopted: November 21, 2013 Page 207

SECTION 7 BLENDER FACILITY REQUIREMENTS & DOCUMENTATION

7.0 GENERAL

(A) A gas blender who intends to supply calibration/span gas to the Colorado AIR 

Program basic inspection stations and/or enhanced program contractor(s), must 

be selected by the Colorado Department of Public Health & Environment 

pursuant to 42-4-306(3)(A)(l)(C).

(B) If a company has more than one facility that will be providing gases to Colorado, 

each must be included in the selection. The selection of one blending facility 

owned by a company does not imply or impart authority to other facilities within 

that company to supply precision gas products in Colorado.

(C) The CDPHE shall be notified of a pending sale of a blending facility at least 60 

days prior to change of ownership.

(D) Contracts shall be for a one year period, but may be renewed annually.

7.1 CONTRACT PROPOSAL PACKET

The certification request packet shall contain information described in the following paragraphs. 

Information submitted should be as complete as possible. However, should some information be 

unavailable, so indicate and provide reasons, therefore, for AIR Program consideration.

7.2 CONFIDENTIAL AND COMMERCIAL INFORMATION

To the extent authorized by 24-72-101, C.R.S., the Colorado Department of Public Health & 

Environment shall maintain the confidentiality of any information which is included in the blender's 

bid and which is clearly marked as proprietary or confidential.

7.3 APPLICATION

The following items are to be included in blenders request for air program approved status:

(A) COVER SHEET - An application cover sheet must be signed by the President or 

Chief Financial Officer of the gas blending company.

(B) BLENDING FACILITY DESCRIPTION-Provide a complete description of the 

blending facility to include:

— Facility location

— Physical dimensions of lab and production areas

— Number of employees

— General description of blending facility and procedures

(C) INSTRUMENTATION - Provide description of all instrumentation utilized in the 

blending and analysis of AIR Program calibration/span gases. Provide 
Regulation Number 11

Adopted: November 21, 2013 Page 208

instrumentation brand, model, type (NDIR, FID, GC, etc.). As well as calibration 

and maintenance schedules and personnel responsible.

(D) REFERENCE STANDARDS - Indicate the cylinder numbers, SRM/CRM 

numbers, concentrations and expiration dates for each NIST traceable reference 

standard to be used in the preparation and/or naming of AIR Program gases.

(E) BUSINESS STATUS REPORT - Application for certification shall contain 

information to verify blending facility's status as a bona fide blender of precision 

gases. Include evidence that applicant is a registered corporation in Colorado 

and/or a registered out-of-state corporation.

(F) DISTRIBUTORS AND MARKETING - Applicant shall provide a description of 

expected distribution and marketing plans for providing calibration/span gas to 

the basic AIR program. Include a current listing of the names, addresses and 

phone numbers of the distributors used by the applicant. Such information shall 

be updated as necessary and notification of any change provided to the state in a 

timely manner. Lists of distributors will be made available to AIR Program 

inspection stations.

(G) RECALL OF NON-CONFORMING GASES/BASIC PROGRAM - Certified 

blenders shall be responsible for the recall and replacement of non-conforming 

calibration/span gases. Blenders will be required to replace suspected nonconforming cylinders by overnight service. Should such a discovery extend past 

a single cylinder to a batch or lot, a total recall of all cylinders will take place. 

(See Section 4).

Applicant shall provide procedures intended for use should such a recall be necessary.

(H) QUALITY ASSURANCE - Applicant shall include information regarding internal 

quality assurance program(s). Provide details of techniques, methodology and 

documentation utilized in QA program. Include calibration and maintenance 

schedules for all equipment and instrumentation used.

(I) SAFETY REGULATIONS - Certification application must include assurance the 

applicant is in compliance with all applicable DOT and OSHA regulations and 

standards.

(J) LIABILITY - Provide a copy of product liability insurance demonstrating adequate 

protection (minimum $300,000) exists for catastrophic failure situations (e.g., 

cylinder or valve rapture, noxious gas leakage, etc.). Evidence of bonding 

coverage shall be provided upon request.

APPENDIX B

ATTACHMENT I Program Contact/Addresses/Phone Numbers I TO THE CALIBRATION AND 

SPAN GAS CERTIFICATION PROCEDURES

ATTACHMENT I

PROGRAM CONTACT/ADDRESSES/PHONE NUMBERS
Regulation Number 11

Adopted: November 21, 2013 Page 209

PROGRAM CONTACT; The main contact on matters concerning air program gases, requirements and 

specifications is:

COLORADO DEPARTMENT OF PUBLIC HEALTH & ENVIRONMENT

VEHICLE EMISSION TECHNICAL CENTER

15608 EAST 18TH AVENUE

AURORA, COLORADO 80011

(303) 364-4135

ATTN: SPAN GAS VERIFICATION PROGRAM

OR

COLORADO AIR PROGRAM STANDARDS LAB

11609 TELLER STREET

BROOMFIELD, COLORADO 80020

(303) 404-0268

COLORADO DEPARTMENT OF PUBLIC HEALTH & ENVIRONMENT

VEHICLE EMISSION TECHNICAL CENTER

15608 EAST 18TH AVENUE

AURORA, COLORADO 80011

(303) 364-4135

ATTN: SPAN GAS VERIFICATION PROGRAM

OR

COLORADO AIR PROGRAM STANDARDS LAB

11609 TELLER STREET

BROOMFIELD, COLORADO 80020

(303) 404-0268.

APPENDIX B

ATTACHMENT II “Colorado Approved” Label Samples

TO THE CALIBRATION AND SPAN GAS CERTIFICATION PROCEDURES

Appendix B – Attachment II
Regulation Number 11

Adopted: November 21, 2013 Page 210
Regulation Number 11

Adopted: November 21, 2013 Page 211
Colorado Air Quality Control Commission

Meeting Minutes

40 CFR Part 51 Appendix V 2.1(g)
STATE OF COLORADO

John W. Hickenlooper, Governor

Larry Wolk, MD, MSPH

Executive Director and Chief Medical Officer

COLORADOAIR QUALITY CONTROL COMMISSION

http://www.cdphe.state.co.us

4300 Cherry Creek Drive South

EDO-AQCC-A5

Denver, Colorado 80246-1530

Phone (303) 692-3100

Fax (303) 691-7702

TDD (303) 691-7700

Colorado Department

of Public Health 

and Environment

Colorado Air Quality Control Commission

November 21, 2013

MEETING MINUTES

Location: Colorado Department of Public Health & Environment

4300 Cherry Creek Drive South, Sabin Room

Denver, CO 80246

Members Present: Saeed Barhaghi David Brown Ashley Campsie

John Clouse Teresa Coons John Loewy

Jana Milford Laura Teague Will Toor

Members Absent: None

Commission Staff: Mike Silverstein Theresa Martin

Division Staff: Will Allison Garry Kaufman Daniel Bon

Gordon Pierce Pat McLaughlin

Attorney General’s Office: Tom Roan

______________________________________________________________________________

CALL TO ORDER AND DETERMINATION OF A QUORUM

Chair Loewy called the meeting to order at 9:22 AM and determined that a quorum of 

Commissioners was present with six Commissioners. Loewy noted that due to the inclement 

weather and the delay of Commissioner’s Barhaghi, Coons and Toor, items on the agenda would 

be re-arranged to allow the three Commissioners to participate in the Oil & Gas Request for 

Rulemaking Hearing.

CONSENT AGENDA

APPROVAL OF MINUTES

October 17, 2013 Meeting Minutes

Review and approval of the October 17, 2013 meeting minutes of the Air Quality Control 

Commission.
2

RULEMAKING HEARING

Regulation Number 11

The Commission considered housekeeping changes to the vehicle inspection and maintenance 

program.

Motion: To adopt the Consent Agenda items as proposed by the Division

Moved: Commissioner Clouse

Second: Commissioner Campsie

Discussion: none

Carried: 6-0

REGULAR AGENDA

PUBLIC HEARING

Designations for PM2.5 Annual Standard

On December 14, 2012, the U.S. Environmental Protection Agency revised the annual National 

Ambient Air Quality Standard (NAAQS) for fine particulate matter (PM2.5), lowering the 

annual standard to 12 μg/m3. As a result, states are required to submit area designations to EPA 

by December 12, 2013. The Division proposed that the entire state, except for tribal lands, be 

designated as attainment/unclassifiable.

Motion: To adopt the Division designations for PM2.5 Annual Standard and accept 

that the entire state except for tribal lands be designated as 

attainment/unclassifiable

Moved: Commissioner Teague

Second: Commissioner Brown

Discussion: none

Carried: 7-0

BRIEFINGS, DISCUSSIONS AND REPORTS

Commissioner Informational Items

Commissioners had no discussion items.

Division Director’s Report – Will Allison: Allison provided an update on the Division’s flood 

response efforts and EPA’s proposed power plant rule for CO2.

REQUEST FOR RULEMAKING HEARING – FEBRUARY 19, 20 & 21, 2014

Loewy noted that the Division was proposing revisions to Regulation Numbers 3, 6 and 7 and 

that the Commission had noted received the proposed revisions until November 18, 2013. 

Loewy commented that under the Commission’s Procedural Rules that the proposal should have 

been filed with Commission at least thirty days before this meeting. However, Section V.C.2. of 

the Procedural Rules allows the Commission the discretion to grant a petitioner’s request for the 

Commission to hear a late petition upon showing of good cause. Loewy noted that the Division 

had requested that the Commission hear the late petition and described circumstances that may 

be considered good cause.
3

Motion: To acknowledge that the Division had shown good cause and to grant the 

Division’s request for the Commission to entertain this late petition.

Moved: Commissioner Toor

Second: Commissioner Clouse

Discussion: none

Carried: 7-0

Loewy noted that in light of the nature of this request that the Commission should take note of 

the Conflicts of Interest provisions set forth in the Procedural Rules and asked that Tom Roan 

describe the specifics, in which he did so. Loewy asked if any Commissioner wished to disclose 

an apparent or potential conflict. Disclosures were made by the following Commissioners: 

Loewy, Clouse, Campsie, Brown, Milford, Toor, Teague, Coons. No recusals occurred and the 

Request for Rulemaking Hearing began.

Garry Kaufman of the Division provided the presentation to the Commission which included an 

overview of the proposal and the proposed revisions to Regulation Numbers 3, 6 and 7. 

Kaufman noted that the Division was requesting that the Commission set this item for hearing in 

February.

The Commission took public comments on this agenda item. Elected officials from Colorado 

included: Elise Jones, Boulder County Commissioner; State Representatives Max Tyler, Su 

Wright, and Mike Foote; and State Senator Matt Jones. There were many citizens, industry and 

environmental representatives both in person and via the phone provided comment to the 

Commission.

Motion: To grant the Division’s request to consider proposed revisions to Regulation 

Number 3 and set this matter for hearing beginning on February 19, 2014

Moved: Commissioner Teague

Second: Commissioner Milford

Discussion: None

Carried: 9-0

Motion: To grant the Division’s request to consider proposed revisions to Regulation 

Number 6 and set this matter for hearing beginning on February 19, 2014

Moved: Commissioner Teague

Second: Commissioner Coon

Discussion: None

Carried: 9-0

Motion: To grant the Division’s request to consider proposed revisions to Regulation 

Number 7 and set this matter for hearing beginning on February 19, 2014

Moved: Commissioner Teague

Second: Commissioner Campsie

Discussion: None

Carried: 9-0
4

Motion: To direct the Commission staff to take the steps necessary to cause the 

rulemaking process to commence, including the publication of notice.

Moved: Commissioner Teague

Second: Commissioner Coons

Discussion: None

Carried: 9-0

Loewy commented that he would be serving as the Hearing Officer to this rulemaking. Loewy 

noted that the Commission would be accepting alternative proposals and supporting materials on 

the date of the Status Conference, which would be December 19, 2013. If an applicant planned 

to submit an alternative proposal, Loewy requested that such intent be noted in their Request for 

Party Status, which would be due on December 13, 2013.

WORKING SESSION

Climate Change and Greenhouse Gas Workgroup

Patrick Cummins Executive Director, Western Climate Initiative, Inc. (WCI) provided an

overview of WCI’s efforts and recent developments to reduce greenhouse gas emissions in the 

West. Public comment was provided by Dianna Orf.

BRIEFINGS, DISCUSSIONS AND REPORTS

Regulation Number 9: Annual Update

Pat McLaughlin of the Division provided an annual update to the Commission on the projected 

costs for the Smoke Management Program.

Attorney General’s Report – Tom Roan

• Court of Appeals decision regarding CMA vs Urbina, Court ruled in favor of the State

Administrator’s Report – Mike Silverstein

• Cancellation of December 19, 2013 meeting and review January of 2014 agenda items

• An overview of the Regs 3, 6 and 7 prehearing process

PUBLIC COMMENT

Chair Loewy asked if there were any members of the public who wished to make a comment on 

any air pollution issue not on the agenda. Public comment was received from David Wofsey of 

Sonic Spark.

Adjourn at 3:01 PM
Legal Opinion of the Colorado State Attorney General

40 CFR Part 51 Appendix V 2.1(c) and (e)
JOHN W. SUTHERS

Attorney General

CYNTHIA H. COFFMAN

Chief Deputy Attorney

General

DANIEL D. DOMENICO 

Solicitor General

STATE OF COLORADO

DEPARTMENT OF LAW

OFFICE OF THE ATTORNEY GENERAL

RALPH L. CARR

COLORADO JUDICIAL CENTER

1300 Broadway, 10th Floor

Denver, CO 80203

Phone 720-508-6000

Tracking Number: 2013-00908

OPINION OF THE ATTORNEY GENERAL RENDERED IN

CONNECTION WITH THE RULES ADOPTED BY THE

Air Quality Control Commission

ON 11/21/2013

5 CCR 1001-13

REGULATION No. 11 MOTOR VEHICLE EMISSIONS INSPECTION PROGRAM

 

The above-referenced rules were submitted to this office on 11/22/2013 as required by section 24-4-103, C.R.S. This

office has reviewed them and finds no apparent constitutional or legal deficiency in their form or substance.

 

November 27, 2013 13:09:32 MST

JOHN W. SUTHERS

Attorney General

by DANIEL D. DOMENICO

Solicitor General
Regulation or Regulation Revisions as Published in the 

Colorado Code of Regulations

(this is the version that is published by Lexis Nexis)

40 CFR Part 51 Appendix V 2.1(b)
DEPARTMENT OF PUBLIC 

HEALTH AND ENVIRONMENT 

AIR QUALITY CONTROL COMMISSION 

REGULATION NUMBER 11 

MOTOR VEHICLE EMISSIONS INSPECTION PROGRAM 

5 CCR 1001-13 

EDITOR'S NOTES* 

Authority Cited: 

§§ 42-4-306.5 through 42-4-316, C.R.S. (1994 Supplement) as amended. 

History and Amendments: 

Adopted 08/24/78. Pp. 1-40 adopted 11/20/80, EFFECTIVE 12/30/80, 3 CR 12. P. 6 adopted as emergency 

regulation 03/12/81, EFFECTIVE 03/12/81, 4 CR 4. Pp. 1-4.01 adopted 04/09/81, EFFECTIVE 05/30/81, 4 CR 

5. Pp. 1-23 adopted 10/08/81, EFFECTIVE 11/30/81, 4 CR 11. P. 18 adopted as emergency regulation 

01/28/82, EFFECTIVE 01/28/82, 5 CR 3. Pp. 6, 18 adopted 04/22/82, EFFECTIVE 05/30/82, 5 CR 5. Pp. 6, 

14-1.02 adopted 07/22/82, EFFECTIVE 08/30/82, 5 CR 8. Pp. 14-19.02, 23 adopted 11/18/82, EFFECTIVE 

12/30/82, 5 CR 12. Pp. 2-6 adopted 09/22/83, EFFECTIVE 10/30/83, 6 CR 10. Pp. 1-27 adopted 11/10/83, 

EFFECTIVE 01/01/84, 6 CR 12. Pp. 23-25 adopted 01/18/84, EFFECTIVE 11/30/84, 7 CR 11. Pp. 26-27 

adopted 11/15/84, EFFECTIVE 12/30/84, 7 CR 12. Pp. 26-27 adopted 12/19/85, EFFECTIVE 01/30/86, 9 CR 

1. Pp. 1-25 adopted 01/15/87, EFFECTIVE 03/02/87, 10 CR 2. Pp. 1-6, 17-25 adopted 02/18/88, EFFECTIVE 

03/30/88, 11 CR 3. Pp. 1-28 adopted 01/19/89, EFFECTIVE 03/02/89, 12 CR 2. Pp. 1-29 adopted 10/19/89, 

EFFECTIVE 11/30/89, 12 CR 11. Pp. 1-26 adopted 10/18/90, EFFECTIVE 11/30/90, 13 CR 11. Pp. 1-26 

adopted 11/15/90, EFFECTIVE 12/30/90, 13 CR 12. Pp. 1-27 adopted 04/18/91, EFFECTIVE 05/30/91, 14 CR 

5. Pp. 1-164 adopted as emergency regulation 12/16/93, EFFECTIVE 12/16/93, 17 CR 1. Pp. 1-5 adopted 

01/20/94, EFFECTIVE 03/30/94, 17 CR 3. Pp. 1-125 adopted 03/17/94, EFFECTIVE 04/30/94, 17 CR 4. Pp. 1-

115 adopted 09/22/94, EFFECTIVE 11/30/94, 17 CR 11. Pp. 3-6, 17-22, 27-28, 35-38, 51-52, 59-60 adopted as 

emergency regulation 12/15/94, EFFECTIVE 12/15/94, 18 CR 2. Pp. 1-59 adopted 01/19/95, EFFECTIVE 

03/30/95, 18 CR 3. Pp. 1-60.1 adopted 05/18/95, EFFECTIVE 07/30/95, 18 CR 7. Pp. 1-11, 13-14, 19, 28-29, 

32-37, 39-41, 44, 46-4, 51-53 adopted 11/16/95, EFFECTIVE 01/30/96, 19 CR 1. Pp. 1-60 adopted 03/21/96, 

EFFECTIVE 05/30/96, 19 CR 5. Pp. 1-184 adopted 07/17/97, EFFECTIVE 09/30/97, 20 CR 9. 

A.G. Opinions: 

1 AG 392; 3 AG 301; 4 AG 78; 4 AG 100; 4 AG 273; 5 AG 69; 5 AG 114; 5 AG 244; 5 AG 356; 6 AG 285; 6 

AG 364; 7 AG 275; 7 AG 296; 9 AG 20; 10 AG 51; 11 AG 86; 12 AG 48; 12 AG 374; 13 AG 357; 14 AG 399; 

14 AG 145; 17 AG 30; 17 AG 98; 17 AG 143; 17 AG 422; 18 AG 80; 18 AG 117; 18 AG 255; 19 AG 23; 19 

AG 129; 20 AG 270; 

Annotations: 

Part A, Section V. adopted 3/21/96, was not extended by House Bill 97-1193 and therefore expired May 15, 

1997. 

*This Title Page does not constitute an official part of any regulation. Information contained on the Title Page is provided by the Publisher from 

sources deemed reliable and is solely for informational and historical purposes. See cautionary note in Introductory Materials, How to Use the 

CCR. 

©2013 State of Colorado 

All Rights Reserved. (800) 833-9844 
EDITOR'S NOTES (continued) 

History and Amendments: 

Pp. 1-57 adopted 11/19/98, EFFECTIVE 12/30/98, 21 CR 12. Pp. 1-61 adopted 02/19/99, EFFECTIVE 

04/30/99, 22 CR 4. Pp. 7-8.01, 27-28, 51-53, 61-64 adopted 01/10/00, EFFECTIVE 03/01/00, 23 CR 2. Pp. 27-

29, 41, 63-64 adopted 11/16/00, EFFECTIVE 12/30/00, 23 CR 12. Pp. 1-64.01 adopted 12/20/01, EFFECTIVE 

03/02/02, 25 CR 2. Pp. 1-9, 64.2 adopted 07/18/02, EFFECTIVE 09/30/02, 25 CR 9. Pp. 1-28, 64.3-64.4 

adopted 08/15/02, EFFECTIVE 10/30/02, 25 CR 10. Pp. 1-10.2, 19-26.2, 64.5-64.8 adopted 10/17/02, 

EFFECTIVE 12/30/02, 25 CR 12. Pp. 1-64.8 adopted 11/21/02, through I.C.3.b EFFECTIVE 01/30/03, 26 CR 

1. Pp. 1-2, 64.9-64.10 adopted 12/19/02, EFFECTIVE 03/02/03, 26 CR 2. Rules I.C.3 adopted 09/18/03, 

EFFECTIVE 11/30/03, 26 CR 11. Part A (pp. 1-2) and F (pp. 53-54) adopted 12/18/03, EFFECTIVE 03/01/04; 

Pp. 2.2, 3 adopted due to technical correction, 27 CR 2. Part A, Sections IV.D.3, IV.D.4 (p. 9), Part F, Sections 

III.C, IV.B (p. 55), Part G, Section XII (p. 64.12) adopted 03/12/04, EFFECTIVE 05/31/04, 27 CR 5. Part A to 

Part G (pp. 1-64.16) adopted 02/17/05, EFFECTIVE 05/01/05, 28 CR 4. Pp. 1-12, 57-58, new Rule XVIII (p. 

