NIST OWM Analysis

2023 NCWM Interim S&T Agenda Items 

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NIST Office of Weights and Measures (OWM) Analysis 

Specifications and Tolerances (S&T) 

2023 NCWM Interim Meeting Agenda 

The NIST OWM Analysis is submitted to the assist the Weights and Measures community as it deliberates 

on items before the Conference. OWM offers these comments and recommendations based upon 

information and input available as of the date of this report. 

Language shown in bold face print by striking out information to be deleted and underlining information 

to be added. Requirements that are proposed to be nonretroactive are printed in bold faced italics. 

For additional information or assistance please contact an OWM Technical Advisor: 

Mrs. Tina Butcher, S&T Committee, tina.butcher@nist.gov or (301) 975-2196 

Mr. Rick Harshman, S&T Committee, richard.harshman@nist.gov or (301) 975-8107 

Mr. Jan Konijnenburg, NIST Associate, jan.konijnenburg@nist.gov 

Ms. Diane Lee, S&T Committee, diane.lee@nist.gov or (301) 975-4405 

Ms. Juana Williams, S&T Committee, juana.williams@nist.gov or (301) 975-3989 
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Subject Series List for the Specifications and Tolerances Committee

Handbook 44 – General Code...................................................................................................... GEN Series

Scales...................................................................................................................................... SCL Series

Belt-Conveyor Scale Systems................................................................................................BCS Series

Automatic Bulk Weighing Systems..................................................................................... ABW Series

Weights..................................................................................................................................WTS Series

Automatic Weighing Systems...............................................................................................AWS Series

Weigh-In-Motion Systems used for Vehicle Enforcement Screening ..................................WIM Series

Liquid-Measuring Devices....................................................................................................LMD Series

Vehicle-Tank Meters.............................................................................................................VTM Series

Liquefied Petroleum Gas and Anhydrous Ammonia Liquid-Measuring Devices..................LPG Series

Hydrocarbon Gas Vapor-Measuring Devices........................................................................HGV Series

Cryogenic Liquid-Measuring Devices ..................................................................................CLM Series

Milk Meters...........................................................................................................................MLK Series

Water Meters.........................................................................................................................WTR Series

Mass Flow Meters................................................................................................................ MFM Series

Carbon Dioxide Liquid-Measuring Devices.......................................................................... CDL Series

Hydrogen Gas-Metering Devices......................................................................................... HGM Series

Electric Vehicle Refueling Systems.......................................................................................EVF Series

Vehicle Tanks Used as Measures.......................................................................................... VTU Series

Liquid Measures....................................................................................................................LQM Series

Farm Milk Tanks................................................................................................................... FMT Series

Measure-Containers...............................................................................................................MRC Series

Graduates............................................................................................................................... GDT Series

Dry Measures ........................................................................................................................DRY Series

Berry Baskets and Boxes....................................................................................................... BBB Series

Fabric-Measuring Devices......................................................................................................FAB Series

Wire-and Cordage-Measuring Devices................................................................................WAC Series

Linear Measures......................................................................................................................LIN Series

Odometers .............................................................................................................................ODO Series

Taximeters...............................................................................................................................TXI Series

Timing Devices ......................................................................................................................TIM Series

Grain Moisture Meters (a).................................................................................................... GMA Series

Grain Moisture Meters (b).................................................................................................... GMB Series

Near-Infrared Grain Analyzers................................................................................................NIR Series

Multiple Dimension Measuring Devices............................................................................. MDM Series

Electronic Livestock, Meat, and Poultry Evaluation Systems and/or Devices.......................LVS Series

Transportation Network Measuring Systems.........................................................................TNS Series

Other Items................................................................................................................................... OTH Series
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Table A

Table of Contents

Reference Key Title of Item S&T Page

Subject Series List for the Specifications and Tolerances Committee ................................. 2

Table 1. Glossary of Acronyms and Terms............................................................................ 7

Table 2. Reporting Structure................................................................................................... 8

GEN – General Code................................................................................................................. 9

GEN-23.1 G-N.3. Test Methods ........................................................................................ 9

OWM Executive Summary for GEN-23.1 – G-N.3. Test Methods ..................................................... 10

SCL – Scales ...........................................................................................................................14

SCL-22.2 A UR.1. Selection Requirements, UR.1.X. Cannabis................................................14

SCL-23.1 S.1.12. Manual Weight Entries ..........................................................................24

OWM Executive Summary for SCL-23.1 – S.1.12. Manual Weight Entries ......................................25

SCL-23.2 Table S.6.3.a. Marking Requirements, and Table S.6.3.b. Notes for Table S.6.3.a. 

Marking Requirements...........................................................................................................29

OWM Executive Summary for SCL-23.2 – Table S.6.3.a. Marking Requirements, and Table 

S.6.3.b. Notes for Table S.6.3.a. Marking Requirements.............................................................29

SCL-23.3 Verification Scale Division e: Multiple Sections Including, T.N.1.3., Table 6., 

T.N.3., T.N.4., T.N.6., T.N.8., T.N.9., T.1., T.2., S.1.1.1., T.N.1.2., Table S.6.3.a., Table S.3.6.b., 

Appendix D, S.1.2.2., Table 3., S.5.4., UR.3., Table 8. ...............................................................32

WIM – Weigh-in-Motion Systems – Tentative Code..............................................................43

WIM-23.1 Remove Tentative Status and Amend Numerous Sections Throughout...................43

OWM Executive Summary for WIM-23.1 – Remove Tentative Status and Amend Numerous Sections 

Throughout ........................................................................................................................................... 44

Section 2.25. Weigh-In-Motion Systems Used for Vehicle Screening and Enforcement – Tentative 

Code ..................................................................................................................................................... 46

LMD – Liquid Measuring Devices ..........................................................................................62

LMD-23.3 Automatic Temperature Compensation Task Group ............................................62

OWM Executive Summary for LMD-23.1 – Automatic Temperature Compensation Task Group .... 62

LMD-23.4 N.3.5. Wholesale Devices.................................................................................63

OWM Executive Summary for LMD-23.4 – N.3.5. Wholesale Devices........................................66

VTM – Vehicle Tank Meters ....................................................................................................72

VTM-18.1 S.3.1 Diversion of Measured Liquid and S.3.1.1. Means for Clearing the 

Discharge Hose and UR.2.6. Clearing the Discharge on a multiple-product, single discharge hose...72

OWM Executive Summary for VTM-18.1 – S.3.1 Diversion of Measured Liquid and S.3.1.1. Means 

for Clearing the Discharge Hose and UR.2.6. Clearing the Discharge on a multiple-product, single 

discharge hose. ..................................................................................................................................... 73

VTM-20.2 A Table T.2. Tolerances for Vehicle Mounted Milk Meters......................................85

OWM Executive Summary for VTM-20.2 – Table T.2. Tolerances for Vehicle Mounted Milk Meters.

 .............................................................................................................................................................. 85

LPG – Liquified Petroleum Gas and Anhydrous Liquid-Measuring Devices ......................99

LPG-15.1 D N.3. Test Drafts...............................................................................................99

OWM Executive Summary for LPG-15.1 – N.3. Test Drafts. ........................................................... 100

LPG-22.3 W S.2.5. Zero-Set-Back Interlock., S.2.5.2. Zero -Set-Back Interlock for Stationary 

Customer -Operated Electronic Retail Motor-Fuel Devices. .....................................................110
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OWM Executive Summary for LPG-22.3 – S.2.5. Zero-Set-Back Interlock., S.2.5.2. Zero -Set-Back 

Interlock for Stationary Customer -Operated Electronic Retail Motor-Fuel Devices. ...................... 113

LPG-23.1 S.2.5. Zero-Set-Back Interlock........................................................................118

OWM Executive Summary for LPG-23.1 – S.2.5. Zero-Set-Back Interlock.................................... 119

LPG-23.2 S.2.6. Automatic Timeout...............................................................................122

OWM Executive Summary for LPG-23.2 – S.2.6. Automatic Timeout. ........................................... 123

MLK – Milk Meters.................................................................................................................126

MLK-23.2 Table T.1. Tolerances for Milk Meters..................................................................... 126

OWM Executive Summary for MLK-23.2 – Table T.1. Tolerances for Milk Meters....................... 126

MFM – Mass Flow Meters .....................................................................................................129

MFM-15.1 D N.3. Test Drafts......................................................................................................... 129

OWM Executive Summary for MFM-15.1 – N.3. Test Drafts. ......................................................... 130

HGM – Hydrogen Gas-Measuring Devices ..........................................................................140

HGM-23.1 UR.3.8. Safety Requirement ..................................................................................... 140

OWM Executive Summary for HGM-23.1 – UR.3.8. Safety Requirement....................................... 141

EVF – Electric Vehicle Fueling Systems..............................................................................144

EVF-21.1 D A.1. General........................................................................................................... 144

OWM Executive Summary for EVF-21.1 – A.1. General ................................................................. 145

EVF-21.5 D T.2. Load Test Tolerances...................................................................................... 151

OWM Executive Summary for EVF-21.5 – T.2. Load Test Tolerances............................................ 152

EVF-23.1 S.2.5.1. Money-Value Divisions Digital, S.8.(a) Minimum Measured Quantity, 

S.5.3.(d) Abbreviations and Symbols; Joule, N.1. No Load Test, T.5. No Load Test, N.2. Starting 

Load Test, T.6. Starting Load, Appendix D–megajoule .................................................................... 158

Source: NIST USNWG EVF&S-EVFE Subgroup............................................................................ 158

EVF-23.2 S.2.7. Indication of Delivery..................................................................................... 166

OWM Executive Summary for EVF-23.2 – S.2.7. Indication of Delivery ........................................ 167

EVF-23.3 S.2.7. Indication of Delivery...................................................................................... 170

OWM Executive Summary for EVF-23.3 – S.2.7. Indication of Delivery ........................................ 170

EVF-23.4 S.5. Markings, and N.5. Test of an EVSE System.................................................... 173

OWM Executive Summary for EVF-23.4 S.5. – Markings and N.5. Test of an EVSE System. ....... 176

EVF-23.5 S.5.2. EVSE Identifications and Marking Requirements and T.2. Load Accuracy 

Test tolerances ................................................................................................................................... 182

OWM Executive Summary for EVF-23.5 – S.5.2. EVSE Identifications and Marking Requirements 

and T.2. Load Accuracy Test Tolerances........................................................................................... 183

EVF-23.6 S.5.2. EVSE Identification and Marking Requirements and T.2. Tolerances........... 191

OWM Executive Summary for EVF-23.6 – S.5.2. EVSE Identification and Marking Requirements., 

and T.2. Tolerances. ........................................................................................................................... 196

EVF-23.7 N.1. No Load Test, N.2. Starting Load Test, N.5.2. Accuracy Testing, and 

Appendix D: maximum deliverable amperes..................................................................................... 208

OWM Executive Summary for EVF-23.7 – N.1. No Load Test, N.2. Starting Load Test N.5.2. Accuracy 

Testing, and Appendix D: maximum deliverable amperes ................................................................ 210

GMA – Grain Moisture Meters 5.56 (a).................................................................................216

GMA-19.1 D Table T.2.1. Acceptance and Maintenance Tolerances Air Oven Method for All 

Grains and Oil Seeds. ......................................................................................................................... 216
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OWM Executive Summary for GMA-19.1 – Table T.2.1. Acceptance and Maintenance Tolerances Air 

Oven Method for All Grains and Oil Seeds. ...................................................................................... 217

Item GMA-19.1–Table T.2.1. Acceptance and Maintenance Tolerances Air Oven Method for All 

Grains and Oil Seeds. ......................................................................................................................... 217

GMA-23.1 N.1.3. Meter to Like-Type Meter Method Transfer Standards and Table T.2.2. 

Acceptance and Maintenance Tolerances Meter to Like-Type Meter Method .................................. 221

OWM Executive Summary for GMA-23.1 – N.1.3. Meter to Like-Type Meter Method Transfer 

Standards and Table T.2.2. Acceptance and Maintenance Tolerances Meter to Like-Type Meter Method

 ............................................................................................................................................................ 222

Multiple Dimension Measuring Devices ..............................................................................224

MDM-22.1 D S.1.7. Minimum Measurement. ............................................................................... 224

OWM Executive Summary for MDM-22.1 – S.1.7. Minimum Measurement. .................................. 225

OTH – Other Items ................................................................................................................231

OTH-16.1 D Electric Watthour Meters Code under Development ................................................ 231

OWM Executive Summary for OTH-16.1 – Electric Watthour Meters Code Under Development .. 231

Block 1 Items (B1) Minimum Draft Size When Using a Field Standard

Meter ....................................................................................................................237

OWM Executive Summary for Block 1 Items (B1) – Minimum Draft Size When Using a Field Standard 

Meter .................................................................................................................................................. 238

B1: LMD-23.1 N.3.5. Wholesale Devices ......................................................................................... 241

B1: VTM-23.1 N.3. Test Drafts ......................................................................................................... 241

B1: MLK-23.1 N.3. Test Drafts ......................................................................................................... 241

Item Block 2 (B2) Define True Value for Use in Error Calculations ...................................244

B2: SCL-20.3 A S.5.4. Relationship of Minimum Load Cell Verification Interval to the Scale 

Division 246

B2: SCL-20.4 A Table 3. Parameters of Accuracy Classes. ............................................................ 247

B2: SCL-20.5 A Table S.6.3.a. Marking Requirements, Note 3. ..................................................... 248

B2: SCL-20.6 A T.N.1.2. Accuracy Classes and T.N.1.3. Scale Division. ...................................... 249

B2: SCL-20.7 A Table 6. Maintenance Tolerances ......................................................................... 249

Item Block 3 (B3) Tolerances for Distance Testing in Taximeters and Transportation 

Network Systems ............................................................................................................255

OWM Executive Summary for Item Block 3 (B3) – Tolerances for Distance Testing in Taximeters and 

Transportation Network Systems TXI-20.1 T. Tolerances and TNS-20.1 T. Tolerances .................. 256

Item B3 – TXI-20.1 T. Tolerances and TNS-20.1 T. Tolerances ....................................................... 256

B3: TXI-20.1 D T. Tolerances ........................................................................................................ 257

B3: TNS-20.1 D T. Tolerances ........................................................................................................ 257

Item Block 4 (B4) Electronically Captured Tickets or Receipts .........................................260

OWM Executive Summary for Item Block 4 (B4) – Electronically Captured Tickets or Receipts ... 261

B4: GEN-21.2 D G-S.5.6. Recorded Representations. ................................................................... 262

B4: LMD-21.2 D S.1.6.5. Money Value Computations., UR.3. Use of a Device. ........................... 262

B4: VTM-21.1 D S.1.1. Primary Elements., UR.2. User Requirements........................................... 265

B4: LPG-21.1 D S.1.1. Primary Elements., UR.2. User Requirements........................................... 266

B4: CLM-21.1 D S.1.4.1. Printed TicketRecorded Representation., UR.2.6.3. Printed 

TicketRecorded Representation.......................................................................................................... 268

B4: MLK-21.1 D S.1.4.2. Printed Ticket Recorded Representation., UR.2.6.3. Printed 

TicketRecorded Representation.......................................................................................................... 269

B4: MFM-21.2 D S.6. PrinterRecorded Representations., UR.2.6. Ticket Printer, Customer 

Ticket, Recorded Representation., UR.3.4. Printed Ticket. Recorded Representation. .................... 269
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B4: CDL-21.1 D S.1.4.1. Printed TicketRecorded Representations., UR.2.4.2. Tickets or 

Invoices. Recorded Representation. .................................................................................................. 270

B4: HGM-21.1 D S.2.6. Recorded Representations, Point of Sale Systems., S.6. Printer. 

Recording Element., UR.3.2. Vehicle-mounted Measuring Systems Ticket Printer Recording 

Element., UR.3.3. Printed Ticket. Recorded Representation. ............................................................ 270

B4: OTH-21.2 D Appendix D – Definitions.: recorded representations, recording element. .......... 271

Block 5 Items (B5) Test Drafts..............................................................................................277

OWM Executive Summary for Block 5 Items (B5) – Test Drafts ..................................................... 278

B5: LMD-23.2 N.3.5. Wholesale Devices ......................................................................................... 279

B5: VTM-23.2 N.3. Test Drafts ......................................................................................................... 279

Item Block 6 (B6) Commercial and Law Enforcement, Axle and Axle Group Weights...281

B6: SCL-22.1 Recorded Representation of Axle or Axle Group Weights ........................................ 284

B6: SCL-22.3 D UR.3.3. Single-Draft Vehicle Weighing., and UR.3.4. Axle and Axle Group 

Weight Values. ................................................................................................................................... 285

Item Block 7 (B7) Tolerances on Tests Using Transfer Standards................................. 297

OWM Executive Summary for Item Block 7 (B7) – Tolerances on Tests Using Transfer Standards 298

B7: CLM-22.1 D T.3. On Tests Using Type 2 Transfer Standards. ................................................ 299

B7: CDL-22.1 D T.3. On Tests Using Type 2 Transfer Standards. ................................................ 299

B7: HGM-22.1 D T.4. Tolerance Application on Tests Using Type 2 Transfer Standard Test 

Method. ................................................................................................................................... 299

Item Block 8 (B8) G-T.5. Tolerances on Tests When Transfer Standards are Used., 

Appendix A, Section 3.2. Tolerances for Standards., and Appendix D – Definitions: 

standards, field., transfer standard. and standard, transfer. Appendix A: 

Fundamental Considerations, 3. Testing Apparatus ....................................................302

B8: GEN-19.1 D G-T.5. Tolerances on Tests When Transfer Standards are Used., Appendix A, 

Section 3.2. Tolerances for Standards., and Appendix D – Definitions: standards, field., transfer 

standard. and standard, transfer. ......................................................................................................... 302

B8: OTH-22.1 D Appendix A: Fundamental Considerations, 3. Testing Apparatus ...................... 302

OWM Executive Summary for Item Block 8 (B8) – G-T.5. Tolerances on Tests When Transfer 

Standards Are Used, Appendix A, Section 3.2. Tolerances for Standards., and Appendix D – 

Definitions: Standards, Field., and Standard, Transfer. Appendix A: Fundamental Considerations, 3. 

Testing Apparatus ............................................................................................................................... 304
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Table 1.

Glossary of Acronyms and Terms

Acronym Term Acronym Term

ABWS Automatic Bulk Weighing System NEWMA Northeastern Weights and Measures 

Association

AAR Association of American Railroads NIST National Institute of Standards and 

Technology

API American Petroleum Institute NTEP National Type Evaluation Program

CNG Compressed Natural Gas OIML International Organization of Legal 

Metrology

CWMA Central Weights and Measures 

Association OWM Office of Weights and Measures

EPO Examination Procedure Outline RMFD Retail Motor Fuel Dispenser

FHWA Federal Highway Administration S&T Specifications and Tolerances

GMM Grain Moisture Meter SD Secure Digital

GPS Global Positioning System SI International System of Units

HB Handbook SMA Scale Manufactures Association

LMD Liquid Measuring Devices SWMA Southern Weights and Measures 

Association

LNG Liquefied Natural Gas TC Technical Committee

LPG Liquefied Petroleum Gas USNWG U.S. National Work Group

MMA Meter Manufacturers Association VTM Vehicle Tank Meter

MDMD Multiple Dimension Measuring 

Device WIM Weigh-in-Motion

NCWM National Conference on Weights and 

Measures WWMA Western Weights and Measures 

Association

 
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Table 2. Reporting Structure

Source: Name and affiliation of submitter. 

Submitter’s Purpose and Justification: The submitter’s concise statement as to the intent or purpose of this proposal. 

The justification describes the national importance, background on the issue, and may contain references to supporting 

data or documents. The justification may be summarized by OWM.

OWM Executive Summary: High level points that summarize the Technical Aspects of the item and 

recommendations pertaining to the Item Under Consideration.

Table 3. Summary of Recommendations

Item Under Consideration – The latest language that the Committee has moved forward as the Item membership is 

considering. OWM has applied the appropriate formatting according to NIST Handbooks.

NIST OWM Detailed Technical Analysis – A detailed analysis with background information and recommendations 

from the Office of Weights and Measures (OWM).

Summary of Discussions and Actions – An OWM summary of details and discussion on this Item. This includes 

discussion and decisions of the Standing Committee. This may also include information from sectors, trade 

associations, task groups, and subcommittees.

Regional Association Reporting - Taken directly from the Regional Association Meeting finalized report.

• Each region will be identified separately.

• The meetings within each region will be in chronological order.
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Details of All Items

(In order by Reference Key)

GEN – General Code

GEN-23.1 G-N.3. Test Methods

Source: Seraphin Test Measure Company

Submitter’s Purpose and Justification:

There are several proposals on the S&T agenda with the objective to recognize meters for use as field 

standards or as transfer standards. This proposal offers an option to a add a paragraph to the General Code 

to state that other field standards and transfer standards may be approved by the State weights and measures 

Director for use to test commercial devices, rather than adding paragraphs to each specific code for this 

purpose. Several device codes already contain references regarding transfer standards used to test 

commercial measurement devices (e.g., Cryogenic Liquid-Measuring Devices Code, Carbon Dioxide 

Liquid-Measuring Devices Code and Hydrogen Gas-Measuring Devices Code). Rather than revising a 

specific code in Handbook 44 every time a new field or transfer standard is proposed or developed, it is 

better to have an overall statement in the General Code that recognizes the use of other field and transfer 

standards that meet the requirements for use as field or transfer standards. The joint OWM/Seraphin 

proposal (GEN-19.1 and OTH-22.1) provides definitions and criteria to be included in Handbook 44 and 

in the Fundamental Considerations in Appendix A. It also prescribes the tolerances to be applied when 

using Type 2 transfer standards. For those who believe a specific statement in Handbook 44 is needed to 

recognize additional field and transfer standards, the proposed addition of G-N.3. will provide the reference 

they want without the need to change individual codes on a regular basis to recognize each particular field 

or transfer standard.

Some regulators may argue that if Handbook 44 does not specifically recognize a specific type of field or 

transfer standard, then the use of the field or transfer standard is not allowed. However, this approach 

would mean that every type of field or transfer standard must be specifically recognized in an HB44 code 

and then the Handbook must be changed every time a new standard is proposed to be recognized. The 

Fundamental Considerations already recognize the authority of the Director to recognize new standards and 

transfer standards for use to test commercial devices. Footnote 2 to Section 3.1. includes the statement, 

“This section shall not preclude the use of additional field standards and/or equipment, as approved by the 

Director, for uniform evaluation of device performance.” 

Others may argue that this paragraph in the General Code is not needed, since (1) the definitions of field 

standard and transfer standard and (2) the Fundamental Considerations already provide for the recognition 

and use of other field standards and transfer standards.

The submitter requests that this be a retroactive section and request a Voting status for this item. 
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OWM Executive Summary for GEN-23.1 – G-N.3. Test Methods

OWM Recommendation: We recognize that GEN-23.1 could be used as a roadmap to what is being 

proposed in Block 8 to support those States needing a specific requirement in the handbook that address 

the use of Standards within a Jurisdiction. NIST OWM supports this as a Voting item along with the 

changes where it ensures continuity in terms, as described in the detailed technical analysis section. 

• Some States have argued the need for specific requirements in NIST HB44 for specific standards 

that can be used for testing commercial devices and this new proposal would address that concern. 

• Item GEN-23-1 provides requirements in NIST HB 44 General Code for all standards to meet the 

guidance as specified in the fundamental considerations thereby eliminating the need for specific 

guidance for each type of standard used to test commercial devices. 

• Block 8 is a proposal to clarify the fundamental considerations concerning all standards use to test 

commercial devices.

• With both GEN-23.1 and the Block 8 items, weights and measures Jurisdictions will have the 

necessary tools to determine the appropriate Standards for use when testing commercial devices and 

these proposed items eliminate the need for specific changes to NIST HB 44 Test Draft Sections as 

proposed in S&T Item LPG-15.1, MFM-15.1, and Block 1, and the technical problems associated 

with these proposed changes to NIST HB 44. See NIST OWM comments in this analysis 

concerning items LPG-15.1, MFM-15.1 and Block 1.