64.18), adopted 11/17/05, EFFECTIVE 01/30/06, 29 CR 1. Part A, II (Definitions), Part C, XII (Subparts A, E), 

Part F, VI (Subpart B), Part G, XIX, and Appendix A (Attachments I and II) adopted 06/21/07, EFFECTIVE 

08/30/07, 30 CR 8. Part A, IV.F. repealed, Part G, Part H (re-lettered from G), XX adopted 10/18/07, 

EFFECTIVE 11/30/07; rule replaced in its entirety due to technical corrections, 30 CR 11. Part F entire section, 

Part G, IV.B, VI.B, VIII.B.1, IX, Part H, XXI adopted 03/20/08, EFFECTIVE 04/30/08, 31 CR 4. Parts A 

through G, Part H, XXII adopted 10/16/08, EFFECTIVE 11/30/08, 31 CR 11. Rule replaced in its entirety, 

adopted 12/12/08, EFFECTIVE 01/30/09, 32 CR 1. Rule replaced in its entirety, adopted 03/18/10, 

EFFECTIVE 05/15/10, 33 CR 9. Part F, VI.A, Part H, XXV adopted 08/19/10, EFFECTIVE 09/30/10, 33 CR 

18. Part F, III.E adopted as emergency regulation 10/21/10, EFFECTIVE 11/01/10, 33 CR 23. 

Emergency regulation Part F, III.E [TN 2010-00978] expired EFFECTIVE 03/01/11; Part F, III.C, III.D [TN 

2010-00980] adopted 01/20/11, EFFECTIVE 03/02/11, 34 CR 3. Part A, V.A; Part H, XXVIII [TN 2011-

00379] adopted 09/15/11, EFFECTIVE 10/30/11, 34 CR 19. Rule replaced in its entirety [TN 2012-00124] 

adopted 05/17/12, EFFECTIVE 06/30/12, 35 CR 11. Part C, VIII.B.5.b.(3) amended to correct publisher's error, 

35 CR 15. Parts A through F, Part H, XXX [TN 2012-00860] adopted 12/20/12, EFFECTIVE 02/15/13, 36 CR 

2. Part C, IV [TN 2013-00165] amended by technical correction, 36 CR 4. Part A, Sections I, II; Part C, 

Sections III, IV, VIII.B.3, VIII.D.4; Part D, Sections I.B.1, I.B.15; Part H, Section XXXI; Appendix A, 

Introduction paragraph, Attachment I through Attachment V; Appendix B [TN 2013-00908] adopted 11/21/13, 

EFFECTIVE 12/30/13, 36 CR 23. 

A.G. Opinions: 

21 AG 402; 22 AG 120; 23 AG 43; 23 AG 333; 25 AG 57; 25 AG 313; 25 AG 361; 25 AG 432; 26 AG 29; 26 

AG 72; 26 AG 439; 27 AG 79-80; 27 AG 173; 28 AG 94; 29 AG 24; 30 AG Aug 1001-13; 30 AG Nov 1001.1; 

31 AG Apr 1001-13; 31 AG Nov 1001-13; 32 AG Jan 1001-13; 33 AG Apr 1001-13; 33 AG Sep 1001-13; 33 

AG Nov 1001-13; 34 AG Feb 1001-13; 34 AG Oct 1001-13; 35 AG Jun 1001-13; 36 AG Jan 1001-13; 36 AG 

Feb 1001-13; 36 AG Dec 1001-13 

Annotations: 

5 CCR 1001-13 Page 2 
36 CR 23 and 24, 12-13 

TABLE OF CONTENTS 

Rule Title Page 

PART A 

PART B 

PART C 

PART D 

PART E 

PART F 

PART G 

PART H 

APPENDIX A 

APPENDIX B 

General Provisions, Area of Applicability, and Schedules for Obtaining Certification of Emissions Control, Definitions, Exemptions, and Clean Screen/ 

Remote Sensing 2 

Standards and Procedures for the Approval, Operations, Gas Span Adjustment, Calibration and Certification of the Air Pollution Control Division (Division) Approved Test Analyzer Systems for Use in the Basic and Enhanced 

Program Areas, Test Analyzer Systems for Licensed Dealers in the Enhanced 

Area, and Clean Screen Test Analyzer Systems 11 

Inspection Procedures and Requirements for Exhaust Emissions, Fuel Evaporation Control, Visible Smoke Emissions, Emissions Control Systems, OnBoard Diagnostics Clean Screening; and Practices to Ensure Proper Emissions Related Adjustments and Repairs 16 

Qualification and Licensing of Emissions Mechanics, Emissions Inspectors, 

and Clean Screen Inspectors; Licensing of Emissions Inspection and Readjustment Stations, Inspection-Only Stations, Inspection-Only Facilities, Fleets, 

Motor Vehicle Dealer Test Facilities and Enhanced Inspection Centers, Clean 

Screen Inspection Sites; and Registration of Emissions Related Repair 

Facilities and Technicians 30 

Prohibited Acts and Penalties to Ensure Proper Inspection Procedures, Adherence to Prescribed Procedures and Effective Emissions Related Repairs 41 

Maximum Allowable Emissions Limits for Motor Vehicle Exhaust, Evaporative 

and Visible Emissions for Light-Duty and Heavy-Duty Vehicles 45 

Reserved 

Statements of Basis, Specific Statutory Authority and Purpose 49 

Technical Specifications 78 

Attachment I, PDF 1000 Scanner 98 

Attachment II, Thermal Transfer Printer 98 

Attachment III, Colorado Automobile Dealers Transient Mode Test Analyzer 

System 98 

Attachment IV, Specifications for Colorado 97 Analyzer 98 

Attachment V, Specifications for Colorado On-Board Diagnostic (OBD) StandAlone Analyzer 108 

Attachment I, Program Contact/Addresses/Phone Numbers 131 

Attachment II, "Colorado Approved" Label Samples 131 

© 2013 State of Colorado 

All Rights Reserved. (800) 833-9844 

5 CCR 1001-13 
© 2013 State of Colorado 36 CR 23 and 24, 12-13 Page 1 

All Rights Reserved 

PART A: General Provisions, Area of Applicability, and Schedules for Obtaining Certification of 

Emissions Control, Definitions, Exemptions, and Clean Screen/Remote Sensing 

PART B: Standards and Procedures for the Approval, Operations, Gas Span Adjustment, 

Calibration and Certification of the Air Pollution Control Division (Division) Approved Test 

Analyzer Systems for Use in the Basic and Enhanced Program Areas, Test Analyzer 

Systems for Licensed Dealers in the Enhanced Area, and Clean Screen Test Analyzer 

Systems 

PART C: Inspection Procedures and Requirements for Exhaust Emissions, Fuel Evaporation 

Control, Visible Smoke Emissions, Emissions Control Systems, On-Board Diagnostics Clean 

Screening; and Practices to Ensure Proper Emissions Related Adjustments and Repairs 

PART D: Qualification and Licensing of Emissions Mechanics, Emissions Inspectors, and 

Clean Screen Inspectors; Licensing of Emissions Inspection and Readjustment Stations, 

Inspection-Only Stations, Inspection-Only Facilities, Fleets, Motor Vehicle Dealer Test 

Facilities and Enhanced Inspection Centers, Clean Screen Inspection Sites; and Registration 

of Emissions Related Repair Facilities and Technicians 

PART E: Prohibited Acts and Penalties to Ensure Proper Inspection Procedures, Adherence to 

Prescribed Procedures and Effective Emissions Related Repairs 

PART F: Maximum Allowable Emissions Limits for Motor Vehicle Exhaust, Evaporative and 

Visible Emissions for Light-Duty and Heavy-Duty Vehicles 

PART G: Reserved 

PART H: Statements of Basis, Specific Statutory Authority and Purpose 

APPENDIX A: Technical Specifications 

APPENDIX B: Standards and Specification for Calibration/Span Gas Suppliers 

REFERENCES 

Pursuant to Section 24-4-103 (12.5), C.R.S., material incorporated by reference is available during 

normal working hours, or copies may be obtained at a reasonable cost, from the Technical Secretary 

of the Air Quality Control Commission c/o the Colorado Department of Public Health and 

Environment, 4300 Cherry Creek Drive South, Denver, Colorado 80246-1530 or material incorporated 

by reference within this regulation may be examined at any state publications depository library. 

References do not include later amendments to or additions of incorporated material. 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
Page 2 

PART A General Provisions, Area of Applicability, Schedules for Obtaining Certification 

of Emissions Control, Definitions, Exemptions, and Clean Screening/Remote 

Sensing 

I. APPLICABILITY 

Subject to the provisions described in Sections I.A and I.B of this Part A and pursuant to the schedule 

in Section I.C. and V.B. of this Part A, all non-diesel fueled motor vehicles which are registered in the 

AIR Program area or which motor vehicle is owned or operated by a non-resident who meets the requirements of Section, 42-4-310(1)(c)(I), C.R.S., will be subject to On-Board Diagnostics and/or an 

exhaust and evaporative emissions, smoke opacity and emissions control, equipment inspection as a 

prerequisite to initial or renewal of the vehicle registration. Any person owning or operating a business 

and any post-secondary educational institution located in the program area as defined in Subsection 

A of this section shall annually inform by written notice all persons employed by such business or attending classes that they are required to comply with the provisions of this regulation. The provisions 

of this regulation applicable to Larimer and Weld counties shall not be included in the state implementation plan. 

I.A. Geographic Areas of Applicability 

This regulation shall apply to the AIR Program area as defined in Section 42-4-304(20), 

C.R.S. as amended by Senate Bill 09-003. 

I.B. Vehicles Eligible for AIR Program Inspection Procedures 

This regulation shall apply to all motor vehicles as defined in Section 42-4-304(18), C.R.S. 

Vehicles that are registered in a program area and are being operated outside such area but 

within another program area shall comply with the requirements of the area where such 

vehicles are being operated. Vehicles registered in a program area that is being temporarily 

operated outside the state at the time of registration or registration renewal may apply to the 

department of revenue for a temporary exemption from program requirements. Upon return 

to the program area, such vehicles must be in compliance with all requirements within fifteen 

days. A temporary exemption shall not be granted if the vehicle will be operated in an 

emissions testing area in another state unless proof of emissions from that area is submitted. 

Pursuant to Section, 42-4-310(1)(c)(I), C.R.S. motorists operating vehicles in the enhanced 

program area shall comply with the provisions of the enhanced program. 

The burden of proof in establishing an exemption from inclusion in all or any part of the AIR 

Program inspection requirements is on the vehicle owner. 

I.C. Schedules for Obtaining Certifications of Emissions Control 

I.C.1. REPEALED 

I.C.2. Inspection schedules during calendar year 1995 and thereafter, vehicles 

are to be inspected according to the schedules established in Sections, 

42-4-304(3)(b)(11), and, 42-4-310(1)(b)(II), C.R.S. as amended. 

5 CCR 1001-13 CODE OF COLORADO REGULATIONS 
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I.C.3. No used vehicle which is required to be registered in the program area shall 

be registered, unless such vehicle has a Certification of Emissions Control, 

or of Emissions Exemption. The seller of a used vehicle is required to obtain 

a Certification of Emissions Control for the new owner at the time of sale. 

This paragraph (3) does not apply to the sale of a motor vehicle that is inoperable or otherwise cannot be tested in accordance with this regulation if the 

seller of the motor vehicle provides a written notice to the purchaser pursuant to Section 42-4-310(4), C.R.S. If a motor vehicle is being registered for 

the first time in the program area, the owner shall obtain the certification and 

submit it with the application for registration to the Department of Revenue 

or an authorized agent of the Department of Revenue. 

I.C.3.a. On or after October 1, 1989, no used vehicle which is required to 

be registered in the program area shall be registered, unless 

such vehicle has a Certification of Emissions Control, or of 

Emissions Exemption. The seller of a used vehicle is required to 

obtain a Certification of Emissions Control for the new owner at 

the time of sale. This paragraph (3) does not apply to the sale of 

a motor vehicle which is inoperable or otherwise cannot be 

tested in accordance with this regulation or that is being sold 

pursuant to Part 18 (Vehicles Abandoned on Public Property) or 

Part 21 (Vehicles Abandoned on Private Property) of Article 4 of 

Title 42, C.R.S. if the seller of the motor vehicle provides a 

written notice to the purchaser pursuant to Section 42-4-310(4), 

C.R.S. If a motor vehicle is being registered for the first time in 

the program area, the owner shall obtain the certification and 

submit it with the application for registration to the Department of 

Revenue or an authorized agent of the Department of Revenue. 

I.C.3.b. An inspection is not required prior to the sale of a motor vehicle 

with at least twelve months remaining before the vehicle's 

certification of emissions compliance expires if such certification 

was issued when the vehicle was new. 

I.C.3.c. Effective January 1, 2015, a motor vehicle being registered in the 

program area for the first time may be registered without an 

inspection or certification if the vehicle has not yet reached its 

seventh model year pursuant to Section 42-4- 

310(1)(a)(II)(C)C.R.S. 

I.C.4. Any motor vehicle may be voluntarily inspected and a Certification of 

Emissions Control obtained which shall be valid as specified in Section 

I.C.2. of this Part A. 

I.C.5. (Reserved) 

I.C.5.a. As it pertains specifically to federally owned or leased vehicles; 

tactical military vehicles are not required to be inspected. 

I.C.5.b. Federal installation managers are to declare all federal 

employee-owned vehicles operated on the installation and 

demonstrate that these vehicles have complied with periodic 

inspection requirements pursuant to 40 CFR Section 

51.356(A)(4). Inspection results shall be reported to the 

Department of Revenue AIR Program section and up-dated 

based on inspection cycles. 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
Page 4 

I.C.6. (Reserved) 

I.C.7. Fleets of twenty or more eligible vehicles shall be periodically inspected, 

comply with inspection provisions and obtain a Certification of Emissions 

Control. 

I.C.7.a. Fleets may pursue licensing as a fleet inspection station under 

Part D of this Regulation Number 11 pursuant to Section, 42-4-

309, C.R.S. and comply with the provisions of that section. 

I.C.7.b. Fleets may elect to comply with periodic inspection requirements 

under the provisions of Section 42-4-309 (2)(a), C.R.S. to include 

the inspection schedules of Sections 42-4-304(3)(b)(11) and 42-4- 

310(1)(b)(11)(a), C.R.S. 

I.C.7.c. As it pertains to the fleet vehicles provisions pursuant to Section, 

42-4-309, C.R.S. and this Section I.C.7., municipal fleets of 

twenty vehicles or more may comply with periodic inspection 

requirements as specified in Section 42-4-309(2)(a), C.R.S. to 

include inspection schedule of Sections 42-4-304(3)(b)(11) and 

42-4-310 (1)(b)(II)(a), C.R.S. 

I.C.8. New motor vehicles being registered with a Manufacturer's Statement of 

Origin (MSO), Manufacturer's Certificate of Origin (MCO) or similar document shall be issued a registration without a Certificate of Emissions 

Control. 

Such new motor vehicles are to be issued a Verification of Emissions Test exemption 

windshield sticker at the time of sale that shall be valid for a period of seven (7) years. 

The selling dealer is responsible for obtaining the Verification of Emissions Test. 

New vehicles under this section shall also include those new vehicles leased under 

an MSO or MCO or similar document and seven years without an inspection. Such 

new leased vehicles are to be issued a Verification of Emissions Test exemption 

windshield sticker at the time of initiation of the lease that shall be valid for a period of 

seven (7) years. 

After the seventh year, such vehicles shall be issued a registration only with a 

Certificate of Emissions Control. The inspection schedule for these vehicles shall 

then revert to a biennial inspection cycle. 

A used motor vehicle may be registered in the program area without an inspection if, 

on the date of vehicle registration, at least twelve months remain before the 

expiration of the Verification of Emissions Test exemption if such certification was 

issued when the vehicle was new. 

Effective January 1, 2015 vehicles that were originally issued a Verification of 

Emissions Test exemption windshield sticker at the time of new vehicle sale 

that was valid for a period of four years shall have that time period extended 

to seven years. 

I.C.9.a. Compliance with AIR Program inspection requirements will not 

be required for wholesale transactions between motor vehicle 

dealers licensed pursuant to Article 6 of Title 12, C.R.S. 

I.C.9.b. Motor vehicle dealers shall have motor vehicles inventoried or 

consigned for retail sale inspected annually. A further inspection 

is not required at the time of sale if: 

5 CCR 1001-13 CODE OF COLORADO REGULATIONS 
© 2013 State of Colorado 36 CR 23 and 24, 12 - 13 Page 5 

All Rights Reserved 

i. For a 1982 or later motor vehicle, there are at least twelve 

months remaining before the vehicle's certification of emission compliance expires and the dealer has had the vehicle 

inspected since acquiring it. 

For a 1981 or earlier motor vehicle, the vehicle has a valid 

certification of emission compliance and the dealer has had 

the vehicle inspected since acquiring it. Such a vehicle purchased from a licensed motor vehicle dealer may be registered in the program area without an inspection if, on the 

date of vehicle registration, at least nine months remain before the expiration of such certification. 

I.C.10. Reserved 

I.C.11. Eligible fleets as defined in Section 42-4-309, C.R.S. that declare not to 

self-inspect shall be inspected according to the same schedules, subject 

to the same emissions related repair requirements and waiver provisions 

as non-fleet vehicles. 

I.C.12. For the purposes of 42-4-309(6)(B) if a vehicle fails the test or is 

untestable due to mechanical and/or electrical/electronic problem, the 

motorist shall have the same recourse as that of not passing an 

inspection. However, Section 42-4-309(6), C.R.S. and the regulations 

implementing such provision, shall not be federally enforceable, and shall 

not be incorporated into the State Implementation Plan. 

II. DEFINITIONS 

1. "Accreditation" means certification that the instrument and instrument manufacturer meet the 

operating criteria specifications and requirements of the Colorado Department of Health, Air 

Quality Control Commissions as specified in Part B of this regulation. 

2. "Air Intake Systems" are those systems that allow for the induction of ambient air (to include 

preheated air) into the engine combustion chamber for the purpose of mixing with a fuel for 

combustion. 

3. "AIR Program Station" is an Automobile Inspection and Readjustment (AIR) Station that 

qualifies and is licensed to operate as an emissions inspection and readjustment station. 

4. "Air System" is a system for providing supplementary air into the vehicle's exhaust system to 

promote further oxidation of HC and CO gases and to assist catalytic reaction. 

5. "BAR 90" refer to the California Bureau of Automotive Repair specifications for Exhaust Gas 

Test Analyzer Systems (TAS) that became effective in 1990. "BAR 97" refers to the California 

Bureau of Automotive Repair specifications for Exhaust Gas Test Analyzer Systems (TAS) 

that became effective in 1997. 

6. "Basic Engine Systems" are those parts or assemblies which provide for the efficient 

conversion of a compressed air/fuel charge into useful power to include but not limited to 

valve train mechanisms, cylinder head to block integrity, piston-ring-cylinder sealing integrity 

and post-combustion emissions control devise integrity. 

7. "Calibration" is the process of establishing or verifying the total response curve of an exhaust 

gas analyzer. Calibration is a laboratory procedure using several different calibration gases 

having precisely known concentrations. 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
Page 6 

8. "Calibration Gases" are gases of precisely known concentration that are usually used in the 

laboratory as references for establishing or verifying the calibration curve of an exhaust gas 

analyzer. 

9. "Catalytic Converter" is a post-combustion device that oxidizes HC and CO gases and/or 

reduces oxides of nitrogen. 

10. "Certification" means assurance by the authorized source, whether it is a laboratory, the 

manufacturer, or the State, that a specific product or statement is in fact true and meets all 

required accreditation requirements. 

11. "Certification of Emissions Control" shall have the same meaning as set forth in Section 42-4-

304(3)(1), C.R.S. 

12. "Chlorofluorocarbon" (CFC) is a class I stratospheric ozone depleting compound as listed in 

Appendix A, final rule vol.57.mp 147 Federal Register, 40 CFR Part 82. 

13. "Clean Screen Inspection Site" is that location within the program area as defined in Section 

42-4-304(20)(a), C.R.S., approved by the Division and the Department of Revenue. 

14. "Clean Screen Inspector" is a person found qualified by the Division, and licensed by the 

Executive Director to operate Clean Screen Inspection equipment. 

15. "Clean Screen Program" is that program as defined in Section 42-4-304(3.5), C.R.S. 

16. "Clean Screened Vehicle" is a vehicle that is eligible for inspection, has at least two 

consecutive passing remote sensing emissions readings performed on different days or at 

different approved Clean Screen Inspection Sites prior to its registration renewal date, or for 

vehicles identified as low emitters on the low emitting vehicle index, one passing remote 

sensing reading prior to its registration date, and has otherwise complied with the provisions 

of Section IV of this Part A, Section XII of Part C and Section VI of Part F. 

17. "Clean Screen Data Manager" is that person or entity that contracts with the state to provide 

clean screen data management functions. This same person or entity may also act as 

general contractor in conducting and facilitating clean screen inspections. 

18. "Colorado 94" refers to those test analyzer systems that are based on BAR 90 but modified 

as specified by the Division for use in the AIR Program for the period of time after January 

1,1994. "Colorado AIR Program BAR 97 Exhaust Gas Analyzer" or Colorado 97" refers to 

those test analyzer systems that are based on BAR 97, but modified as specified by the 

Division for all fleet inspection stations and inspection-only facilities that become licenses 

after May 1, 2010. 

19. "Colorado Automobile Dealer Transient Mode Test Analyzer System" is a dynamometer 

based inspection system capable of performing an inspection grade (IG 240) emissions 

inspection procedure under simulated driving conditions. The procedure is intended for 

determining the compliance status for used vehicles prior to retail sale. 