Table 3. Summary of Recommendations

GEN-23.1 – G-N.3. Test Methods

V D W A I Notes* Comments

Submitter 

OWM

 Supports with suggested changes as 

noted in our technical analysis

WWMA 

SWMA 

NEWMA 

CWMA 

NCWM

Letters of Support Letters of Opposition Notes

Industry

Manufacturers

Retailers and 

Consumers

Regulators
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Table 3. Summary of Recommendations

GEN-23.1 – G-N.3. Test Methods

V D W A I Notes* Comments

*Notes Key:

1 − Submitted modified language

2 − Item not discussed

3 − No meeting held

4 − Not submitted on agenda

5 − No recommendation or not considered

Item Under Consideration:

Amend Handbook 44, General Code, as follows:

G-N.3. Test Methods. – Permissible test methods for verifying compliance of weighing and measuring 

systems with the provisions of the General Code and Specific Codes include, but are not limited to, 

test methods and apparatus that have been approved by the State Director of weights and measures 

as outlined in Appendix A - Fundamental Considerations, Section 3. Testing Apparatus.

NIST OWM Detailed Technical Analysis: 

S&T Agenda item LPG-15.1 and MFM-15.1 are proposed changes to the test draft paragraphs in NIST HB 

44, LPG code and MFM code with the purpose statement to accept meters for use as standards. Many 

comments were heard expressing technical concerns with the proposed changes and comments that 

acceptance of a standard used to test commercial devices within a jurisdiction is the responsibility Director 

within a weights and measures jurisdiction, which is specified in HB 44 Fundamental Considerations. The 

Director’s responsibilities are further clarified in S&T Agenda Item Block 8. As was pointed out by the 

submitter of this item, some regulators may argue that if Handbook 44 does not specifically recognize a 

specific type of field or transfer standard, then the use of the field or transfer standard is not allowed. 

However, this approach would mean that every type of field or transfer standard must be specifically 

recognized in a HB 44 code and then the Handbook must be changed every time a new standard is to be 

recognized. 

This proposed paragraph is a change to the General Code that places a requirement in the HB 44 to meet 

the need of those regulators that need a specific requirement in the HB 44 and further supports what is in 

HB 44 Fundamental Considerations. This proposal also eliminates the need to place a paragraph in each 

section of HB 44 that addresses specific standards for use in testing commercial and law enforcement 

devices. As such, S&T Agenda items LPG-15.1, MFM-15.1, and Item Block 1 may be better addressed by 

this proposal and its companion proposal Block 8. NIST is also in support of the changes to the Item Under 

Consideration that were proposed by Mr. Bob Murnane at the CWMA meeting which replaces “State 

Director” with “Director” and also removes “of weights and measures” to match other language in the NIST 

HBs and is a more general title. 

Summary of Discussions and Actions:

GEN-23.1 addresses the concern some states may have and/or have argued the need for specific 

requirements in NIST HB44 for standards that can be used for testing commercial devices. This proposed 
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General Code requirement along with item block 8 provides the requirements for use of various test 

standards to test commercial devices. LPG-15.1, MFM-15.1 and Block 1 are all proposed changes to Test 

Draft section in the handbook with a purpose statement “to allow field standards meters to be used to test 

and place into service dispensers and delivery system flow meters”. States already have the authority to 

select a test standard for use and changes to the test draft section of the handbook would not help but add 

to confusion as to which test draft applies. Also, one of the proposals prohibits a full test of the meter 

because the change prohibits testing at the minimum test draft. As noted in the NIST OWM technical 

analysis to Items LPG-15.1, MFM-15.1 and Block 1 the purpose for these items is more appropriately 

addressed in GEN-23.1 and Block 8. 

At the CWMA 2022 Interim Meeting there were also suggested changes to the Item Under Consideration 

and these are addressed below:

• The proposed changes from the Central Weights and Measures Association to add as follows “... of 

commercial weighing and measuring systems..” may limit the scope of the field reference standard 

since NIST HB 44 does include other devices such as law enforcement devices. The CWMA also 

suggested striking the following “...State Directors for Weights and Measures...” and we concur with 

this change and note that Handbook 130 Uniform Weights and Measures Law, Section 1, Definitions 

1.4 gives a State the latitude to define the position within an agency. 

• As such, NIST OWM suggest the following change:

G-N.3. Test Methods. – Permissible test methods for verifying compliance of weighing and measuring 

systems with the provisions of the General Code and specific codes include, but are not limited to, 

test methods and apparatus that have been approved by the State Director of weights and measures

as outlined in Appendix A - Fundamental Considerations, Section 3. Testing Apparatus. 

Regional Association Reporting:

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting the following comments were received: Mr. Robert Murnane

(Seraphin Test Measure Company) provided the reason for this addition and stated that rather than adding 

paragraphs for each code regarding use of testing equipment (it resides in Appendix A; puts it out there for 

everyone) putting it in the general code will keep us from having to go back to it. He recommended this as 

a Voting item. 

Mr. Michael Keilty (Endress+Hauser) opposed this item. He noted that Mr. Murnane also submitted the 

item under Block 8 and stated that everything in this proposal is repeated in Block 8 by the fundamental 

considerations; it is redundant. Mr. Keilty recommended the item be withdrawn. 

During open hearings there was testimony heard about redundancy between this item and Block 8. 

The WWMA S&T Committee recommended that this item be assigned a Developing status with the 

recommendation that the submitters of GEN-23.1 and Block 8 make one cohesive item or develop them in 

tandem and reduce redundancies. 
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Southern Weights and Measures Association

The following comments were received during the 2022 SWMA Annual Meeting: Dr. Matt Curran

(Florida) commented that he was not clear on who the submitter of this item is. He cautioned that this item 

would allow the use of a device not in the handbook and would lay the burden of responsibility for the use 

of that device solely on the Director. He also stated concern that this would move us away from uniformity.

Mr. Robert Murnane (Seraphin Test Measures), the submitter of this item, stated that the Handbook already 

gives the Director the authority to use any device, and that this would make it easier to adopt new 

technologies as they are developed. He recommended moving this forward as a Voting item.

Mr. Tim Chesser (Arkansas) echoed Mr. Curran’s concerns. He also stated that he liked the item, and that 

it would give us some teeth when making accommodations for alternate test methods. 

Mr. Keilty (Endress + Hauser) stated that we discuss new technology and how to deal with it in every 

meeting. He added that lines 12-15 were redundant to S&T Block 8 page 310, lines 33-46. He also stated 

that this issue is ultimately addressed by the Fundamental Considerations and recommended that the item 

be withdrawn.

Mr. Hal Prince (Florida) stated that he didn’t see a need for this proposal. Mr. Ken Ramsburg (Maryland)

echoed Mr. Prince. 

The SWMA S&T Committee believes that the need for this item is ambiguous, and that it would be 

redundant to Block 8 if those items are added to the handbook as well. 

The SWMA S&T Committee recommends that this item move forward as a Developing Item.

Northeastern Weights and Measures Association

At the 2022 Interim Meeting, Mr. Bob Murnane (Seraphin Test Measure) commented that the reason for 

this proposal is to put a reference in the General Code to Section 3 of the Fundamental Considerations.

This would make it clear that directors have authority to use master meters and would eliminate the need 

to change all codes. Mr. Michael Keilty (Endress Hauser) commented that he believes this item is redundant 

in conjunction with the other blocked items authored by the submitter and recommends the item be 

withdrawn. Ms. Diane Lee (NIST OWM) commented that this item clarifies in General Code that the 

choice of master meter rests on individual states. NIST believes the item has merit. A full analysis has not 

been developed but will provide for Interim. Mr. Bob Murnane (Seraphin Test Measure) responded to Mr. 

Keilty’s comments regarding redundancy and reiterated that this item would make it clear that directors 

have authority to use master meters and would eliminate the need to change all codes. Mr. Lou Sakin 

(Holliston, Massachusetts) recommended this item have a Voting status. Mr. Jim Willis (New York) 

indicated that this item will have a Voting status.

After hearing comments from the floor, the Committee agreed that the item has merit. The Committee 

agreed with the commenters that this item will give clarity as to the use of master meters and recommends 

a Voting status.

Central Weights and Measures Association

Mr. Bob Murnane (Seraphin): add “commercial” to line 12 between the words “of” and “weighing”. 
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The CWMA S&T Committee believes this item is fully developed and recommended Voting status with 

the following changes: 

G-N.3. Test Methods. – Permissible test methods for verifying compliance of commercial weighing 

and measuring systems with the provisions of the General Code and Specific Codes include, but are 

not limited to, test methods and apparatus that have been approved by the State Director of weights 

and measures as outlined in Appendix A - Fundamental Considerations, Section 3. Testing 

Apparatus.

SCL – SCALES

SCL-22.2 A UR.1. Selection Requirements, UR.1.X. Cannabis 

Source: NCWM Cannabis Task Group

Submitter’s Purpose and Justification:

Establish uniform scale suitability requirements among the states for sales of cannabis. 

As states legalize sales of cannabis in its various forms, the need has arisen for uniform standards for scale 

suitability. Uniform requirements from one state to the next, will strengthen each jurisdiction’s ability to 

effectively regulate the industry in a fair and equitable manner. Uniform standards also provide industry 

with expectations regardless of the jurisdiction, reducing potential conflict or confusion. 

Some states may already have scale suitability requirements differing for those proposed here. The task 

group is hopeful that differences can be resolved so that the standards are the same in every jurisdiction. 

The proposed suitability requirements are based on existing standards as set forth by the California Division 

of Standards, Division of Measurement Standards. 

The submitter requested that this item be a Developing Item.

OWM Executive Summary for SCL-22.2 – UR.1. Selection Requirements, UR.1.X. Cannabis

1

OWM Recommendation: 

Additional consideration and development of this item by the Cannabis Task Group and/or its Scales 

Focus Subgroup is needed. For this reason, OWM recommends this item remain assigned to the Task 

Group

Note: The original proposal associated with this item has been replaced by the Scales Subgroup of the 

NCWM Cannabis Task Group (CTG) with the proposal shown in the Item Under Consideration. It is 

important to note, however, that when the revised proposal was submitted to the NCWM, just prior to 

the November 15, 2022 deadline, proposed new paragraph UR.3.1.2. Required Minimum Loads 

for Cannabis products was unintentionally omitted. The CTG plans to request the paragraph be 

included as part of the proposal during the 2023 NCWM Interim Meeting. 

No longer are maximum scale division values proposed for the weighing of cannabis products as was 

the case with the original proposal. Consequently, no longer do the comments and recommendations 

that OWM developed previously for this item apply. 
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OWM Executive Summary for SCL-22.2 – UR.1. Selection Requirements, UR.1.X. Cannabis

The following represents OWM’s executive summary for the current proposal and provides justification 

for the “Assigned” status recommendation:

• Although OWM doesn’t believe it was the intent of the CTG Scales Focus Group, adding the 

terminology, “and weighing of all Cannabis products,” to each of the three accuracy class 

classifications in Table 7a (i.e., Class I, Class II, and Class III) leads one to believe that a scale of 

any one of those three accuracy classes would be permissible for use to weigh all cannabis products. 

• It is OWM’s understanding that some participants of the CTG believe NIST HB 44 requirements 

cannot be applied to scales used commercially to weigh cannabis products unless Table 7a explicitly 

indicates such use. We do not share this opinion and note that the description in Table 7a for Class 

III scales specifies “All commercial weighing not otherwise specified...,” which would include 

scales used to weigh cannabis products. That is, the description of “Weighing Application or Scale 

Type” in HB 44 Scales Code Table 7a for Class III scales adequately captures scales used to weigh 

cannabis products. 

• There are several commercial uses of scales excluded from Table 7a in which jurisdictions 

continually regulate those scales without concern. For example, scales used in a grocery store to 

weigh bakery items, meat products, delicatessen products, and produce are not explicitly identified 

in the existing table; yet these scales are regularly regulated by weights and measures officials 

throughout the US. The different uses of these scales are encompassed in the terminology, “All 

commercial weighing not otherwise specified...” as would be the case for scales used to weigh 

cannabis products.

• We take no position, however, on adding an additional example device type to HB 44 Scales Code 

Table 7a if others believe it is essential, since the title of the table specifies that the different device 

types listed are only “typical.” Yet, because the “Note” included at the bottom of Table 7a specifies 

a scale with a higher accuracy class than that specified as “typical” may be used, it is unnecessary 

to add the additional device type to more than one accuracy class classification in the table. Adding 

it to the Class III description alone would suffice given that Class I and Class II scales are of higher 

accuracy class. Additionally, we believe adding the additional device type description to the 

Accuracy Class I and Class II classifications would cause unnecessary confusion due to the Note 

explaining that a higher accuracy class may be used. 

• OWM currently participates on the Scales Focus Subgroup of the NCWM Cannabis Task group. 

Most recently, several members of the subgroup have voiced support for the development of a scale 

suitability guidance document that could not only be used by the Cannabis industry, but other 

industries as well. We too would be in favor of developing such a document and believe it would 

be helpful in selecting a suitable scale.

____________________ 

1 In contrast to hemp, marijuana remains a Schedule I substance under the Controlled Substances Act. NIST does not have a 

policy role related to the production, sale, distribution, or use of cannabis (including hemp and marijuana). NIST participates 

in the National Conference of Weights and Measures (NCWM) as part of NIST’s statutory mission to promote uniformity in 

state laws, regulations, and testing procedures. 

 
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Table 3. Summary of Recommendations

SCL-22.2 – UR.1. Selection Requirements, UR.1.X. Cannabis

V D W A I Notes* Comments

Submitter 

OWM

 Refer to OWM’s technical analyses 

for reasons.

WWMA 

SWMA 

NEWMA  1

CWMA 

NCWM

Letters of 

Support

Letters of 

Opposition

Notes

Industry

Manufacturers  A&D Engineering (01-04-22)

SMA Support continued development. Refer to SMA’s 

position statement from its Fall 2022 Meeting.

Retailers and 

Consumers

Regulators  Florida Dept Agriculture letter of support. (12-07-

21)

*Notes Key:

1 − Submitted modified language

2 − Item not discussed

3 − No meeting held

4 − Not submitted on agenda

5 − No recommendation or not considered

Item Under Consideration:

Amend NIST Handbook 44, Scales Code as follows:

UR.1.1. General.

(a) For devices marked with a class designation, the typical class or type of device for particular 

weighing applications is shown in Table 7a. Typical Class or Type of Device for Weighing 

Applications. 

(b) For devices not marked with a class designation, Table 7b. Applicable to Devices not Marked 

with a Class Designation applies.
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Table 7a.

Typical Class or Type of Device for Weighing Applications

Class Weighing Application or Scale Type

I Precision laboratory weighing and weighing of all Cannabis products

II Laboratory weighing, precious metals and gem weighing, grain test scales, and weighing of 

all Cannabis products

III

All commercial weighing not otherwise specified, grain test scales, retail precious metals 

and semi-precious gem weighing, grain-hopper scales, animal scales, postal scales, vehicle 

on-board weighing systems with a capacity less than or equal to 30 000 lb, and scales used 

to determine laundry charges, and weighing of all Cannabis products

III L 

Vehicle scales (including weigh-in-motion vehicle scales), vehicle on-board weighing 

systems with a capacity greater than 30 000 lb, axle-load scales, livestock scales, railway 

track scales, crane scales, and hopper (other than grain hopper) scales

IIII Wheel-load weighers and portable axle-load weighers used for highway weight enforcement

Notes:

A scale with a higher accuracy class than that specified as “typical” may be used.

The use of italicized text in the references to “Cannabis” in this table is only to denote its proper 

taxonomic term; the italicized font does not designate a “nonretroactive” status as is the 

convention used throughout NIST Handbook 44.

(Amended 1985, 1986, 1987, 1988, 1992, 1995, 2012, and 2021) 

UR.3.1.2 Required Minimum Loads for Cannabis products. – The recommended minimum loads 

specified in Table 8 shall be considered required minimum loads for scales used to 

weigh Cannabis and Cannabis-containing products.

[Nonretroactive as of January 1, 20XX]

NIST OWM Detailed Technical Analysis: 

No additional technical analysis is being provided nor is needed beyond the recommendations made in the 

executive summary portion of this report.

Summary of Discussions and Actions:

During the 2022 NCWM Interim meeting, the Committee received somewhat a wide range of comments 

during open hearings. Most who commented supported further development of the item, although there 

were also several questions raised concerning the need for the proposed changes. 

Mr. Doug Musick (Kansas) acknowledged that he agreed with the concept of the proposal while noting too 

that the NCWM had failed to adopt strong standards in that NISI Handbook 44 Scales Code Table 8 

specifies “recommended” minimum loads, making them difficult to enforce. He also noted that HB 44 

already addresses scale suitability, and that any proposal should address more than just a single commodity; 

but rather, all products of high cost. 
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Mr. Evan Foisy (A&D Engineering) read the position statement provided by A&D Engineering to the 

Committee in advance of the 2022 NCWM Interim Meeting as follows:

A&D opposes this item completely and recommends that it be withdrawn. The addition of such specific 

user requirements for a commodity is unprecedented for HB 44. We fail to see the rationale for including 

readability requirements for Cannabis when such requirements have never been required for gold or other 

precious metals with a higher dollar per gram value.

If the Committee decides that such specifications are warranted, A&D proposes that the requirements be 

changed to 0.01 g for net weighments up to 100 g capacity. The technology exists and is already in use to 

not limit the readability to 0.1 g for capacities from 10 g up to 100 g. Having different accuracy 

requirements for Cannabis consumers who purchase less than 10 g vs. those who purchase more than 10 g 

is not promoting fairness and equity in the market. The maximum that any state allows for a single user 

purchase is 2.5 oz (approximately 71 g). By offering 100 g x 0.01 g, the entire range of consumer purchases 

will be covered equally and consistently. 

Example: Deli scales allow the same increment size whether you’re getting 1 slice or 10. Cannabis should 

be no different.

The SMA supported continue development of the item with the recommendation that NIST Handbook 44 

Scales Code Table 8 titled “Recommended Minimum Load” be considered in its further development. 

NIST OWM provided the Committee a high-level summary of its analysis of the item, many of the points 

of which questioned not only the need for the proposed change, but also the effect the change (if adopted) 

would have for setting a precedent for producers of other commodities to use in support of making similar 

changes to HB 44 intended to address products they produce. OWM, in its comments to the Committee, 

emphasized that HB 44 already provides the necessary tools (in the way of General Code and Scales Code 

requirements) for officials to be able to enforce scale suitability. It also provides officials the needed 

discretion to decide (at time of inspection), based on the many important factors needing to be considered, 

whether or not a scale is or is not suitable for its given application. OWM recommended, as an alternative 

to the proposal, the development of a scale suitability guide, which should include all important factors 

(and not just scale division value) that need to be considered when determining scale suitability. 

Several who commented before the Committee also questioned use of the term “scale division” in the 

proposal and whether any maximum increments proposed should, instead, be based on “scale verification 

division.” 

In considering the comments received during open hearings, the Committee agreed to maintain the 

Assigned status of the item.

The NIST OWM Technical Advisors assigned to the S&T Committee opted to participate virtually in the 

2022 NCWM Annual Meeting due to COVID-19. During S&T open hearings, there was an audio problem 

with the virtual platform being used by the NCWM that prevented those participating virtually to hear much 

of the open hearing testimony. With regard to this particular item, no testimony could be heard by those 

attending virtually. A member of the national S&T Committee, who had attended the 2022 NCWM Annual 

Meeting in person reported that the Committee was given an update from Mr. Charles Rutherford (NCWM 

Cannabis Task Group Co-Chair). In his update, Mr. Rutherford requested that this item remain Assigned 

to the Task Group for further discussion. The Scales Focus Group will be regrouping, with Mr. Lou Sakin 

(Towns of Holliston, Hopkinton, Northbridge, Massachusetts) as the Chair, for further development of the 

item. The Committee agreed that this item will retain an Assigned status.
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Regional Association Reporting:

Western Weights and Measures Association

During the 2021 Annual Meeting Open Hearings the following comments were heard:

Mr. Josh Nelson (Ex-Officio NCWM S&T Committee) put forward to address some issues for cannabis, 

recommend developing - still needs work and continue to work forward.

Mr. Matt Douglas (California - DMS), California supports further development, add non retroactive date -

subsection A states up to capacity... lists suitability requirements based on California, however, this info is 

not a standard. 

Mr. Eric Golden (Cardinal Scales) in Section A, B, and C be better to say 0.1 g for net weighments up to 

10 grams, then B 10 to 100 grams, then C say over 100, etc.

Mr. Kurt Floren (Los Angeles County, California) remarked that Mr. Golden stated perfectly what is 

lacking. There has to be ranges put in as to where the graduations are appropriate.

Ms. Erin Sullivan (Colorado Department of Agriculture) asked if this pertain to cannabis in any form or 

concentration?

Mr. Nelson remarked this is what is going into NIST HB44 - each jurisdiction has to define their own. For 

Oregon, medical is much different than retail. Retail has to abide by this and medical does not. Verbiage 

in A, B, and C does need additions.

Ms. Sullivan is this grows vs. dispensaries? Different products in processing facilities are weighed with 

many containers on the scales. Do states determine the regulation?

Mr. Nelson asked if it is up to the states to determine how to apply tares and increments in which product 

is weighed.

Mr. Kurt Floren (Los Angeles County, California): cannabis products: later we’ll see proposed def. of 

cannabis and cannabis products, are we anticipating the adoption of the proposed language?

Mr. Nelson remarked it is not limited to flowers or bud. Mentions dabs. Is there a packaging requirement 

for the label? Oregon does. There must be a legal for trade scale that can prove they are meeting net 

contents. They must ensure that their process is being executed correctly. He thinks this is not limited to 

flower/bud.

Mr. t Floren this raises the point that further consideration needs to be put into terms. Brownies, cannabis 

infused pizza... and other items sold by weight. Are we setting the terms for pure cannabis product or are 

the scales being used for any cannabis containing product?

Mr. Nelson welcomes written input for this topic from anyone. Mr. Don Onwiler was a big proponent in 

this; Mr. Nelson will continue to develop this. 

Mr. Golden asked for clarification on Mr. Nelson: geared towards net sales, packaging for the customer. 

Is this part of the track and trace program for growers or just for retail?
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Mr. Nelson remarked this needs to be expanded upon, in Oregon. Even the growers have to do track and 

trace. Any scale weight that is used for the cannabis tracking system needs to be Weights and Measures 

compliant. Maybe has to address even a class III scale. They will look more into it. 

Mr. Joe Moreo (Ag. Com. Sealer) stated over time we are going to need one level for concentrates, one for 

food, one for flower, one size fits all will not work. 

Mr. Nelson agrees that one size does not fit all. This will start to give limitations as to what a particular 

weight will be. Not trying to pigeonhole any device into one category, just trying to figure out what works, 

that’s the intent. 

The WWMA S&T Committee recommended the item be assigned a Developmental status so that the 

submitter could continue to work on this as they commented during open hearings. 

During the WWMA’s 2022 Annual Meeting the following comments were received: 

Mr. Charles Rutherford (NCWM Cannabis Task Group): Everything in this book isn't updated. 

They have added “and cannabis” to Table 7. cannabis talks about cannabis and hemp. They expect 

to finish soon. What is in the book is old and doesn’t apply any more. 

During open hearings, due to timing constraints, the Committee did not take comments on Assigned Items. 

The Committee did allow the source to provide updates on these items. An update from the NCWM 

Cannabis Task Group Co-Chair Charlie Rutherford was provided. The WWMA S&T Committee 

recommends that this item remain Assigned. 

Southern Weights and Measures Association

During the 2021 Annual Meeting Open Hearing, Mr. Russ Vires (SMA) stated that they have no position 

on this item at this time. 

Mr. Matt Curran (Florida) stated that he supports this as a Voting item. He also provided comments in 

support of this item from Mr. Eric Golden (Cardinal Scale). Cardinal offered some changes as well. The 

suggested changes are as follows: 

UR.1.X. Cannabis. – The scale division for scales weighing Cannabis shall not exceed: 

(a) 0.01 g for net weighments up to capacity up to 10g, 

(b) 0.1 g for net weighments greater than 10g, up to 100g, capacity, and 

(c) 1 g for net weighments greater than 100g, up to capacity. 