20. "Colorado On-Board Diagnostic (OBD) Test Analyzer System" or "OBD TAS" refers to the 

analytical and testing instrumentation used to verify automotive emissions and to prompt the 

emissions inspector through the elements of an official Colorado OBD emissions inspection. 

21. "Compliance" means verification that certain submission data and hardware submitted by a 

manufacturer for accreditation consideration, meet all required accreditation requirements. 

5 CCR 1001-13 CODE OF COLORADO REGULATIONS 
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22. "Diagnostic Trouble Code (DTC)" is an alpha-numeric code representing a specific fault or 

problem identified by the OBD system on a vehicle. OBD diagnostic trouble codes are 

standardized across all vehicle manufacturers and are defined individually in the Society of 

Automotive Engineers Recommended Practice J2012. 

23. "Division" is the Air Pollution Control Division of the Colorado Department of Public Health 

and Environment. 

24. "Electrical, Electronic, or Electro-mechanical Span" is the adjustment of an exhaust gas 

analyzer using an electronic signal rather than a calibration or span gas as a reference 

source. 

25. "Emissions Control Systems" are those parts, assemblies or systems originally installed by 

the manufacturer in or on a vehicle for the purpose of reducing emissions. 

26. "Estes Park Area" means that part of the program area west of Range 71 West in Larimer 

County. 

27. "Executive Director of the Department of Revenue" or "Executive Director" is the 

representative of the Department of Revenue or designee responsible for the field 

enforcement of the AIR Program, licensing of emissions mechanics, clean screen inspectors 

and inspection stations. 

28. "Fuel Control Systems" are mechanical, electro-mechanical, galvanic or electronic parts or 

assemblies that regulate the air/fuel ratio in an engine for the purpose of providing a 

combustible charge. 

29. "Fuel Filler Neck Restrictor system" is the orifice and obstruction ("Flapper Door") in the gas 

tank filler neck that prevents the insertion of a "leaded gasoline" nozzle and deters the 

introduction of "leaded fuel". 

30. "Gas Span" is the adjustment of an exhaust gas analyzer to correspond with known 

concentrations of span gases. 

31. "Gas Span Check" is a procedure using known concentrations of span gases to verify the gas 

span adjustment of an analyzer. 

32. "Gross Vehicle Weight (GVW) Rating" is the maximum recommended combined weight of the 

motor vehicle and its load as prescribed by the manufacturer and expressed on a permanent 

identification label affixed to the motor vehicle. 

33. "Heavy Duty Vehicles (HDV)" are those motor vehicles for model years 1978 and earlier 

having a GVW rating of greater than 6000 pounds and for model years 1979 and newer, 

having a GVW rating of greater than 8,500 pounds. 

34. "Idle Mode" means a condition where the vehicle engine is warm and running at the rate 

specified by the manufacturer's curb idle, where the engine is not propelling the vehicle, and 

where the throttle is in the closed or idle stop position. 

35. "Ignition Systems" are those parts or assemblies that are designed to cause and time the 

ignition of a compressed air/fuel charge. 

36. "Inspection Area" is the area that is occupied by the analyzer, sample hose and the vehicle 

being inspected. 

37. "Inspection-only station" is that licensed station within the basic program area as defined in 

Section 42-4-304(2), C.R.S., which meets the requirements of Section 42-4-308, C.R.S., 

which facility the operator is licensed to operate by the Executive Director as an inspectiononly station. 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
Page 8 

38. "Instrument" is the complete system that samples and reads out the concentration of pollutant 

HC and CO gas plus CO2 gas. The instrument includes the sample handling system, the 

exhaust gas analyzer and the enclosure cabinet. 

39. "Light Duty Vehicles (LDV)" are those motor vehicles (to include trucks) for model years 1978 

and earlier having a GVW rating of 6,000 pounds or less and for model years 1979 and 

newer having a GVW rating of 8,500 pounds or less. 

40. "Low Emitting Vehicle Index" refers to a statistical table summarizing the probability of 

vehicles passing the IM 240 inspection. The statistical table will be updated annually by each 

July 1 st. The low emitting vehicle index must meet the requirements of Part F, VI.B. based on 

a tabulation of the previous calendar year's IM 240 inspection program results. 

41. "Malfunction Indicator Light (MIL)" is a warning light located on the dash of vehicles equipped 

with On-Board Diagnostic (OBD) systems that notifies the motorist that a malfunction to the 

vehicle's emissions control system has been detected. 

42. "Motor Vehicle Emissions Compliance Inspectors (ECI)" are those persons employed and 

authorized by the Department of Revenue for licensing and enforcement of the AIR Program. 

43. "North Front Range Area" is the portion of the Program Area located in Larimer and Weld 

Counties as set forth in Section 42-4-304(20) as amended by Senate Bill 09-003. The North 

Front Range area is a State-Only program and is not part of any State Implementation Plan 

with the US EPA. 

44. "On-Board Diagnostics II (OBD or OBDII) Test" means the electronic retrieval of stored 

readiness status, diagnostic trouble codes, malfunction indicator light (MIL) illumination 

status, and other information from a vehicle's OBD system to determine if any emission 

related trouble codes are present and if the MIL is commanded to be on, which would 

indicate the existence of an emission related malfunction with the vehicle. 

45. "Original Condition" means the condition as installed by the manufacturer but not necessarily 

to the original level of effectiveness. 

46. "Program Area" is that geographic area defined in Section 42-4-304(20), C.R.S. as amended 

by Senate Bill 09-003. 

47. "Registration Renewal Date" is the last day of the month in which the vehicle registration 

expires as defined in Section 42-3-103, C.R.S. 

48. "Span Gases" are gases of known concentration used as references to adjust or verify the 

adjustment of an exhaust gas analyzer's span settings. 

49. "State Emissions Technical Center Personnel" are those persons employed by or authorized 

by the Department of Health for technical or administrative support of the AIR Program. 

50. "Test Analyzer Systems" (TAS) in the context of this regulation is that analytical 

instrumentation used to measure automotive emissions and prompt the operator through 

other elements of an emissions inspection. 

51. "True Concentration" is the concentration of the gases of interest as measured by a 

standardized instrument which has been calibrated with 1% precision gases traceable to the 

National Institute for Standards and Technology. 

52. "Zero Gas" is a gas, usually air or nitrogen, which is used as a reference for establishing or 

verifying the zero point of an exhaust gas analyzer. 

5 CCR 1001-13 CODE OF COLORADO REGULATIONS 
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III. EXEMPTION FROM SECTION 42-4-314, C.R.S. FOR DEPARTMENT OF DEFENSE 

PERSONNEL PARTICIPATING IN THE PRIVATELY OWNED VEHICLE IMPORT 

CONTROL PROGRAM 

U.S. Department of Defense (DOD) personnel participating in the DOD POV 

(privately owned vehicle) Import Control Program operating a 1975 or subsequent 

model year automobile, are exempt from the prohibition of C.R.S., 42-4-314(2), 

C.R.S. insofar as it pertains to filler neck restrictors, catalytic converter systems, and, 

if applicable, exhaust gas oxygen (02) sensor(s), if one of the following conditions 

are met: 

III.A.1. The automobile will be driven to the port and surrendered for exportation 

under said program within ten (10) working days of disconnection, 

deactivation, or inoperability of the restrictor, catalytic converter systems, 

or exhaust gas oxygen (02) sensor(s); or 

III.A.2. The reconnection, reactivation, or reoperability of the restrictor, catalytic 

converter systems, and, if applicable, exhaust gas oxygen (0 2 ) sensor(s), 

is made within ten (10) working days from the time the owner picked up 

the automobile at the port. 

III.B. Persons disconnecting, deactivating, or rendering inoperable any filler neck restrictor, 

catalytic converter system, exhaust gas oxygen (02) sensor(s) on 1975 or 

subsequent model year automobile of DOD personnel participating in the DOD POV 

Import Control Program which will be driven to the port and surrendered for 

exportation under said program within ten (10) working days are exempt from the 

prohibition of 42-4-314, C.R.S. 

Unless otherwise exempt under this Section III of Part A, vehicles shall be required to 

be configured as a vehicle certified by the EPA for sale and use within the United 

States pursuant to 40 CFR, Part 86, Subpart A. 

IV. CLEAN SCREEN/REMOTE EMISSIONS SENSING 

IV.A. Geographic Area of Applicability 

IV.A.1. (Reserved) 

IV.A.2. The Division shall implement an expanded clean screen program in the 

enhanced program area. 

IV.A.3. (Reserved) 

IV.B. Vehicles Eligible to participate in the Clean Screen/Remote Emissions Sensing 

Program 

IV.B.1. The clean screen program established in this Section IV. of Part A shall 

apply to eligible motor vehicles as defined in 42-4-310(5)(a), C.R.S., for 

which registration will expire within twelve months, a certificate of 

emissions control is a prerequisite to renewal and which are registered in 

a clean screen program county. 

IV.B.2. The counties of Adams, Arapahoe, Boulder, Broomfield, Denver, Douglas, 

Jefferson, Larimer, and Weld are clean screen counties. 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
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IV.C. REPEALED 

IV.D. Schedule for collection of emissions inspection fees by county clerks and recorders. 

The clerks and recorders for the counties of Adams, Arapahoe, Boulder, Broomfield, Denver, 

Douglas, Jefferson, Larimer and Weld shall collect an emissions inspection fee in the amount 

specified pursuant to Section 42-3-304(19)(a)(I), C.R.S. at the time of registration of a motor 

vehicle that the Department of Revenue has determined to have been clean screened, unless 

a valid certification of emissions compliance has already been issued for the vehicle being 

registered indicating that the vehicle passed the applicable emissions test at an enhanced 

inspection center, motor vehicle dealer test facility or fleet inspection station. 

V. EXPANSION OF THE ENHANCED EMISSIONS PROGRAM TO THE NORTH FRONT 

RANGE AREA 

V.A. Program Commencement 

Beginning November 1, 2010, unless the Division comes back to the Commission and the 

Commission agrees to a later date, motor vehicles registered in the North Front Range Area, 

and vehicles operating in the North Front Range Area that meet the requirements of Section 

42-4-310(1)(c)(I), C.R.S. shall be subject to an Enhanced emissions inspection as defined in 

Section 42-4-304(8.5). Notwithstanding the above, the Estes Park Area, located west of 

Range Seventy-one (71) West, shall be excluded from the Enhanced Emissions Program. 

Such inspection shall be the same as the inspection required in the Adams, Arapahoe, 

Boulder, Broomfield, Denver, Douglas, and Jefferson county portions of the Program Area 

The Vehicle Emissions Inspection program in the North Front Range area is a State-Only 

program and is not part of any state implementation plan with the US EPA. 

V.B. Requirement to Obtain Certification of Emission Control and Emissions Inspection 

Schedule 

V.B.1. Except as otherwise provided in Title 42, Article 4, Part 3, C.R.S. and this 

Regulation Number 11, a motor vehicle that is subject to the North Front 

Range Area Inspection and Maintenance Program pursuant to Subsection 

V.A. above may not be registered or sold without a valid Certification of 

Emissions Control. In order to obtain a Certification of Emissions Control 

the vehicle must either pass the applicable emissions inspection or obtain 

a waiver from the Department of Revenue under this Regulation Number 

11. 

V.B.2. Subject to the phase-in provision in Subsection V.B.3. below, emissions 

inspections shall be conducted and Certification of Emissions Controls 

shall remain valid in accordance with the schedules set forth in Section 

42-4-304(3), C.R.S., Section 42-4-310(1)(b)(II), C.R.S. and Part A, Section 

I.C. of this Regulation Number 11. 

V.B.3. In order to better balance the number of inspections from year to year, odd 

number model year motor vehicles that require biennial inspections under 

Subsection V.B.2. above, shall be inspected commencing January 1, 

2011. This phase-in shall not excuse a vehicle from an inspection in 2010 

that is required due to the sale or transfer of the motor vehicle. 

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III. EMISSIONS CONTROL SYSTEMS INSPECTION PROCEDURES 

Motor vehicles shall be configured as required for sale or use within the United States pursuant to 40 

CFR, Part 86, Subpart A; unless specific documentation in the form of a state issued vehicle 

evaluation form (DR2365) or an EPA (EPA form 3520) or DOT exemption is submitted. To ensure 

compliance with this requirement, for all inspections performed through December 31, 2014, the 

emissions mechanic or emissions inspector shall inspect all model year 1975 through 1995 and 

newer model year vehicles and assess the integrity of the emissions control system in accordance 

with the procedures set forth in this Section III. Effective January 1, 2015, the emissions mechanic or 

emissions inspector shall inspect all model year 1975 through 1995 model year vehicles and assess 

the integrity of the emissions control system in accordance with the procedures set forth in this 

Section III. 

III.A. All model year 1975 through 1995 model year vehicles shall be visually inspected for 

the presence and operability of the air system, catalytic converter system(s) and 

oxygen (02) systems. If these parts or systems are not operating as designed, 

inoperable or have been removed or otherwise tampered with, the vehicle will not 

qualify for a Certification of Emissions Control. In assessing whether the proper 

emissions control systems are present, the emissions mechanic or emissions 

inspector shall examine the emissions control information decal within the engine 

compartment to determine the appropriate emissions control systems for that 

particular vehicle. If an emissions control information decal is missing, incomplete, 

illegible or is not appropriate for the specific vehicle, the emissions mechanic or 

inspector may contact a state emissions technical center for guidance, use other 

reference materials or refer the vehicle to a state emissions technical center for 

further evaluation. 

For the period December 1, 2012 through December 31, 2015, in place of the visual 

inspection, the emissions control systems, model year 1996 and newer vehicles may be 

inspected using the vehicle's on-board diagnostic (OBD) systems. To utilize this alternative 

inspection procedure, the emissions inspector must interrogate the vehicle's OBD system 

using Division approved procedures and equipment. If the emissions inspector is unable to 

interrogate the OBD system, or if the interrogation reveals either that the malfunction 

indicator light (MIL) is commanded on or that any OBD monitors are not set, the vehicle shall 

be visually inspected in accordance with the procedures set forth in Subsection III.A. 

An assessment of the emissions control system malfunction/service-maintenance 

indicator(s) performance shall be conducted by the emissions mechanic or emissions 

inspector on those vehicles so equipped. 

For those vehicles equipped with "check engine" dash indicator lights or similar emissions 

control systems malfunction or service-maintenance indicator(s), the following procedure if 

applicable will be performed to assess the integrity of the system: 

• Ignition Off, Engine Off = indicator(s) off 

• Ignition On, Engine Off = indicator(s) on or displayed 

• Ignition On, Engine Running = indicator(s) off 

The failure of the system to respond as described above shall be reported to the motorist, but 

shall not be used to fail the vehicle. 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
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The repair/replacement of catalytic converters must incorporate the same type, style 

and location on the exhaust system relative to engine as originally designed by the 

vehicle manufacturer. If a new original equipment manufacturer (OEM) part is not 

used, only an EPA "accepted" after-market component appropriate to that application 

may be used. Verification of the correct application and certification status must be 

performed at the time of reinspection. The submittal and review of repair receipts as 

specified in Subsection VII.B of this section is required in order to substantiate proper 

repairs of applicable emissions control system. 

If the necessary part(s) will not be available prior to the month of expiration of the 

present vehicle registration, and the owner obtains a signed form or statement to that 

effect from a manufacturer's dealer for that make vehicle, or from an automotive parts 

supplier which in the normal course of business supplies part(s) for that vehicle, Department of Revenue personnel after verification may issue a temporary Certification 

of Emissions Control. The form or statement provided must specifically identify by 

part numbers and description, the necessary part(s). The owner then has until the 

expiration of the temporary certification to complete the necessary repairs or replacement. 

IV. ON-BOARD DIAGNOSTIC INSPECTION PROCEDURES 

Effective January 1, 2015, light-duty vehicles to include light-duty trucks of model year 1996 through 

those vehicles that have reached their eleventh model year old equipped with California on-board 

diagnostic (OBDII) or EPA on-board diagnostic systems (EPA, OBD) shall be evaluated to determine 

operability and integrity of the applicable system(s). The OBD system will be connected to the TAS 

and interrogated. Fault codes and diagnostics shall be reported to the motorist with other emissions 

inspection information but with the exception of dynamometer incompatible vehicles as noted in Part 

C, Section II.B.4. shall not be used to fail the vehicle. 

V. EVAPORATIVE FUEL CONTROL INSPECTION PROCEDURES 

Model year 1975 and newer vehicles shall be inspected for the presence and integrity of the gasoline 

cap(s). The gasoline cap(s) of such vehicles inspected in the nine county Front Range enhanced 

program area as defined in Section 42-4-304(9)(a)., shall also be inspected for sealing integrity as 

specified in Part F, Section IV of this regulation. 

Vehicles with a missing gasoline cap(s) shall not qualify for issuance of a Certificate of Emissions 

Control. Motorists whose vehicles have gasoline cap(s) demonstrating excessive leakage shall be 

notified of the deficiency, repair/replacement and a full retest shall be mandatory. 

VI. FREE REINSPECTION 

Vehicles which fail any or all elements of an emissions inspection are eligible for one free 

reinspection within ten (10) calendar days if presented to the same station or facility as initially 

inspected and failed. In the case of the contractor operated enhanced inspection center network, the 

ten (10) day free reinspection shall be honored at any enhanced inspection center. 

VII. REPAIR INFORMATION 

Any after-repairs reinspection of a vehicle initially failed calls for the submittal of a completed official 

AIR Program emissions repair form. 

VIII. CERTIFICATION OF EMISSIONS CONTROL 

In order to obtain a Certificate of Emissions Control, the vehicle must meet the following conditions: 

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VIII.A. Certification of Emissions Compliance may be issued if: 

VIII.A.1. The vehicle emissions levels are the same as or less than the applicable 

emissions limits; or 

VIII.A.2. For vehicles in model years seven through ten subject to an on-board 

diagnostic inspection, the OBD system meets the passing criteria 

established in Part F, Section VII. of this regulation, and 

VIII.A.3. There are no smoke emissions visible from the vehicle engine crankcase 

and/or tailpipe, and 

VIII.A.4. For 1975 through 1995 model years, the vehicle passes the emissions 

control systems inspection, and 

VIII.A.5. Under enhanced inspection requirements, the vehicle owner/operator of a 

1995 or newer model year vehicle shall demonstrate compliance with any 

federal emissions recall-pursuant to 40 CFR Part 85.1902 (d) or remedial 

repair plan pursuant to Section 207 (C) of the federal Clean Air Act for 

which owner notification occurs after 01 January 1995. 

VIII.B. A Certification of Emissions Waiver may be issued if: 

VIII.B.1. The vehicle passes the emissions control systems inspection (1975 and 

newer model year vehicles only) required by Part C, Section III. A, B and 

C.; and 

VIII.B.2. Basic Program 

For model year 1981 and earlier at least seventy-five dollars ($75) has been spent on 

emissions related adjustments and repairs as specified in Part C, Sections IX and X 

provided that proof of repair costs for that specific vehicle has been provided to 

Department of Revenue personnel or designee in the form of an itemized bill, invoice, 

work order, manifest, or statement in which emissions related parts and/or repairs, 

are specifically identified. 

For model years 1982 and newer, at least two hundred dollars ($200) has been spent 

on emissions related adjustments and repairs as specified in Part C, Sections IX and 

X, provided that proof of repair costs for that specific vehicle has been provided to 

Department of Revenue personnel or their designee in the form of an itemized bill, 

invoice, work order, manifest, or statement in which emissions related parts and/or 

repairs, are specifically identified. 

VIII.B.3. Enhanced Program 

For model year 1968 and newer, at least seven hundred fifteen dollars ($715) or as 

adjusted annually by the Consumers Price Index for Urban Consumers (CPIU) of the 

previous year as compared to 2003 has been spent on emissions related adjustments and repairs as specified in Part C, Sections IX and X, provided that proof of 

repair costs for that specific vehicle has been provided to Department of Revenue 

personnel or their designee in the form of an itemized bill, invoice, work order, manifest, or statement in which emissions related parts and/or repairs, are specifically 

identified. The Division shall adjust the amount that must be expended by the motorist in order to qualify for a Certificate of Emissions Waiver, which amount shall be established for each calendar year through 2004 by the Division pursuant to the criteria 

specified in Section 42-4-310(1)(d)(VI),C.R.S. 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
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For model year 1967 and earlier at least seventy-five dollars ($75) has been spent on 

emissions related adjustments and repairs as specified in Part C, Sections IX and X 

provided that proof of repair costs for that specific vehicle has been provided to and 

verified by the emissions inspector in the form of an itemized bill, invoice, work order, 

manifest, or statement in which emissions related parts and/or repairs, are 

specifically identified. 

If no emissions reduction is achieved, the motorist is to be referred to the Department 

of Revenue or its designee pursuant to Sections IX. G. and X. of this Part C. 

VIII.B.4. An emissions reduction as determined either by the Division-approved 

Colorado 94 of Colorado BAR 97 Test Analyzer System has resulted due 

to emissions related repairs and the applicable cost limit has been met. 

Proof of these emissions related repairs are required and to be retained by 

the AIR Program station, facility or center until purged by state program 

personnel. The vehicle must have passed the emissions control systems 

inspection and there were no smoke emissions visible from the vehicle 

engine crankcase or exhaust system. 

VIII.B.5. Engine operational parameter verification. 

VIIl.B.5.a. All engine parameter adjustments for idle speed, proper air/fuel 

ratio and cold enrichment, as well as proper ignition dwell and 

timing (if applicable), have been set to or verified as being set to 

manufacturers specification by a licensed mechanic or registered 

repair facility/technician. 

VIII.B.5.b. For those 1981 and newer vehicles equipped with computer 

based, engine management systems, also known as closed 

loop, feedback controls shall have the following additional 

sensors/systems verified to be operating within vehicle 

manufacturer specifications. 

VIII.B.5.b.(1) As applicable to the vehicle being inspected, the 

oxygen sensor, throttle position sensor, coolant temperature 

sensor, manifold absolute pressure sensor. 

VIII.B.5.b.(2) The engine management control system will be 

scanned for default/malfunction codes with those systems or 

components identified corrected. 

VIII.B.5.b.(3) Primary and secondary ignition system integrity shall 

be verified for correct operation. 

VIII.B.5.b.(4) A fuel delivery system utilizing a carburetor will be 

inspected for leaks, idle speed control adjustments, float operation and cold enrichment. A fuel delivery system utilizing 

fuel injection, be it throttle body or multiport configuration, 

shall be checked for injector function, cold enrichment and 

injector spray patterns. Fuel injectors shall also be evaluated 

for proper volume and injection pulse width. Fuel system 

pressure shall be checked for residual and running pressure. 

VIII.B.5.b.(5) A cylinder leak down procedure shall be performed 

on all cylinders of the engine with the results reported to the 

motorist. 

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VIIl.B.5.b.(6) With the exception of item (5) above, component/ 

system deficiencies found to be out of manufacturer's 

operational specification(s) will be corrected. The cost of 

such repairs shall be creditable towards issuance of a 

waiver. 

VIII.C. If in the opinion of a registered emissions repair facility/technician, a vehicle which is 

properly adjusted to all manufacturers emissions related specifications and all 

emissions control systems appear to be operating as required, yet the vehicle 

continues to exceed one or more emissions limits and the repair expenditure limits 

have not been met, a waiver shall be issued upon physical verification of systems 

operation and vehicle performance by emissions technical center personnel. 

VIII.D. For vehicles registered and operated in the enhanced area, upon verification by a 

Department of Revenue Motor Vehicle Emissions Compliance Inspector, a waiver not 

to exceed one inspection cycle may be granted to obtain necessary emissions 

related repairs on a vehicle in the case of economic hardship when the Certificate of 

Emissions Waiver requirements of this section have not been met. It must be verified 

that the vehicle owner in question is participating in an established and recognized 

public assistance program. The provisions of this Paragraph D shall only apply to a 

vehicle once. To obtain a hardship waiver, the registered owner of the vehicle in 

question shall satisfy the following requirements: 

VIII.D.1. The vehicle must fail for carbon monoxide, hydrocarbons, and/or oxides of 

nitrogen failures. 

VIII.D.2. The hardship waiver will not be approved for vehicles that are tampered, 

missing equipment, fail the evaporative inspection, or fail for visible 

smoke. 

VIII.D.3. The vehicle owner must be participating in an established and recognized 

public assistance program. 

VIII.D.4. The vehicle must be the sole means of transportation for the vehicle 

owner, and the owner must not have more than two vehicles registered in 

his/her name. 

VIII.D.5. Such extension may be granted only once per vehicle. 

VIII.E. A Certificate of Emissions Waiver will not be issued to a vehicle that is eligible for the 

Emissions Control Systems Performance Warranty, 207(b) of the federal Clean Air 

Act. Per the provisions of the 207(b) Performance Warranty, the repair costs 

necessary for compliance with AIR Program emissions limits specified in Part F of 

this regulation will be borne by the vehicle manufacturer or his authorized dealer 

representative. 

VIII.F. The emissions mechanic or emissions inspector shall generate the appropriate 

vehicle inspection report forms, electronic records, Certificate of Emissions Control, 

as required by the Department of Revenue or the Division and distribute to the 

motorist and the Departments of Health and Revenue. The emissions mechanic or 

emissions inspector will remove all expired Verification of Emissions Test windshield 

stickers. The vehicle inspection report is to be electronically identified by the issuing 

emissions mechanic or emissions inspector. 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
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IX. ADJUSTMENT PROCEDURES 

The emissions mechanic is to secure high altitude specifications for idle speed, idle mixture, ignition 

timing, dwell, and fast idle speed for the purpose of adjustment. If no high altitude specifications are 

available through the Department of Health or other reference sources refer to the emissions decal, 

other applicable specifications guide, or sea level specifications for proper specifications. 

IX.A. With a dwell meter, check to determine if the ignition dwell is within the 

recommended tolerance of ±2° of specifications. Reset if the ignition dwell is not 

within tolerance. 

IX.B. Connect tachometer to determine if idle speed is correct. If not, set to manufacturer's 

specifications with a tolerance of ±50 rpm. 

IX.C. With the engine idling at the correct speed, check ignition timing to determine if it is 

within +4° to -2° of the recommended setting, if no high altitude specifications are 

available. 

IX.D. Using an infrared analyzer, propane enrichment kit, and/or tachometer, adjusts the 

idle air/fuel ratio using manufacturer's suggested procedures and specifications, if 

applicable. 

IX.E. After completing the preceding steps, readjust idle speed to manufacturer's 

specifications, if not within tolerance. 

IX.F. Using the manufacturer's suggested procedure, check the fast idle speed and adjust 

to manufacturer's specifications. 

IX.G. If the vehicle continues to exceed applicable emissions limits, or continues to fail 

OBD, the vehicle must undergo specific emissions related adjustments and repairs. 

Adjustments and repairs must be accomplished to the point of compliance, or the 

applicable cost ceiling must have been met. If the applicable emissions related 

adjustment and repair requirements have been met but an emissions reduction has 

not resulted, the vehicle owner may be referred to a Department of Revenue Motor 

Vehicle Emissions Compliance Inspector to get a waiver. Repairs must have been 

reasonably calculated to achieve a reduction in emissions of those components of 

the inspection the vehicle failed, pursuant to manufacture's specifications as required 

by Sections 42-4-306(7)(a)(II)(A) and 42-9-111,C.R.S. 

X. EMISSIONS RELATED REPAIRS 

X.A. Emissions related repairs generally include only those adjustments to and 

maintenance and repair of the motor vehicle that are directly related to the reduction 

of exhaust emissions necessary to comply with the applicable emissions limits and 

procedures. The expenditure for emissions related repairs does not include the 

inspection fee as specified in Section 42-4-311, C.R.S. or expenses associated with 

the adjustments to and maintenance, replacement, and repair of air pollution control 

equipment on the vehicle if the need for such adjustment, maintenance, or repair 

pursuant to Part C, Section III is due to disconnection of, tampering with, or abuse to 

such air pollution control equipment. Air pollution control equipment is any part, 

assembly or system originally installed by the manufacturer for the sole or primary 

purpose of reducing emissions. 

X.B. Repairs and maintenance to the following systems shall qualify as emissions related 

repairs insofar as the purpose is to reduce exhaust emissions: 

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— Air Intake Systems 

— Ignition Systems 

— Fuel Control Systems 

— Emissions Control Systems 

— Basic Engine Systems 

— For microprocessor (02 ) based air/fuel control systems, cooling systems. 

X.C. Within the basic program, emissions related adjustments and repairs must have been 

performed by a licensed emissions mechanic or repair facility/technician registered 

with the Division pursuant to Part D of this regulation in order to be creditable to the 

repair cost waiver limits. 

In order to be creditable to the enhanced repair cost limits, adjustments and repairs must 

have been performed by a repair facility/technician registered with the Division pursuant to 

Part D of this regulation. 

Only the appropriate emissions failure related parts costs should apply to applicable waiver 

limits for repairs not performed at a licensed emissions inspection station or registered repair 

facility/technician. 

Xl. ENGINE CHANGES 

XI.A. For those vehicles in which the original engine has been replaced, the emissions 

limits and applicable emissions control equipment for the year and model of the 

vehicle body/chassis, as per registration/title or replacement engine, whichever is 

newest, shall apply. For those diesel powered vehicles which have been converted to 

operate on fuel(s) other than diesel; the emissions limits and applicable emissions 

control equipment for the year, make and model of the gasoline powered engine 

equivalent as originally manufactured, for the vehicle body/chassis, per the 

registration or replacement engine, whichever is newest, shall apply as determined 

by emissions technical center personnel or designee and specified on an official AIR 

Program vehicle evaluation form (DR2365). 

XI.B. For 1975 and newer vehicles in which the original engine has been replaced, if either 

the vehicle body/chassis original engine, as per registration/title or replacement 

engine as manufactured had a catalytic converter system, air injection reaction 

system, and/or microprocessor based air/fuel control system, these emission control 

systems must be present, intact and operational before a Certification of Emissions 

Control may be issued. 

XI.C. For those vehicles titled/registered as model year 1975 and newer, that were 

assembled by other than a licensed manufacturer such as kit-cars, registered/titled 

according to Section(s) 42-6-108 and/or 42-5-205, C.R.S. and assigned a state or 

manufacturer specific identification number, the applicable emissions control 

equipment and standards will be based upon a determination by technical center 

personnel of the vintage of the vehicle engine. The technical center personnel may 

issue an affidavit and the year of the engine shall be presumed to be that stated by 

the vehicle owner unless it is determined by state emissions technical center 

personnel or designee, after physical inspection of the vehicle engine, that the year 

of the engine is other than stated by the owner. 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
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XII. CLEAN SCREEN INSPECTION PROGRAM PROCEDURES 

XII.A. Eligibility to participate 

XII.A.1. Vehicles specified in Part A, Section IV.B., are eligible for participation in 

the Clean Screen Program. 

XII.A.2. Clean Screen inspections applicable to the program are those performed 

within twelve months prior to an individual vehicle's registration renewal 

date. 

XII.A.3. Vehicles are eligible for participation in the Clean Screen Program when 

the two most recent consecutive emissions readings observed during the 

12-months prior to its registration date comply with the standards specified 

in Part F, Section VI. and: the most recent passing emissions reading 

occurred on a different day or at a different site location from the prior 

reading. Additionally, vehicles that are identified as low emitters on the 

low emitting vehicle index are eligible for participation in the clean screen 

program when the most recent emissions reading observed during the 12-

months prior to their registration date complies with the standard specified 

in Part F, Section VI. 

XII.A.4. The following vehicles are ineligible for participation in the Clean Screen 

Program: 

XII.A.4.a. New Vehicles as specified in Section 42-4-310(b)(II)(A), C.R.S. 

XII.A.4.b. Vehicles involved in a change of ownership. 

XII.A.4.c. Vehicles owned by the United States government or any agency 

thereof pursuant to Section 42-4-310(I)(b)(1), C.R.S. 

XII.B. All aspects of inspection must be performed by a licensed Clean Screen Inspector. 

XII.C. Clean Screen Test Analyzer Systems 

XII.C. 1. Vehicles participating in the Clean Screen Program shall be tested as 

specified in this Part C utilizing a Clean Screen Test Analyzer System 

recognized by the Division as having complied with the performance and 

design requirements specified in Part B, Section IX. of this regulation. 

XII.C.2. Clean Screen Test Analyzer Systems will be periodically calibrated and 

maintained as required in Part B, Section IX. of this regulation. 

XII.C.3. The inspection data processing system(s) used by the Data Manger and 

Clean Screen Inspector will be that approved by the Division, and the 

Department of Revenue. 

XII.D. Vehicle owners participating in the Clean Screen Program are not subject to the 

provisions of Part C, Sections I. through XI. 

XII.E. Certification of Emissions Control. 

In order to obtain a Certificate of Emissions Control the following conditions must be met: 

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XII.E.1. The vehicle emissions levels are the same as or less than the limits 

specified in Part F, Section VI. 

XII.E.2. The most recent two consecutive emissions readings were observed 

within twelve months of the registration renewal date provided that the 

most recent passing emissions reading must have occurred on a different 

day or at a different site location from the prior reading. 

XII.E.3. No non-complying emissions readings are observed between or 

subsequent to the last pair of complying readings. 

XII.E.4. For vehicles that are identified as low emitters on the low emitting index 

the most recent emission reading was observed within 12-months of the 

registration renewal date. For these vehicles, identification as a low 

emitter on the low emitting vehicle index shall take the place of the second 

remote sensing reading otherwise required under Section XII.E.2., above. 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
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PART D Qualification and Licensing of Emissions Mechanics, Emissions Inspectors, 

and Clean Screen Inspectors; Licensing of Emissions Inspection and 

Readjustment Stations, Inspection-Only Stations, Inspection-Only Facilities, 

Fleets, Motor Vehicle Dealer Test Facilities, Enhanced Inspection Centers; 

Qualification of Clean Screen Inspection Sites; and Registration of Emissions 

Related Repair Facilities and Technicians 

I. LICENSING OF EMISSIONS INSPECTION AND READJUSTMENT STATIONS, 

INSPECTION-ONLY STATIONS, INSPECTION-ONLY FACILITIES, ENHANCED 

INSPECTION CENTERS, FLEET INSPECTION STATIONS AND MOTOR VEHICLE 

DEALER TEST FACILITIES 

I.A. Emissions Site Requirements for the Licensing of Emissions Inspection and 

Readjustment Stations, Inspection-Only Stations, Inspection-Only Facilities, Fleet 

Inspection Stations and Motor Vehicle Dealer Test Facilities: 

I.A.1. Applicability 

All emissions inspection and readjustment stations, inspection-only stations, 

inspection-only facilities, fleet inspection stations, and motor vehicle dealer test 

facilities are required to meet all applicable standards pursuant to this Part D and the 

Department of Revenue's adopted regulations in order to qualify for licensing for 

operation in Colorado's AIR Program. 

To achieve the uniformity and security needed in test site locations; in order to meet 

federal EPA regulations contained in Federal Register vol. 57, Number 215, of the 

Federal Register and meet the statutory requirements contained in Sections 42-4-301 

through 42-4-316, C.R.S.; the Air Quality Control Commission adopts this standard 

for emissions site requirements. 

I.A.2. Standards for emissions inspection sites: 

I.A.2.a. All facilities shall be a permanent type of structure. 

I.A.2.b. All sites must be capable of receiving mail. 

I.A.2.c. All test facilities shall have a minimum of two off-street parking 

spaces for staging to accommodate additional vehicles. 

I.A.2.d. All test site facilities shall have a customer waiting area that 

provides for observation of the entire emissions inspection 

process. Observation can be, direct observation, observation by 

electronic equipment, or other methods that prove to be as 

effective with prior approval of the Department of Revenue. 

I.A.2.e. All test sites shall be capable of conducting all aspects of the 

inspection process within the confines of a building or structure, 

and maintaining ambient air temperatures between 41 degrees 

and 110 degrees Fahrenheit in the inspection area as defined in 

Section I. C. 1. of Part C of this regulation. Inspections are not 

required to be performed within the confines of a structure or 

building provided ambient temperatures are within such 

parameters. 

"v.1-001 

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I.A.2.f. All test site facilities shall have an adequate exhaust removal 

system which shall be designed so as to not alter the inspection 

results and to assure safe ambient air quality of the inspection 

area as established by the Occupational Safety and Health 

Administration pursuant to 29 CFR, Part 1910, Subpart Z. 

I.A.3. Pursuant to Sections 42-4-306(4)(a) and 42-4-307 (8)(a), C.R.S. as 

amended, the Division shall develop or contract for the development of a 

training program for emissions mechanics and emissions inspectors. The 

training program shall be comprehensive in nature and address all 

aspects of vehicle inspection procedures specified for this regulation. 

I.A.3.a. Participation by emissions inspectors intending to operate in the 

enhanced program area shall be required. 

I.A.3.b. Participation by emissions mechanics intending to operate in the 

basic program area shall be voluntary. 

I.A.3.c. Training classes shall be funded by tuition charged to the 

participants. 

I.A.3.d. The following tuition rates and fees shall apply 

I.A.3.d.(1) The training class fee shall be no greater than $150 per 

participant. 

I.A.3.d.(2) The instructor's fee for presenting a class shall not exceed 

$400. 

I.A.3.d.(3) The training manual for those emissions mechanics who 

choose not to participate in a training class shall be no 

greater than $25. 

I.A.3.e. These same training provisions shall be applicable to the 

requalification provisions of Section II.B. of this Part D. 

I.B. The following tools, reference manuals and diagnostic equipment shall be available 

for performance of inspections; and within the basic program, emissions related 

adjustments and repairs. 

I.B.1. Division approved calibrated and spanned Test Analyzer System (TAS) or 

On-Board Diagnostic Test Analyzer System (OBD TAS). 

I.B.1.a. 

I.B.1.b. 

As a provision of continued license to perform AIR Program 

inspections, the TAS must be updated as required, pursuant to 

this regulation. 

The station or facility owner or operator shall maintain a full 

service/maintenance contract with the equipment manufacturer 

or equipment manufacturer's designee valid for the duration of 

the program but renewable on an annual basis 

I.B.2. Rules for the operation of AIR Program inspection stations provided by the 

Colorado Department of Revenue. 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
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I.B.3. Tachometer capable of reading 4,6 and 8 cylinders, 0-6,000 RPM 

minimum at no greater than 10 RPM of actual speed. 

I.B.4. Emissions control systems applications guide as incorporated into the 

TAS, and oxygen sensor/check engine light, systems maintenance guide 

in either printed or electronic medium. 

I.B.S. Dwell meter. 

I.B.6. Ignition timing light. 

I.B.7. Propane enrichment kit for idle mixture adjustment and diagnostics. 

I.B.B. Commercially available reference manuals giving idle speed, idle mixture, 

mixture control dwell or fuel injection duration, timing, dwell, fast idle 

speed specification, high altitude specifications and information covering 

the emissions control systems description, diagnostic and repair 

procedures for the year models of vehicles involved in the AIR Program. In 

either printed or electronic medium. 

I.B.9. Sufficient hand tools including but not limited to suitable computer scanner 

diagnostic link, digital volt/ohm meter, vacuum pump and other automotive 

diagnostic equipment for proper performance of the inspections, 

adjustments and emissions related repairs as applicable to the licensed 

entity. 

I.B.10. Division approved span gas and equipment for performing gas span 

checks and calibrations. 

I.B.11. Suitable non-reactive tail pipe extenders or probe adapter for inspecting 

vehicles with screened or baffled exhaust systems, or exhaust systems 

with multiple tail pipes. 

I.B.12. The analyzer manufacturer's maintenance and calibration manual must be 

retained in the inspection area. 

I.B.13. (Reserved) 

I.B.14. Items #5, 6, 7, 8 and 9 above are not required for licensing as an 

inspection-only station or inspection-only facility. 

I.B.15. Items #3 through 11 above are not required for a vehicle fleet self 

inspection station pursuant to 42-4-309 C.R.S. 

I.C. A licensed emissions mechanic or emissions inspector who has successfully 

completed a hands-on proficiency check administered by the Department of Revenue 

in accord with the Commission regulations and those of the Department of Revenue, 

and the criteria specified in Part D of this regulation is or will be available to make a 

proper inspection. Enhanced inspection centers shall be open 8:30 am - 7:30 p.m. 

weekdays, and Saturday 8:00 a.m. -1:00 p.m. 

I.D. An emissions inspection-only station and inspection-only facility, must so indicate 

same by posting a sign in a readily visible location, and that no emissions related 

adjustments or repair services are available should the vehicle fail the inspection 

procedure. 

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All Rights Reserved 

This rule revision will result in: 

1) Improved convenience and reduced costs for state and local government fleet operators, by 

making emissions compliance easier and faster, 

2) Legal and regulatory clarity in the rule language, while not affecting procedures and operation 

of the program or its customers, 

3) A lean and streamlined regulation by removing repealed and obsolete provisions. 

Specific Statutory Authority 

The Commission has the authority to promulgate rules governing the operation of the clean screen 

program pursuant to Section 42-4-306(23). The Commission has the authority to promulgate rules 

governing the issuance of economic hardship waivers pursuant to Section 42-4-306 (7) (a) (II) (C), 

C.R.S. ; the labeling of the North Front Range as state-only falls under the general authority of the 

Commission to promulgate rules pursuant to Section 42-4-306 (1) C.R.S.; establishing cutpoints and 

pass-fail criteria in Section 42-4-306 (6)(a) C.R.S.; operating the remote sensing high emitter project 

in Section 42-4-307.7 C.R.S. 

Additional findings under Sections 25-7-110.5(5) and 25-7-110.8, C.R.S 

None of the revisions in this rulemaking exceed federal requirements. With the exception of the 

revision addressing the two-speed idle emissions test, these rules are not federally mandated, nor are 

there any counterpart federal rules. The rule is based upon reasonably available, validated, 

reviewed, and sound scientific methodologies, and the Commission has considered all information 

submitted by interested parties. This revision will result in cost savings and efficiencies to state and 

local government vehicle fleets with minimal impact on air quality and emissions, and that the cost 

savings to government and the public justify the slight air quality impact. This proposed rule change 

will provide clarity for citizens, government vehicle fleet operators, and the automotive repair industry 

and achieve any necessary reduction in air pollution. These rules will maximize the air quality 

benefits of the regulation in the most cost-effective manner. 

XXX. AMENDMENTS 

ADOPTED DECEMBER 20, 2012 

This revision to Regulation Number 11, Parts A, B, C, D, E, F and H — is to amend language that 

would extend model-year exemptions; require on-board diagnostic inspections; no longer require 

visual inspections of emission control systems on 1996 model-year and newer vehicles; require 

retesting after failing gas cap integrity test; delete obsolete language; and revise typographical, 

grammatical, and formatting errors. 