(Added 20XX) 

Mr. Charlie Rutherford (Cannabis Committee) stated that he supports this item moving forward as a Voting 

item with the changes suggested by Cardinal Scale and Dr. Curran. 

This Committee recommended that this item be moved forward as a Voting item if the changes suggested 

above are made. 

During SWMA’s fall 2022 Annual Meeting, Mr. Rutherford stated that Table 1A has been updated in the 

item. The SWMA S&T Committee recommended this item remain as an Assigned Item.
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Northeastern Weights and Measures Association

During the 2021 Interim Meeting Open Hearing the following comments were heard. 

Mr. Golden) made suggestions to change the language in this item to the following:

UR.1.X Cannabis

(a) 0.01g for net weighments up to 10 g 

(b) 0.1g for net weighments greater that 10g , up to 100 g, and 

(c) 1 g for net weighments greater than 100g , up to capacity 

Mr. Lou Sakin (Hopkinton/Northbridge, Massachusetts) commented that he agrees with changes above. 

 

Discussions were heard regarding the agreement with table 8 in scale code as this requirement is more 

restrictive than table 8 parameters.

Mr. Golden commented that national uniformity would be good and many states have informational 

publications that outline requirements in their state for Cannabis scale requirements.

Mr. Jimmy Cassidy (Massachusetts) recommended Voting status with the changes above. 

Mr. Matt Curran (Florida) commented that harmonization with table 8 would be a good idea if possible. 

Mr. Sakin questioned if Cannabis should be in italics. The Committee suggests making the change to italics 

for Cannabis. 

The NEWMA Specifications and Tolerances Committee recommended that this item be given Voting status 

with suggested edits. 

During the 2022 Annual Meeting Open Hearings the following comments were heard:

Mr. James Cassidy (Massachusetts) commented as the Co-Chair of the NCWM Cannabis Task Group. He 

supported the Assigned status so the Task Group can continue to develop the item from comments received 

at the 2022 Interim. Mr. Russ Vires (SMA) supported continued development and indicated that a user 

requirement typically does not pertain to a specific commodity. Mr. Vires suggested the words “retail 

cannabis” should be added to the “Class II” section of Table 7a and the words “bulk cannabis processing 

and sales” should be added to the “Class III” section of Table 7a. Mrs. Tina Butcher (NIST OWM) read 

the following statement: “As a non-regulatory metrology institute, NIST defers to federal agencies with 

regulatory authority under the Controlled Substances Act (CSA) for the scheduling of drugs or other 

substances. NIST does not have a policy role related to the production, sale, distribution, or use of cannabis 

(including hemp and marijuana). While the 2018 Farm Bill removed hemp from the list of controlled 

substances under Schedule 1 of the CSA, marijuana remains on that list. NIST must respect that distinction 

even as it exercises its statutory authority to develop and disseminate national weights and measures 

standards for the production, distribution, and sale of products in the commercial marketplace. NIST 

remains committed to providing technical assistance to the weights and measures community. OWM has 

provided key technical points for the community to consider in its deliberations of cannabis-related 

proposals, and OWM would be happy to provide any necessary clarification. OWM comments are intended 
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to encourage technically sound application of legal metrology laws, regulations, and practices to the 

measurement and sale of these products.”

After hearing comments from the floor, the Committee recognized the need for further development of the 

item and recommended that the item retain an Assigned status. The Committee recommends the NCWM 

Cannabis Task Group work with the SMA and other stakeholders to further develop this item. 

During NEWMA’s fall 2022 Interim Meeting, the following was reported: 

The Committee recognized comments received the from Cannabis Task Group from the CTG Scales Focus 

Group Chair, Mr. Lou Sakin. Mr. Rutherford (NCWM Cannabis TG Co-Chair) commented that the Scales 

Focus Group is under new leadership and the Chair is Mr. Lou Sakin. Mr. Rutherford pointed out that the 

Item Under Consideration is not current and current language was sent to the NEWMA. Mr. Rutherford 

requested a Voting status for this item. Mr. Sakin indicated that the new language was submitted to SWMA 

and NEWMA. The TG chose to modify tables instead of changing the entire code. He believes that the 

item is fully developed and ready for a Voting status. Mr. Cassidy requested that this item move forward 

as Voting with changes as proposed in the submitted documentation. 

After hearing comments from the floor, the Committee agreed that the item has merit. The Committee 

agreed that the item, with recommended changes below, is ready for a Voting status. 

Section 2.20 UR.3.1.2 Required Minimum Loads for Cannabis products. 

The recommended minimum loads specified in Table 8 shall be considered required minimum loads 

for scales used to weigh Cannabis and Cannabis-containing products. 

[Nonretroactive as of January 1, 20XX] 

and 

Table 7a.

Typical Class or Type of Device for Weighing Applications

Class Weighing Application or Scale Type

I Precision laboratory weighing and weighing of all Cannabis products

II Laboratory weighing, precious metals and gem weighing, grain test scales, and weighing of 

all Cannabis products 

III

All commercial weighing not otherwise specified, grain test scales, retail precious metals 

and semi-precious gem weighing, grain-hopper scales, animal scales, postal scales, vehicle 

on-board weighing systems with a capacity less than or equal to 30 000 lb, and scales used 

to determine laundry charges, and weighing of all Cannabis products 

III L 

Vehicle scales (including weigh-in-motion vehicle scales), vehicle on-board weighing 

systems with a capacity greater than 30 000 lb, axle-load scales, livestock scales, railway 

track scales, crane scales, and hopper (other than grain hopper) scales

IIII Wheel-load weighers and portable axle-load weighers used for highway weight enforcement

Notes: A scale with a higher accuracy class than that specified as “typical” may be used.

The use of italicized text in the references to “Cannabis” in this table is only to denote its proper 

taxonomic term; the italicized font does not designate a “nonretroactive” status as is the convention 

used throughout NIST Handbook 44.
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Table 7a.

Typical Class or Type of Device for Weighing Applications

Class Weighing Application or Scale Type

(Amended 1985, 1986, 1987, 1988, 1992, 1995, 2012, and 2021)

Central Weights and Measures Association

During the 2021 Interim Meeting Open Hearing, the Committee heard comments from the floor. Mr. Loren 

Minnich (Kansas) stated he’s not sure of the intent and that it needs more developing. Mr. Golden agreed 

with is it “e” or “d”, will send notes to Committee. Mr. Ivan Hankins (Iowa) would support item with Mr. 

Golden’s language. Mr. Golden continued by recommending the following change to which will add clarity 

to the listed weight ranges in SCL22.2 (in red): 

SCL-22.2 UR.1. Selection Requirements, UR.1.X. Cannabis 

UR.1.X. Cannabis. – The scale division verification scale interval, e, for scales weighing Cannabis 

shall not exceed:

(a) 0.01g for net weighments up to capacity up to 10g, 

(b) 0.1g for net weighments greater than 10g, up to 100g, capacity, and 

(c) 1g for net weighments greater than 100g, up to capacity. 

(Added 20XX)

CWMA S&T Committee recommended as Voting Item with the proposed changes from Cardinal Scales.

During the 2022 CWMA Annual Meeting Open Hearings the following comments were heard: 

Mr. Doug Musick (Kansas) welcomed the attempt to define suitability; recommended the following: 

SCL-22.2 UR.1. Selection Requirements, UR.1.X. Cannabis 

UR.1.X. Cannabis. – A retail Cannabis scale shall not be used to weigh net loads smaller than 100 

displayed scale divisions “d”,

(a) 0.01g for net weighments 10g or less, 

(b) 0.1g for net weighments greater than 10g and up to 100g, and 

(c) 1g for net weighments greater than 100g. 

(Added 20XX) 

Mr. Russ Vires (SMA) stated the addition of a User Requirement is not the best approach in this situation; 

User Requirements do not typically apply to a specific commodity. Supported continuing as Developing 

and the following proposed changes should be considered instead: 

- The words “retail cannabis” should be added to the “Class II” section of Table 7a.
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- The words “bulk cannabis processing and sales” should be added to the “Class III” section of Table 

7a.

Mr. Charlie Stutesman (Kansas) questioned why only metric units are referenced and not also include inchpound units.

The CWMA S&T Committee recommended this item remain with the NCWM Cannabis Task Group and 

that the suggested changes are considered.

During the 2022 CWMA Interim Meeting open hearings, the following comments were heard:

Mr. Rutherford (ASTM International) remarked the old version is still listed in today’s agenda. Pushing 

the suitable scales discussion to a later date. The submitter provided updates to Table 7a. which add 

Cannabis verbiage to the weighing application column for Classes I, II, and III. 

The CWMA S&T Committee recommended this item remain Assigned with the NCWM Cannabis Task 

Group.

SMA

During the 2021 fall meeting, the SMA supported the continued development of this item.

During the 2022 spring meeting, the SMA supported the continued development of this item.

Rationale: The addition of a User Requirement is not the best approach in this situation; User Requirements 

do not typically apply to a specific commodity. The following proposed changes should be considered 

instead:

• The words “retail cannabis” should be added to the “Class II” section of Table 7a.

• The words “bulk cannabis processing and sales” should be added to the “Class III” section of Table 

7a.

During the 2022 fall meeting, the SMA supported the continued development of this item.

Rationale: The addition of a User Requirement is not the best approach in this situation; User

Requirements do not typically apply to a specific commodity. The following proposed changes should be 

considered instead:

• The words “retail cannabis” should be added to the “Class II” section of Table 7a.

• The words “bulk cannabis processing and sales” should be added to the “Class III” section of 

Table 7a.

SCL-23.1 S.1.12. Manual Weight Entries

Source: NTEP Weighing Sector
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Submitter’s Purpose and Justification:

Provide Specifications corresponding with User Requirements that limit how manual weight entries are 

allowed. 

The instances in which manual weight entries are allowed are limited by UR.3.9. but there are no 

corresponding limitations in S.1.12. This addition will allow the evaluation of devices, software, or systems 

for compliance with these limitations and provide manufacturers specific requirements to comply with 

when designing a commercial device.

The submitter acknowledges that this is a complicated requirement to incorporate into the design of a device 

or system and some may argue that it should remain a user requirement. 

The submitter requested a Voting status. 

OWM Executive Summary for SCL-23.1 – S.1.12. Manual Weight Entries

OWM Recommendation: NIST OWM is of the opinion that the current proposal incorporates user 

requirements in a specification which should be avoided. Therefore, NIST OWM recommends this item 

to be Developing. 

• In the proposal, the restrictions laid down in UR.3.9 are implemented as requirements in S.1.12. 

However, they remain requirements on the application of the device which do not belong in the 

specifications of the scales code.

• Furthermore, the condition “When being used in a direct sale application” is contradicting 

requirement (c) in the proposal. Generating labels for standard weight packages is in general not a 

direct sales application.

• NIST OWM suggest to refer to UR.3.9 as a condition for specification S.1.12. 

e.g., “S.1.12. Manual Weight Entries. – A device when being used for direct sale in an application 

mentioned in UR.3.9 shall accept ...”

Table 3. Summary of Recommendations

SCL-23.1 – S.1.12. Manual Weight Entries

V D W A I Notes* Comments

Submitter 

OWM 

WWMA 

SWMA 

NEWMA 5

CWMA 

NCWM

Letters of Support Letters of Opposition Notes

Industry
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Table 3. Summary of Recommendations

SCL-23.1 – S.1.12. Manual Weight Entries

V D W A I Notes* Comments

Manufacturers

Retailers and Consumers

Regulators

*Notes Key:

1 − Submitted modified language

2 − Item not discussed

3 − No meeting held

4 − Not submitted on agenda

5 − No recommendation or not considered

Item Under Consideration:

Amend Handbook 44, Scales Code, as follows:

S.1.12. Manual Weight Entries. – A device wWhen being used in a for direct sale application and 

when in a zero-balance condition, a device or a Point-of-Sale System** shall accept an entry of a 

manual gross or net weight value only when: the scale gross or net* weight indication is at zero. 

(a) a point-of-sale system interfaced with a scale is giving credit for a weighed item;

(b) an item is pre-weighed on a legal for trade scale and marked with the correct net weight;

(c) a device or system is generating labels for standard weight packages;

(d) postal scales or weight classifiers are generating manifests for packages to be picked up at 

a later time; or 

(e) livestock and vehicle scale systems generate weight tickets to correct erroneous tickets.

Recorded representations for manual weight entries, except those on labels generated for packages of 

standard weights, shall identify the weight value as a manual weight entry by one of the following 

terms: “Manual Weight,” “Manual Wt,” or “MAN WT.” The use of a symbol to identify multiple 

manual weight entries on a single document is permitted, provided that the symbol is defined on the 

same page on which the manual weight entries appear and the definition of the symbol is automatically 

printed by the recording element as part of the document. 

[Nonretroactive as of January 1, 1993] [*Nonretroactive as of January 1, 2005] [*Nonretroactive as 

of January 1, 20XX]

(Added 1992) (Amended 2004 and 20XX) 

NIST OWM Detailed Technical Analysis: 

Item SCL-23-1 proposes that the conditions stated in UR.3.9 are copied to the scales specification section. 

UR.3.9 states: 
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Manual entries are permitted in the following applications only when: 

(a) a point-of-sale system interfaced with a scale is giving credit for a weighed item;

(b) item is pre-weighed on a legal-for-trade scale and marked with the correct net weight;

(c) a device or system is generating labels for standard weight packages; 

(d) postal scales or weight classifiers are generating manifests for packages to be picked up at a 

later time; or

(e) livestock and vehicle scales generate weight tickets to correct erroneous tickets.

The justification given by the submitter consists of two elements:

• The ability to evaluate the restrictions on manual weight entry during type evaluation. 

• To provide specific requirements to the manufacturer.

In the proposal, the requirements from UR.3.9 are literally copied into S.1.12. However, as these 

requirements are written they remain requirements on the device application and not the device itself. 

Therefore, they remain user requirements. 

The key here is that the requirements in UR.3.9 should not be implemented in S.1.12 as requirements but 

as conditions instead. As a matter of fact, one of the restrictions is already mentioned as a condition in 

S.1.12. The current specification states: “A device when being used for direct sale shall accept an entry 

of a manual gross or net weight value only when ...”. This means that the manual weight entry can only 

exist on devices used for direct sale. Yet, it is considered a condition and not a requirement.

During type evaluation the manufacturer can be asked about its intended application (if this is not already 

clear by the instruments characteristics). The fact that the conditions for manual weight entry are laid down 

in the user requirement section instead of the specification sections does not mean they cannot be taken into 

consideration during type evaluation. Furthermore, the limitation of a manual weight entry function can be 

mentioned in the NTEP Certificate of Conformance.

Regarding the second part of the justification (provide guidance to the manufacturer), the user requirements 

in UR.3.9 are part of the scales code of HB44 and therefore already available to the manufacturer. Simply 

copying the user requirements to the specification section as proposed seems to have little added value.

Regional Association Reporting:

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting the following comments were received: 

Mr. Kurt Floren (County of Los Angeles, California) commented the item needs further development and 

explanation of the application. It was mentioned the item is going in the scales code and will impact specific 

performance requirements. Mr. Floren commented on the direct sale application and reference the sub 

sections when making further comments. He noted the direct sale application would not be known until 

after the device is installed. Questions arose on subsection “A”, which speaks to the interface, the purpose 

remains unclear. Subsection “C” references the pre-packing and labeling of standard packages which does 
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not meet a direct sale application. Subsections “B” and “D” are not direct sale applications and require 

further clarification. Mr. Floren believes the item is not ready for Voting and supports a Developing status.

Mr. Raymond Johnson (Fairbanks Scales, representing the Scale Manufactures Association) commented 

the SMA has not met and has not formulated a position on this item. The SMA is scheduled to meet in 

November 2022.

Mr. Matt Douglas (State of California, Division of Measurement Standards) agreed with Mr. Floren and 

his previous comments. He further commented the language needs a lot of wordsmithing to address 

concerns, including addressing the retroactive status which would require an introduction of a third 

retroactive date with double asterisk. Section S.12 is for direct sales, and it is not clear how the language 

applies to this method of sale. Mr. Douglas also noted the content should be broken into two sections.

During open hearings the Committee heard testimony that the SMA has not evaluated this proposal and has 

not taken a position or developed comments on the item. The Committee heard several questions and 

concerns regarding the direct sale application which conflicts with the subsections, along with the nonretroactive date formatting. The Committee believes these concerns should be addressed for the item to 

move forward. 

The WWMA S&T Committee recommended that this item be assigned a Developing status.

Southern Weights and Measures Association

No comments were received on this item during the 2022 SWMA Annual Meeting.

The SWMA S&T Committee recommended this item move forward as a Developing Item.

Northeastern Weights and Measures Association

No comments were heard from the floor. The Committee does not have a recommendation as to the status 

of this item.

Central Weights and Measures Association

Mr. Loren Minich (Kansas) remarked it should not change the application, it just makes it easier to 

understand how it’s applied. A, B, C, D are now user requirements. This communicates with manufacturers 

so they understand how they should be designed. Changing to S specification so that it applies to 

manufacturing. It is only allowed in direct sale manual weight entries.

Mr. Greg VanderPlaats (Minnesota) suggested a change, move “when in zero balance condition” to the list 

so it’s more understood that manual entry is only allowed when at zero balance condition.

The CWMA S&T Committee believes this item is fully developed and recommends Voting status.

SMA

At the 2022 Fall Meeting the SMA supported the item. Rationale: this item provides clarity in the 

specification when a manual weight entry is permitted.
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SCL-23.2 Table S.6.3.a. Marking Requirements, and Table S.6.3.b. Notes for Table 

S.6.3.a. Marking Requirements

Source: NTEP Weighing Sector 

Submitter’s Purpose and Justification:

Add an additional marking requirement for single draft weigh-in-motion vehicle scale to include a vehicle 

type restriction.

As discussed at the NTEP Weighing Sector Meeting, multiple vehicle types are tested during the NTEP 

publication 14 test. If a specific vehicle type is failed or not tested, there needs to be a restriction on the 

vehicle types passed on the certificate. This restriction must also be marked on the device. 

The Sector requested that this be a Voting Item in 2023. 

OWM Executive Summary for SCL-23.2 – Table S.6.3.a. Marking Requirements, and Table 

S.6.3.b. Notes for Table S.6.3.a. Marking Requirements

OWM Recommendation: The analysis is based on the revised proposal that was posted on the 

NCWM website on 12/19/2022. NIST OWM is of the opinion that the item is fully developed. 

Therefore, NIST OWM recommends making it a Voting item.

Table 3. Summary of Recommendations

SCL-23.2 – Table S.6.3.a. Marking Requirements, and Table S.6.3.b. Notes for Table S.6.3.a. 

Marking Requirements

V D W A I Notes* Comments

Submitter 

OWM 

WWMA  The regional recommendations are 

based on the original proposal. SWMA 

NEWMA 5

CWMA 

NCWM

Letters of Support Letters of Opposition Notes

Industry

Manufacturers

Retailers and Consumers

Regulators
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Table 3. Summary of Recommendations

SCL-23.2 – Table S.6.3.a. Marking Requirements, and Table S.6.3.b. Notes for Table S.6.3.a. 

Marking Requirements

V D W A I Notes* Comments

*Notes Key:

1 − Submitted modified language

2 − Item not discussed

3 − No meeting held

4 − Not submitted on agenda

5 − No recommendation or not considered

Item Under Consideration:

Table S.6.3.a. 

Marking Requirements

Weighing Equipment

To Be Marked With ⇓ Weighing, 

LoadReceiving, 

and 

Indicating 

Element in 

Same 

Housing or 

Covered on 

the Same 

CC1

Indicating 

Element 

not 

Permanentl

y Attached 

to 

Weighing 

and LoadReceiving 

Element or 

Covered by 

a Separate 

CC

Weighing 

and LoadReceiving 

Element Not 

Permanently 

Attached to 

Indicating 

Element or 

Covered by a 

Separate CC

Load Cell 

with CC 

(11) 

Other 

Equipment 

or Device 

(10) 

Minimum and Maximum 

Speed (25)

X X

Maximum Speed Change (26) X X

Vehicle Direction Restriction 

(27)

X X

Vehicle Type Restriction (28) X

And 
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Table S.6.3.b. 

Notes for Table S.6.3.a. Marking Requirements 

28. Weigh-in-Motion vehicle scales must be marked with a vehicle type restriction, if applicable, 

which shall be readily apparent when viewing the reading face of the scale indicator. 

(Added 20XX)

NIST OWM Detailed Technical Analysis: 

This detailed technical analysis is based on the revised proposal that was posted on the NCWM website on 

12/19/2022. 

This item originated during a discussion at the 2022 Weighing Sector meeting about the suitability of certain 

single draft weigh-in-motion (DS-WIM) vehicle scales to weigh tanker trucks carrying a liquid product. 

Some SD-WIM vehicle scales may not be able to weigh these trucks properly due to the dynamic behavior 

of the fluid in the tank. 

In case a scale fails the test with a tanker truck carrying liquid product, or the scale has never been tested 

with a tanker truck, the device application should be limited to non-liquid carrying vehicles only. Such 

limitation should be marked on the instrument making the operator aware of the limitation.

Although the proposal originated because of inaccurate weighments of trucks carrying liquids, restrictions 

may be imposed on any vehicle type that cannot be accurately weighed on a certain installation. Therefore, 

it is important that the proposed marking requirement can be applied to any type of vehicle. To avoid 

confusion with the vehicle types defined by FHWA, the proposed requirement does not use the term 

“Vehicle Type”.

NIST OWM supports the proposed move of the markings for “Minimum and Maximum Speed”, 

“Maximum Speed Change” and “Vehicle Direction Restriction” to the indicating element. It makes sense 

that all these markings are grouped together with the proposed marking for vehicle restrictions. And since 

the markings should be clearly visible to the operator, they should be affixed to the indicating element 

instead of the weighing and load-receiving element, as proposed by the originator of this item. 

Regional Association Reporting (based on the original proposal):

Western Weights and Measures Association

The WWMA S&T Committee recommended this item move forward as a Developing Item. 

Southern Weights and Measures Association

No comments were received on this item during the 2022 SWMA Annual Meeting. 

The SWMA S&T Committee recommended this item move forward as a Developing Item.

Northeastern Weights and Measures Association

No comments were heard from the floor. 
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The NEWMA S&T Committee does not have a recommendation as to the status of this item.

Central Weights and Measures Association

Mr. Loren Minich (Kansas) remarked if the installation isn’t tested with all vehicle configurations, then the 

use would be restricted to only the vehicles that were evaluated during type evaluation. This new marking 

requirement would be visible to the operator. May it also apply to field testing, and not just type evaluation?

Mr. Lenny Goebel (Illinois) questions if the limitation / marking would apply to different axle 

configurations for different vehicles.

Mr. Doug Musick (Kansas) stated he does not like the word “type”. Does it differentiate between liquids 

and solids in a tanker? He recommends item be Developing.

The CWMA S&T Committee recommended this as a Developing Item. The submitter should consider 

clarifications related to the comments provided.

SMA

During the 2022 Fall Meeting the SMA supported the item. Rationale: The Weighing Sector has already 

reviewed and placed this into the test method.

SCL-23.3 Verification Scale Division e: Multiple Sections Including, T.N.1.3., Table 6., 

T.N.3., T.N.4., T.N.6., T.N.8., T.N.9., T.1., T.2., S.1.1.1., T.N.1.2., Table S.6.3.a., Table S.3.6.b., 

Appendix D, S.1.2.2., Table 3., S.5.4., UR.3., Table 8. 