This Statement of Basis, Specific Statutory Authority, and Purpose complies with the requirements of 

the Colorado Administrative Procedures Act, Section 24-4-103, C.R.S., and the statutory authority 

provided in Sections 42-4-301 through 42-4-316, C.R.S. 

Basis and Purpose 

The Commission's December 2012 amendments are intended to assure that emission reduction 

benefits are maintained while at the same time increasing the flexibility and convenience of motor 

vehicle emission inspections. The amendments increase new vehicle model-year exemptions from 

emissions testing from four to seven years. The amendments provide for OBD inspections of 1996 

year-model and newer motor vehicles for the first two testing cycles (four model years) after the 

seven year new vehicle exemption runs out. Procedures are included to default to the use of OBD 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
Page 76.2 

testing on vehicles that are not readily testable using IM 240; and to default to IM 240 testing on 

vehicles that are not readily testable with OBD. Visual inspections of emission control equipment are 

eliminated on 1996 year-model and newer motor vehicles. To clarify and assure compliance with the 

federal requirements at Title 40, Part 51, Subpart S, 51.357, the already current practice of requiring 

a full retest after a gas cap failure is being specified as part of the evaporative fuel control inspection 

procedures. 

Federal Requirements 

The current inspection and maintenance program, except in the North Front Range is contained in 

Colorado's ozone State Implementation Plan (SIP). Any revision to the program requires that air 

quality credits achieved from the program are not lost. 

In general, EPA rules require certain nonattainment areas implement Inspection and Maintenance 

programs as part of a SIP. Under the Clean Air Amendments of 1990, the Denver metropolitan area 

was required to implement an "Enhanced" IM Program, specifically for carbon monoxide. Since that 

time, the state has come into attainment with carbon monoxide, but the program remains a necessary 

element of Colorado's ozone SIP. The North Front Range area of the program operates as a stateonly program 

Specific Statutory Authority 

Sections 42-4-306 and 42-4-310, C.R.S. authorize the Air Quality Control Commission 

("Commission") to promulgate rules for inspection of motor vehicle emissions. Section 42-4-306(8) 

authorizes the Commission to exempt motor vehicles from emission inspections. Section 42-4- 

306(3)(b)(V)(B) authorizes the Commission to promulgate rules for alternative motor vehicle emission 

inspections, including on-board diagnostics (OBD) inspections. 42-4-306(6)(a) authorizes the 

Commission to promulgate rules on inspection procedures, including those related to OBD and 

evaporative gases. 

Findings Pursuant to 25-7-110.8, C.R.S. 

The revision of the rule is to lessen the regulatory burden on the motoring public through expanding 

the new vehicle exemption period to seven years and the introduction of OBD inspection to select 

vehicles, among other measures, while maintaining the current air quality benefits received from the 

program, in a cost effective manner, at similar or reduced costs to the current program. 

The rule revision is based on reasonably available, validated, reviewed, and sound scientific 

methodologies. All validated, reviewed, and sound scientific methodologies and information made 

available by interested parties has been considered. Evidence in the record supports the finding that 

the rule shall result in a continued demonstrable reduction in air pollution. The rule revision is the 

most cost-effective alternative, provides the regulated community flexibility, and achieves the 

necessary reduction in air pollution. The revised rule will maximize the air quality benefits of the 

regulation in the most cost-effective manner. 

XXXI. AMENDMENTS 

ADOPTED NOVEMBER 21, 2013 

This revision to Regulation Number 11 is to amend language that will clarify provisions contained in the 

existing regulation concerning model year exemptions and program implementation dates, updating the 

listed repair waiver cost limit from $450 to the currently used $715 limit, modifying qualification criteria 

used to grant an economic hardship waiver, and incorporating a new Test Analyzer Specification for 

On-board Diagnostics in Appendix A. Obsolete technical specifications and procedures are being 

deleted and formatting, grammatical and typographical corrections are being made. 

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All Rights Reserved 

This Statement of Basis, Specific Statutory Authority, and Purpose complies with the requirements of 

the Colorado Administrative Procedures Act, Section 24-4-103, C.R.S., and the statutory authority 

provided in Sections 42-4-301 through 42-4-316, C.R.S. 

Basis and Purpose 

The Commission's November 2013 amendments are intended to clarify, amplify, and streamline the 

rule in support of previous recent changes to the Automobile Inspection and Readjustment Program. 

The proposed modifications are considered minor and will not result in any significant change in 

program costs or air quality benefits. 

The basis of these modifications is to address any ambiguities that may exist in the interpretation of 

new program changes, as well as add a new Test Analyzer Specification for On-board Diagnostics as 

• required by Regulation Number 11, Part B, Section X. 

Federal Requirements 

The current inspection and maintenance program is contained in Colorado's ozone State 

Implementation Plan (SIP), with the exception of Larimer and Weld Counties in the North Front Range. 

Any revision to the program requires that air quality credits achieved from the program are not lost. 

In general, EPA rules require certain nonattainment areas implement Inspection and Maintenance 

programs as part of a SIP. Under the Clean Air Amendments of 1990, the Denver metropolitan area 

was required to implement an "Enhanced" IM Program, specifically for carbon monoxide. Since that 

time, the state has come into attainment with carbon monoxide, but the program remains a necessary 

element of Colorado's ozone SIP. The North Front Range area of the program operates as a stateonly program 

Specific Statutory Authority 

Sections 42-4-306 and 42-4-310, C.R.S. authorize the Air Quality Control Commission 

("Commission") to promulgate rules for inspection of motor vehicle emissions. Section 42-4-306(8) 

authorizes the Commission to exempt motor vehicles from emission inspections. Section 42-4- 

306(3)(b)(V)(B) authorizes the Commission to promulgate rules for alternative motor vehicle emission 

inspections, including on-board diagnostics (OBD) inspections. 42-4-306(6)(a) authorizes the 

Commission to promulgate rules on inspection procedures, including those related to OBD and 

evaporative gases. 

Findings Pursuant to 25-7-110.8, C.R.S. 

The revision of the rule is to clarify provisions contained in rule or that are administrative in nature. 

These changes do not increase the regulatory burden on the motoring public, while maintaining the 

current air quality benefits received from the program, in a cost effective manner, at similar or 

minimally reduced costs to the current program. 

The rule revision is based on reasonably available, validated, reviewed, and sound scientific 

methodologies. All validated, reviewed, and sound scientific methodologies and information made 

available by interested parties has been considered. Evidence in the record supports the finding that 

the rule shall result in a continued demonstrable reduction in air pollution. The rule revision is the 

most cost-effective alternative, provides the regulated community flexibility, and achieves the 

necessary reduction in air pollution. The revised rule will maximize the air quality benefits of the 

regulation in the most cost-effective manner. 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
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APPENDIX A Technical Specifications 

Revised Sept 09, 1994 

INTRODUCTION 

The Colorado AIR Program is in the process of modifying its current automotive inspection and 

maintenance program to comply with the Clean Air Amendments of 1990. Colorado's current program 

is based upon BAR 84 inspection technology utilizing a decentralized program format encompassing 

nine Front Range counties. In order to achieve compliance with the Clean Air Amendments of 1990, 

Colorado will change to a program format that will have a contractor based operation conducting the 

IM 240 emissions test and a population of independent inspectors conducting inspections utilizing a 

new Colorado 94 emissions analyzer. The contractor is based in the "enhanced" program area, 

basically the Denver metropolitan area and will inspect 1982 and newer vehicles. Independent 

inspection facilities will inspect vehicles of all years within the "basic" program area as well as being 

able to inspect 1981 and older vehicles within the "enhanced" area. 

The demands for more accurate analytical information as well as a more automated inspection 

process with real-time data transfer has superseded the capabilities of BAR 84 technology. Current 

BAR 90 analytical technology is acceptable, but other system enhancements are necessary to meet 

Colorado's inspection needs. These enhancements and other technical details are described in the 

remainder of this document. 

1.0 GENERAL 

1.1 Design Goals 

The specifications that have been developed are designed utilizing a personal computer 

system. The analyzer system must be capable of performing uniform and consistent emission 

tests for Colorado's Automotive Inspection and Readjustment (AIR) Program. Features of the 

analyzer include: vehicle emissions measurements of hydrocarbon (HC), carbon monoxide 

(CO), carbon dioxide (CO2)and oxygen(02); engine RPM measurements, exhaust dilution 

determinations, pressure test system for EVAP; data entry; data retrieval tables; a dedicated 

printer (for vehicle inspection certificates) and an additional printer for diagnostics and 

general purpose printouts; data recording on double sided high density 1.44 megabyte (Mb) 

3.5" floppy diskette and a 120Mb (or greater) hard drive; modem for "on-line real time" data 

transmission; CRT information display to the inspector; bar code (2D) reader and printing 

capabilities; and fully menu driven, interactive simple microprocessor controlled operation. 

Additional, automatic features required include: gas calibrations, zero and span checks, 

pressure calibrations, gas auditing procedure; leak checks, HC hang-up checks, audit menus 

(i.e., data read system), test sequencing, and low-flow checks. The analyzer shall be 

designed and constructed to provide reliable and accurate service in the automotive 

environment. The software used in the analyzer shall consist of a process control system as 

well as data look-up files. Security shall be provided to prevent unauthorized modifications to 

the software or test data and recording unauthorized entry (tampering) and locking out of the 

inspection process when detected. 

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All Rights Reserved 

2.18 Vehicle Diagnosis 

The analyzer shall be capable of menu selection that will allow the analyzer to be used as an 

ordinary garage type emissions analyzer for general automotive repair work and diagnostics. 

2.19 Software Loading 

The inspector shall not have to load the microcomputer's operating or applications software to 

operate the analyzer. On each POWER ON of the analyzer, the analyzer shall automatically 

do all microcomputer component self-diagnostics, memory checking, and loading of all 

necessary operating software without inspector intervention. Upon satisfactory computer 

component check out, the applications software is to present a menu of available analyzer 

operations. All offered features are to be menu-driven. For each feature, a context sensitive, 

on-line help facility is to be provided which can be accessed preferably with a single 

keystroke. 

3.0 DISPLAY PROMPTS AND PROGRAMMING CRITERIA REQUIREMENTS 

Operational software requirements will be available from the Division upon request. 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
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ATTACHMENT I PDF 1000 Scanner 

This document is contained in the Air Pollution Control Division's Emissions Technical Center 

Procedures Manual and is incorporated by reference. 

ATTACHMENT II Thermal Transfer Printer 

This document is contained in the Air Pollution Control Division's Emissions Technical Center 

Procedures Manual and is incorporated by reference. 

ATTACHMENT III Colorado Automobile Dealers Transient Mode Test Analyzer System 

This document is contained in the Air Pollution Control Division's Emissions Technical Center 

Procedures Manual and is incorporated by reference. 

ATTACHMENT IV Specifications for Colorado 97 Analyzer 

INTRODUCTION 

Colorado's current enhanced I/M program contains a two-speed idle (TSI) emissions testing 

component, the Colorado 94 Test Analyzer System that is based upon BAR 90 technology. The TSI 

program utilizes a decentralized, independent inspection only format encompassing the nine Front 

Range counties. The DMA program is expanding to the North Front Range counties of Weld and 

Larimer in 2010. This inspection only population of independent inspectors will conduct inspections 

utilizing a new Colorado 97 emissions analyzer. 

The demands for more accurate analytical information as well as a more automated inspection 

process with real-time data transfer has superseded the capabilities of BAR 90 (Colorado 94) 

technology. System enhancements are necessary to meet Colorado's inspection needs. These 

enhancements and other technical details are described in this document. 

1.0 GENERAL 

It is expected that the Colorado 97 software will be Colorado 94 software upgraded to BAR 97 and 

SAE J1978 and J1979 compliance. 

1.1 Design Goals 

The specifications that have been developed are designed utilizing a personal computer 

system. The analyzer system must be capable of performing uniform and consistent emission 

tests for Colorado's Automotive Inspection and Readjustment (AIR) Program. Features of the 

analyzer include: vehicle emissions measurements of hydrocarbon (HC), carbon monoxide 

(CO), carbon dioxide (CO2)and oxygen(02); engine RPM measurements, exhaust dilution 

determinations, pressure test system for EVAP; OBD II monitor readiness and diagnostic 

trouble code retrieval; data entry; data retrieval tables; a dedicated printer (for vehicle 

inspection certificates; data recording on hard drive or removable media ; modem for "on-line 

real time" data transmission; monitor information display to the inspector; bar code reader 

and printing capabilities; and fully menu driven, interactive simple microprocessor controlled 

operation. 

5 CCR 1001-13 CODE OF COLORADO REGULATIONS 
© 2013 State of Colorado 36 CR 23 and 24, 12-13 Page 99 

All Rights Reserved 

Additional, automatic features required include: gas calibrations, zero and span checks, 

pressure calibrations, gas auditing procedure; leak checks, HC hang-up checks, audit menus 

(i.e., data read system), test sequencing, and low-flow checks. The analyzer shall be 

designed and constructed to provide reliable and accurate service in the automotive 

environment. The software used in the analyzer shall consist of a process control system as 

well as data look-up files. Security shall be provided to prevent unauthorized modifications to 

the software or test data and recording unauthorized entry (tampering) and locking out of the 

inspection process when detected. 

The emissions analyzer software shall be designed for maximum operational simplicity. 

It shall also be capable of providing emission-reading characteristics, independent of the 

inspection function, which can be used for vehicle diagnostic. 

1.2 Useful Life 

The useful life of the analyzer shall be a minimum of five years. 

1.3 Nameplate Data 

A nameplate including the following information shall be permanently affixed to the housing of 

the analyzer: 

Name and Address of Manufacturer 

Model Description 

Serial Number 

Date of Assembly 

The manufacturer shall affix a stick-on type label to the analyzer that contains a toll-free 

telephone number for customer service. This number can also be included in a service 

software message. 

1.4 Manuals 

Each analyzer shall be delivered with the following manuals: 

A. Reference Operating Instructions 

B. Operation Instruction Manual 

C. Maintenance Instruction Manual (limited) 

D. Initial Start-up Instructions 

Colorado 97 Analyzer manufacturers may consolidate manuals. The manuals shall be 

constructed of durable materials and shall not deteriorate as a result of normal use over a 

five-year period. The analyzer housing shall provide convenient storage for each manual in a 

manner that will: 

E. Allow easy use. 

F. Prevent accidental loss or destruction. 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
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1.5 Certification Documentation 

The analyzer software shall be fully documented. Two copies of the documentation listed 

below shall be submitted to Colorado Department of Public Health and Environment as part 

of the certification application. 

A. Complete program listings. Program listings may be on disk. They are not 

required to be submitted with the application for certification. 

B. Functional specifications. 

C. Functional flowcharts of the software. 

D. Example inputs and outputs from all processes. 

E. Detailed interface information on system components including the 

identification of protocol and output specifications. 

F. All file layouts with file names, file types, file security, field names, field 

types, field sizes, and field editing criteria. 

Documentation provided by the vendor to meet this requirement will be treated as proprietary 

information by Colorado Department of Public Health and Environment. 

Prior to certification of any Colorado 97 emissions analyzer for sale in Colorado, the 

manufacturer of such analyzer shall provide the Division with software source codes and all 

other technical information (including, but not limited to all working codes, schematics and 

drawings) necessary to operate, maintain, calibrate and repair such analyzer in the event that 

the manufacturer or its agent ceases providing adequate maintenance, calibration and repair 

services in Colorado. The manufacturer shall keep such information current, and will provide 

the Division with copies of any and all changes. So long as such maintenance, calibration 

and repair, services are available from the manufacturer or its agent, the Division shall 

protect such information as confidential commercial data if it is clearly marked as such. In the 

event that the manufacturer becomes insolvent or stops providing adequate maintenance, 

repair or calibration services in Colorado all such information shall be the property of the 

Division and may be released to a third party as necessary to repair, calibrate and maintain 

the analyzers. 

1.6 Warranty Coverage/Service Contract 

A written warranty coverage agreement, signed by an authorized representative of the 

equipment manufacturer and the vehicle inspection station owner, which provides a complete 

description of coverage for all systems and components and all manufacturer provided 

services listed in Section 1.8, must accompany the sale or lease of each Colorado 97 

emissions analyzer. 

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An extended service contract shall be available upon the expiration of the manufacturers 

original warranty period. Original manufacturer's warranty shall be a minimum of one year 

from the date of purchase. The "service contract" shall be offered in one-year increments. 

The "service contract" agreement shall include the inspection station owner's name, 

inspection station address, telephone number, inspection station identification number, 

analyzer serial number and detailed terms of the agreement. The agreement must extend for 

at least one year and if purchased, the expiration date must be entered to software file and 

monitored by the system clock. Approaching expiration messages must be displayed at daily 

system start-up beginning thirty days prior to expiration and messaging "30 days until 

expiration, 29 days etc." Renewals shall be offered at the inspection station owner's request 

and governed by "good business" practices between the parties involved. Service contract 

agreements must be available by the manufacturer for the mandated life of Colorado AIR 

Program. Cost disclosures and detailed descriptions of coverage's must be available in 

printed form and distributed to all Colorado 97 users. Cost disclosure shall also be made for 

"consumable" inventory items 1.8B. This information would most appropriately be presented 

with the original manufactures warranty. 

1.7 Tampering Resistance 

Controlled access design shall be the responsibility of the manufacturer and is subject to 

approval by Colorado Department of Public Health and Environment. Analyzer service 

personnel, inspectors or others shall be prohibited, to Colorado Department of Public Health 

and Environment satisfaction, from creating or changing any test results, programs or data 

files contained in the analyzer. Manufacturers shall utilize special BIOS partitions, or other 

appropriate software and hardware provisions, deemed necessary to protect the UM files and 

programs. The protection features shall prevent access to the secured floppy disk drive and 

those portions of the hard disk containing UM programs and test data or files. 

The emission analyzer and the sampling system shall be made tamper-resistant to the 

Colorado Department of Public Health and Environment satisfaction. At a minimum, the 

manufacturer shall develop tamper-resistant features to prevent unauthorized access through 

the cabinet. Microswitches, keyed locks, or software algorithms requiring the use of a 

password which can be changed by the Colorado Department of Public Health and 

Environment would all be acceptable provided the physical or logical design effectively 

prevents unauthorized access. 

Manufacturers may offer analyzers with additional disk drives that can run optional software 

application programs. 

If tampering occurs, a software lockout algorithm shall be activated which aborts any existing 

test sequence and prevents further inspections until an authorized AIR Program official clears 

the lockout. 

The lockout system shall be designed so that an AIR Program official from the audit menu 

can activate it. Only AIR Program Auditors may remove lockouts put in place from the audit 

menu. Manufacturers shall develop a system by which their service technicians shall be 

prevented from clearing "tamper" lockouts. 

Optional software packages shall not interfere with the normal operation of the I/M inspection 

and testing software, and shall not compromise the tamper-resistant features of the analyzer. 

Manufacturer field service representatives will not have access to DOS, unless assurances 

acceptable to Colorado Department of Public Health and Environment have been provided 

that insure, integrity of the system will not be jeopardized. 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
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1.8 Manufacturer Provided Services 

The manufacturer shall agree to provide the following services to the inspection station as 

part of the manufacturer's original warranty and thereafter as a portion of the service contract 

agreement. The cost of a service agreement is to be listed on a year-by-year basis. Future 

charges cannot exceed the amount published. 

A. Delivery, installation, calibration, and verification of the proper operating 

condition of a Colorado 97 emissions analyzer. 

B. Quarterly (90 days) examination, calibration, and routine maintenance of 

the analyzer and sampling systems. Full systems support and repair, 

including loaner units. Upon initial sale or loan, provide "extra" printer 

medium (1 ea.) sample filter(s) (2), sample hose (1) and sample probes 

(1). Maintain the "extra" consumable inventory upon examination and 

provide a software history file for the replacement of consumables 

accessible to AIR Program officials. Consumables and the cost(s) thereof 

must be disclosed in the service agreement. 

C. Instruct all certified inspectors employed by the inspection station at the 

time of installation in the proper use, maintenance, and operation of the 

analyzer. The analyzer shall contain a feature that will allow an inspector 

to go through the complete inspection procedure without generating an 

official inspection record. This function will be used for evaluating 

inspector performance, by AIR Program officials, or by the manufacturer 

for demonstration purposes. The "training mode" shall not require the use 

of an inspector's access code or allow access to secured areas of 

hardware or software. The display shall show a message throughout the 

inspection that this is not an official inspection. Vehicle inspection reports 

shall indicate to the satisfaction of Colorado Department of Public Health 

and Environment that they are for training only. No official Certificate of 

Compliance will be generated during the training exercise. 

D. On-site service response by a qualified repair technician within two (2) 

business days, (48 hours) excluding Sundays and national holidays, of a 

request from the inspection station. The names, toll-free telephone 

numbers, and service facility addresses of all manufacturer 

representatives responsible for equipment service shall be provided to the 

inspection station. A service representative shall be available at all times 

during normal working hours. Sundays and national holidays are not 

included. All system repairs, component replacements, and/or analyzer 

adjustments, shall be accomplished on-site within 48 hours after a service 

request has been initiated. If the completion of this work is not possible 

within this time period, a Colorado 97 loaner unit shall be provided until 

the malfunctioning unit is properly repaired and returned to service. 

Service representatives shall have a software driven menu option that 

allows the transfer of inspection station, inspector information and other 

applicable data files from one analyzer to another without manual inputs 

and without transfer of previous test files. 

E. Updates of the "Functional" software will be limited to once per year at no 

cost. 

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Updates of operational software, i.e., file based information will be on an "as 

required" basis. All forms of software updating will utilize modem technology for the 

updating process. File updates are at no cost and every effort will be made to 

minimize them. 

F. The analyzer software shall be designed so that AIR Program officials can 

insert a disk, prepared by the manufacturer, into the Program system host, 

and update the existing software version, via modem. A system of manual 

updating by program officials utilizing the auditor's menu shall also be 

available. Look-up up tables and message screens shall be designed 

sufficiently separate from the main operations software so that it is not 

possible, to interfere in any way with the operations of the analyzer. 

Colorado Department of Public Health and Environment will require the manufacturer 

to render updates as necessary in the first year of the program to ensure the program 

meets all design criteria. Thereafter software updates will be limited to once per year 

at no cost. Since modem software updating will be utilized, there are no costs to the 

analyzer owner. A software version number, consisting of a four character alphanumeric code made up of the last two digits of the year followed by a two character 

version number, shall be recorded in the analyzer and included on each vehicle test 

record. The analyzer manufacturer shall not modify any existing software version 

without obtaining written approval from Colorado Department of Public Health and 

Environment. 

Colorado Department of Public Health and Environment may require the 

manufacturers to conduct on-site or laboratory testing of in-use analyzers in order to 

document continued compliance. When an analyzer is removed from the field, for 

repair or testing, manufacturers shall supply the inspection station from which it was 

removed with a temporary replacement unit meeting all program requirements. 

Manufacturers shall pay for all necessary shipping and transfer costs for the 

replacement of the analyzer selected for compliance testing. Manufacturers shall also 

pay for any required testing performed by their personnel or by an independent 

company. 

The manufacturers shall provide training to AIR Program officials on all operational, 

maintenance, and quality control features of the analyzers, including full access to 

and use of inspection menus, audit menus and calibration menus, as well as optional 

programs offered to inspectors. Such training shall be conducted at the 

manufacturer's expense as a condition of certification and thereafter at reasonable 

intervals upon written request by Colorado Department of Public Health and 

Environment 

1.9 Certification Requirements 

The manufacturer shall submit a formal certificate to Colorado Department, of Public 

Health and Environment that states that any analyzer sold or leased by the 

manufacturer or its authorized representatives for use in Colorado AIR Program will 

satisfy all design and performance criteria described in these specifications. The 

manufacturer shall also provide sufficient documentation to demonstrate 

conformance with these criteria including a complete description of all hardware 

components, the results of appropriate performance testing, and a point-by-point 

response to specific requirements. Previous certification by the California Bureau of 

Automotive Repair (BAR) is necessary for the analytical bench. 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
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In addition, a full description of the company's service procedures and policies, as 

well as sample contracts, warranties, and extended service agreements, shall be 

provided as part of the certification application to ensure proper maintenance of all 

analyzers throughout their useful life. One fully functional analyzer shall be presented 

for evaluation and one additional fully functional analyzer for the certification process. 

If certified these units will remain in AIR Program possession for continued in-use 

evaluation for the life of the AIR Program. In the event that 1 % of overall unit sales 

exceed this two-unit base, in-use evaluation will require 1 % of overall unit sales for in 

use evaluation. 

2.0 HARDWARE SPECIFICATIONS 

2.1 General 

Colorado 97 hardware shall be compliant with the BAR 97 Section 2 specification, the August 

2008 revision available at: 

http://www.smogcheck.ca.gov/70 siteWideInfo/Library/09 IndustryResources.html 

And/or current SAE on-board diagnostic "J" standards including but not limited to J1978 and 

J1979 available from SAE. 

NOTE: The Colorado 97 is not an ASM system. ASM hardware, i.e. the dynamometer and 

NOx sensor, are not needed. By extension, ASM software is also unnecessary. 

2.2 Span Gases 

The Colorado 97 shall use the same span gases utilized for calibration of the Colorado 94 

TAS namely: 

AIR 94 Low Range: 

300 ppm propane 

1.0% carbon monoxide 

6.0% carbon monoxide 

Balance: oxygen-free nitrogen 

AIR 94 Mid Range: 

1200 ppm propane 

4.0% carbon monoxide 

12.0% carbon monoxide 

Balance: oxygen-free nitrogen 

2.3 Audit Gases 

Audit gases shall be those described in Colorado Air Quality Control Commission Regulation 

Number 11. 

5 CCR 1001-13 CODE OF COLORADO REGULATIONS 
© 2013 State of Colorado 36 CR 23 and 24, 12-13 Page 105 

All Rights Reserved 

3.0 SOFTWARE COMPONENTS 

3.1 Communication and Data Field Specification 

Operational software requirements at a minimum must support the existing Colorado 94 

Communication Protocol and Data Field Specification. For inquiries referencing the 

Communication and Data Field Specification, please contact the Colorado Air Pollution 

Control Division 

3.2 Society of Automotive Engineers (SAE) "J" Standards 

The Colorado 97 shall be compliant with current SAE on-board diagnostic "J" standards 

including but not limited to J1978 and J1979. 

3.3 OBD II 

The Colorado 97 must be capable of accessing OBD II readiness monitors and diagnostic 

trouble codes. The operational software requirements will be available from the Division 

upon request. 

3.4 Forms 

The Colorado 97 shall be capable of completing the current, print on demand Vehicle 

Inspection Report (VIR) form. Examples of the VIR are following this Section 3.0. 

3.5 Upgrades 

Software shall be updated/upgraded per Section 1.8 of this Attachment IV. 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
Stab of Colorado I A2510FEL9H 

YEAR 2007 PT 

CRUISER 

PLATE FACILITY 5025E INSPECTOR 55555 

DATE 26-OCT-2011 

VOID 

Page 106 

Vehicle Inspection Report— Passing Form 

VEHICLE INSPECTION REPORT 

STATE OF COLORADO 

RESULTS 

A25IOFEL9H 

11111111111M Overall Result Emissions EqUipmentinspection On Board Diagnostica I Smoke Total. Amount Paid 

PASS PASS PASS PASS I PASS 040 

VEHICLE INFORISIRDON OFFICIAL USE ONLY 

DATE: 26-OCT-2011 11:29-A I YEAR: 2007 STATION: 5025E TEST: 2 

YIN; MAKE: CFIR LANE: ' OI TVFY: 1311B6 

PLATE: MODEL: P1 CRUISER , ODOMETER: 22000 YYFY: EVA 

EMISSIONS TEST INFORMATION EQUIPMENT INSPECTION 

READINGS LIMITS RESULTS Catalytic Converter Presence: PASS 

HC GPM 0.0099 4.0000 PASS Air Injection Sysmn Prracece: PASS 

CO GPM 0.0011 20.0000 PASS Oxygen Sensor Presence: PASS 

CO2 GPM 204.1342 . Use Cap Presence: PASS 

NOtt GPM 0.0002 0.0090.:;;7' <le Cap Integrity: 

, .-Old ,'4, IUD DIAEINOS c , 

thick Engine Light PASS 7 0.. -?,r'-r' ,r i 

DiRrostio %rouble Codex 

Circeit 

elicli.I.Sidifinetkir44 

lidaieirIiinei-MisS i 

• 2 ...... ,LINIMM 

CONS MER 1 TION „....1 

Congratulations, your vehicle has i.r*i h4OCtibILA-704 We 1, '0voioS _ marl Rd low the 

instruction regarding thermion raneehaddideof Nair mrturaI.000Ce- ing your registration in 

palm to Certificate of Emissions C hcIrM, todM socommatell 

- 

at do time of registration. Ana 

24 Nostra. you tan =OW your of Emission Control is loot, a 

new inspection is required at the owns? • • !ifirIIII00°stra ts contact Air Cam Colorado at 

300-456-7090 or the Department of Rev 'dit r /it — Mica Arm. tall $41-20041127. 

Retain this document in the vehicle an proof 

PLEASE REMOVE THE TIFICATE OF EMISS 60 BELOW, AND INCLUDE IT WITH. YOUR 

RENEWAL CARD AND REGISTRATION PAYMENT. d? S DOCUMENT OR PAYMENT TO YOUR 

RENEWAL CARD. 

CUT MAE 

5 CCR 1001-13 CODE OF COLORADO REGULATIONS 
ON BOARD DIAGNOSTICS 

Check Engine Light: FAIL 

Diagnostic Trouble Codes: 

Check Engine Light Command Status: On 

0113. LogIne Coolant remperantre Circuit Malfunction 

❑ 130. 02 sensor Given Malfunction (Hank I Sensor II 

0172, System too Rich (Bank I ) 

© 2013 State of Colorado 36 CR 23 and 24, 12-13 Page 107 

All Rights Reserved 

Vehicle Inspection Report — Failing Form 

VEHICLE INSPECTION REPORT 

STATE OF COLORADO 

RESULTS 

111610D1,1)91 

11111111111111 I 

Overall Result Emissions I Equipment Inspection On Board Dlogriostes Smoke Total Amount Peed 

FAIL FAIL 1 FAIL ADVISE _ FAIL 0.00 

VEHICLE INFORMATION OFFICIAL USE ONLY 

DATE: 20-SEP•201 2 10:32:06 YEAR: 2001 STATION: 5014k TIKSI: I 

VIN: MAKE: FORD IA NE: 01 IVEY: F161 

PLATE: 'IF.ST I MODEL: FOCUS ODOMETER: I 234f, VVFY: 

EMISSIONS TEST INFORMATION EQUIPMENT INSPECTION 

READINGS LIMITS RESULTS Catalytic Converter Presence: FA II 

HC GPM 31625 1.24100 FAIL Air Injection System Presence: FAIL 

CO GPM 27.1893 15.0000 FAIL Oxygen Sensor Presence: FAIL 

CO2 GPM 433.R854 Gas Cap Presence: PASS 

No% GPM 2.9067 1.5000 FAIL _ Gas cap linearity: FAIL 

CONSUMER INFORMATION 

Your vehicle has failed to comply with required Slate regulations Mr emissions imps-Wm -1. AI! items listed as failure must he adinosed 

prior to your next inspection. For questions, comments and complaints contact Air Care Colorado at 303-156-70411 or the Department 

of Revenue at 303-205-5603 and if located outside the Denver Mclm Area. call 811R-200-11827. You arc entitled to one free 

reinspection within 10 calendar days. the reinspection can be performed at any one of Air Care Colorado's centers. Die intermation 

recorded on this report is estremely valuable to a repair technician when having your vehicle repaired. If your vehicle fails the 

reinspection. you may be entitled to a waiver. Waiver eligibility info rmation. to include hardship waivers. is available at the inspection 

station or by calling the D•partment of Revenue at 303-205-5603. 

HIGH HC READINGS HIGH CO READINGS HIGH NOx READINGS 

111011 I IC READINGS Atli'. A RFS1.11 I 

OF UNBIIRNED OR PARTIALLY 

BIJRNED FUEL. 

111011 CO READINGS OCCUR WHEN 

THE AIR FUEL MIXTURE IS RR) 

RICH. 

111011 NOx RFADINGS ARE TI IF 

RESULT OF HIGH COMBUSTION 

TEMPERATURES ANDOR 

PRESSURES. 

( 1111-FtV 

VEHICLE REPAIR FORM 

This form mini be eompleted In the person performing the repairs AND accompany -the sdehiele at the time of reinspect ion. 

Mork here if some or all repairs were warranty or recall related: C:3 Parts Costs: 

Repaired by Vehicle Owner: 1:3 Repaired by Repair Facility:1= Labor costs: 

Repair Dale: Miseellaneum Costs: S 

Name or Rcpair Facility: Diagnostic Cost s: 

Name of Person Filling Out Farm: "fetal Repair Co,Os: 

I echnic last Number: 

Fat iliry Number: 

Signature: 

VIN: 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
Page 108 

ATTACHMENT V Specifications for Colorado On-Board Diagnostic (OBD) Stand-Alone 

Analyzer 

INTRODUCTION 

This document contains specifications for manufacturers to design a Colorado (CO) Onboard 

Diagnostic (OBD) Test Analyzer System (CO-OBD-TAS) for use in the Colorado Automobile 

Inspection and Readjustment (AIR) program. The CO-OBD-TAS certified for use shall be capable of 

conducting OBD emissions inspections, malfunction indicator lamp/check engine light (MIL) visual 

inspections, gas cap visual and pressure tests and a visual opacity check. 

Changes to Regulation 11 allow for OBD Inspections as of January 1st 2015. Light-duty vehicles in 

their eighth through eleventh (8th-11th) model years will receive a mandatory (i.e., pass/fail 

determination) OBD inspection. 

The OBD, MIL, gas cap and opacity inspections shall be conducted in accordance with the 

procedures set forth in AQCC Regulation No. 11, 40 C.F.R. Part 51, and EPA guidance document 

420-R-01-015, Performing Onboard Diagnostic System Checks as Part of a Vehicles Inspection and 

Maintenance Program. 

Design Goals 

The CO-OBD-TAS must be designed and constructed to provide reliable and accurate service in the 

automotive service environment and have a useful life of at least five years. The software used in the 

CO-OBD-TAS must consist of a process control system capable of using reference data. The 

software also must be designed for maximum operational simplicity and be capable of providing 

testing information that can be used for vehicle diagnostics. In addition, the CO-OBD-TAS must 

include security measures that will prevent unauthorized modifications to the software or inspection 

data, record unauthorized entry, also known as tampering, and prevent subsequent inspections when 

tampering is detected. 

The CO-OBD-TAS specifications contain the minimum requirements for CO-OBD-TAS used to 

perform emissions inspections in the AIR Program. Manufacturers may include additional items with 

approval from the Colorado Department of Public Health and Environment (CDPHE). 

It is expected that the CO-OBD-TAS software will be SAE 1978 and J1979 compliant. The OBD 

inspection will include a visual and functional (bulb) check of the Malfunction Indicator Light (MIL) and 

an electronic examination of the vehicle's OBD computer. As outlined in the EPA guidance 

document, there are seven steps in this OBD inspection: 

• Initiate the inspection by collecting and entering the vehicle identification information; 

• Perform a visual inspection of the MIL and perform a key-on, engine-off inspection; 

• Locate the vehicle's data link connector (DLC) and connect the OBD test equipment; 

• Start and run the vehicle; 

• With the OBD test equipment connected, determine the following: 

o The status of the vehicle's non-continuous readiness monitors; 

o The status of the MIL (commanded on or off); 

o The Diagnostic Trouble Codes (DTCs); 

5 CCR 1001-13 CODE OF COLORADO REGULATIONS 
C 2013 State of Colorado 36 CR 23 and 24, 12-13 Page 109 

All Rights Reserved 

• Electronically record the results of the OBD inspection; and 

• Turn off the vehicle and disconnect the scan tool. 

Pass/Fail Requirement 

The CO-OBD-TAS shall fail vehicles for the following reasons: 

o Gas Cap visual fails; or 

o Gas Cap integrity does not meet the standards; or 

o Visual opacity greater than 5%; or 

o The MIL does not illuminate at all during the Bulb check (Fail); or 

o The MIL stays illuminated when the vehicle is running (Fail); or 

o MIL status is commanded on; regardless of whether or not the MIL is actually illuminated 

(Fail). 

The CO-OBD-TAS shall pass vehicles for the following reasons: 

o Gas Cap visual inspection passes; 

o Gas Cap integrity is within standards; 

o Visual opacity less than 5%; 

o The readiness requirements in Section 4 are met; 

o The MIL visual bulb check passes; 

o The MIL is not commanded on; and 

o No Fraud is detected, as per Section 7. 

Readiness Monitors 

As part of the OBD inspection, the status of the vehicle's non-continuous readiness monitors is to be 

queried. The OBD TAS Manufacturer will implement EPA's listing of "Manufacturers Known to Have 

OBD Readiness Issues" and apply corrections to the readiness monitor requirements for those 

vehicles. 

Otherwise the following readiness monitors requirements apply: 

o The oxygen sensor and/or heated oxygen sensor monitor(s) shall be ready if supported; 

o The catalyst monitor shall be ready if supported; and 

o A 2001 or newer model year shall have no more than one (1) supported readiness monitor 

not ready; or 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
Page 110 

o A 2000 or older model year shall have no more than two (2) supported readiness monitors 

not ready 

If the readiness monitor requirements are not met and the MIL is not commanded on then the 

inspection shall be automatically aborted with the reason printed out the vehicle Inspection Report 

(VIR). 

If a vehicle is unable to receive an OBD inspection (i.e. unable to communicate, DLC or readiness 

monitor issues), then the inspection will be aborted and the reason printed out the vehicle Inspection 

Report (VIR). 

Keyless Ignitions 

If a vehicle has a keyless ignition, then the OBD TAS software shall bypass the MIL bulb check. The 

software shall determine keyless ignition systems electronically, by way of an OBD test information 

look-up table. The software shall provide for an override (changes the default, from the table, for the 

keyless ignition data field) in case the keyless ignition vehicle is not listed in the table. 

OBD Retest Requirements 

The same readiness monitor requirements in Section 4 shall apply to OBD re-tests. 

OBD Fraud Prevention 

The contractor will build an OBD inspection fraud detection module as approved by the CDPHE in the 

CO-OBD-TAS software. 

OBD Equipment Requirements 

The CO-OBD-TAS must include hardware and software necessary to access the on-board computer 

systems on all model-year 1996 and newer vehicles. The equipment design and operation of the COOBD-TAS must meet the federal requirements contained in Title 40 of the Code of Federal 

Regulations (CFR), Chapters 85.2207-2231 and the recommended practices regarding OBD 

inspections contained in the J1962, J1978 and J1979 published by the Society of Automotive 

Engineers (SAE). The CO-OBD-TAS must be able to connect to the vehicle's OBD connector and 

access, at a minimum, the following OBD data: 

o The engine revolutions per minute (RPM); 

o The readiness monitor status; 

o The malfunction indicator light (MIL) status; 

o The OBD communications protocol; 

o The electronic VIN; and 

o The diagnostic trouble codes (DTCs). 

At a minimum, the CO-OBD-TAS must also be capable of communicating with all OBD vehicles that 

use the following communications protocols: 

o International Organization for Standardization (ISO) 9141; 

5 CCR 1001-13 CODE OF COLORADO REGULATIONS 
C 2013 State of Colorado 36 CR 23 and 24, 12-13 Page 111 

All Rights Reserved 

o Variable pulse width (VPW) as defined in the SAE's J1850; 

o Pulse width modulation (PWM) as defined in the SAE's J1850; 

o Keyword protocol 2000 (KWP); and 

o Controller area network (CAN) as defined in the ISO 15765-4.3:2001. 

The OBD interrogation process must be fully integrated into the CO-OBD-TAS, automated, and 

require no inspector intervention to collect and record the OBD data retrieved via the OBD connector 

link. No separate interface may be used. 

The CO-OBD-TAS shall meet the design and performance specifications in the Air Quality Control 

Commission's (AQCC) Regulation Number 11. 

Gas Cap Tester 

The gas cap tester must be able to supply air pressure significant enough to produce and measure a 

leak rate of 60 cubic centimeters per min (cc/min) of air at 30 inches of water pressure. The tester 

must be tamper resistant; control the air supply pressure and prevent over pressurization; provide a 

visual or digital signal that the required air supply pressure is within the acceptable range and a flow 

comparison test is ready to be conducted; be supplied with a reference passing gas cap, or 

equivalent, with a nominal 52-56 cc/min leak rate; and be supplied with a reference failing gas cap, or 

equivalent, with a nominal 64-68 cc/min leak rate. 

The tester may use: a squared edged circular orifice to generate the required leak rate; and ambient 

air or any convenient low pressure source. 

The gas cap tester connector must be a minimum length of 20 feet so that it can reach gas caps that 

are attached to vehicles. 

The CO-OBD-TAS must prevent all inspections if the gas cap tester calibration has not passed in the 

last 24 hours. 

Gas Cap adapters must be available for at least 95 percent of the gas caps used for the most recent 

12 model-year light-duty vehicles and trucks. Varying internal volumes of the gas caps and adapter 

assemblies must not affect the accuracy of the inspection results. Adapters must be made available 

the first day of each year upon the introduction of new model-year vehicles. 

Opacity 

The CO-OBD-TAS software shall require an entry for a visual opacity inspection. 

Recording of Test Results/Documentation 

The CO-OBD-TAS shall automatically record the date, start time, station, and inspector ID for each 

test. Required data for each element of the inspection shall be collected and entered into the CO-COOBD-TAS. A data specification is available from CDPHE upon request. Due to possible systems 

changes or new requirements, the required data list may be changed. 

The CO-OBD-TAS shall print the test results in the form of a state-approved Vehicle Inspection 

Report (VIR, Form DR2071). The CO-OBD-TAS shall print these forms from plain security paper or 

some other paper as approved by CDPHE. The VIR shall contain at a minimum the OBD test results. 

VIRs for vehicles with a passing OBD test shall include a Certificate of Emissions Compliance (CEC) 

printed on the VIR. 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
Page 112 

Computers and Peripheral Requirements 

The CO-OBD-TAS functions must be controlled by a personal computer (PC), or functional 

equivalent, and include the hardware and software needed to perform the functions required by this 

specification. 

The CDPHE reserves the right to add additional programs and performance requirements, up to the 

technical limits of the hardware, to improve the AIR program. 