Source: NCWM Verification Scale Division e Task Group

Submitter’s Purpose and Justification:

To update Handbook 44, Section 2.20 Scales and relevant portions of OIML R76, using items from the 

S&T Block 2 items as a reference point to:

1. Clarify how error is determined in relation to the verification scale division (e) and the scale 

division (d)

2. Clarify which is the proper reference; the verification scale division (e) or the scale division (d) 

throughout this section

3. Ensure proper selection of a scale in reference to the verification scale division (e) and the scale 

division (d) 

4. Clarify the relationship between the verification scale division (e) or the scale division (d)

OWM Executive Summary for SCL-23.3 – Verification Scale Division e: Multiple Sections 

Including, T.N.1.3., Table 6., T.N.3., T.N.4., T.N.6., T.N.8., T.N.9., T.1., T.2., S.1.1.1., T.N.1.2., Table 

S.6.3.a., Table S.3.6.b., Appendix D, S.1.2.2., Table 3., S.5.4., UR.3., Table 8.

OWM Recommendation: This item is new and incorporates the NCWM’s Verification Scale Division 

(e) Task Group’s recommendations from its July 21, 2021 into the Committee’s 2023 agenda (NCWM 

Publication 15). Since the changes proposed by this item represent the TG’s most recent recommendations, 
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OWM Executive Summary for SCL-23.3 – Verification Scale Division e: Multiple Sections 

Including, T.N.1.3., Table 6., T.N.3., T.N.4., T.N.6., T.N.8., T.N.9., T.1., T.2., S.1.1.1., T.N.1.2., Table 

S.6.3.a., Table S.3.6.b., Appendix D, S.1.2.2., Table 3., S.5.4., UR.3., Table 8.

OWM recommends the committee reconcile the changes proposed by this item with those in the Block 2 

items and then withdraw Block 2 from its agenda. 

• We are pleased that the TG has recommended the Committee assign this item to the TG for further 

development. OWM looks forward to participating on the TG and sharing its perspective of the 

proposed changes with its members. 

Item Under Consideration:

Amend Handbook 44 Scales Code as follows: 

Part 1. Amendment of T.N.1.3. and related sections

T.N.1. Principles.

T.N.1.1. Design. – The tolerance for a weighing device is a performance requirement independent 

of the design principle used.

T.N.1.2. Accuracy Classes. – Weighing devices are divided into accuracy classes according to the 

number of scale divisions (n) and the value of the scale division (d).

T.N.1.3. Verification Scale Division. – The tolerance for a weighing device is related to the value 

of the scale division (d) or the value in the order of magnitude of the verification scale division (e) 

and is generally expressed in terms of d or e.

(Amended 20XX)

Appendix D. Definitions

scale division, number of (n). – See “verification scale division, number of (n).” Quotient of the capacity

divided by the value of the verification scale division. [2.20] 

n = Capacity

e 

(Amended 20XX)

Verification scale division, value of (e). – A value, expressed in units of weight (mass) and specified by 

the manufacturer of a device, by which the tolerance values and the accuracy class applicable to the device 

are determined. The verification scale division is applied to all scales, in particular to ungraduated devices 

since they have no graduations. The verification scale division (e) may be different from the displayed 

scale division (d) for certain other devices used for weight classifying or weighing in pre-determined 

amounts, and certain other Class I and II scales.[2.20] 

(Amended 20XX)
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verification scale division, number of (n). – Quotient of the capacity divided by the value of the 

verification scale division. [2.20] 

n= Capacity/e

(Added 20XX)

Table 6. 

Maintenance Tolerances

(All values in this table are in scale divisions)

Tolerance in Verification Scale Divisions (e)

1 2 3 5

Class Test Load Applied

I 0 - 50 000 50 001 - 200 000 200 001 +

II 0 - 5 000 5 001 - 20 000 20 001 +

III 0 - 500 501 - 2 000 2 001 - 4 000 4 001 +

IIII 0 - 50 51 - 200 201 - 400 401 +

III L 0 - 500 501 - 1 000 (Add 1 d e for each additional 500 d e or fraction 

thereof)

(Amended 20XX)

T.N.3. Tolerance Values.

T.N.3.1. Maintenance Tolerance Values. – The maintenance tolerance values are as specified in 

Table 6. Maintenance Tolerances.

T.N.3.2. Acceptance Tolerance Values. – The acceptance tolerance values shall be one-half the 

maintenance tolerance values.

T.N.3.3. Wheel-Load Weighers and Portable Axle-Load Weighers of Class IIII. – The tolerance 

values are two times the values specified in T.N.3.1. Maintenance Tolerance Values and T.N.3.2. 

Acceptance Tolerance Values.

(Amended 1986) 

T.N.3.4. Crane and Hopper (Other than Grain Hopper) Scales. – The maintenance and acceptance 

tolerances shall be as specified in T.N.3.1. Maintenance Tolerance Values and T.N.3.2. Acceptance 

Tolerance Values for Class III L, except that the tolerance for crane and construction materials hopper 

scales shall not be less than 1 e d or 0.1 % of the scale capacity, whichever is less.

(Amended 1986 and 20XX) 

T.N.4. Agreement of Indications.

T.N.4.3. Single Indicating Element/Multiple Indications. – In the case of an analog indicating 

element equipped with two or more indicating means within the same element, the difference in the 

weight indications for any load other than zero shall not be greater than one-half the value of the 

verification scale division (e) (d) and be within tolerance limits.

(Amended 1986 and 20XX) 
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T.N.6. Sensitivity. – This section is applicable to all nonautomatic-indicating scales marked I, II, III, III 

L, or IIII.

T.N.6.1. Test Load. 

(a) The test load for sensitivity for nonautomatic-indicating vehicle, axle-load, livestock, and 

animal scales shall be 1 d e for scales equipped with balance indicator, and 2 d e or 0.2 % of 

the scale capacity, whichever is less, for scales not equipped with balance indicators.

(b) For all other nonautomatic-indicating scales, the test load for sensitivity shall be 1 d e at zero 

and 2 d e at maximum test load.

(Amended 20XX)

T.N.8. Influence Factors. – The following factors are applicable to tests conducted 

under controlled conditions only, provided that:

(a) types of devices approved prior to January 1, 1986, and manufactured prior to January 1, 1988, need

not meet the requirements of this section;

(b) new types of devices submitted for approval after January 1, 1986, shall comply with the

requirements of this section; and 

(c) all devices manufactured after January 1, 1988, shall comply with the requirements of this section.

(Amended 1985) 

T.N.8.1.3. Temperature Effect on Zero-Load Balance. – The zero-load indication shall not vary by 

more than: 

(a) three divisions e per 5 °C (9 °F) change in temperature for Class III L devices; or

(b) one division e per 5 °C (9 °F) change in temperature for all other devices.

(Amended 1990 and 20XX) 

T.N.9. Radio Frequency Interference (RFI) and Other Electromagnetic Interference Susceptibility.

– The difference between the weight indication due to the disturbance and the weight indication without 

the disturbance shall not exceed one e scale division (d); or the equipment shall:

(a) blank the indication; or

(b) provide an error message; or 

(c) the indication shall be so completely unstable that it cannot be interpreted, or transmitted into 

memory or to a recording element, as a correct measurement value.

The tolerance in T.N.9. Radio Frequency Interference (RFI) and Other Electromagnetic Interference 

Susceptibility is to be applied independently of other tolerances. For example, if indications are at allowable 

basic tolerance error limits when the disturbance occurs, then it is acceptable for the indication to exceed 

the applicable basic tolerances during the disturbance. 

(Amended 1997 and 20XX) 
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T.1. Tolerance Values.

T.1.1. General. – The tolerances applicable to devices not marked with an accuracy class shall have 

the tolerances applied as specified in Table T.1.1. Tolerances for Unmarked Scales.

(Amended 1990) 

Note: When Table T.1.1. refers to T.N. sections it shall be accepted that the scale division d on 

the unmarked scale always equals the verification scale division e.

(Amended 1990 and 20XX) 

T.2. Sensitivity Requirement (SR).

T.2.2. General. – Except for scales specified in paragraphs T.2.3. Prescription Scales through T.2.8. 

Railway Track Scales: 2 (e) d, 0.2 % of the scale capacity, or 40 lb, whichever is least.

(Amended 20XX)

T.2.4. Jewelers’ Scales.

T.2.4.2. With More Than One-Half Ounce Capacity. – 1 (e) d or 0.05 % of the scale capacity, 

whichever is less.

(Amended 20XX)

 T.2.7. Vehicle, Axle-Load, Livestock, and Animal Scales. 

T.2.7.1. Equipped With Balance Indicators. – 1 (e) d. 

(Amended 20XX)

T.2.7.2. Not Equipped With Balance Indicators. – 2 (e) d or 0.2 % of the scale capacity, 

whichever is less.

(Amended 20XX)

 T.2.8. Railway Track Scales. – 3 (e) d or 100 lb, whichever is less.

(Amended 20XX)

S.1.1.1. Digital Indicating Elements.

(a) A digital zero indication shall represent a balance condition that is within ± 1⁄2 the value of the 

scale division d. 

(b) After zero setting (gross zero or net zero after a tare operation) the effect of zero deviation 

on the result of the weighing shall be not more than ± 0.25 e.

[Nonretroactive as of January 1, 20XX]

(b) (c) A digital indicating device shall either automatically maintain a “center-of-zero” 

condition to ± 1⁄4 scale division or less, or have an auxiliary or supplemental “center-ofzero” indicator that defines a zero-balance condition to ± 1⁄4 of a scale division or less. A 

“center-of-zero” indication may operate when zero is indicated for gross and/or net mode(s). 

A digital indicating device shall have a “center-of-zero” indicator that indicates a zero 

balance condition when the deviation from zero is not more than ± 0.25 e. A “center-of-zero” 

indicator may operate when zero is indicated for gross and/or net mode(s). The “center-of-
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zero” indicator is not mandatory on a device equipped with an auxiliary indicating device or 

equipped with a zero tracking mechanism.

[Nonretroactive as of January 1, 1993] 

(c) (d) For electronic cash registers (ECRs) and point-of-sale systems (POS systems) the display 

of measurement units shall be a minimum of 9.5 mm (3/8 inch) in height. 

[Nonretroactive as of January 1, 2021] 

(Added 2019)

 (Amended 1992, 2008, and 2019, and 20XX) 

Part 2. Amendment of T.N.1.2. and related sections

T.N.1.2. Accuracy Classes. – Weighing devices are divided into accuracy classes according to the number 

of verification scale divisions (n) and the value of the verification scale division (d) (e). 

(Amended 20XX)

Table S.6.3.a.

Marking Requirements

Weighing Equipment 

To Be Marked With ⇓

Weighing, 

LoadReceiving, 

and 

Indicating 

Element in 

Same 

Housing or 

Covered on 

the Same 

CC1

Indicating 

Element not 

Permanently 

Attached to 

Weighing and 

LoadReceiving 

Element or 

Covered by a 

Separate CC

Weighing and 

LoadReceiving 

Element Not 

Permanently 

Attached to 

Indicating 

Element or 

Covered by a 

Separate CC

Load 

Cell with 

CC

(11)

Other 

Equipmen

t or Device

(10)

Manufacturer’s ID (1) X X X X X

Model Designation and Prefix (1) X X X X X

Serial Number and Prefix (2) X X X X X (16)

Certificate of Conformance Number 

(CC) (23) X X X X X (23)

Accuracy Class (17) X X (8) X (19) X

Nominal Capacity (3)(18)(20) X X X

Value of Scale Division, “d” (3)(4) X X

Value of Verification Scale 

Division, “e” (3)(4) X X 

Temperature Limits (5) X X X X

Many rows of the table are not included in this proposal for brevity. 

(Added 1990) (Amended 1992, 1999, 2000, 2001, 2002, and 2004, and 20XX) 

Amend Table S.6.3.(b) as follows:
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Table S.6.3.b.

Notes for Table S.6.3.a. Marking Requirements

3. The device shall be marked with the nominal capacity. The nominal capacity may be prefaced by the 

terms “capacity” or “Max.”

The For any scale where the value of “e” is equal the value of “d” (see S.1.2.2.), the nominal capacity 

shall be shown together with the value of the scale division “d” or “e” (e.g., 15 × 0.005 kg, 30 × 0.01 lb,

or capacity = 15 kg, d = 0.005 kg, or Max 15 kg e = 0.005 kg) in a clear and conspicuous manner and 

be readily apparent when viewing the reading face of the scale indicator unless already apparent by the 

design of the device. Each scale division value “d” or “e” or weight unit with its associated nominal 

capacity shall be marked on multiple range or multi-interval scales. For any scale that has no “d” or 

any scale where “e” does not equal “d” refer to Note 4.

[Nonretroactive as of January 1, 1983] 

(Amended 2005 and 20XX) 

4. Required only if different from “d.” Exceptions to Note 3 regarding marking of “e” and “d.”.

(a) For an ungraduated scale such as an equal arm scale where the scale graduations do not 

represent a fixed weight quantity, the nominal capacity shall be shown together with the 

verification scale division “e” (e.g. capacity 1,000 g e = 0.1 g, or Max 1,000 g e = 01 g). These 

devices have no “d.”

(b) For a scale where e does not equal d, such as a scale equipped with an auxiliary indicating device 

or a weight classifier marked for special use, the nominal capacity shall be shown together with 

the scale division ”d” and the verification scale division “e,” (e.g., capacity 1,000 g e = 0.1 g d = 

0.01 g, or Max 1,000 g e = 0.1 g d = 0.01 g).

[Nonretroactive as of January 1, 1986] 

(Amended 20XX)

Remainder of the table is omitted for brevity with this proposal.

Appendix D. Definitions

auxiliary indicating device. – a means to increase the display resolution of a weighing device, such as 

a rider or vernier on an analog device, or a differentiated least significant digit to the right of the 

decimal point on a digital device. [2.20] 

(Added 20XX)

extended displaying device. – a means to temporarily change the scale division (d) to a value less than 

the verification scale division (e), following a manual command. [2.20] 

(Added 20XX)

weight classifier. – A digital scale that rounds weight values up to the next scale division. These scales 

usually have a verification scale division (e) that is smaller than the displayed scale division (d). [2.20] 

(Added 1987) (Amended 20XX)

S.1.2.2. Verification Scale Interval Division “e”. 

For scales in classes I, II, III, III L, and IIII, the value of “e” shall equal the value of “d.” On a 

multi-interval scale or on a multiple range scale, the value of “e” shall be equal to the value of 

“d” for each partial range or range. 
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The requirement that e = d does not apply to:

(a) a scale equipped with an auxiliary indicating device conforming to S.1.2.2.1., or 

(b) a weight classifier marked for special use and complying with S.1.2.2.4., or 

(c) an ungraduated scale, such as an equal arm scale where the scale graduations do not 

represent a fixed weight quantity. Ungraduated devices are marked with “e” but have no 

scale divisions “d.” 

(Added 20XX)

S.1.2.2.1. Class I and II Scales and Dynamic Monorail Scales. – If e ≠ d, the verification scale 

interval “e” shall be determined by the expression:

d < e < 10 d 

If the displayed division (d) is less than the verification division (e), then the verification 

division shall less than or equal to 10 times the displayed division.

The value of e must satisfy the relationship, e = 10k of the unit of measure, where k is a positive 

or negative whole number or zero. This requirement does not apply to a Class I device with 

d < 1 mg where e = 1 mg. If e ≠ d, the value of “d” shall be a decimal submultiple of “e,” and 

the ratio shall not be more than 10:1. If e ≠ d, and both “e” and “d” are continuously 

displayed during normal operation, then “d” shall be differentiated from “e” by size, shape, 

color, etc. throughout the range of weights displayed as “d.” 

(Added 1999)

Scales Equipped with an Auxiliary Indicating Device. – Only a Class I or II scale may be 

equipped with an auxiliary indicating device. A multi-interval scale or a multiple range scale 

shall not be equipped with an auxiliary indicating device. The auxiliary indicating device 

may be either a rider or vernier on an analog device, or a scale division “d” to the right of the 

decimal point on a digital device that is differentiated in size or color. 

The verification scale division “e” on a scale equipped with an auxiliary indicating device 

shall be determined as follows:

(a) The value of “e” shall be greater than “d” and less than or equal to 10 “d” (d < e < 10 

d), and 

(b) The value of “e” must satisfy the relationship, e = 10k of the unit of measure, where k 

is a positive or negative whole number or zero. 

The requirement in subpart (a) does not apply to a Class I device with e = 1 mg, where d shall

be less than “e” (d < e). 

Examples: If e = 1 g for Class I or II, then “d” may only be 0.5 g, 0.2 g, or 0.1 g 

 If e = 1 mg for Class I, then “d” may be 0.5 mg, 0.2 mg, 0.1 mg, 0.05 mg, 0.02 

mg, etc.

(Added 1999) (Amended 20XX)
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S.1.2.2.3. Deactivation of a “d” Resolution. – It shall not be possible to deactivate the “d” 

resolution on a Class I or II scale equipped with an auxiliary indicating device if such action 

affects the scale’s ability to round digital values to the nearest minimum unit that can be 

indicated or recorded as required by paragraph G-S.5.2.2. Digital Indication and 

Representation.

(Added 20XX)

S.1.2.2.4. Weight Classifiers. – On a weight classifier, such as a postal or shipping scale that 

rounds up and is marked for special use, the value of “e” shall be equal to or less than “d.”

(Added 20XX)

S.1.2.2.5. Extended Displaying Device. – A scale with an auxiliary indicating device shall 

not be equipped with an extended displaying device. When a scale is equipped with an 

extended displaying device, displaying an indication with a scale division “d” smaller than 

“e” shall be possible only: 

(a) while pressing a key; or

(b) for a period not exceeding 5 seconds after a manual command. 

Printing or transferring data via interface shall not be possible while the extended displaying 

device is in operation.

(Added 20XX)

The middle section of the table is omitted for brevity.

[Nonretroactive as of January 1, 1986] 

(Amended 1986, 1987, 1997, 1998, 1999, 2003, and 2004, and 20XX) 

Table 3.

Parameters for Accuracy Classes

Class

Value of the Verification Scale 

Division 

(d or e1)

Number of Verification Scale4 Divisions 

(n)

Minimum Maximum

SI Units

I equal to or greater than 1 mg 50 000 --

II 1 to 50 mg, inclusive 100 100 000

equal to or greater than 100 mg 5 000 100 000

III2,5 0.1 to 2 g, inclusive 100 10 000

equal to or greater than 5 g 500 10 000

III L3 equal to or greater than 2 kg 2 000 10 000

IIII equal to or greater than 5 g 100 1 200
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Amend Footnotes 1 and 3 to Table 3. As follows: 

1

For Class I and II devices equipped with auxiliary reading means (i.e., a rider, a vernier, or a least 

significant decimal differentiated by size, shape, or color), the value of the verification scale division “e” 

is the value of the scale division immediately preceding the auxiliary means. The verification scale 

division e does not always equal the displayed scale division d. To ensure the correct value for e is used, 

refer to required markings on the device (see also notes 3 and 4 in Table S.6.3.b.).

2

 A Class III scale marked “For prescription weighing only” may have a verification scale division (e) not 

less than 0.01 g. 

(Added 1986) (Amended 2003) 

3

 The value of a verification scale division (e) for crane and hopper (other than grain hopper) scales shall 

be not less than 0.2 kg (0.5 lb). The minimum number of verification scale divisions (n) shall be not less 

than 1000.

S.5.4. Relationship of Minimum Load Cell Verification Interval Value to the Verification Scale 

Division. – The relationship of the value for the minimum load cell verification scale interval, vmin, to the 

verification scale division, d e, for a specific scale using National Type Evaluation Program (NTEP) 

certified load cells shall comply with the following formulae where N is the number of load cells in a single 

independent1 weighing/load-receiving element (such as hopper, railroad track, or vehicle scale 

weighing/load-receiving elements):

(a) vmin ≤ d* e for scales without lever systems; and

 √N

(b) vmin ≤ d* e for scales with lever systems.

 √N x (scale multiple)

1

”Independent” means with a weighing/load-receiving element not attached to adjacent elements and with its

own A/D conversion circuitry and displayed weight.

[*When the value of the scale division, d, is different from the verification scale division, e, for the scale, 

the value of e must be used in the formulae above.]

This requirement does not apply to complete weighing/load-receiving elements or scales, which satisfy

all the following criteria:

- the complete weighing/load-receiving element or scale has been evaluated for compliance with

T.N.8.1. Temperature under the NTEP;

- the complete weighing/load-receiving element or scale has received an NTEP Certificate of

Conformance; and

- the complete weighing/load-receiving element or scale is equipped with an automatic zero-tracking

mechanism which cannot be made inoperative in the normal weighing mode. (A test mode which

permits the disabling of the automatic zero-tracking mechanism is permissible, provided the scale

cannot function normally while in this mode.

[Nonretroactive as of January 1, 1994]

(Added 1993) (Amended 1996, 2016 and 20XX) 
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UR.3. Use Requirements.

UR.3.1. Recommended Minimum Load. – A recommended minimum load is specified in Table 8 

since the use of a device to weigh light loads is likely to result in relatively large considerable relative

errors.

(Amended 20XX)

Table 8. 

Recommended Minimum Load

Class Value of Verification Scale Division e

(d or e*)

Recommended Minimum Load in scale 

divisions d (See notes) (d or e*)

I equal to or greater than 0.001 g 100

II 0.001 g to 0.05 g, inclusive 20

equal to or greater than 0.1 g 50

III All** 20

III L All 50

IIII All 10

*For Class I and II devices equipped with auxiliary reading means (i.e., a rider, a vernier, or a least 

significant decimal differentiated by size, shape or color), the value of the verification scale division “e” 

is the value of the scale division immediately preceding the auxiliary means. For Class III and IIII 

devices the value of “e” is specified by the manufacturer as marked on the device; “e” must be less than 

or equal to “d.”

The displayed scale division d is not always equal to the verification scale division e. To ensure the correct 

values are used, refer to required markings on the device (see also notes 3 and 4 in Table S.6.3.b.). 

For an ungraduated device, the scale division d shall be replaced with the verification scale division e in the 

last column.

**A minimum load of 10 d 5 e is recommended for a weight classifier marked in accordance with a statement 

identifying its use for special applications.

(Amended 1990 and 20XX) 

Previous Action:

New Item in 2023 

Original Justification:

The Verification Scale Division e Task Group has recommended a significant number of changes to the 

Scale Code. Those changes are reflected below. Before addressing the changes though, it is important to 

identify the problem that the changes are trying to fix. 

The Task Group identified two significant flaws in the current Code after comparison with R76. The 

changes are proposed to ensure Handbook 44 uses correct measurement principles. They are not proposed 

for the purpose of harmony with R76. Those two flaws are found in the following paragraphs from the 

current Scales Code.

T.N.1.2. Accuracy Classes. – Weighing devices are divided into accuracy classes according to the number 

of scale divisions (n) and the value of the scale division (d).
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T.N.1.3. Scale Division. – The tolerance for a weighing device is related to the value of the scale 

division (d) or the value of the verification scale division (e) and is generally expressed in terms of d or e.

NIST OWM Detailed Technical Analysis: 

This item was submitted to the NCWM in November 2022. OWM has not reviewed the proposal in its 

entirety. For this reason, no technical analysis is being provided at this time. 

Regional Association Reporting:

Western Weights and Measures Association

Southern Weights and Measures Association

Northeastern Weights and Measures Association

Central Weights and Measures Association

WIM – Weigh-in-Motion Systems – Tentative Code

WIM-23.1 Remove Tentative Status and Amend Numerous Sections Throughout

Source: New York City DOT, C2SMART, Kistler, and Maryland DOT

Submitter’s Purpose and Justification:

Provide a legal document that can be used by local and State agencies to certify Weigh-In-Motion (WIM) 

systems used for automated weight enforcement.