The manufacturer may offer a CO-OBD-TAS with additional disk drives that can run optional software 

hardware application programs, however, the computer must not be bootable from any additional 

drive, nor must any program run from one of these drives have access to the computer's operating 

system. Additional drives must be located in a limited access secured area within the CO-OBD-TAS 

cabinet. The peripheral equipment, such as bar code readers, OBD scanners, and keyboards may 

use wireless communication to interact with the CO-OBD-TAS. 

VID Communications Overview 

A required component of the AIR program is the electronic transmission of inspection data. The 

Centralized Emissions Testing Contractor for the Colorado AIR program has an electronic network 

that enables the CO-OBD-TAS to automatically connect to a centralized vehicle identification 

database (VID). The CO-OBD-TAS must demonstrate the ability to receive, install, use, and transmit 

data to and receive data from the VID using the communications protocol. The communications 

protocol will be provided by the CDPHE. 

Each inspection station must obtain and maintain VID communication services. The CO-OBD-TAS 

must use the communications protocol to access the features of the VID communications services in 

order to conduct vehicle inspections. 

Printer 

A laser printer or a CDPHE approved equivalent printer must be supplied with each CO-OBD-TAS 

purchased, leased, or upgraded. The CO-OBD-TAS's printer must be interchangeable with a locally 

purchased off-the-shelf laser printer. 

Power and Telephone Cord 

The modem must be, at a minimum, designed to connect to the CO-OBD-TAS with a modular 

telephone connector that has a standard wiring configuration. The connector must be located on the 

back of the CO-OBD-TAS cabinet. Alternatives to this requirement may be proposed to the CDPHE 

for evaluation. 

The telephone and power cords must be at least 25 feet long and enclosed in a protective cable 

meeting the Underwriter's Laboratory approval. Alternative methods to protect the telephone and 

power cords may be submitted to the CDPHE for approval. The manufacturer shall design the cabinet 

so that convenient storage is provided for the excess telephone and power cords. 

Power Requirements 

The CO-OBD-TAS must operate on an alternating current (AC) and must not be powered by a 

portable AC generating unit. Input power must be 115 volts of alternating current (VAC) with 60 hertz. 

The instruments must meet the specified requirements over an input voltage variation of at least +/-

12 volts. 

5 CCR 1001-13 CODE OF COLORADO REGULATIONS 
© 2013 State of Colorado 36 CR 23 and 24, 12-13 Page 113 

All Rights Reserved 

Construction 

The CO-OBD-TAS must be designed and constructed to provide reliable and accurate service in the 

automotive service environment. The CO-OBD-TAS must be supplied with a cabinet that is equipped 

with a storage area large enough to secure all accessories and operating manuals. 

Materials 

The materials used in construction of the CO-OBD-TAS must be resistant to corrosive substances 

found in the automotive service environment and be designed to last for at least five years. The 

exterior and interior finish of the entire cabinet and console must be sufficiently durable to withstand 

the chemicals and environmental conditions normally encountered in the automotive service 

environment for the period of the warranty. 

Mobility 

The CO-OBD-TAS may be permanently mounted or mobile with the use of wheels. Wheels must be 

at least five inches in diameter and have a locking mechanism capable of preventing movement on a 

15 degree incline. 

The CO-OBD-TAS must be designed to move over rough surfaces, through three-inch deep holes, 

and on 15 degree inclines without tipping over. The CO-OBD-TAS must not tip over when placed at 

the center of an inclined plane and rotated 360 degrees stopping in the position where it is most likely 

to tip over. The incline plane must make an angle of 10 degrees with the horizontal floor. In addition, 

the CO-OBD-TAS must not become unstable or tip over when rolled straight off the edge of a twoinch high platform or when one wheel is rolled over a drain, two inches below the surface, or inside an 

18-inch diameter depression. 

Electrical Design 

Fuses or circuit breakers must be used to protect individual electrical circuits in the CO-OBD-TAS. 

The main circuit breaker and fuses must be readily accessible from the exterior of the cabinet. COOBD-TAS operation must be unaffected by electrical line noise and voltage surges. The CO-OBDTAS must be protected from voltage surges to prevent damage to the internal components from a 

simultaneous start up of a 220 volt compressor, an arc welder, hydraulic controls, and other 

equipment commonly found in the typical automotive service environment. 

Bar Code Scanner 

The bar code scanner must be able to read a one-dimensional (1-D) and a two-dimensional (2-D) bar 

code through a windshield and use visible laser diode technology or an equivalent approved by the 

CDPHE. The bar code scanner must not be able to read Universal Product Code (UPC) 1-D bar 

codes. The bar code scanner must be able to withstand multiple drops to concrete covering a 

distance of at least 4 feet and be environmentally sealed to withstand the normal operating conditions 

of an automotive service environment. 

Additional Specifications 

The useful life of the CO-OBD-TAS shall be a minimum of five years. 

A nameplate including the following information shall be permanently affixed to the housing of the 

CO-OBD-TAS: Name and Address of Manufacturer, Model Description, Serial Number, and Date of 

Assembly. 

Each CO-OBD-TAS shall be delivered with the following manuals: Reference Operating Instructions, 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
Page 114 

Operation Instruction Manual, Maintenance Instruction Manual (limited), and Initial Start-up 

Instructions 

CO-OBD-TAS manufacturers may consolidate manuals. The manuals shall be constructed of durable 

materials and shall not deteriorate as a result of normal use over a five-year period. The CO-OBDTAS housing shall provide convenient storage for each manual in a manner that will allow easy use 

and prevent accidental loss or destruction. 

The CO-OBD-TAS software shall be fully documented. Two copies of the documentation listed below 

shall be submitted to CDPHE as part of the Certification application. 

Functional Specifications 

CO-OBD-TAS manufacturers shall provide for use during the Acceptance Testing Process: 

o Functional flowcharts of the software; 

o Example inputs and outputs from all processes; 

o Detailed interface information on system components including the identification of protocol 

and output specifications; and 

o All file layouts with file names, file types, file security, field names, field types, field sizes, and 

field editing criteria. 

Documentation provided by the vendor to meet this requirement will be treated as proprietary 

information by Colorado Department of Public Health and Environment. 

Prior to certification of any CO-OBD-TAS for sale in Colorado, the manufacturer shall provide the 

CDPHE technical information (including, but not limited to all working codes, schematics and 

drawings) necessary to operate, maintain and repair such CO-OBD-TAS in the invent that the 

manufacturer ceases providing adequate maintenance, and repair services in Colorado. 

The CO-OBD-TAS manufacturer shall keep such information current, and will provide CDPHE with 

copies of any and all changes. So long as such maintenance and repair services are available from 

the manufacturer or its agent, the CDPHE shall protect such information as confidential commercial 

data if it is clearly marked as such. In the event that the manufacturer becomes insolvent or stops 

providing adequate maintenance or repair services in Colorado all such information shall be the 

property of the CDPHE and may be released to a third party as necessary to repair and maintain the 

CO-OBD-TAS. 

Warranty Coverage 

A written warranty coverage agreement, signed by an authorized representative of the equipment 

manufacturer and the vehicle inspection station owner, which provides a complete description of 

coverage for all systems and components and all manufacturer provided services must accompany 

the sale or lease of each CO-OBD-TAS. Original manufacturer's warranty shall be a minimum of one 

year from the date of purchase. An extended service contract shall be available upon the expiration 

of the manufacturers original warranty period. 

5 CCR 1001-13 CODE OF COLORADO REGULATIONS 
C 2013 State of Colorado 36 CR 23 and 24, 12-13 Page 115 

All Rights Reserved 

Tampering Resistance 

Controlled access design shall be the responsibility of the manufacturer and is subject to approval by 

CDPHE. CO-OBD-TAS service personnel, inspectors or others shall be prohibited, to satisfaction of 

CDPHE, from creating or changing any test results, programs or data files contained in the CO-OBDTAS. The CO-OBD-TAS shall be made tamper-resistant to the satisfaction of CDPHE and DOR. 

If tampering occurs, a software lockout algorithm shall be activated which aborts any existing test 

sequence and prevents further inspections until an authorized AIR Program official clears the lockout. 

Auditing Requirements 

Title 42, Article 4, Part 3, C.R.S. establishes the I/M Program-based authority of the Colorado 

Department of Revenue (DOR). As such, DOR is responsible for emissions inspector and station 

licensing as prescribed by C.R.S., AQCC Regulation 11, and DOR Regulation 1. In order to maintain 

the integrity of the I/M Program, DOR conducts various quality assurance audits of the CO-CO-OBDTAS units. The specification for this audit will be provided by CDPHE and DOR. 

Manufacturer Provided Services 

The CO-OBD-TAS manufacturer shall agree to provide the following services to the inspection station 

as part of the manufacturer's original warranty: 

The delivery, installation, calibration, and verification of the proper operating condition of a CO-OBDTAS. 

Instruction of all certified inspectors employed by the inspection station, at the time of installation, in 

the proper use, maintenance, and operation of the CO-OBD-TAS. 

On-site service response by a qualified repair technician within two (2) business days, (48 hours) 

excluding Sundays and national holidays, of a request from the inspection station. 

CDPHE will require the manufacturer to render updates as necessary in the first year of the program 

to ensure the program meets all design criteria. Thereafter software updates will be limited to once 

per year at no cost. Since modem software updating will be utilized, there are no costs to the COOBD-TAS owner. A software version number, consisting of a four character alpha-numeric code 

made up of the last two digits of the year followed by a two character version number, shall be 

recorded in the CO-OBD-TAS and included on each vehicle test record. The CO-OBD-TAS 

manufacturer shall not modify any existing software version without obtaining written approval from 

CDPHE. 

CO-OBD-TAS manufacturers shall provide training to AIR Program officials on all operational, 

maintenance, and quality control features of the CO-OBD-TAS units, including full access to and use 

of inspection menus and audit menus. Such training shall be conducted at the manufacturer's 

expense as a condition of certification. 

Certification Requirements 

The CO-OBD-TAS manufacturer shall submit a formal certificate to CDPHE that states that any COOBD TAS sold or leased by the manufacturer or its authorized representatives for use in Colorado 

AIR Program will satisfy all design and performance criteria described in these specifications. The 

manufacturer shall also provide sufficient documentation to demonstrate conformance with these 

criteria including a complete description of all hardware components, the results of appropriate 

performance testing, and a point-by-point response to specific requirements. 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
Page 116 

In addition, a full description of the company's service procedures and policies, as well as sample 

contracts, warranties, and extended service agreements, shall be provided as part of the certification 

application to ensure proper maintenance of all CO-OBD-TAS throughout their useful life. One fully 

functional CO-CO-OBD-TAS shall be presented for evaluation and certification process. 

The Acceptance Testing Procedure (ATP) for CO-OBD-TAS will include a verification that the unit 

meets all requirements in this specification and federal requirements contained in 40 CFR §§85.2207 

- 85.2231 and the recommended practices contained in the J1962, J1978, and J1979 published by 

the SAE. The ATP procedures and acceptance criteria are contained in the EPA's guidance 

document, "Performing Onboard Diagnostic System Checks as Part of a Vehicle Inspection and 

Maintenance Program" (EPA, 2001) or EPA's applicable update to this document. 

ver. 9-16-13 

APPENDIX B Standards and Specifications for Calibration/Span Gas Suppliers 

INTRODUCTION 

This Appendix B describes the standards and specifications for the suppliers of span and calibration 

gases to the Colorado AIR Program, including facility requirements and documentation required of 

potential suppliers. 

CONTENTS 

SECTION 1: Definitions 

SECTION 2: Basic and Enhanced Idle Air Program - Technical Requirements 

SECTION 3: Calibration/Span Gas Approval & Labeling 

SECTION 4: Cylinder Tracking and Recall 

SECTION 5: Enhanced IM & IG 240 Air Program - Technical Requirements 

SECTION 6: Colorado Approval Process 

SECTION 7: Blender Facility Requirements & Documentation 

ATTACHMENT I Program Contact/Addresses/Phone Numbers 

ATTACHMENT II "Colorado Approved" Label Samples 

SECTION 1 DEFINITIONS 

AIR: Colorado's "Automotive Inspection & Readjustment" Program. 

ANALYTICAL ACCURACY: The relative percent deviation of the stated concentration of the 

components of a gas blend from the "true" value as determined by comparison with Colorado AIR 

Program standards. 

(% DEV = STATED CONC - "TRUE" CONC/"TRUE" CONC X 100) 

AUDIT GAS: Reference gas standards with direct traceability to NIST and/or EPA, to be used by AIR 

Program QA/QC personnel. 

5 CCR 1001-13 CODE OF COLORADO REGULATIONS 
0 2013 State of Colorado 36 CR 23 and 24, 12-13 Page 117 

All Rights Reserved 

APCD: Colorado "Air Pollution Control Division". 

AUTHORIZED GAS BLENDER: A blender of precision gas products selected to provide such 

products pursuant to the requirements of 42-4-306(3)(A)(I)(C). 

BALANCE GAS: The balance or makeup gas for Colorado AIR Program gases shall be as follows: for 

basic program tri-blend span gases, nitrogen shall be the balance gas. For the enhanced IM 240 

program standards and span gases, air shall be the balance gas. The balance gas for mixtures 

containing nitric oxide (NO) shall be nitrogen. 

BAR: California "Bureau of Automotive Repair" 

BLEND TOLERANCE: Deviation between the requested or nominal concentration and the measured 

or certified concentration of a gas mixture. 

CALIBRATION STANDARD: A precision blended gas used to generate calibration curves, with an 

analytical accuracy of +/- 1%, traceable to NIST gas standards. (Enhanced Program) 

CALIBRATION/SPAN GAS: A blend of carbon monoxide (CO), carbon dioxide (CO2), and propane, 

with a balance gas of nitrogen (NO2), which is used to calibrate the Colorado 94 test analyzers. 

(Basic program) 

CALIBRATION ZERO AIR: The gas used as a diluent for gas dividers or to establish analyzer zero 

during calibration curve generation. Impurities shall not exceed 0.1 ppm carbon response, 0.5 ppm 

CO, 1 ppm CO2, 0.1 ppm NOx, and 1 ppm moisture. Blended air shall have oxygen content between 

20.6% and 21% 

CALIBRATION ZERO NITROGEN: The gas used as a diluent for gas dividers or to establish analyzer 

zero during calibration curve generation shall have a minimum purity of 99.997% with impurities not to 

exceed 0.1 ppm carbon response, 0.5 ppm CO, 1 ppm CO2, 0.1 ppm NOx, 1 ppm moisture and 0.5 

ppm 02. 

CAPSL: Colorado AIR Program Standards Lab. 

CDPHE: Colorado Department of Public Health & Environment. 

CERTIFIED GAS BLENDER: A blender of precision gas products, approved by the Colorado AIR 

Program. A certified blender has met or exceeded the requirements set forth by the CDPHE to 

provide a consistently high quality calibration and span gas to both the Basic and Enhanced Air 

Program. 

CGA: Compressed Gas Association 

CRM: Certified Reference Material 

DOT: Department of Transportation 

FID: HC analyzer using a flame ionization detector 

FED FUEL: A mixture of 40% hydrogen (+/- 2%) and 60% helium 

FID OXIDIZER: Zero grade air with oxygen content between 20.6% And 21 % 

GOLD STANDARDS: NIST traceable air program standards named by EPA at the National Vehicle 

Fuels and Emission lab (NVFEL), Ann Arbor, Michigan 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
Page 118 

NIST: National Institute of Standards and Technology 

STATE: The State of Colorado 

SRM: Standard reference material. The highest integrity gas standard, prepared by, and only 

available from, NIST. 

VETC: Vehicle Emission Technical Center, 15608 East 18th Avenue, Aurora, Colorado 80011. 

WORKING SPAN GAS: Gases used in the enhanced IM 240 Air Program for high and mid-scale 

span checks and/or adjustments as well as analyzer cross-checks. These gases shall have an 

analytical accuracy of +/- 2%. 

WORKING ZERO GAS: Air or nitrogen used in the daily zeroing of enhanced program analyzers. 

Impurities shall not exceed 1 ppm carbon response, 2 ppm CO, 0.04% CO2, 0.3 ppm NOx, and 1% 

moisture. Air shall have oxygen content between 20.6% and 21%. Nitrogen shall contain a maximum 

of 0.5% 02. 

SECTION 2 BASIC & ENHANCED IDLE AIR PROGRAMITECHNICAL REQUIREMENTS 

2.0 GENERAL 

This section describes the calibration/span gas requirements, specifications for these gases, and 

types of cylinders allowed. Such specifications shall be included in any request for bids issued 

pursuant to 42-4-306(3)(a)(I)(c). 

2.1 GAS REQUIREMENTS 

The following identifies the calibration/span gas blends required for the Colorado basic & enhanced 

idle AIR Program: 

CALIBRATION/SPAN GASES 

AIR94LOW 

300 ppm Propane (as THC) 

1.0 % Carbon Monoxide 

6.0 % Carbon Dioxide 

Balance Nitrogen 

AIR94MID 

1200 ppm Propane (as THC) 

4.0 % Carbon Monoxide 

12.0 % Carbon Dioxide 

Balance Nitrogen 

2.2 GAS BLEND ACCURACIES 

The combined errors due to blending and naming of the above calibration/span gases shall not 

exceed +/- 2% for each component. 

5 CCR 1001-13 CODE OF COLORADO REGULATIONS 
© 2013 State of Colorado 36 CR 23 and 24, 12-13 Page 119 

All Rights Reserved 

2.3 ANALYTICAL ACCURACY 

The analytical accuracies for idle air program gases are: 

(A) Calibration/span gas: +1-2% of nominal value 

(B) Audit gases: +/- 1% of nominal value 

2.4 BLEND TOLERANCE 

Zero blend tolerance is required for basic & enhanced idle AIR Program calibration span gases. 

2.5 BLENDER REFERENCE STANDARDS 

Each authorized gas blender shall present documentation of its own internal standards for approval. 

The state provides two methods for standard documentation: 

(I) Blender may prepare a reference cylinder of each gas blend intended for the AIR 

Program to be named vs. Colorado's gold standards. Cylinder(s) shall be sent to the 

state for naming and labeling. This standard will become the blender's reference 

standard for the analysis of production span gases. 

NOTE: The associated costs of shipping reference cylinders to and from Colorado will be the 

responsibility of the blender. No shipping costs will be borne by the state. 

(II) Blenders certified by the State of California, Bureau of Automotive Repair, may elect 

to submit copies of their current certification including a listing of all SRM's, CRM's, or 

other reference gases accepted by bar, as pertaining to the analysis of I/M span 

gases. BAR acceptance of these standards will be sufficient to obtain approval of 

same for the AIR Program. 

2.6 CYLINDERS 

The cylinders to be used in the Colorado 94 analyzers in the field shall be low pressure, non refillable, 

disposable canisters. 

High pressure, refillable cylinders will be used by AIR Program audit/QC teams and, in some cases, 

by analyzer manufacturers. Approval of span gas in high pressure cylinders will be on an individual 

basis. (See Section 3) 

2.7 DISPOSABLE CYLINDERS 

(A) Disposable cylinders shall be in accordance with dot specification 39 for non 

refillable, disposable cylinders. (260 PSIG service pressure, 325 PSIG test pressure, 

650 PSIG minimum burst pressure) [CFR Title 49, Part 178, Section 178.65, Oct 1, 

1996] 

(B) Nominal size shall not exceed 750 cubic inches +/- 5% (approximately 9 inches 

inside diameter by 16 inches high, providing an equivalent water capacity of 27 lbs.) 

As a minimum, cylinders shall contain 7.5 cubic feet of gas blend at 260 PSIG 

cylinder pressure. 

(C) Cylinders shall be designed with an integral stand to facilitate upright storage. 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
Page 120 

(D) Cylinder outlet shall be CGA 165, 1/4" SAE flare, 45 degree male. Shutoff valves 

shall be of the non refillable type. 

(E) Cylinders shall be equipped with a safety relief device in accordance with DOT 

regulations [CFR 49, 173.34,(D), Oct, 1996]. The safety relief device must comply 

with the requirements of the compressed gas association pamphlet S.1.1, 8th Edition, 

1994. 

(F) Cylinders shall have a built in safety shield to protect the shut off valve. 

(G) No material shall be used in cylinder fabrication or assembly, or in cylinder charging 

equipment, which is incompatible with the gas blend as to cause contamination or 

degradation. 

(H) Blenders must comply with applicable DOT specifications for the shipment of 

cylinders. [CFR Title 49, Volume 2, Part 173, Subpart B, Oct, 1996]. 

2.8 HIGH PRESSURE REFILLABLE CYLINDERS 

(A) Refillable cylinders must be aluminum and made in accordance with DOT 

specifications 3AA or 3AL [CFR Tide 49, Volume 2, Part 178, Subpart C, Oct, 1996], 

whichever is applicable. 

(B) All cylinders must comply with applicable DOT Regulations and requirements for 

safety and shipment. [CFR Title 49, Volume 2, Part 173, Subpart B, Oct, 1996] 

2.9 LABELING 

(A) Caution labels shall be affixed to all cylinders and shall comply with applicable DOT 

and OSHA regulations. 

(B) "Colorado Approved" labels will be provided by the Colorado AIR Program (Section 

3) and shall be affixed to the upper portion of the canisters. 

2.10 EXPIRATION 

Triblend span gas cylinders containing CO, CO2, and propane in nitrogen, shall have an expiration 

date of 36 months after date of fill. 