1. INTRODUCTION

The Brooklyn-Queens Expressway (BQE) is an aging and deteriorating 6-lane highway which comprises a 

critical link of I-278 - the sole Interstate highway in Brooklyn, connecting it to Manhattan, Staten Island, 

and Queens in New York. Constructed in 1954 and comprised of varying and complex structure types, the 

segment of the BQE between Atlantic Ave. Interchange to the South and Sands St. to the North is nearing 

the end of its design life. Urgent repairs are underway, while roughly 110 spans may be in need of 

intervention by 2028, and another 75 spans may be in need of intervention within the next decade. Weigh 

in Motion (WIM) sensors, installed in October 2019, have revealed overweight vehicles, excessively 

exceeding FHWA legal load limits, with gross vehicle weights (GVW) that range from just over 80,000 lbs 

to as high as 200,000. The continued presence of overweight vehicles on the BQE contributes to the 

continued structural deterioration of this aging piece of infrastructure. The New York State legislature 

recently authorized the New York City Department of Transportation to conduct automated overweight 

vehicle enforcement through a WIM demonstration program; however, a universal standard has not yet 

been established that specifically defines a protocol for calibration and certification by the New York State 

local Division of Weights and Measures.

In response to this challenge, this proposal seeks an amendment of Section 2.25 of NIST Handbook 44 to 

allow for Weigh-In-Motion Systems Used for Automated Vehicle Weight Enforcement. The remainder of 

this proposal lays out the justification for the amendment, using the BQE as an example to establish the 

urgent need for the amendment, supported by data received from other State programs, including New 
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Jersey, Maryland, and Indiana. The City of New York is not alone in its struggle to maintain the safety and 

the structural integrity of its infrastructure. Guarding against violations of vehicle weight restrictions that 

are enacted to protect critical infrastructure is an issue of national concern.

The combined interstate data presented here stresses the national importance of establishing protocols for 

automated vehicle weight enforcement using WIM, citing:

• the deleterious effects of overweight vehicles and axles on primary structural components and 

pavements;

• the difficulty associated with the use of screening combined with stationary weighing stations to 

enforce vehicle weight regulations; 

• the percentages of overweight vehicles on major interstates across the nation; and the proven 

accuracy of WIM equipment used in several states across the nation.

The submitters requested that this be a Voting item in 2023.

OWM Executive Summary for WIM-23.1 – Remove Tentative Status and Amend Numerous 

Sections Throughout

OWM Recommendation: The analysis is based on the revised proposal that was posted on the NCWM 

website on 12/1/2022. NIST OWM is of the opinion that the item currently has merit, but that it is not 

yet fully developed. NIST OWM recommends making this item Developing to give the submitters the 

opportunity to address raised concerns.

• The submitter has demonstrated there is a need for permanent and direct enforcement. The proposed 

code is intended to address this need.

• The proposed tolerances and test procedures are comparable to the OIML recommendation R 134 

which is used in multiple countries as the standard for weighing road vehicles in motion (for both 

direct enforcement and other applications).

However, there are several issues that need to be addressed:

• Since the proposal has a significant impact on the enforcement of vehicle weight limits, it is 

important that all stakeholders be involved in the development of the code. Not only should be the 

technical requirements of the system be taken into consideration, but also the practical 

implementation of field testing after installation. (See the Detailed Technical Analysis below for a 

list of possible stakeholders).

• Due to the large tolerance of WIM systems, the measured weight value must be corrected for the 

uncertainty of the measurement, so it is guaranteed that the weight used for the citation never 

exceeds the actual weight of the vehicle. Although the submitters state that the measured weight 

value should be corrected, the language in the proposal does not clearly elaborate how or when the 

measurement value is to be corrected.

• The proposed methods for weighing axle loads are in general considered unsuitable. However, due 

to the large tolerance, it may be possible that these methods do meet the fundamental considerations. 
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OWM Executive Summary for WIM-23.1 – Remove Tentative Status and Amend Numerous 

Sections Throughout

The submitters should investigate whether the proposed methods for determining the axle load, 

axle-group load and gross vehicle weight of the reference vehicles, are indeed suitable. 

• The proposal should contain provisions to support unattended operation in order to prevent any 

reasonable doubt about the measurement. The different stakeholders involved in the future 

development of the proposal should decide on the different provisions that need to be part of the 

code (e.g., pictures of the vehicle, license plate and its position on the road, and other registrations 

of the circumstances).

• The submitters should provide justification for the proposed vehicle types to be used as reference 

vehicle. The selected reference vehicles must be representative to the traffic that can be expected 

traveling over the WIM installation. E.g., vehicles carrying fluids or vehicles with a steel leaf spring 

suspension. The ultimate criteria for the selection of the reference vehicles must be agreed upon by 

all stakeholders.

• The submitters should demonstrate the acceptable level of performance and reliability of these WIM 

systems. And demonstrate that the proposed test procedures are effective and sufficient. Any data 

presented should be complete and traceable to the national standards. 

Table 3. Summary of Recommendations

WIM-23.1 – Remove Tentative Status and Amend Numerous Sections Throughout

V D W A I Notes* Comments

Submitter 

OWM 

WWMA 

SWMA 

NEWMA 

CWMA 

NCWM

Letters of Support Letters of Opposition Notes

Industry

• International Road 

Dynamics

• New York University

November 15, 2022

November 14, 2022

Manufacturers

Retailers and 

Consumers

Regulators • Maryland DOT November 15, 2022
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Table 3. Summary of Recommendations

WIM-23.1 – Remove Tentative Status and Amend Numerous Sections Throughout

V D W A I Notes* Comments

*Notes Key:

1 − Submitted modified language

2 − Item not discussed

3 − No meeting held

4 − Not submitted on agenda

5 − No recommendation or not considered

Item Under Consideration (per 12/1/2022):

Amend Handbook 44 Weigh-In-Motions Systems Code as follows:

Table of Contents

Weigh-In-Motions Systems Used for Vehicle Enforcement – Tentative Code 

... 

T.2. Tolerance Values for Accuracy Class A and Class E. 

... 

Additional letters, presentation, and data may have been submitted for consideration with this item. Please 

refer to https://www.ncwm.com/publication-15 to review these documents.

Section 2.25. Weigh-In-Motion Systems Used for Vehicle Screening and Enforcement – Tentative 

Code

This tentative code has a trial or experimental status and is not intended to be enforced. The 

requirements are designed for study prior to the development and adoption of a final code. Officials 

wanting to conduct an official examination of a device or system are advised to see paragraph G-A.3. 

Special and Unclassified Equipment.

A. Application

A.1. General. – This code applies to fixed (not portable)systems used to weigh vehicles, while in motion, 

for the purpose of screening and sorting the vehicles based on the vehicle weight to determine if a static 

weighment is necessary (Class A), and enforcing the weight limit of road vehicles (Class E). 

A.2. Exception. – This code does not apply to weighing systems intended for the collection of statistical 

traffic data.

A.3. Additional Code Requirements. – In addition to the requirements of this code, weigh-in-motion 

screening systems shall meet the requirements of Section 1.10. General Code. 
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S. Specifications

S.1. Design of Indicating and Recording Elements and of Recorded Representations.

S.1.1. Ready Indication. – The system shall provide a means of verifying that the system is 

operational and ready for use. 

S.1.2. Value of System Division Units. – The value of a system division “d” expressed in a unit of 

weight shall be equal to: 

(a) 1, 2, or 5; or 

(b) a decimal multiple or submultiple of 1, 2, or 5. 

Examples: divisions may be 10, 20, 50, 100; or 0.01, 0.02, 0.05; or 0.1, 0.2, 0.5, etc. 

S.1.2.1. Units of Measure. – The system shall indicate weight values using only a single unit of 

measure. 

S.1.3. Maximum Value of Division. – The value of the system division “d” for a Class A and Class 

E, weight-in-motion system shall not be greater than 50 kg (100 lb).

S.1.4. Value of Other Units of Measure.

S.1.4.1. Speed. – Vehicle speeds shall be measured in miles per hour or kilometers per hour.

S.1.4.2. Axle-Spacing (Length). – The center-to-center distance between any two successive 

axles shall be measured in:

(a) meters and decimal submultiples of a meter;

(b) feet and inches; or

(c) feet and decimal submultiples of a foot.

S.1.4.3. Vehicle Length. – If the system is capable of measuring the overall length of the vehicle, 

the length of the vehicle shall be measured in feet and/or inches, or meters.

S.1.5. Capacity Indication. – An indicating or recording element shall not display nor record any 

values greater than 105 % of the specified capacity of the load receiving element. 

S.1.6. Identification of a Fault. – Fault conditions shall be presented to the operator in a clear and 

unambiguous means. The following fault conditions shall be identified:

(a) Vehicle speed is below the minimum or above the maximum speed as specified.

(b) The maximum number of vehicle axles as specified has been exceeded.

(b) A change in vehicle speed greater than that specified has been detected. 

(c) Imbalanced weight between the left and right wheels has exceeded the specified values.
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(d) The vehicle changes lanes within the sensor locations.

S.1.7. Recorded Representations.

S.1.7.1. Values to be Recorded. – At a minimum, the following values shall be printed and/or 

stored electronically for each vehicle weighment. Consult the specific jurisdictional legislation 

for additional values that may be required to issue enforcement violations. All gross vehicle, 

axle, and axle group weights must be printed and/or stored with the corrected values that 

include any necessary reductions due to the system tolerance and adopted violation 

thresholds.

(a) transaction identification number; 

(b) station ID;

(c) lane identification (required if more than one lane at the site has the ability to weigh a 

vehicle in motion);

(d) vehicle speed;

(e) number of axles; 

(f) weight of each axle;

(g) weight of each axle group; 

(h) identification and weight of axle groups; 

(i) axle spacing;

(j) total vehicle weight;

(k) weight limits as specified in paragraph S.2.1;

(l) total vehicle length;

(m) all fault conditions that occurred during the weighing of the vehicle; 

(n) violations, as identified in paragraph S.2.1. Violation Parameters, which occurred during 

the weighing of the vehicle; and 

(o) time and date. 

S.1.8. Value of the Indicated and Recorded System Division. – The value of the system’s division 

“(d),” as recorded, shall be the same as the division value indicated.

S.2. System Design Requirements. 

S.2.1. Violation Parameters. – The instrument shall be capable of accepting user-entered violation 

parameters for the following items:

(a) single axle weight limit;
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(b) axle group weight limit;

(c) gross vehicle weight limit; and

(d) bridge formula maximum. 

The instrument shall display and/or record violation conditions when these parameters have been 

exceeded.

S.3. Design of Weighing Elements.

S.3.1. Multiple Load-Receiving Elements. – An instrument with a single indicating or recording 

element, or a combination indicating-recording element, that is coupled to two or more load-receiving 

elements with independent weighing systems, shall be provided with means to prohibit the activation

of any load-receiving element (or elements) not in use, and shall be provided with automatic means to 

indicate clearly and definitely which load receiving element (or elements) is in use.

S.4. Design of Weighing Devices, Accuracy Class.

S.4.1. Designation of Accuracy. – Weigh-in-motion systems meeting the requirements of this code 

shall be designated as accuracy Class A and Class E. 

Note: This does not preclude higher accuracy classes from being proposed and added to this Code in 

the future when it can be demonstrated that weigh-in-motion systems grouped within those accuracy 

classes can achieve the higher level of accuracy specified for those devices.

S.5. Marking Requirements. – In addition to the marking requirements in G-S.1. Identification (except 

G.S.1.(e)), the system shall be marked with the following information: 

(a) accuracy class;

(b) value of the system division “d”; 

(c) operational temperature limits;

(d) number of instrumented lanes (not required if only one lane is instrumented); 

(e) minimum and maximum vehicle speed;

(f) maximum number of axles per vehicle; 

(g) maximum change in vehicle speed during weighment; and 

(h) minimum and maximum load. 

S.5.1. Location of Marking Information. – The marking information required in Section 1.10. 

General Code, G-S.1. Identification and Section 2.25. Weigh-in-Motion Systems, S.5. Marking 
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Requirements shall be visible after installation. The information shall be marked on the system or 

recalled from an information screen.

N. Notes

N.1. Test Procedures. 

N.1.1. Selection of Test Vehicles. – All dynamic testing associated with the procedures described in 

each of the subparagraphs of N.1.5 shall be performed with a minimum of two the following test 

vehicles for each Class A and Class E. 

N.1.1.1. Selection of Test Vehicles for Class A – A minimum of two vehicles below shall be 

used. 

(a) The first test vehicle may be a two-axle, six-tire, single-unit truck; that is, a vehicle with 

two axles with the rear axle having dual wheels. The vehicle shall have a maximum gross 

vehicle weight of 10 000 lb.

(b) The second test vehicle shall be a five-axle, single-trailer truck with a maximum gross 

vehicle weight of 80 000 lb.

N.1.1.2. Selection of Test Vehicles for Class E – A minimum of three vehicles below shall be 

used. 

(a) The first test vehicle may be a two-axle, six-tire, single-unit truck or Federal 

Highway Administration (FHWA) Class 5; that is, a vehicle with two axles with the 

rear axle having dual wheels 

(b) The second test vehicle shall be a five-axle, single-trailer truck or FHWA Class 9 3S2 

Type. 

(c) The third test vehicle shall be a three-axle, single-unit truck or FHWA Class 6. 

(d) The gross vehicle weights shall be as stated in N.1.2.3. 

Note: Consideration should be made for testing the systems using vehicles which are typical to the 

system’s daily operation. Violation thresholds may be dependent on additional items, not 

specified in this code. 

N.1.1.1.3. Weighing of Test Vehicles. – All test vehicles shall be weighed on a reference scale, 

meeting the requirements of Appendix A, before being used to conduct the dynamic tests.

N.1.1.2.4. Determining Reference Weights for Axle, Axle Groups, and Gross Vehicle Weight. – 

The reference weights shall be the average weight value of a minimum of three static weighments 

of all single axles, axle groups, and gross vehicle weight on a reference scale before being used 

to conduct the dynamic tests.

Note: The axles within an axle group are not considered single axles. 
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N.1.2. Test Loads. 

N.1.2.1. Static Test Loads. – All static test loads shall use certified test weights.

N.1.2.2. Dynamic Test Loads for Class A. – Test vehicles used for dynamic testing shall be 

loaded to 85 % to 95 % of their legal maximum Gross Vehicle Weight for a minimum of 20 runs 

per test vehicle type. The “load” shall be non-shifting and shall be positioned to present as close 

as possible, an equal side-to-side load.

N.1.2.3. Dynamic Test Loads for Class E. – Test vehicles used for dynamic testing shall be 

loaded in two (2) different load conditions. The “load” shall be non-shifting and shall be 

positioned to present as close as possible, an equal side-to-side load.

(a) an empty load condition for a minimum of 15 runs per test vehicle type, and 

(b) a fully load condition (> 90% of the scale capacity or > 90% of the maximum capacity 

of the vehicle, whichever is less) for a minimum of 30 runs per test vehicle type

N.1.3. Reference Scale. – Each reference vehicle for the dynamic test shall be weighed statically 

either on a multiple platform vehicle scale or a single platform vehicle scale. 

N.1.3.1. Multiple Platform Vehicle Scale – It is comprised of three individual weighing/loadreceiving elements, each an independent scale. The three individual weighing/load receiving 

elements shall be of such dimension and spacing to facilitate: 

the single-draft weighing of all reference test vehicles; 

(a) the simultaneous weighing of each single axle and axle group of the reference test vehicles 

on different individual elements of the scale; and

(b) gross vehicle weight determined by summing the values of the different reference axle and 

reference axle groups of a test vehicle. 

N.1.3.2. Single Platform Vehicle Scale – Each individual axle or axle group of the reference 

test vehicles shall be measured on the single platform vehicle scale. Only the single axle or axle 

group for measurement shall be on the single platform, while other single axles or axle groups 

shall be off the platform. The GVW shall be determined by summing all the single axles and 

axle groups. 

The scale shall be tested immediately prior to using it to establish reference test loads and in no 

case more than 24 hours prior. To qualify for use as a suitable reference scale, it must meet NIST 

Handbook 44, Class III L maintenance tolerances. 

N.1.3.3. Location of a Reference Scale. – The location of the reference scale must be considered 

since vehicle weights will change due to fuel consumption. 

N.1.4. Test Speeds. – All dynamic tests shall be conducted at the designated speed(s). 

N.1.4.1. Test Speeds for Class A – Speed shall be within 20% below or at the posted speed limit.

N.1.4.2. Test Speeds for Class E – Three speeds shall be used.
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(a) high speed – maximum posted speed limit.

(b) low speed – less than 10 mph.

(c) operation speed – average between N.1.4.2.(a) high speed and N.1.4.2.(b) low speed. 

N.1.5. Test Procedures. 

N.1.5.1. Dynamic Load Test for Class A. – The dynamic test for Class A shall be conducted 

using the test vehicles defined in N.1.1.1. Selection of Test Vehicles for Class A. The test shall 

consist of a minimum of 20 runs for each test vehicle at the speed as stated in N.1.4.1. Test Speeds 

for Class A. 

At the conclusion of the dynamic test, there will be a minimum of 20 weight readings for each 

single axle, axle group, and gross vehicle weight of the each test vehicle. The tolerance for each 

weight reading shall be based on the percentage values specified in Table T.2.2-1 Tolerances for 

Accuracy Class A. 

N.1.5.2. Vehicle Position Test for Class A. – During the conduct of the dynamic testing for Class 

A, ensure the vehicle stays within the defined roadway along the width of the sensor. The test shall 

be conducted with 10 runs with the vehicle centered along the width of the sensor; 5 runs with the 

vehicle on the right side along the width of the sensor; and 5 runs with the vehicle on the left side 

along the width of the sensor. Only gross vehicle weight is used for this test and the tolerance for 

each weighment shall be based on the tolerance value specified in T.2.3. Tolerance Value for 

Vehicle Position Test.

N.1.5.3. Dynamic Load Test for Class E. – The dynamic test for Class E shall be conducted 

using the test vehicles defined in N.1.1.2. Selection of Test Vehicles for Class E. The test shall 

consist of a minimum of 45 runs for each test vehicle. A minimum of 15 runs at empty load 

condition and a minimum of 30 runs at fully load condition. 

At the conclusion of the dynamic test, there will be a minimum of 45 weight readings or 15 

weight readings at each speed for each single axle, axle group, and gross vehicle weight. The 

tolerance for each weight reading shall be based on the percentage values specified in Table 

T.2.2-2 Tolerances for Accuracy Class E. 

N.1.5.4. Vehicle Position Test for Class E. – During the conduct of the dynamic testing for 

Class E, ensure the vehicle stays within the defined roadway along the width of the sensor. 

Only gross vehicle weight is used for this test and the tolerance for each weighment shall be 

based on the tolerance value specified in T.2.3. Tolerance Value for Vehicle Position Test.

(a) Empty load condition. – The test shall be conducted with 15 runs in total or 5 runs at 

each speed as stated in N.1.4.2. Test Speeds for Class E. The test shall be conducted 

with 9 runs with the vehicle centered along the width of the sensor (3 runs per speed); 

3 runs with the vehicle on the right side along the width of the sensor (1 run per 

speed); and 1 run with the vehicle on the left side along the width of the sensor (1 run 

per speed). 

(b) Fully load condition. – The test shall be conducted with 30 runs in total or 10 runs at 

each speed as stated in N.1.4.2. Test Speeds for Class E. The test shall be conducted 

with 18 runs with the vehicle centered along the width of the sensor (6 runs per speed); 
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6 runs with the vehicle on the right side along the width of the sensor (2 run per 

speed); and 6 runs with the vehicle on the left side along the width of the sensor (2 

run per speed).

See Table N.1.5. below to summarize all the test runs.

Table N.1.5.

Number of Test per Each Test Vehicle for Class E

Load Condition Speed Vehicle Position

Fully Load

(30 runs)

High Speed (10 runs) Left (2 runs), Center (6 runs), Right (2 runs)

Low Speed (10 runs) Left (2 runs), Center (6 runs), Right (2 runs)

Operation Speed (10 runs) Left (2 runs), Center (6 runs), Right (2 runs)

Empty Load

(15 runs)

High Speed (5 runs) Left (1 run), Center (3 runs), Right (1 run)

Low Speed (5 runs) Left (1 run), Center (3 runs), Right (1 run)

Operation Speed (5 runs) Left (1 run), Center (3 runs), Right (1 run)

45 runs 15 runs x 3 speeds 9 runs (left) + 27 runs (center) + 9 runs (right)

N.1.5.3.5. Axle Spacing Test. – The axle spacing test is a review of the displayed and/or recorded 

axle spacing distance of the test vehicles. The tolerance value for each distance shall be based on 

the tolerance value specified in T.2.4. Tolerance Value for Axle Spacing. 

T. Tolerances

T.1. Principles.

T.1.1. Design. – The tolerance for a weigh-in-motion system is a performance requirement 

independent of the design principle used. 

T.2. Tolerance Values for Accuracy Class A and Class E. 

T.2.1. Tests Involving Digital Indications or Representations. – To the tolerances that would 

otherwise be applied in paragraphs T.2.2. Tolerance Value for Dynamic Load Test and T.2.3. Tolerance 

Value for Vehicle Position Test, there shall be added an amount equal to one-half the value of the scale 

division to account for the uncertainty of digital rounding.

T.2.2. Tolerance Values for Dynamic Load Test. – The tolerance values applicable during dynamic 

load testing are as specified in Table T.2.2-1 for screening and Table T.2.2-2 for enforcement. 

T.2.2.1. Tolerance Value for Class A for Screening Purpose

Table T.2.2-1.

Tolerances for Accuracy Class A

Load Description* Tolerance as a Percentage of Applied Test Load

Axle Load ± 20 % 

Axle Group Load ± 15 % 

Gross Vehicle Weight ± 10 % 
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Table T.2.2-1.

Tolerances for Accuracy Class A

Load Description* Tolerance as a Percentage of Applied Test Load

* No more than 5 % of the weighments in each of the load description subgroups shown in this table shall 

exceed the applicable tolerance.

T.2.2.2. Tolerance Value for Class E for Enforcement Purpose

Table T.2.2-2.

Tolerances for Accuracy Class E

Load Description* Tolerance as a Percentage of Applied Test Load

Axle Load ± 15 % 

Axle Group Load ± 10 % 

Gross Vehicle Weight ± 6 % 

* No more than 5 % of the weighments in each of the load description subgroups shown in this table 

shall exceed the applicable tolerance. No single error may exceed a GVW tolerance of ± 10 % (100% 

compliance).

T.2.3. Tolerance Value for Vehicle Position Test. – The tolerance value applied to each gross 

vehicle weighment is ± 10 % of the applied test load. 

T.2.4. Tolerance Value for Axle Spacing. – The tolerance value applied to each axle spacing 

measurement shall be ± 0.15 m (0.5 ft).

T.3. Influence Factors. – The following factor is applicable to tests conducted under controlled 

conditions only. 

T.3.1. Temperature. – Systems shall satisfy the tolerance requirements under all operating 

temperature unless a limited operating temperature range is specified by the manufacturer.

T.4. Radio Frequency Interference (RFI) and Other Electromagnetic Interference Susceptibility. – 

The difference between the weight indication due to the disturbance and the weight indication without the 

disturbance shall not exceed the tolerance value as stated in Table T.2.2 Tolerances for Accuracy Class A. 

UR. User Requirements

UR.1. Selection Requirements. – Equipment shall be suitable for the service in which it is used with 

respect to elements of its design, including but not limited to, its capacity, number of scale divisions, value 

of the scale division, or verification scale division and minimum capacity. 

UR.1.1. General. – The typical class or type of device for particular weighing applications is shown 

in Table 1. Typical Class or Type of Device for Weighing Applications. 

Table 1.

Typical Class or Type of Device for Weighing Applications

Class Weighing Application

A Screening and sorting of vehicles based on axle, axle group, and gross vehicle weight.
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Table 1.

Typical Class or Type of Device for Weighing Applications

Class Weighing Application

E Enforcing of vehicles based on axle, axle group, and gross vehicle weight

Note: A WIM system with a higher accuracy class than that specified as “typical” may be used.

UR.2. User Location Conditions and Maintenance. – The system shall be installed and maintained as 

defined in the manufacturer’s recommendation. 

UR.2.1. System Modification. – The dimensions (e.g., length, width, thickness, etc.) of the load 

receiving element of a system shall not be changed beyond the manufacturer’s specifications, nor shall 

the capacity of a scale be increased beyond its design capacity by replacing or modifying the original 

primary indicating or recording element with one of a higher capacity, except when the modification 

has been approved by a competent engineering authority, preferably that of the engineering department 

of the manufacturer of the system, and by the weights and measures authority having jurisdiction over 

the system.