2.11 QUALITY ASSURANCE 

All gas blenders shall have in place a fully documented and implemented quality assurance program 

as a prerequisite to certification. This QA program shall include, but not be limited to: 

(A) Regular equipment maintenance and calibration, performed in accordance with 

manufacturer guidelines, as a minimum. 

(B) Documentation of the analysis of each batch or lot of gas produced. A copy of the 

certificate of analysis from each batch or lot shall accompany each approval request. 

(C) Blender may choose to retain a cylinder from each batch/lot for internal 

documentation. However, one cylinder from each batch/lot must accompany each 

request for "Colorado Approved" labels. This sample cylinder will not be returned. 

5 CCR 1001-13 CODE OF COLORADO REGULATIONS 
C 2013 State of Colorado 36 CR 23 and 24, 12 -13 Page 121 

All Rights Reserved 

(D) Documentation of maintenance and calibration of equipment and instrumentation 

shall be made available upon request. 

2.12 BREACH OF TERMS 

Each contract entered into pursuant to 42-4-306(3)(a)(I)(C), shall authorize the APCD to suspend the 

blender's authority to supply precision gas products to inspection and readjustment stations, 

inspection-only facilities, fleet inspection stations, motor vehicle dealer facilities and enhanced 

inspection centers in the event the gas blender violates the terms of the contract and this appendix B. 

The APCD may terminate such a suspension once the blender corrects the problems that led to the 

violation. An onsite inspection of the blender's facility by an APCD representative may be required to 

ensure that the relevant requirements are being observed. 

SECTION 3 CALIBRATION/SPAN GAS APPROVAL & LABELING 

3.0 GENERAL 

Information in this section describes the calibration/span gas approval process as well as the 

procedure for obtaining "Colorado Approved" labels. 

3.1 CALIBRATION SPAN GAS APPROVAL PROCEDURE 

Batches or lots of span gas will be produced referencing procedures and specifications contained 

herein. Authorized blender shall analyze a representative number of cylinders from each batch or lot. 

Authorized blender shall then request from the CDPHE a number of Colorado approved labels 

corresponding to the number of cylinders in that batch or lot. The request for labels must include: 

(I) Analytical report to contain: 

(A) Actual analysis of samples in batch 

(B) Number of cylinders in batch 

(C) Fill date 

(D) Number of labels required 

(E) Batch or lot number 

(II) One representative cylinder from each batch or lot of span gas produced to be 

verified by analysis and retained for future reference. 

NOTE: This sample cylinder will not be returned. Cylinder will be archived by the state until 

the expiration date expires (36 months from fill date). This sample may be analyzed as a spot 

check or reference gas in matters concerning potential inquiries into batch integrity. 

Upon approval, blender will be sent an appropriate number of "Colorado Approved" labels to 

be affixed to cylinders in that batch or lot. 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
Page 122 

Samples, along with request for "Colorado Approved" labels, should be sent to: CDPHE 

VEHICLE EMISSION TECHNICAL CENTER 

15608 E. 18TH AVENUE 

AURORA, COLORADO 80011 

ATTN: SPAN GAS VERIFICATION PROGRAM 

3.2 CALIBRATION/SPAN GAS APPROVAL/HIGH PRESSURE CYLINDERS 

Approval of calibration/span gases in high pressure cylinders will be done on an individual basis. 

Each cylinder seeking approval must be submitted for verification against AIR Program standards. A 

certificate of analysis shall accompany each cylinder and shall contain the following information: 

(A) Cylinder number 

(B) Components contained 

(C) Analytical results 

(D) Analytical accuracy 

(E) Statement of traceability 

(F) Analysis date 

(G) Fill date 

Upon approval, blender will be notified that the cylinder is ready for pickup by the purchaser. 

Approved cylinder, with "Colorado Approved" label attached, may be picked up during normal 

business hours (8:00 am - 5:00 pm) Monday through Friday. Cylinders shall be sent to the above 

address.(See 3.1) 

3.3 SHIPPING COSTS 

Blenders shall provide for the shipping of all cylinders seeking Colorado approval for use in the AIR 

Program. The pick-up and delivery of individual high pressure cylinders is also the responsibility of 

the blender and/or the purchaser of that cylinder. These cylinders are expected to be picked-up within 

30 days of notification of approval. No costs pertaining to the pick-up or delivery of span gases shall 

be borne by the state. 

3.4 LABELING 

"Colorado Approved" labels will be provided by the State of Colorado. These labels will include 

information necessary to track span gases throughout the system as well as identify each cylinder as 

Colorado approved. Information contained on the label will include: 

(A) Blender name 

(B) Blending facility 

(C) Batch or lot number 

5 CCR 1001-13 CODE OF COLORADO REGULATIONS 
© 2013 State of Colorado 36 CR 23 and 24, 12-13 Page 123 

All Rights Reserved 

(D) Identify "low" (yellow label) or "mid" (white label) SPAN GAS 

(E) Fill date 

(F) Expiration date 

(G) AIR Program number 

(H) Bar code containing cylinder tracking information 

(For a sample of the "Colorado Approved" labels, see attachment II) 

3.5 AIR PROGRAM NUMBER 

"Colorado Approved" labels will contain an AIR Program number. Each certified blender will be 

assigned a letter code that will precede the numbering of batch cylinders. These coded numbers will 

be generated by the state and assigned to each cylinder as batches of span gas are produced. 

Cylinder numbers will be held on file for the life span of the cylinder to assist in tracking, auditing and 

accounting purposes. 

SECTION 4 CYLINDER TRACKING & RECALL 

4.0 GENERAL 

This section describes the method of tracking calibration/span gas throughout the AIR Program area. 

This system protects the inspection stations and provides for a replacement, in an expedient manner, 

should a non-conforming calibration/span gas be discovered. 

4.1 TRACKING CYLINDERS VIA BAR CODE 

Each "Colorado Approved" label will contain a bar code to be scanned whenever a cylinder of 

calibration/span gas is put into service on a Colorado 94 analyzer or Motor Vehicle Dealer Transient 

Mode Test Analyzer System. Scanned information will be stored in a file, accessible through a host 

computer linking all inspection stations. AIR Program QA/QC personnel will be able to locate 

individual cylinders, track batches of span gas, etc., throughout the program area. 

Label bar codes will be generated at the time of batch or lot approval and will contain information 

necessary to facilitate the tracking process. Blenders are required to continue to track internally, the 

whereabouts of "Colorado Approved" batches of calibration/span gas prior to retail sale. In the event 

of a recall of a batch of non-conforming calibration/span gas, the blender, through procedure 

described herein (see 4.2), will begin recall. In-use calibration/span gas affected will be identified by 

bar cod; information through system host and replacement procedures will begin. 

4.2 RECALL PROCEDURE 

In the event a non-conforming cylinder of calibration/span gas is discovered at an AIR Program 

inspection station, the following recall procedure will begin: 

(A) Suspected non-conforming span gas confiscated by AIR Program Q/C personnel; 

(B) Cylinder brought to the Colorado AIR Program Standards Lab (CAPSL) for analysis; 

(C) Exposed non-conforming cylinder cross referenced by air number go blender and 

batch; 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
Page 124 

(D) Archived sample retrieved and analyzed vs. suspected non-conforming cylinder. 

Blender advised of results; 

(E) Through host system, the state identifies whereabouts of any non-conforming 

cylinders on line. Blender provided with a listing of affected inspection stations; 

(F) Blender shall immediately begin recall of all remaining unsold cylinders from batch in 

question and, simultaneously, begin process of supplying known conforming 

cylinder(s) to affected inspection stations by overnight service; 

(G) A total recall and replacement of all cylinders in affected batch must be completed 

within 10 days. A detailed report of the recall procedure and analysis of cause of the 

non-conforming product entering the system will be provided to the state within 15 

days. 

(H) The state may elect to withhold certification of future batches until such time as 

blender shows problems have been corrected. 

(I) The state may also suspend the contract with the blender if information obtained 

suggests blending procedures were violated, pending a correction of the problems 

that caused the violation. 

SECTION 5 ENHANCED IM & IG 240 AIR PROGRAM / TECHNICAL REQUIREMENTS 

5.0 GENERAL 

This section addresses the calibration gases, technical requirements, cylinder specifications and 

documentation required for IM & IG 240 testing. 

5.1 GASES 

Gases used in the calibration and support of IM & IG 240 testing shall conform to the provisions 

outlined in CFR Title 40, Part 86, Subpart B, Section 114, as revised July 1, 1992, for exhaust 

emission testing. Concentrations for IM 240 gases are as follows: 

5.2 CALIBRATION GASES/CURVE GENERATION 

(I) High tri-blends: (+/-1% analytical accuracy) 

CO:9000 ppm 

CO2:3.6% 

Propane:600 ppm 

Balance: Air 

(II) High NOx: (+/-1%) 

NOx:450 ppm 

Balance: Nitrogen 

5 CCR 1001-13 CODE OF COLORADO REGULATIONS 
CO 2013 State of Colorado 36 CR 23 and 24, 12-13 Page 125 

All Rights Reserved 

5.2.1 MID-SCALE CALIBRATION GASES/CURVE CONFORMATION 

(I) Mid th-blend: (+1-1%) 

CO:4500 ppm 

CO2:1.8 % 

Propane:300 ppm 

Balance: Air 

(II) Mid NOx tri-blend: (+1-1%) 

NOx:225 ppm 

Balance: Nitrogen 

5.2.2 CALIBRATION ZERO GASES 

(I) Calibration zero AIR 

HC : < 0.1 ppm 

CO : < 0.5 ppm 

CO2 : < 1.0 ppm 

NOx : < 0.1 ppm 

Moisture : < 1.0 ppm 

02: 20.6 % - 21.0 % 

(II) Calibration zero Nitrogen 

Purity : 99.997 % 

HC : < 0.1 ppm 

CO : < 0.5 ppm 

CO2 : < 1.0 ppm 

NOx : < 0.1 ppm 

Moisture : < 1.0 ppm 

02 : < 0.5 ppm 

5.3 DAILY SPAN GASES 

(I) High tri-blend span (+/-2% analytical accuracy) 

CO : 8000 ppm 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
Page 126 

CO2 : 3.2 % 

Propane : 535 ppm 

Balance : Air 

(II) NOx mid span (+1-2%) 

NOx : 75 ppm 

Balance : Nitrogen 

5.4 WORKING ZERO GASES 

(I) Working zero AIR 

HC : < 0.1 ppm 

CO : < 2.0 ppm 

CO2 < 400 ppm 

NOx < 0.3 ppm 

Moisture < 1.0 ppm 

0Y2 : 20.6-21.0 % 

(II) Working zero Nitrogen 

Purity : 99.997% 

HC : < 1.0 ppm 

CO : < 2.0 ppm 

CO2 : < 400 ppm 

NOx : < 0.3 ppm 

Moisture : < 1.0 ppm 

02 : < 0.5 ppm 

5 CCR 1001-13 CODE OF COLORADO REGULATIONS 
© 2013 State of Colorado 36 CR 23 and 24, 12 -13 Page 127 

All Rights Reserved 

5.5 SUPPORT GASES 

A variety of miscellaneous support gases are required for IM & IG 240 testing. Among these are: 

GAS USAGE 

Propane : 99.5% (min) CVS system flow checks 

Methane : 50 ppm/AIR FID check gas 

FID Fuel: 40% H2/60% HE FID burner fuel 

NO2 : 200 ppm/N2 NOx converter efficiency test gas 

AIR : 18%-21% NOx ozonator gas 

5.6 IG 240 GASES 

Calibration, span, working and support gases required by IG 240 systems, are among the gases 

listed (5.2 thru 5.5). Additional gases of specific concentrations and blend make-up may be required 

pending final configuration of the IG system. 

5.7 CYLINDERS 

Calibration and working gas tri or quad-blends used for IM & IG 240 testing, must be supplied in 

aluminum cylinders as well as all no or NOx blends. Other gases may be supplied in steel or 

aluminum cylinders as appropriate. 

High pressure refillable cylinders shall be manufactured in accordance with DOT specifications 3AL 

or 3AA [CFR Title 49, Volume 2, Part 178, Subpart C, Oct I, 1996], whichever is applicable. 

Approved valves and relief devices, appropriate for the intended use, shall be used on all high 

pressure cylinders. [CFR Title 49, Volume 2, Subpart B, Section 173.124, Oct 1, 1996] 

All cylinders shall have appropriate labeling to comply with all DOT regulations concerning 

transportation and safety. [CFR 49, Volume 2, Part 173, Subpart B, Oct 1, 1996]. 

5.8 MISCELLANEOUS 

A full line of gas products shall be made available to the enhanced AIR Program contractor(s) to 

insure safe handling and storage of gas cylinders, such as regulators, carts, restraints, and leak 

detection equipment. The contractor(s), as well as state QA/QC personnel, may also request a variety 

of gas blends, tri-blends, and other specialty gas products associated with automotive emission 

testing. Blender must demonstrate the ability to provide the above gases, equipment and associated 

products, in order to be designated as an approved blender to the Colorado enhanced AIR Program. 

5.9 CERTIFICATES OF ANALYSIS 

Each calibration gas, working span gas, and calibration zero gas shall be documented by a certificate 

of analysis to include; cylinder number, components, analytical results, accuracy, traceability and 

analysis date. A batch analysis certificate stating purity may document zero grade air and nitrogen. 

(Zero AIR certificate must also provide documentation of oxygen content.) 

The enhanced program contractor(s) must produce documentation of cylinder contents of the above 

upon request of state QA/QC personnel. 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
Page 128 

5.9.1 TRACKING CYLINDERS VIA BAR CODE 

Each "Colorado Approved" label will contain a bar code to be scanned whenever a cylinder of 

calibration/span gas is put into service on a Colorado 94 analyzer or Motor Vehicle Dealer Transient 

Mode Test Analyzer System scanned information will be stored in a file, accessible through a host 

computer linking all inspection stations. AIR Program QA/QC personnel will be able to locate 

individual cylinders, track batches of span gas, etc., throughout the program area. 

Label bar codes will be generated at the time of batch or lot approval and will contain information 

necessary to facilitate the tracking process. Blenders are required to continue to track internally, the 

whereabouts of "Colorado Approved" batches of calibration/span gas prior to retail sale. In the event 

of a recall of a batch of non-conforming calibration/span gas, the blender, through procedure 

described herein (see 4.2), will begin recall. In-use calibration/span gas affected will be identified by 

bar code information through system host and replacement procedures will begin. 

SECTION 6 COLORADO APPROVAL PROCESS 

6.0 CALIBRATION STANDARDS AND AUDIT GASES 

All calibration standards used in the Colorado Enhanced IM & IG 240 AIR Program must be 

submitted by the contractor to the state for approval and labeling as "Colorado Approved". In addition, 

all audit gases utilized by AIR Program QA/QC teams will undergo the same verification and/or 

renaming process that will take place at the Colorado AIR Program standards lab (CAPSL) in 

Broomfield, Colorado. At CAPSL, each standard and/or audit gas will be read vs. program gold 

standards, named by EPA's NVFEL, in an effort to tie all primary gases to one source, regardless of 

manufacturer. 

Each calibration standard and audit gas will receive a "Colorado Approved" label displaying the 

concentration of each major component as determined by analysis comparing such calibration 

standard or audit gas to the program gold standards. Labeled values are to be used in curve 

generation by the contractor and by audit teams to verify analyzer accuracy. 

6.1 ZERO AIR/OXYGEN CONTENT 

On a random basis, cylinders of zero air will be analyzed at CAPSL to verify oxygen content. As 

previously stated, the oxygen content of artificial blended air shall be 20.6 to 21 %. This is necessary 

to insure that an air cylinder used as a backup to a zero air generator (zag), will provide air as close 

to ambient in 02 as possible, should a zag be taken offline. FID response has been shown to be 

greatly affected by the 02 content of oxidizer air. Random analysis will provide verification that 02 

content in zero air is within specifications. 

SECTION 7 BLENDER FACILITY REQUIREMENTS & DOCUMENTATION 

7.0 GENERAL 

(A) A gas blender who intends to supply calibration/span gas to the Colorado AIR 

Program basic inspection stations and/or enhanced program contractor(s), must be 

selected by the Colorado Department of Public Health & Environment pursuant to 42- 

4-306(3)(A)(1)(C). 

(B) If a company has more than one facility that will be providing gases to Colorado, 

each must be included in the selection. The selection of one blending facility owned 

by a company does not imply or impart authority to other facilities within that 

company to supply precision gas products in Colorado. 

5 CCR 1001-13 CODE OF COLORADO REGULATIONS 
2013 State of Colorado 36 CR 23 and 24, 12-13 Page 129 

All Rights Reserved 

(C) The CDPHE shall be notified of a pending sale of a blending facility at least 60 days 

prior to change of ownership. 

(D) Contracts shall be for a one year period, but may be renewed annually. 

7.1 CONTRACT PROPOSAL PACKET 

The certification request packet shall contain information described in the following paragraphs. 

Information submitted should be as complete as possible. However, should some information be 

unavailable, so indicate and provide reasons, therefore, for AIR Program consideration. 

7.2 CONFIDENTIAL AND COMMERCIAL INFORMATION 

To the extent authorized by 24-72-101, C.R.S., the Colorado Department of Public Health & 

Environment shall maintain the confidentiality of any information which is included in the blender's bid 

and which is clearly marked as proprietary or confidential. 

7.3 APPLICATION 

The following items are to be included in blenders request for air program approved status: 

(A) COVER SHEET - An application cover sheet must be signed by the President or 

Chief Financial Officer of the gas blending company. 

(B) BLENDING FACILITY DESCRIPTION-Provide a complete description of the blending 

facility to include: 

— Facility location 

— Physical dimensions of lab and production areas 

— Number of employees 

— General description of blending facility and procedures 

(C) INSTRUMENTATION - Provide description of all instrumentation utilized in the 

blending and analysis of AIR Program calibration/span gases. Provide 

instrumentation brand, model, type (NDIR, FID, GC, etc.). As well as calibration and 

maintenance schedules and personnel responsible. 

(D) REFERENCE STANDARDS - Indicate the cylinder numbers, SRM/CRM numbers, 

concentrations and expiration dates for each NIST traceable reference standard to 

be used in the preparation and/or naming of AIR Program gases. 

(E) BUSINESS STATUS REPORT - Application for certification shall contain information 

to verify blending facility's status as a bona fide blender of precision gases. Include 

evidence that applicant is a registered corporation in Colorado and/or a registered 

out-of-state corporation. 

(F) DISTRIBUTORS AND MARKETING - Applicant shall provide a description of 

expected distribution and marketing plans for providing calibration/span gas to the 

basic AIR program. Include a current listing of the names, addresses and phone 

numbers of the distributors used by the applicant. Such information shall be updated 

as necessary and notification of any change provided to the state in a timely manner. 

Lists of distributors will be made available to AIR Program inspection stations. 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13 
Page 130 

(G) RECALL OF NON-CONFORMING GASES/BASIC PROGRAM - Certified blenders 

shall be responsible for the recall and replacement of non-conforming 

calibration/span gases. Blenders will be required to replace suspected nonconforming cylinders by overnight service. Should such a discovery extend past a 

single cylinder to a batch or lot, a total recall of all cylinders will take place. (See 

Section 4). 

Applicant shall provide procedures intended for use should such a recall be 

necessary. 

(H) QUALITY ASSURANCE - Applicant shall include information regarding internal 

quality assurance program(s). Provide details of techniques, methodology and 

documentation utilized in QA program. Include calibration and maintenance 

schedules for all equipment and instrumentation used. 

(I) SAFETY REGULATIONS - Certification application must include assurance the 

applicant is in compliance with all applicable DOT and OSHA regulations and 

standards. 

(J) LIABILITY- Provide a copy of product liability insurance demonstrating adequate 

protection (minimum $300,000) exists for catastrophic failure situations (e.g., cylinder 

or valve rapture, noxious gas leakage, etc.). Evidence of bonding coverage shall be 

provided upon request. 

5 CCR 1001-13 CODE OF COLORADO REGULATIONS 
© 2013 State of Colorado 36 CR 23 and 24, 12-13 

All Rights Reserved 

Page 131 

APPENDIX B 

ATTACHMENT I Program Contact/Addresses/Phone Numbers 

PROGRAM CONTACT; The main contact on matters concerning air program gases, requirements 

and specifications is: 

COLORADO DEPARTMENT OF PUBLIC HEALTH & ENVIRONMENT 

VEHICLE EMISSION TECHNICAL CENTER 

15608 EAST 18TH AVENUE 

AURORA, COLORADO 80011 

(303) 364-4135 

ATTN: SPAN GAS VERIFICATION PROGRAM 

OR 

COLORADO AIR PROGRAM STANDARDS LAB 

11609 TELLER STREET 

BROOMFIELD, COLORADO 80020 

(303) 404-0268 

ATTACHMENT II "Colorado Approved" Label Samples 

BLENDER 

LOT # 

FILL DATE 

EXPIRES 

AIR # 

Colorado 

Approved 

Calibration Gas 

Law 

AIR LIQUIDE 

031820131 

03/18/2013 

05/13/2016 

CO 13L00001 

BLENDER 

LOT # 

FILL DATE 

EXPIRES 

AIR # 

Colorado 

Approved 

Calibration Gas 

imRa4_ MID 

AIR LIQUIDE 

031820132 

03/18/2013 

05/13/2016 

CO 13M00001 

11111111111 111 111111111 

CODE OF COLORADO REGULATIONS 5 CCR 1001-13