UR.2.2. Foundation, Supports, and Clearance. – The foundation and supports shall be such as to 

provide strength, rigidity, and permanence of all components. 

On load-receiving elements, which use moving parts for determining the load value, clearance shall be 

provided around all live parts to the extent that no contacts may result when the load-receiving element 

is empty, nor throughout the weighing range of the system. 

UR.2.3. Access to Weighing Elements. – If necessary, adequate provision shall be made for 

inspection and maintenance of the weighing elements.

UR.3. Maximum Load. – A system shall not be used to weigh a load of more than the marked maximum 

load of the system. 

Appendix D. Definitions

The specific code to which the definition applies is shown in the [brackets] at the end of the definition. 

Definitions for the General Code [1.10] apply to all codes in NIST Handbook 44. 

A 

axle. – The axis oriented transversely to the nominal direction of vehicle motion, and extending the full 

width of the vehicle, about which the wheel(s) at both ends rotate. [2.25] 

axle-group load. – The sum of all tire loads of the wheels on a group of adjacent axles; a portion of the 

gross-vehicle weight. [2.25] 

axle load. – The sum of all tire loads of the wheels on an axle; a portion of the gross-vehicle weight. [2.25]

axle spacing. – The distance between the centers of any two axles. When specifying axle spacing, the axels 

used also need to be identified. [2.25]
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S

single-axle load. – The load transmitted to the road surface by the tires lying on the same longitudinal axis 

(that axis transverse to the movement of the vehicle and about which the wheels rotate). [2.25]

T

tandem-axle load. – The load transmitted to the road surface by the tires of two single-axles lying on the 

same longitudinal axis (that axis transverse to the movement of the vehicle and about which the wheels 

rotate). [2.25]

triple-axle load. – The load transmitted to the road surface by the tires of three single-axles lying on the 

same longitudinal axis (that axis transverse to the movement of the vehicle and about which the wheels 

rotate). [2.25]

W

weigh-in-motion (WIM). – A process of estimating a moving vehicle’s gross weight and the portion of 

that weight that is carried by each wheel, axle, or axle group, or combination thereof, by measurement and 

analysis of dynamic vehicle tire forces. [2.25]

weigh-in-motion screening scale. – A weigh-in-motion system used to identify potentially overweight 

vehicles. [2.25]

wheel weight. – The weight value of any single or set of wheels on one side of a vehicle on a single axle. 

[2.25]

WIM System. – A set of sensors and supporting instruments that measure the presence of a moving vehicle 

and the related dynamic tire forces at specified locations with respect to time; estimate tire loads; calculate 

speed, axle spacing, vehicle class according to axle arrangement, and other parameters concerning the 

vehicle; and process, display, store, and transmit this information. This standard applies only to highway 

vehicles. [2.25]

NIST OWM Detailed Technical Analysis: 

Permanent installed WIM systems are used in several countries around the world and are generally used 

for permanent protection of fragile and critical infrastructure. The submitters clearly showed that there is 

a need for direct and permanent enforcement.

The submitters have requested that the proposal is given a Voting status. However, changing the application 

of the code from screening to direct enforcement requires a new level of reliability. The submitters have 

used the existing code, that was adopted by the conference in 2015, as basis for their proposal. The test 

procedures and tolerances are comparable to internationally used standards which builds confidence. 

Therefore, it can be assumed that the proposal is a good base to start from. But there are still some concerns 

to be addressed in order for it to be suitable for direct enforcement application.

These high-speed weigh-in-motion systems generally have a much large error than static scales. That 

makes them unsuitable for use in commercial applications which are based on a shared risk principle. But 

for law enforcement applications these systems are suitable provided that the risk is placed on the side of 

law enforcement. That means that the measured weight value needs to be corrected with the tolerance of 

the instrument. Although the proposed specification S.1.7.1 contains a sentence that the measurements 
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must be corrected, the proposal does not clearly state how the correction is implemented (a fixed value or 

percentage of the measurement), or who corrects the measurement. If the instrument automatically 

performs the correction, then this must be a specification in the code. If done during the process afterwards, 

then it must be a user requirement. The conference should decide on the most appropriate way to implement 

the correction of the measurement value.

The procedures in the proposal should ensure that the test vehicles comply with the fundamental 

considerations as laid down in appendix A of Handbook 44. Calculations must show that the combined 

accuracy and uncertainty of the reference scale needs to be better than 1/3 of the applicable tolerance. E.g. 

Split weighing is considered an inaccurate way to determine the gross vehicle weight for commercial 

applications. And a single-platform vehicle scale is in general deemed unacceptable for use in determining 

the individual axle and axle-group loads of vehicles and vehicle combinations that are intended to serve as 

a standard reference in testing a WIM vehicle scale system. Previous studies conducted by NIST, 

Measurement Canada, and Kansas have shown very large weighing errors occur when weighing these

components (i.e., axle and axle-groups) if the entire vehicle isn’t level and in the same plane as the platform 

when those components are being weighed. Because the approach requirements for single platform vehicle 

scales do not ensure the level positioning of vehicles during the weight determinations of these components, 

they should not be used.

That being said, in this case the tolerance of the system is much larger than for static scales, which allows 

the reference scale also to have a much larger tolerance. This could mean that the proposed method of 

weighing of a reference vehicle is acceptable. It should be investigated whether the accuracy of weighing 

methods meet the required 1/3 of the tolerance.

The current code in section 2.25 is meant for screening applications only. That means that for the actual 

citation another certified scale is being used, not the WIM installation. In case of the proposed code, the 

citation is based on the output of the WIM installation. Since the weighing process is done without the 

intervention of a law enforcement officer, the records of the weighment must be unambiguous and beyond 

reasonable doubt. That means that the records should contain:

• The measured gross weight

• The corrected weight used for the citation (if a correction is applied)

• Proof of the vehicle’s identity (e.g., picture of the vehicle including license plate)

• Date and time

• Location

• Any other record that may be necessary to avoid any doubt about the violation (e.g., vehicle speed)

It is unclear whether this kind of supporting evidence should be part of the code. The conference should 

decide whether to add this to the code or whether this is covered by other legislation. 

To build confidence in the proposed WIM, adequate performance and reliability of such system should be 

demonstrated. Also, the effectiveness and completeness of the proposed test procedures should be 

demonstrated. Regarding the test procedures, NIST OWM has some concerns:
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• One of the most critical vehicle types to be weighed on a weigh in motion system is a vehicle with 

a shifting load, e.g., a tanker truck carrying fluids. Therefore, these kinds of vehicles should be 

included in the selection of test vehicles.

• Other vehicles with characteristics that could influence the measurement (e.g., vehicles with 

conventional steel leaf spring suspension as prescribed by OIML R 134) should be considered too.

• How does the “fully load condition” of a test relate to the specified scale capacity? E.g., is it 

sufficient to test a 200,000 lb installation with an 80,000 lb test vehicle?

• The objective of the WIM system is to detect and accurately weigh overweighed vehicles. 

Therefore, correct operation of the scale above the weight limit is essential. The proposal should 

answer the following questions:

o Is it the intend to use test vehicles that weigh more than the weight limit of the road the WIM 

system is supposed to protect? If so, what precautions need to be taken to limit the damage to 

the road due to testing?

o If no overweight vehicles are to be used during testing, how is guaranteed that the WIM system 

is providing an accurate weight within tolerance for loads over the weight limit up to the 

capacity of the WIM system?

And last but not least, for such a significant change in the code it is important that all stakeholders are heard 

and consulted. What does this proposal mean for the state inspectors who have to perform regular 

inspections on these WIM systems? Are there any concerns from the transport sector on having these 

devices deployed in the field? In order for the proposal to be adopted, it has to be technically sound and 

supported by a large portion of the legal metrology community. Possible stakeholders are for example 

other WIM manufacturers, highway weight enforcement regulators (who will be using and possibly testing 

them), state and local W&M jurisdictions (who may be the ones testing them), truckers association(s), 

Federal DOT, and perhaps service companies who will be installing and testing the units when they are 

installed.

Regional Association Reporting:

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting the following comments were received:

Ms. Tanvi Pandya (New York City DOT) – Ms. Pandya stated technologies have moved on. Ms. Pandya 

noted New York City DOT has data since 2019 showing that accuracy can be met on the devices. Ms. 

Pandya added the Handbook is outdated and needs to be updated to provide a way to enforce and it cannot 

be overstated the number of overweight vehicles that need to be regulated. Ms. Pandya recommended a 

Voting status.

Mr. Chaekuk Na (Rutgers University) stated the submitters of the item tried to meet the standard and got 

less than 6% error with 100% compliance. Mr. Chaekuk stated Indiana DOT conducted an independent 

test and received results within 5% error.

Mr. Jess Helmlinger (Kistler Group) clarified Mr. Chaekuk’s comments regarding test loads with testing 

occurring with both loaded and unloaded vehicles in live traffic and static weights for fairness. Mr. 
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Helmlinger noted changing the test procedure on live traffic and status weights had no impact. Mr. 

Helmlinger made reference to the current tentative code for the tolerances are wide and questioned how to 

test currently – use live trucks and a reference scale. Mr. Helmlinger confirmed this is for law enforcement 

and not commercial weighing. Mr. Helmlinger stated the submitters have worked with NIST and a 

multitude of states. Mr. Helmlinger stated the item is intended for states that want to use automated 

enforcement and would not force any jurisdiction to use it. Mr. Helmlinger recommended a Voting status.

Mr. Matt Douglas (State of California, Division of Measurement Standards on behalf of S&T Committee) 

sought clarification about the line inside the proposed tolerance table and what the purpose of the second 

statement. On the last line in the table, it says that the gross vehicle weight shall be +/- 10% but it also says 

± 6%.

Mr. Helmlinger addressed Mr. Douglas comments and clarified the 6% is for gross vehicle weight with a 

95% compliance. Mr. Helmlinger referred to the proposed tolerance table and noted the outcome cannot 

have more than 5% of the values outside the tolerance. Mr. Helmlinger stated if any value is outside of 

10% accuracy, then it fails the test. 95% of the values must be within the values.

Mr. Jan Konijnenburg (NIST Associate) confirmed NIST has been involved with this item but has not 

reviewed the proposal in detail to come to a conclusion. Mr. Konijnenburg made reference the WIM code 

that currently exists is idle and obsolete. Mr. Konijnenburg acknowledged this is a method of a WIM 

system enforcement. Mr. Konijnenburg stated he is looking forward to how this will develop. Mr. 

Konijnenburg made no recommendation at this time for the status of this item.

Mr. Raymond Johnson (Fairbanks Scales, Inc., representing the Scale Manufactures Association) 

commented the SMA has not met and has not formulated a position on this item. Mr. Johnson commented 

the SMA is scheduled to meet in November 2022.

Mr. Douglas commented he believes that there is some merit to some of the item. Mr. Douglas 

recommended keeping the accuracy class “A” and add accuracy class “E”.

Mr. Kenn Burt (San Luis Obispo County, California on behalf of S&T Committee) sought clarification if 

industry has seen this proposal and understand what they might be dealing with regard to how the WIM 

system will be used and applied for enforcement?

Ms. Tanvi Pandya (New York City DOT) addressed Mr. Burt’s question regarding industry reviewing this 

item. Ms. Pandya commented the submitters have met regularly and developed a task force. Ms. Pandya 

commented the task force has discussed this for the past several months. Ms. Pandya commented they have 

not directly engaged with the trucking industry but have spoken with some freight industry in general.

Mr. Helmlinger commented the Commercial Vehicle Safety Alliance (CVSA) has been made aware of this 

item.

During open hearings there was testimony that neither the SMA nor NIST has evaluated this proposal. The 

committee looks forward to the analysis of this item by NIST and SMA. The Committee asked the 

submitters questions about the tolerance table “T.2.2. Tolerances for Accuracy Class E”, specifically the 

last line in the table. The submitter clarified their statement made during open hearings in the Committee 

work session. The Committee recommended that the submitter consult the Scales Code for similar 

applications to expressing tolerances.

The WWMA S&T Committee recommended that this item be assigned a Developing status. 
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Southern Weights and Measures Association

The following comments were received during the 2022 SWMA Annual Meeting:

Dr. Nasif presented a presentation he stated that the device currently operates within 6% of the Type III 

ASTM Standard. The submitter stated that their intentions is for direct enforcement fines to not apply 

within 10 % of weight limit based on local enforcement procedures.

Mr. Peter Fedechko (International Road Dynamics) stated that he supports this item.

Mr. Chesser (Arkansas) stated that he liked the language on page 167 lines 25-28. He asked why strike 

paragraph B. He also cited some errors on page 170.

Mr. Paul Floyd (Louisiana) stated that he has concerns about the accuracy of this system. He stated that he 

would support this item for screening purposes and recommends it moving forward as Developing.

The SWMA S&T Committee asked about the speed and weight requirements used for testing in the 

proposal not matching with what the devices will be used to regulate. The Committee also questioned 

whether these devices would receive a type evaluation from NTEP if specifications were added to the 

handbook. Additionally, the Committee questioned whether a direct enforcement procedure should be 

separated from the tentative screening code.

The SWMA S&T Committee recommended this item move forward as a Developing Item.

Northeastern Weights and Measures Association

A presentation was given from the submitters of this item. The submitters reminded the body that this item 

deals exclusively with law enforcement scales, and not commercial scales.

Mr. John Mcguire (New Jersey) inquired about a 10% leeway in gross weight and believes that if a law 

enforcement agency is writing summonses, the tolerance should be tighter. He also inquired if the SMA 

and NIST had a position on this proposal. 

Ms. Dawn Harrison (New York City Department of Transportation) indicated that the 10 % leeway was 

chosen as a local enforcement policy because they believe that percentage on gross vehicle weight falls 

within tolerances of WIM systems and wants to target heaviest offenders. Any violations written by law 

enforcement have to be reviewed prior to issuance. 

Mr. Helmlinger indicated that the system will be tested to a 6% tolerance and fines would be issued at 10%.

Mr. Jim Willis (New York) stated that his understanding is there is a concern with both axel weights and 

gross weights of the overweight vehicles. 

Ms. Diane Lee (NIST OWM) inquired if this system will be used to provide official weight or estimation, 

and if weight is not correct are they going to weigh station to get official weight. 

Mr. Helmlinger indicated that during testing, they will be tested with a certified field reference scale and 

vehicles. 

Mr. Jason Flint (New Jersey) pointed out that the 10% leeway is a local enforcement decision and will not 

appear in the handbook as a tolerance. 
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Mr. Willis has concerns with the number of runs required to test the system. 

Mr. Czinku stated that WIM is a mature technology and can provide reliable output and weighments. 

Mr. John McGuire (New Jersey) recommended the item as developing so a further look can be taken into 

the dynamics of WIM. 

Mr. Jason Flint (New Jersey) suggested that an on-site demonstration be made available so regulators can 

view the system being used.

After hearing comments from the floor, the Committee agreed that the item has merit. Considering the 

underlying questions about tolerances and test procedures, the Committee is recommending a Developing 

status.

Central Weights and Measures Association

Mr. Nassif stated that overweight percentages of trucks are impacting roadways and bridges. The screening 

process in the existing tentative code doesn’t apply to enforcement of overweight commercial trucks.

Mr. Helmlinger stated that the tentative code has large tolerances and that’s why it isn’t being used by most 

states. The technology has improved to 4 % or 5 % tolerance capability since the tentative code was written.

The tentative screening code doesn’t hold up in court when overweight tickets are challenged. These 

changes are for law enforcement purposes; not necessarily commercial. The intent is not to require 

adoption, but to allow the use by states who wish to utilize it.

Mr. Doug Musick (Kansas) stated that testing involves three truck classes, three different loads, and three

different speeds. Is the intention that there are different classes of trucks which are all tested at all three

different loads and speeds? What does FHWA mean? Spell out the acronym. Is that in a CFR. which can 

be referenced?

Mr. Loren Minich (Kansas) remarked that page 168, S.1.7.1. is missing the lettering, but it’s that way in 

the tentative code. Formatting needs fixed. Don’t get rid of the current screening aspect of the tentative 

code. He supports this item moving on its own and not take away the ability of jurisdictions to use the 

tentative code for screening. Maybe add a second class?

The CWMA S&T Committee recommended this as a Developing Item. The Committee would like more 

input from jurisdictions who would be affected by removing the screening aspect of the tentative code.

SMA

During the 2022 Fall Meeting the SMA supported removing the Tentative status from this code and it to 

remain used for Vehicle Screening only.

Rationale: This code is not intended to be used in Commercial applications. Commercial weighing

applications, including WIM applications, are covered in the Scales code.
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LMD – Liquid Measuring Devices

LMD-23.3 Automatic Temperature Compensation Task Group

(This item was numbered as LMD-23.3 on the WWMA, SWMA, and NEWMA Agendas and LMD-23.1 on 

the CWMA agenda.) 

Source: Michael Cleary, Retired State of California

Submitter’s Purpose and Justification:

Revisit implementing Temperature Compensation of motor fuel at retail.

Given the skyrocketing price of gasoline and diesel fuel the Conference should study the impact on the 

American consumer.

OWM Executive Summary for LMD-23.1 – Automatic Temperature Compensation Task Group

OWM Recommendation: This item was withdrawn by all 2023 Fall Regional Weights and Measures 

Associations prior to the 2023 Interim Meeting as such the item does not appear on the Interim Meeting 

Agenda. 

Item Under Consideration:

Form a task group to research the issue of Automatic Temperature Compensation for retail fuels.

NIST OWM Detailed Technical Analysis: 

This item was not included on the 2023 NCWM Interim Meeting Agenda; thus, no NIST OWM analysis is 

provided.

Regional Association Reporting:

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting the following comments were received: Mr. Prentiss Searles

(American Petroleum Institute), stated that this is not a complete request; this task was addressed several 

years ago. There is no change in data or outcome, and we do not need to revisit. 

Mr. Scott Simmons (Colorado Division of Oil and Public Safety) agrees with Mr. Searles’ comments.

Mr. Kevin Schnepp (California Division of Measurement Standards) stated that California did a study and 

concluded that the cost far outweighed the benefit. Mr. Schnepp recommended the withdrawal of this item.

During open hearings, comments from the floor supported the withdrawal of this item. The WWMA S&T 

Committee feels that this item is not a complete proposal, that the proposal does not have merit as the topic 

has previously been reviewed and recommends that this item be withdrawn.

Southern Weights and Measures Association
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At the 2022 SWMA Annual Meeting, Dr. Matt Curran (Florida) stated that NCWM has seen proposals 

similar to this one in the past. He referenced a study from the California Energy Commission that 

determined the net cost difference observed before and after adding temperature compensation was very 

small. He also suggested that, if the item ends up being withdrawn, the submitter may consider sending it 

to FALS.

Mr. Prentiss Searles (API) stated that he did not support this item, and recommend it be withdrawn. Mr. 

Chesser (Arkansas) agreed with Mr. Searles. Mr. Ramsburg (Maryland) opposed this item and 

recommended withdrawal. Mr. Tory Brewer (West Virginia) opposed this item. Mr. Stokes (South 

Carolina) recommended this item be withdrawn. Mr. Murnane (Seraphin) stated that he totally disagrees 

with this item and recommends its withdrawal.

The SWMA S&T Committee recommended this item be withdrawn.

Northeastern Weights and Measures Association

At the 2022 Interim Meeting Mr. Searles , Mr. John McGuire (New Jersey), Mr. Jason Flint (New Jersey) 

requested that the item be withdrawn as no information or direction was given in the proposal. Ms. Diane 

Lee (NIST OWM) indicated that temperature compensation for retail motor fuel devices had been discussed 

in 2005 and was not approved by NCWM. Mr. Lou Sakin (Holliston, Massachusetts) and Mr. John 

Gaccione (Westchester County, New York) referenced a California study which determined cost of 

retrofitting devices would far outweigh any savings.

After hearing comments from the body, the Committee agreed with the comments that this item does not 

have merit and is recommending that this item be Withdrawn.

Central Weights and Measures Association

At the 2022 CWMA Interim Meeting, Mr. Loren Minnich (Kansas) stated that he does not support. He also 

noted that the item be Withdrawn and that it has already been thoroughly studied. 

Mr. Michael Keilty (Endress+Hauser) noted that LMD-23.1 (LM-23.1 is also assigned to a separate item 

Block 1. 

Mr. Craig VanBuren (Michigan) requested that the item be withdrawn. Mr. Greg VanderPlaats(Minnesota)

requested withdraw. Mr. Searles requested that the item be Withdrawn.

The CWMA S&T Committee recommended this item be withdrawn. The Committee requested that these 

items be renumbered.

LMD-23.4 N.3.5. Wholesale Devices.

Source: American Petroleum Institute
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Submitter’s Purpose and Justification:

Clarification that Small Volume Provers are included in N.3.5. Wholesale devices. 

The 1996 NCWM agreed that small volume provers (SVP) are suitable as a test standard. The 1996 changes 

included modifications to paragraph N.3.5. to remove barriers for technology that could achieve the 

maximum flow rate of the product flowing through the meter. 

That said, portions of the text in paragraph N.3.5. have been interpreted to prohibit the use of an SVP 

because the paragraph states, that the delivered quantity for the meter test (1) “should be equal to at least 

the amount delivered by the device in one minute at its maximum discharge rate” and (2) “shall in no case 

be less than 200 L (50 gal).” Given these criteria, an SVP could meet the first requirement, and may not 

meet the second requirement unless the base prover volume was at least 200 L (50 gal). Research indicates 

that a reference to a 50 gallon minimum draft has been in the Handbook since 1937. The size of wholesale 

meter deliveries when the 50 gal minimum was established in paragraph N.3.5. is not reflective of the 

discharge rates of meters used today in commerce.

Therefore, modifications are warranted to paragraph N.3.5. to clarify that SVP’s that are properly sized for 

the test, which can include having a base prover volume of less than 50 gallons, achieve the accuracy 

required to meet the original design of N.3.5. The proposed additions clarify that the test device – whether 

SVP, neck-type prover, or another type of test standard – must be capable of testing the maximum flowrate 

through the meter being tested. The phrase “and shall in no case be less than 50 gal,” is deleted as SVPs 

with smaller volumes (e.g., 20-gallon base prover volume) are capable of testing wholesale devices at 

flowrates exceeding 600 gallons per minute.

In 1996, the weights and measures community gathered data and published a report that recognized the 

suitability of the SVP as a test standard for liquid measuring devices. Additionally, a 105 series 

(Specifications and Tolerances for Reference Standards and Field Standard Weights and Measures) 

standard exists for Dynamic SVPs. 

Over the last 25 years, SVP technology has improved significantly and API Manual of Petroleum 

Measurement Standards (MPMS) Chapter 4.6, Pulse Interpolation, provides the appropriate standards that 

ensure the SVP achieves the necessary measurement tolerances. API standards MPMS has 23 chapters 

with Chapter 4.2, Displacement Provers covering SVPs. The 3rd Edition of the standard was published in 

2003, and an Addendum was issued in 2015. The Committee responsible for Chapter 4.2 includes over 

subject matter experts that assess the data and consider updates and revisions to the standard. The accepted 

technology of the SVP’s achieves an accuracy, at a 95 percent confidence level, that the calculated based 

prover volume is within plus or minus 0.029% when three consecutive runs agree within 0.02% of one 

another. In other words, there is only a 5% probability that the true prover base volume lies outside the 

range of plus or minus 0.029% of the calculated base volume. 

The goals for the proposed modification to paragraph N.3.5 are to:

• Reinforce the 1996 goal to remove any test conditions that would prohibit or restrict the use of an 

SVP or other methodologies 

• Establish fair test conditions within the OEM’s intended range of the meter’s operating conditions

• Specify the minimum test conditions based on the meter’s ratings and the key characteristics for 

the proving device to conduct a test that demonstrates the meter’s performance in a commercial 

application 
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• Encompass the concept of both the volumetric neck-type prover and small-volume prover (SVP) 

test or any other methodologies that may be developed in the future

• Eliminate any language that would circumvent or alter the proper use of testing devices or their 

results

• Provide guidance on test parameters which meet the Fundamental Considerations without the need 

for a laundry list of possible test methodologies and equipment. The decision of whether or not to 

accept a given type of test standard still rests with the Director as outlined in the Fundamental 

Considerations.

In addition to the action taken on the proposed revision to N.3.5., NIST has suggested it may be helpful to 

review and provide updates or supplements to the NIST Examination Procedure Outline 25 for Loading 

Rack Meters and possibly suggest modifications to NIST 105-7, “Specifications and Tolerances for 

Reference Standards and Field Standard Weights and Measures: Specifications and Tolerances for 

Dynamic Small Volume Provers,” 1997, to provide additional guidance on properly sizing and selecting a 

suitable size small volume prover for a given metering system. Such guidance would require input from 

SVP manufacturers as well as regulators.

Some may oppose the removal of the 50-gallon test draft. However, research indicates that a reference to 

a 50-gallon minimum draft has been in the Handbook since 1937. The size of wholesale meter deliveries 

when the 50 gal minimum was established in paragraph N.3.5. is not reflective of the discharge rates of 

meters used today in commerce.

Links to NIST OWM newsletter articles written by Diane Lee on SVPs used in testing commercial 

measuring systems: Weights and Measures Newsletter Archives - Field Standards | NIST

H-003 Part 1 (2005)

H-004 Part 2 

H-007 Part 3

H-010 Part 4

H-012 Part 5

Background Q&A:

1. Can you explain how uncertainty calculations differ between SVP vs can provers? 

• Tank provers provide a cubic inch uncertainty per 1,000 gallon prover by comparing the 

volume in the tank vs the volume of the computer.

• SVPs provide a meter factor that is a ratio of the prover vs the meter for a period between 

detector switches. In addition, calibrations are performed multiple times and a statistical 

uncertainty of ~0.027% between calibrations is required.

2. What are the pros of SVPs vs cans?

Small Volume Prover Volumetric (Can) Prover

Prove in actual operating load conditions (flow, pressure, 

and temperature) by proving into customer loads

Lower cost to operate
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Small Volume Prover Volumetric (Can) Prover

Prove at multiple flow rates Can visually see the quantity by viewing the 

neck

Establish multiple factors that can be applied No moving part

Faster proving runs

No need to pump back

Gravimetric water draw more repeatable

Lower prove uncertainty

Higher turn down ratio

Health Safety Security and Environment (HSSE) -

reduced risk / impact to environment

Digital history of meter performance at all flow rates 

with Meter Factor Control Chart (MFCC) to evaluate the 

health of each meter

Help identify rack issues such as control valve issues as 

well as identify hydraulic issues that have a direct effect 

on measurements.

Repeatability issues are easier to identify

Repeatability is verified by making the comparison over 

5 runs 

Tank Provers repeatability is verified by one run 

after the initial meter factor change

3. How are SVPs certified? 

• NIST Traceable cans in a water draw lab, or NIST Traceable weights in a gravimetric lab.

4. How do the computers calculate the final calibration result?

• Comparing gross standard volume (GSV) of the meter vs the GSV of the prover

5. How are peripheral equipment used in meter proving calibrated /verified (portable electronic 

thermometer (PET), Pressure Gauge, Transmitters)

• PET calibrated via NIST certified 

• Pressure gauges NIST certified

• PET and gauges used to determine if transmitters are in tolerance

The submitter requested that this amendment be retroactive and that the item be a Voting item in 2023.

OWM Executive Summary for LMD-23.4 – N.3.5. Wholesale Devices.

OWM Recommendation: NIST supports these proposed changes to N.3.5 because it helps to broaden 

the original intent of the paragraph. We believe the requirements for test drafts were written around the 

most common test methods at that time. Future requirements for test drafts may be better addressed in 

the General Code with additional guidance in the Fundamental Considerations or another guidance 

document.

• There are several items on the 2023 Interim Meeting agenda that propose changes to Test Draft 

paragraphs in NIST HB 44. 
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OWM Executive Summary for LMD-23.4 – N.3.5. Wholesale Devices.

• The test draft items included on the 2023 Interim Meeting Agenda are LMD 23.4, LPG-15.1, MFM15.1, Block 1, and Block 5. 

• The purpose stated for Items LPG-15.1, MFM-15.1 and Block 1, “...to allow field standard meters 

to be used to test and place into service dispensers and delivery system flow meters..” is already 

addressed in the fundamental considerations section of NIST HB 44, that states the director has the 

authority to select the standard used to test commercial devices and we believe Item GEN-23.1 and 

Block 8 on the 2023 Interim Meeting Agenda adds clarity to how the standard should be selected. 

The Item Under Consideration for these items adds a test draft paragraph that is specific to the use 

of field standard meters. The paragraph is problematic for some types of test because the language 

prevents conducting a complete test of a device. See NIST Technical Analysis for these three 

separate items.

• NIST HB 44 was written to be non-technology specific, but test draft criteria were written around 

the current technology most common at that time. When testing a positive displacement meter using 

an open neck prover there are ramp-up and ramp-down errors that are associated with the test. As 

such, the test draft has to contain enough volume so that these errors do not contribute greatly to the 

test of the meter. With the use of different test standards, the ramp-up and ramp-down errors may 

not be factors that will affect the test but there may be other factors that contribute to error in the 

test that would affect the test draft.

• LMD-23.4 and Block 5 seek to keep the existing N.3.5. paragraph and make it broader to encompass 

other field standards. 

• Over the years some changes have been made to the Test Draft criteria so that the requirement is 

more inclusive of other technology such as the change that was made to N.3.5 in 1996 to remove 

“test draft” and replace it with “delivered quantity” to be more inclusive of SVPs for those states 

using this technology. 

• Technology will continue to change and evolve, and we will need to respond to the number of 

changes, such as the different standards that will be in use, and the factors associated with different 

technologies. We will need to ensure an appropriate test draft is selected so that the errors of test 

method and device under test do not contribute greatly to the test of the device. Coupled with what 

is already in the fundamental considerations for responsibility for selecting a test standard and what 

is being proposed in Items Gen-23.1 and Block 8, we believe a solution may be to add a general 

code requirement with additional guidance in the fundamental consideration for Test draft and 

consider removing Test Draft from the individual codes and addressing it in the general code in test 

notes as a suitability requirement. Currently with no alternate proposal in place for Test Draft, the 

changes in both LMD-23.4 and Block 5 would assist with recognizing the test draft of other 

standards in use. 

• We encourage the submitters of these item, LMD-23.4 and Block 5 to work together to combine the 

changes that are being proposed to the same paragraph, N.3.5. Wholesale Devices. If the submitters 

are in agreement with combining these changes a proposed change for the combined items LMD23.4 and B5: LMD lock 5 is provided below:
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OWM Executive Summary for LMD-23.4 – N.3.5. Wholesale Devices.

N.3.5. Wholesale Devices – The total delivered quantity for any required accuracy test should shall be 

equal to, or is recognized as being representative of, a volume equivalent to at least the amount delivered 

by the device in one minute at its the meter’s maximum discharge rate and shall in no case be less than 200 L 

(50 gal). 

(Amended 1987,and 1996, and 2023)

Table 3. Summary of Recommendations

LMD-23.4 – N.3.5. Wholesale Devices.

V D W A I Notes* Comments

Submitter 

OWM

WWMA 

SWMA 

NEWMA 

CWMA 

NCWM

Letters of Support Letters of Opposition Notes

Industry

Manufacturers

Retailers and 

Consumers

Regulators

*Notes Key:

1 − Submitted modified language

2 − Item not discussed

3 − No meeting held

4 − Not submitted on agenda

5 − No recommendation or not considered

Item Under Consideration:

Amend Handbook 44 Liquid Measuring Devices Code as follows: 

N.3.5. Wholesale Devices – The total delivered quantity for any required accuracy test should be 

equal to, or is recognized as being representative of, a volume equivalent to at least the amount 

delivered by the device in one minute at its the meter’s maximum discharge rate and shall in no case 

be less than 200 L (50 gal). 

(Amended 1987,and 1996, and 2023) 
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NIST OWM Detailed Technical Analysis: 

The proposed changes to LMD-23.5 N.3.5 Wholesale Devices are being made because the base volume of 

some SVPs are smaller than that which is noted in paragraph N.3.5. Wholesale device. SVPs operate by 

collecting a smaller volume, using pulse interpolation, and averaging several runs. As such the test draft 

paragraph N.3.5 in NIST HB 44, LMD code currently in the handbook that states “...shall in no case be 

less than 50 gal conflicts with the base volume capacity of some SVPs, which can be varying sizes including 

20 gal. 

NIST HB 44 was written to be non-technology specific, but test draft criteria were written around the current 

technology that was most common at that time, which were likely positive displacement meters. As such 

the proposals LMD-23.4 and Block 5 seek to keep the existing paragraph and make it broader to encompass 

other field standards. 

The current test draft criteria gives consideration to the ramp-up and ramp-down errors associated with a 

positive displacement meter and the test draft criteria was selected based on these and other factors that 

would affect a fair test. The size of the test draft was selected such that these operational errors do not 

contribute greatly to the test measurement.

With other technologies these errors may not exist but there may be other factors that contribute to error in 

the test that would affect the test draft. 

Over the years some changes have been made to the Test Draft criteria so that the requirement is more 

inclusive of other technology such as the change that was made to N.3.5 in 1996 to remove “test draft” and 

replace it with “delivered quantity” to be more inclusive of SVPs for those states using this technology and 

this current proposal. 

Technology will continue to change and evolve, and we will need to respond to the number of changes, 

such as the different standards that will be in use, and the factors associated with different technologies. 

We will need to ensure an appropriate test draft is selected so that the errors of test method and device under 

test do not contribute greatly to the test of the device. Coupled with what is already in the fundamental 

considerations for responsibility for selecting a test standard and what is being proposed in Items Gen-23.1 

and Block 8, we believe a solution may be to add a general code requirement with additional guidance in 

the fundamental consideration for Test draft and consider removing Test Draft from the individual codes

and addressing it in the general code in test notes as a suitability requirement. 

Currently with no alternate proposal in place for Test Draft, we support the proposed changes in both LMD23.4 and Block 5 that will assist with recognizing the test draft for other standards in use.

We recommend that the submitters of this item, LMD-23.4 and Block 5 work together to combine the 

changes that are being proposed to the same paragraph, N.3.5. Wholesale Devices. If the submitters are in 

agreement with combining these changes a proposed change for the combined items LMD-23.4 and Block 

5 is provided below: 

N.3.5. Wholesale Devices – The total delivered quantity for any required accuracy test should shall

be equal to, or is recognized as being representative of, a volume equivalent to at least the amount 

delivered by the device in one minute at its the meter’s maximum discharge rate and shall in no case 

be less than 200 L (50 gal). 

(Amended 1987,and 1996, and 2023) 
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Regional Association Reporting:

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting the following comments were received: 

Mr. Prentiss Searles (API) - Wanted to re-enforce the 1996 goal to remove test conditions that restrict the 

use of small volume provers. The director has the authority to use or not use the device. Spoke about what 

a captive displacer is. Worked with NIST on this. There was a concern at the Annual conference that 

someone could take a 100-gallon prover and use multiple drafts to test a meter with a 500 gallon per minute 

flow rate, so they added language to address that. 

They are ANSI accredited. 95% confidence level that you will be within .029%. 

Ms. Letitia Arriaga (Marathon Petroleum) - Supports this item. Acknowledges the change from 1996 and 

removes the restriction that prohibits it. 

Mr. Brent Price (Gilbarco) supports this item. He is concerned that this could be restrictive, 50 gallons is 

a lot for a proving size. He likes the wording as is with 1-minute maximum flow rate. Agrees with the 

Central Region’s edits. 

Mr. Searles stated the proposed language from the presentation is ready for a vote. 

Mr. Michael Keilty (Endress+Hauser) - Would not disagree with the use of small volume provers. Works 

on these standards all of the time. As it pertains here in changes to HB 44, he can’t support this revision 

and does not support this moving forward as a Voting item. It doesn’t address the issue at hand, which is 

the small sample size. This only massages the language. He recommends that this item should be a subparagraph, as in Block 1. He recommends that this item remain Developing. 

Mr. Searles remarked it is not capturing the entire amount that is being delivered, it’s 20 gallons. You will 

recognize a representative sample, that's what the 20-gallon prover does. The captive displacer can test 

holding 20 gallons with a resolution of 4 digits from the decimal. It is capable of hitting the accuracy that 

is required. We believe that it is ready for a vote. 

Mr. Keilty stated it is because of the math that Prentiss described, if it is a 20-gallon captive displacement 

prover the flow computer math says that it's 40 gallons. It’s double and that’s what the volume is. 

During open hearings, the submitter provided a presentation (which will be submitted to the NCWM) which 

contained updated language to the proposal. The WWMA S&T Committee recommended that this item be 

assigned a Developing status with the further recommendation that the submitter of this item and Block 5 

item LMD-23.2 work together to develop language that will support both of their purposes, including taking 

into consideration the testimony heard during open hearings. 

Southern Weights and Measures Association

The following comments were received during the 2022 SWMA Annual Meeting: 

Mr. Searles gave a presentation on this item. He stated that the 50-gallon minimum draft size is not relevant 

to adequate testing and should be removed. 
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Mr. Chesser (Arkansas) stated that SVP tolerances are much tighter than traditional methods. 

Mr. Keilty (Endress+Hauser) stated that he agrees with Mr. Searles and supports this item. He also stated 

that he believed this item could describe SVPs separately from fixed neck Provers. He recommended this 

move forward as a Developing Item. 

Mr. Nicholas Suemnick (Marathon Petroleum) supports this item. 

Mr. Brent Price (Gilbarco) stated that he supports this item with Mr. Searles’ changes. 

The SWMA S&T Committee recommended this item move forward as a Voting Item. 

Northeastern Weights and Measures Association

Mr. Prentiss Searles (API) gave a presentation on this item. Mr. Searles indicated that there has been a 

language change to the proposed item after hearing comments from CWMA. Mr. John Hathaway (Total 

Control Systems/Murray Equip) inquired about the use of “should” in the language instead of “shall” or 

“must”. Mr. Keilty commented that he does not challenge the validity of SVPs, but suggested to the 

submitter that the language is confusing and brought up volume equivalence. Mr. Keilty suggested that 

this item should be a line item, separate from wholesale, and should be explained explicitly. Mr. Keilty 

pointed out that there are three different proposals on this subject and recommends developing status. Ms. 

Tisha Arriaga (Marathon Petroleum) commented that she supports the item as Voting. Ms. Arriaga feels 

that the change that occurred in the handbook in 1996 has accepted this test measure. Ms. Diane Lee (NIST

OWM) appreciated the presentation and stated that NIST has been working with API. Ms. Lee noted that 

the requirements for provers in the handbook were created in 1937 and this technology did not exist. Mr. 

Walt Remert (Pennsylvania) commended the outstanding work done by the group and supports the item as 

developing. Mr. Jim Willis (New York) indicated that this item is going the right direction with addressing 

to advances in technology and recommended a Developing status. 

After hearing comments from the floor, the Committee agreed that this item has merit. The Committee 

agreed with the commenters and believed that this item should have a Developing status. 

Central Weights and Measures Association

Mr. Searles (API) stated the goal is to reinforce that SVPs are allowed, approved, and are recognized. Wants 

fair test conditions. This change is only an additional allowance, not a requirement. Feels this is developed 

and ready for Voting. The approach when using a SVP is to start with a primed line, no air is present. After 

that, it is accurate at both the ramp up and ramp down portion of the meter operation. 

Mr. Doug Musick (Kansas) interpretation of maximum discharge rate can change from state to state. Is it 

the marked rate or the rate of the installation? It needs to be clarified. 

Mr. Dmitri Karimov (Liquid Controls) supported “the meter’s” is confusing. Should stay at “its”. Also, 

add the word “continuous” may help. As written, it could imply that tests can be performed by starting and 

stopping. 

Mr. Henry Oppermann (WM Consulting in absentia) submitted comments in writing regarding concerns 

and opposition. 

Mr. Matthew Jambor (Marathon) remarked that SVPs are being used in their terminals. They directly 

communicate with internal software and limits data entry errors associated with using open neck provers. 
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Bias can be present in any system, not specific to SVPs (response to HO letter). Side by side testing has 

been performed in Alabama and Minnesota with traditional provers and SVPs and they netted the same 

results. 

Mr. Keilty stated these are used extensively and are of very high precision. Standards and requirements 

from API are stricter than NIST Handbook 44. Nomenclature LMD-23.2 is also assigned to a separate item 

in Block 5. 

Mr. Musick stated lots of types and names for this kind of equipment. In a lab setting they could be very 

accurate and repeatable. In the field, there is a difference. Some do not meet the 1/3 requirement from 

NIST HB44 Fundamental Considerations. These provers don’t capture the error from meter ramp up and 

ramp down. Ramp up and ramp down are where the errors are, not in the middle of a full flow, which is 

what the SVPs are testing. 

Mr. Craig VanBuren (Michigan) stated their office compared a SVP to a 1000 gal prover in 2005. No 

longer has the data. 

The Committee requested that these items be renumbered. The CWMA S&T Committee believes this item 

is fully developed and recommend Voting status with the following changes: 

N.3.5. Wholesale Devices. – The total delivered quantity for any required accuracy test should be 

equal to, or is recognized as being representative of, a volume equivalent to at least the amount delivered 

by the device in one minute of continuous flow at its the meter’s maximum discharge rate and shall in 

no case be less than 200 L (50 gal). 

(Amended 1987, and 1996, and 2023) 

VTM – Vehicle Tank Meters

VTM-18.1 S.3.1 Diversion of Measured Liquid and S.3.1.1. Means for Clearing the 

Discharge Hose and UR.2.6. Clearing the Discharge on a multipleproduct, single discharge hose.

(Note: At the 2020 Interim Meeting the Committee agreed to combine both VTM-18.1 and VTM-20.1. 

Both items are now one item under VTM-18.1.) 

(Note: At the 2022 Annual Meeting, this item did not receive sufficient votes to pass or to fail and was 

returned to the Committee.)

Source: New York and NIST OWM (Carryover from 2018, VTM 1-B) and Murray Equipment, Inc., 

Total Control Systems 
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Submitter’s Purpose and Justification:

Provide specifications and user requirements for manifold flush systems on a multiple-product, singledischarge hose. Recognize that there is a balance between a mechanism that provides an important safety 

benefit but also, if used incorrectly, facilitates fraud. Ensure that VTM owners understand their 

responsibilities when installing such a system and ensure uniformity in enforcement throughout the country 

and clarify the paragraph to protect vehicle motor fuel quality, retain safe operating procedures when 

handling vehicle motor fuels, and to prevent fraud during delivery of vehicle motor fuels from vehicle tank 

meters.

OWM Executive Summary for VTM-18.1 – S.3.1 Diversion of Measured Liquid and S.3.1.1. Means 

for Clearing the Discharge Hose and UR.2.6. Clearing the Discharge on a multiple-product, 

single discharge hose.

OWM Recommendation: OWM believes the proposed changes represent a reasonable solution that 

will help minimize the potential for fraud with the use of manifold flush systems while allowing 

companies access to the safety-related benefits from the use of such systems in distributing products on 

VTMs. With the most recent version of the Item Under Consideration, OWM believes this item is ready 

for vote.

o A manifold flush system allows liquid to be diverted from the discharge line on single hose multiproduct VTMs so that liquid of one product is not mixed with liquid of another in the discharge line.

o NIST Handbook 44 already includes provisions allowing the use of manifold flush systems.

 However, without appropriate safeguards, these systems represent a significant potential for 

fraud.

 OWM believes the current Item Under Consideration offers additional safeguards that are not 

present in the current NIST HB 44 language.

 These changes will reduce the potential for facilitation of fraud with the design and use of these 

devices.

o When presented for a vote in 2019, this item (though revised multiple times in response to 

comments) failed to obtain sufficient votes to “pass” or “fail” and was returned to Committee.

 Several additional variations to address comments and concerns were subsequently considered. 

o In January 2020, this item was combined with a related Item VTM-20.1 (which proposed limits on 

the use of these systems with specific product types) with the goal of having the submitters of both 

items work together to reach a reasonable compromise between the two proposals.

o Since January 2020, the submitters of both items have worked to find a compromise that best meets 

the needs of the community.

o In developing the current proposal, the submitters considered concerns raised regarding the use of 

these systems, including:

 the potential for facilitation of fraud with the use of these systems;

 the potential for cross contamination of products in different tank compartments; and
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OWM Executive Summary for VTM-18.1 – S.3.1 Diversion of Measured Liquid and S.3.1.1. Means 

for Clearing the Discharge Hose and UR.2.6. Clearing the Discharge on a multiple-product, 

single discharge hose.

 the suitability of using a single meter for multiple product types.

o These concerns were balanced against comments indicating:

 these same product handling practices have occurred for many years without the use of such 

systems; and

 manifold flush systems can offer distinct safety advantages for drivers when flushing product.

o OWM continues to have concerns regarding the safety of delivering products such as gasoline and 

home heating oil through the same meter (and questions whether a single meter is suitable for such 

purposes) 

 However, OWM recognizes this is already a widespread practice in the industry and placing a 

blanket limitation in NIST Handbook 44 may not best serve the community. 

o OWM acknowledges the safety advantages of such a systems to the drivers since the drivers do not 

have to climb on top of the VTM truck to flush product from the line before delivering another 

product. 

o OWM notes that such changes do not preclude a jurisdiction from implementing policies regarding 

the use of a single meter to dispense multiple different product types.

Table 3. Summary of Recommendations

VTM-18.1 - S.3.1 Diversion of Measured Liquid and S.3.1.1. Means for Clearing the Discharge 

Hose and UR.2.6. Clearing the Discharge on a multiple-product, single discharge hose.

V D W A I Notes* Comments

Submitter 

OWM Email comments NIST OWM (01-04-21)

WWMA 

SWMA 

NEWMA 

CWMA 

NCWM

Letters of Support Letters of Opposition Comments

Industry

Manufacturers

Retailers and Consumers
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Table 3. Summary of Recommendations

VTM-18.1 - S.3.1 Diversion of Measured Liquid and S.3.1.1. Means for Clearing the Discharge 

Hose and UR.2.6. Clearing the Discharge on a multiple-product, single discharge hose.

V D W A I Notes* Comments

*Notes Key:

1 − Submitted modified language

2 − Item not discussed

3 − No meeting held

4 − Not submitted on agenda

5 − No recommendation or not considered

Item Under Consideration:

Amend Handbook 44, Vehicle-Tank Meters Code as follows: 

S.3.1. Diversion of Measured Liquid. – No means shall be provided by which any measured liquid 

can be diverted from the measuring chamber of the meter or the discharge line thereof. However, two 

or more delivery outlets may be installed if means are provided to ensure that: 

(a) liquid can flow from only one such outlet at one time; and 

(b) the direction of flow for which the mechanism may be set at any time is definitely and 

conspicuously indicated. 

This paragraph does not apply to the following: 

(1) Equipment used exclusively for fueling aircraft.

(2) Multiple-product, single-discharge hose metering systems that are equipped with systems 

designed to flush the discharge hose, provided the flushing system complies with the 

provisions of paragraph S.3.1.1. Means for Clearing the Discharge Hose, MultipleProduct, Single-Discharge Hose Metering Systems. 

(Amended 2018 and 20XX) 

S.3.1.1. Means for Clearing the Discharge Hose, Multiple-Product, Single-Discharge Hose 

Metering Systems. - Multiple-product, single-discharge hose Mmetering systems may be 

equipped with systems specifically designed to facilitate clearing of the discharge hose prior to 

delivery to avoid product contamination. In such systems. a valve to temporarily divert product 

from the measuring chamber of the meter to a storage tank, shall be installed only if all the 

following are met:

(a) the discharge hose remains of the wet-hose type; 

(b) the valve and associated piping are approved by the weights and measures authority having

jurisdiction over the device prior to commercial use; 

(c) the valve is permanently marked with its purpose (e.g., flush valve); 

(d) the valve is installed in a conspicuous manner and as far from the hose reel as practical; 
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(e) the system clearly and automatically indicates the direction of product flow during 

operation of the flush system; and 

(f) clear means, such as an indicator light or audible alarm, is used to identify when the valve 

is in use on both quantity indications and any associated recorded representations (e.g., 

using such terms as “flushing mode” or “not for commercial use”);

[Nonretroactive as of January 1, 2024] 

(g) effective, automatic means shall be provided to prevent passage of liquid through any 

such flush system during normal operation of the measuring system; and

[Nonretroactive as of January 1, 2024] 

(h) no hoses or piping are connected to the inlet when it is not in use. 

(Added 2018) (Amended 20XX)

UR.2.6. Clearing the Discharge Hose.

UR.2.6.1. Clearing the Discharge Hose, General. – A manifold flush or similar system 

designed to accommodate the flushing of product on single-hose, multiple-product systems is 

not to be used during a commercial transaction. The following restrictions apply: 

(a) The inlet valves for the system are not to be connected to any hose or piping (dust 

covers are permitted) when not in use.

(b) When the flushing system is in operation, the discharge hose is only to be connected 

to the port for the product type being flushed from the discharge line.

(c) Following the flushing process, indications and recording elements must be reset to 

zero prior to beginning a commercial delivery.

(Added 20XX)

UR.2.6.2. Minimizing Cross Contamination. – When dissimilar products are dispensed 

through a single meter, the user shall take steps to ensure the system is properly flushed to 

minimize the potential for cross contamination of product in receiving tanks on subsequent 

deliveries. Dispensing products having radically different characteristics (e.g., gasoline and 

diesel fuel) through a single meter delivery system is not recommended.

(Added 20XX)

UR.2.6.3. Records. Whenever, prior to delivery, a different product is pumped through the 

discharge hose to avoid contamination, a record including the date, time, original product, new 

product, and gallons pumped shall be maintained. These records shall be kept for a period of 12 

months and available for inspection by the weights and measures authority. 

(Added 2018) 

NIST OWM Detailed Technical Analysis: 

Mrs. Tina Butcher (NIST OWM), Mr. Jim Willis (New York), and Mr. Jim Hathaway (Murray Equipment) 

met on December 2, 2021 to discuss the proposed changes to VTM-18.1. There were specific concerns 

raised with VTM-20.1, which was previously included with this proposal that still needed to be addressed 
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which included concerns with contamination, safety, and fraud. It was agreed that in order to further 

develop a joint proposal, there was a need to resolve the concerns addressed in VTM-20.1 to the extent 

possible. Mrs. Tina Butcher (NIST OWM), Ms. Diane Lee (NIST OWM), Mr. Jim Willis (New York), and 

Mr. John Hathaway (Murray Equipment) met again on January 3, 2021. As a result of this meeting all 

parties agreed with the existing Item Under Consideration. In addition, the meeting participants agreed 

with adding a new User Requirement under UR.2.6. Clearing the Discharge Hose to the Item Under 

Consideration to address the concerns with the use of manifold flush systems with dissimilar fluids a 

follows: 

UR.2.6.2. Minimizing Cross Contamination. – When dissimilar products are dispensed through 

a single meter, the user shall take steps to ensure the system is properly flushed to minimize the 

potential for cross contamination of product in receiving tanks on subsequent 

deliveries. Dispensing products having radically different characteristics (e.g., gasoline and diesel 

fuel) through a single meter delivery system is not recommended.

UR.2.6.3. Records. – Whenever, prior to delivery, a different product is pumped through the discharge 

hose to avoid contamination, a record including the date, time, original product, new product, and gallons 

pumped shall be maintained. These records shall be kept for a period of 12 months and available for 

inspection by the weights and measures authority. 

(Added 2018)

Discuss points during the December 2, 2021, and January 4, 2022 meetings are outlined below: 

• Contamination and Safety: 

o There is no disagreement over concerns about contamination and safety that can come about from 

inadvertent mixing of products in a storage tank. 

o These concerns, however, are not unique to the use of manifold flush systems.

 Whether product is flushed using a manifold flush system or by flushing into a compartment 

from the top opening, the risk of contamination is present and is of concern. 

o If flushing is to be prohibited and/or the use of single meter/multiple product applications, it should 

be universally applied and presented as a separate proposed change to NIST Handbook 44, not just 

to systems equipped with manifold flush systems.

o Establishing minimum flush requirements might also assist with minimizing contamination.

o See recommendations below under “Dissimilar Fluids” and “Minimum Measured Quantity” that 

might help address these two concerns.

o It might also be acknowledged that the use of manifold flush systems is intended to address a 

different aspect of safety and that is safety of the driver when conducting a flush operation; the 

manifold flush system provides a safer way of accomplishing the task than climbing onto the top 

of a vehicle tank. 

Dissimilar Fluids:

• The original proposal in 20.1 (from Murray Equipment) expresses concerns about the use of a 

single meter to deliver multiple products and suggests language that would limit the use of 
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manifold flush systems only to those systems which have individual meters dedicated to 

individual products. 

• Such concerns would appear to apply to all systems, not just those equipped with manifold

flush systems.

• If a prohibition is to be added to NIST Handbook 44 regarding the use of individual meters for 

multiple products, this should be done as a separate requirement not included as part of 

paragraph S.3.1. 

Minimum Measured Quantity (MMQ):

• The concept of establishing a minimum delivery size would seem to help minimize concerns 

over possible contamination however it may be problematic to craft a requirement to 

adequately cover all applications. 

Fraud.

• The concerns about potential fraud are quite valid and have been expressed in OWM’s 

comments from the inception of these requirements.

• The provisions for manifold flush were modified to include various provisions to limit that 

potential.

• Proposed changes to the existing language in the original Item 18.1 and as shown in the current 

“Item Under Consideration” include additional recommendations to minimize the potential for 

fraud when installing and using manifold flush systems. If the additional provisions are 

adopted, this would help reduce that potential.

Additional Points – Mechanical Metering Systems:

• Some manufacturers raised questions regarding whether communication between the manifold 

flush system and mechanical metering systems is feasible, raising concerns about the newly 

proposed changes to S.3.1.1. Means for Clearing the Discharge Hose paragraphs (f) and (g). 

• Those manufacturers expressed intent to explore this point more carefully.

NIST OWM provided previous comments to this item. Some oppose modifications that will restrict the 

use of manifold flush systems with only certain products. Some oppose use of manifold flush systems 

unless there is a restriction placed on the products with which the system can be used. The submitters 

(including NIST OWM) will need to work together to find a solution amenable to both views. 

• As noted by Mr. Jim Willis (New York) during the NEWMA meeting, New York, Murray Control 

Systems, and NIST OWM will work together to finalize a recommendation for this item.

• NIST OWM looks forward to working with the other submitters (New York and Murray

Equipment) to find a solution that is more widely supported.

• For reference, OWM has retained the technical comments offered in its original analysis below.
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Background to Consider:

o Based on comments at the 2019 NCWM Annual Meeting from the submitters of Item VTM-18.1 

(New York & NIST OWM) and with support from the Meter Manufacturers Association, the 

Committee agreed to modify items (f) and (g) in the proposal and to designate part (g) as 

nonretroactive as of January 2022 to become retroactive January 2025.

o At the July 2019 meeting, comments from Murray Equipment noted significant problems with 

fraud in Europe where they are permitted, suggesting the item be withdrawn.

o Comments from Florida at the July 2019 meeting suggested limiting the application to only certain 

products. This issue is addressed in the new Item 20.1 from Murray Equipment, which was 

subsequently withdrawn and is now included in this item (VTM-18.1).

o When presented for a vote, the revised item failed to obtain sufficient votes to “pass” or “fail” 

and was returned to Committee.

o In reviewing the proposals, one needs to recall that a manifold flush system allows liquid to be 

diverted from the discharge line on single hose multi-product VTMs so that liquid of one 

product is not mixed with liquid of another in the discharge line.

o OWM acknowledges the safety advantages of such a system since the operator does not have 

to climb on top of the VTM truck to flush product from the line before delivering another 

product.

o However, without appropriate safeguards, these systems represent a significant potential for 

fraud. Concerns have been voiced over this potential at multiple national and regional 

meetings.

• OWM offered the following comments on Item 18.1:

o At its Fall 2019 meeting, NEWMA recommended changes to extend the nonretroactive date. 

OWM recognizes this extension may help move the item forward and, thus, help reduce the 

potential for fraud when using these systems. OWM would also like to hear from the Meter 

Manufacturers Association regarding the difficulty designing communications between the 

metering system and the flushing system and the feasibility of an earlier nonretroactive date.

o At its Fall 2019 meeting, NEWMA also recommended eliminating the retroactive date. Given the 

potential to facilitate fraud and a number of comments received to that effect over the past several 

years, OWM is concerned with the proposed elimination of the retroactive date. However, if this 

will allow the item to progress it may represent a viable solution. OWM heard from New York

regarding the extensive number of systems already in the field, particularly mechanical ones which 

may not lend themselves to modification. OWM is also interested in how others view the proposal 

to eliminate the retroactive date.

o The remaining regional associations recommended the item be given Developing status to permit 

the submitters to address concerns raised during the Annual Meeting.

o Comments from the SWMA voice serious concern about the potential for cross contamination of 

products. The proposal in Item 20.1 may help to address this by including limitations on the type 

of products with which these systems can be used.
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o OWM believes the term “operational” should be deleted from proposed paragraph UR.2.6.1. since 

the key point is that the system should not be used when a commercial transaction is in progress.

• OWM offered the following comments to consider in addressing the recommendations originally 

presented in VTM-20.1 and now included as part of this item (VTM-18.1):

o OWM notes that one jurisdiction (New York) in NEWMA specifically opposes the limitation of 

product types. The S&T Committee will have to consider how to address this.

o After discussing the proposed limitation of using manifold flush systems to only products other 

than engine fuels with News York W&M, OWM recognizes there may be instances where a VTM 

is used to transport only engine fuels of different types and grades. OWM recognizes that a blanket 

limitation may unintentionally impact applications that may not have been considered under Item 

20.1.

o While OWM continues to have concerns regarding the safety of delivering products such as 

gasoline and home heating oil through the same meter (and questions whether a single meter is 

suitable for such purposes), OWM recognizes this is already a widespread practice in the industry 

and placing a blanket limitation may not best serve the community. OWM suggests working with 

the submitter of 20.1 to see if there are ways to resolve specific concerns without impacting other 

applications.

o In its review of these issues, OWM also noted the need to clarify when paragraph S.3.1.1. applies 

and suggests the addition of the terms “multiple-product, single discharge hose” to both the title 

and preamble.

Summary of Discussions and Actions:

Manifold flush systems are typically used on VTM’s with multiple compartments, delivering multiple 

products through a single hose. The purpose of the system is to allow the driver a means of clearing the 

hose of product prior to delivery (e.g., clearing the hose of diesel fuel before delivering clear kerosene). 

These types of systems are often marketed as a safety feature in that it eliminates the need for the driver to 

climb on top of the truck to clear the hose. Such systems are also useful in helping avoid crosscontamination. Typically, the driver attaches the nozzle to the manifold and pumps product back into the 

supply tank via the manifold until the previous product is flushed from the hose. There is often a sight 

gauge which allows the driver to tell when the product is flushed.

The obvious concern is that this makes it very easy for the driver to circulate product through the meter

prior to delivery, which goes against S.3.1. It should be noted that it also goes against S.3.1. when the 

driver climbs on top of the tanker and clears the hose. The submitter has voiced concerns involving the 

safety of this practice noting that the operator could be subject to falls from the tanker. The distance 

between the flush system and the hose reel is also a factor in how easy it is for the driver to facilitate fraud.

Manifold flush systems are available from OEMs and can be found in various catalogs. Looking on multiple 

websites, these systems are being installed across the country and for some manufacturers seem to be 

standard equipment for new trucks. The submitter of VTM-1 has also seen these systems installed on trucks 

that are for sale where the seller notes the system as a selling point. He can foresee these systems being 

mandated in the future as a safety requirement and would like W&Ms to have a clear policy before that 

happens.
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Another concern is with systems fabricated onsite. These systems are often difficult to distinguish and 

installed in an inconspicuous manner. While the submitter of VTM-1 has ordered many of these systems 

out-of-service until repaired, it can be frustrating for the owner because the truck was used in another state 

for years and approved by weights and measures jurisdiction in the other state. This lack of uniformity is 

problematic for both officials and private industry.

This item was originally submitted by New York Department of Agriculture as a Developing Item. The 

item was intended to encourage uniformity in how manifold flush systems were being designed, installed, 

and regulated with the goal of minimizing the facilitation of fraud through the use of these systems while 

realizing the safety benefits provided by such systems.

This item was one of two separate parts of VTM-1 (previously VTM-1A and VTM-1B) considered by the 

Committee at the 2018 NCWM Annual Meeting. The item voted on at the 2018 Annual Meeting, VTM1A was adopted and VTM-1B was assigned an Informational status and carried-over to the next cycle.

In the period between 2018 and 2021, the Item Under Consideration underwent multiple changes based on 

feedback received at regional and national meetings and, more recently based on collaborations amongst 

the submitter of this and other related items, which resulted in the current Item Under Consideration. In 

developing the current proposal, the submitters considered concerns raised regarding the use of these 

systems, including the potential for facilitation of fraud with the use of these systems; the potential for cross 

contamination of products in different tank compartments; and the suitability of using a single meter for 

multiple product types. These concerns were balanced against comments indicating that product handling 

practices have occurred for many years without the use of such systems and there are distinct safety 

advantage for drivers when these manifold flush systems are used.

At the 2022 NCWM Interim Meeting, the Committee heard from Mr. Willis and provided an update that 

contained amended language with modifications to UR.2.6.2 and creating UR.2.6.3. The amendments were 

agreed upon by the other joint submitters, NIST OWM, and Murray Equipment. Mr. Willis stated that the 

new proposed language would hold device owners responsible for ensuring there is no cross-contamination 

of fuels and also allows jurisdictions to prohibit using manifold flush systems or dispensing dissimilar 

products through a single meter. The Meter Manufacturers Association (MMA), Mr. John Hathaway 

(Murray Equipment), Ms. Cheryl Ayer (New Hampshire), and Mr. John McGuire (New Jersey) also voiced 

support for the amended language and urged the item be given a Voting status. Mr. Hal Prince (Florida) 

opposed the entire item, indicating the use of a single meter to dispense different products is not legal in 

his state and has concerns of cross-contamination of fuel. During the Committee work session, the 

Committee assigned this item a Voting status with the amended language seen above as the Item Under 

Consideration. The item as presented to the 2022 NCWM Interim Meeting can be seen below the Item 

Under Consideration.

At the 2022 NCWM Annual Meeting, the Committee heard in its open hearings and voting session that 

some commenters were in favor of making the item retroactive. 

Mr. Dmitri Karimov (speaking on behalf of the MMA) commented that the proposed changes are intended 

to reduce the potential for fraud and increase driver safety and the MMA supports the proposal as written.

Mrs. Tina Butcher (NIST OWM) reiterated comments presented in the OWM’s Executive Summary (as 

shown earlier in this item). She commented that OWM believes the proposed changes are a reasonable 

solution to incorporate additional provisions that will help further reduce the potential for fraud when these 

systems are in use and acknowledges the potential benefits to driver safety during a flushing operation. The 

proposed changes offer additional safeguards to already existing language. She also shared that the three 

submitters (New York, Murray Equipment, and NIST) have done a lot of work on this item since January 
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2020 and have strived to balance the concerns and comments expressed over fraud and cross-contamination 

with those of the distinct safety advantages for the driver. She also observed that the practice of flushing 

is already a widespread practice, but additional provisions are needed to limit fraud when manifold flush 

systems are used.

Mr. Willis shared that these manifold flush systems are already in widespread use in New York. Smaller 

businesses use them and this provides a safer method for the flushing operation. He believes the item is 

fully developed and ready for a vote.

Mr. Hathaway stated his support for the item and indicated he agrees with most of the changes made and 

supports the item as a voting item. Contamination is not eliminated entirely with these systems, but is 

minimizes, particularly with the addition of the proposed user requirement UR.2.6.2. Minimizing Cross 

Contamination. He continues to believe, however, that companies should not dispense dissimilar fuels 

through a single manifold system. In those cases, there needs to be two sets of meters and two manifold 

systems. 

The Committee also heard comments in opposition to the proposal and original paragraph and also heard 

questions and concerns regarding the proposed nonretroactive status of some portions of the proposal.

Mr. Hal Prince (Florida) opposed the proposal, noting he cannot endorse a device that can facilitate cross 

contamination of fuel. He stated that Florida will not allow these systems to be used. His major concern 

is with systems delivering engine fuels; he believes manifold flush systems should be prohibited on such 

systems. Mr. Prince also noted the irony of changes made to ASTM standards relative to ensuring high 

quality fuels and then two weeks later considering the approval of a proposal such as this. He commented 

that the proposed language in UR.2.6.2. Minimizing Cross Contamination is a bit misleading, noting the 

act of properly flushing a system can cause contamination.

Mr. Charlie Stutesman (Kansas) observed that product flushing is already being done, but in a less safe 

manner. He commented that drivers should probably not go to the top of the vehicle tank for safety reasons 

and, if it’s safer to carry out that procedure on the ground, this is the direction to go. Mr. Stutesman also 

noted his state is starting to see meters equipped with multiple calibration factors and he expects more 

vehicles will be going to a single meter system so we need something to address this. He questioned 

whether manifold systems can be retrofitted and asked if the requirements can be made retroactive rather 

than allowing these systems to operate without the additional safeguards.

Mr. Kevin Schnepp (California) indicated he agrees with the concerns shared by Mr. Prince and Mr. 

Stutesman. He also opposed the last sentence in the recommended UR.2.6.2. Minimizing Cross 

Contamination, noting that the word “recommended” is not sufficient for regulatory action. He also 

observed that the phrase “radically different” is rather subjective making enforcement difficult.

Ms. Angela Godwin (San Bernadino County, California) agreed with the concerns regarding the 

nonretroactive status of some portions of the proposal and recommends those be made retroactive.

Ms. Ayer supported the item but likes the idea of making the nonretroactive portions of the proposal 

retroactive.

During the voting session, Mr. Willis suggested some changes that might help address Mr. Prince’s concern. 

He offered a proposed change of adding the phrase “at the discretion of the jurisdiction” to portions of the 

proposal to make it clear that the use of these systems is up to the jurisdiction with regulatory authority and 

allow decisions to be made within the jurisdiction regarding their use. However, this suggestion did not 

appear to satisfy the concerns raised.
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In its addendum sheets, the Committee also recognized comments from previous meetings that time may 

be needed to facilitate the changes required. The Committee recommended no change to the Item Under 

Consideration in Publication 16 and presented the item for a vote. At the voting session, the Committee 

again heard comments opposing the non-retroactive status. However, the Committee presented the item as 

written based on the rationale shared in its addendum sheets.

This item did not receive sufficient votes to pass or to fail and was returned to the Committee. The 

Committee hopes the submitters will consider the comments heard during the meeting and continue work 

on the item.

Regional Association Reporting:

Western Weights and Measures Association

During the 2021 Annual Meeting Open Hearing the following comments were heard: 

Mr. Matt Douglas (California - DMS) remarked that California supported further development. Has there 

been any further development since the Annual Meeting? 

The WWMA S&T Committee recommended the status remain Developmental. The Committee 

recommended that the submitters (NIST, New York, and Murray Equipment) continue their work together 

to further develop the item.

During the WWMA 2022 Annual Meeting the following comments were received: 

Mr. Scott Simmons (Colorado Division of Oil and Public Safety) supported this item. Flushing is 

happening already. It is dangerous to flush into the tank. You can run different products through the 

electronic meters very easily due to multipoint calibration. They need to be able to flush products through 

and do so safely. He thinks this is fully developed and it's time for it to pass and be part of the code. 

Mr. Michael Keilty (Endress+Hauser and Chair of the NTEP Measuring Sector) stated they talked about 

test drafts and this item. The Measuring Sector has no recommendations. The absence of the word 

electronic; how would you do this with an analog system? It was described that you cannot do this with an 

analog system. 

Mr. Kevin Schnepp (California Division of Measurement Standards) stated he did not opposed to this item, 

wants to bring up that his concerns have not been addressed, “radically different characteristics” and "not 

recommended" is not an avenue for enforcement. Needs further developing. 

Mr. Scott Simmons (Colorado Division of Oil and Public Safety) - it may not be appropriate for older 

analog devices; however, they have been doing it and will continue to do it on the newer technology. Does 

not need to be retroactive. Agrees with Mr. Schnepp to a point but doesn't want that to prevent this from 

going forward. 

During open hearings, the Committee heard testimony in support of the item but there are concerns about 

language contained in UR.2.6.2. including “radically different” and “not recommended” with reference to 

enforceability. There were also comments regarding applicability to analog devices. The WWMA S&T 

Committee recommends that this item be assigned a Developing status. 

Southern Weights and Measures Association
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During the 2021 Annual Meeting Open Hearing no comments were received on this item. NIST requests 

this item remain Developmental. 

This Committee recommended the status remain Developing at the request of the submitter. 

The following comments were received during the 2022 SWMA Annual Meeting: 

Mr. Jason Glass (Kentucky and NCWM S&T Committee member) proposed the following amendment to 

this proposal: 

VTM 18.1 

UR 2.6.2. 

This system shall not be used for products, that when exposed to one another, will cause either of 

those products to not meet their respective quality specifications.

Mr. Prince (Florida) stated that he has been concerned with weak language on cross contamination in the 

past. 

Mr. Keilty (Endress+Hauser) stated that “electronic” should be added between hose and metering on page 

187 line 10. 

The SWMA S&T Committee recommended moving this item forward as a Voting Item with the proposed 

language from Mr. Glass replacing the current UR 2.6.2. language. 

Northeastern Weights and Measures Association

During the 2021 NEWMA Interim Meeting open hearings, comments were heard from Mr. Jim Willis (New 

York) as submitter of this item. He stated that communication was in process with Murray Controls in 

regard to changes to this proposal. The flushing “systems” have been around for decades and not just as 

OEM systems. The driver would climb on top the truck to flush a line. Now they can flush the hose without 

the danger of falling off the truck. Some suggestions have been made to limit the products carried on the 

truck to similar products. NYS does not support such language as the flush system actually allows for the 

safe clearing of the hose and minimizes contamination. A flush manifold enables a truck to carry different 

products at the same time.

 

Mr. Willis recommended further development.

Mr. Lou Sakin (Hopkinton/Northbridge, Massachusetts) asked when development may be finished. Mr.

Willis responded that hopefully by the NCWM Interim Meeting.

Mr. John McGuire (New Jersey) supported Developing status. 

The NEWMA Specifications and Tolerances Committee recommended that this item remain in Developing 

status and encouraged New York, NIST, and Murray Controls to continue working towards full 

development. 

During the 2022 Interim meeting Mr. Willis recalled a recent incident in New York where a tank-truck that 

was next to inspectors testing a vehicle tank meter experienced an issue after possible switch loading in 

which static discharge caused an explosion. An employee of company received burns and a broken leg 

while the inspectors were knocked to the ground. Mr. Willis urged a Voting status on this item due to safety 

considerations. Mr. Michael Keilty (Measuring Sector Chairman) commented that this system should be 
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identified as “electronic” as it will not work with an analog system. Mr Keilty also noted that in UR-2.6.2 

“dispensing products with radically different characteristics...not recommended” is vague. Mr. Hathaway 

commented that he was surprised it was not accepted at NCWM Annual in 2022 and would like to 

understand what could be changed so that it passed. Mr. Hathaway noted that flush systems are being used, 

there is code in HB44 that describes them and the language in this item is making it a more controlled 

system to prevent contamination and fraud. Mr. Mcguire, Mr. Willis, Mr. James Cassidy (Massachusetts), 

Ms. Ayer, and Mr. Marc Paquette (Vermont) all voiced support for a Voting status. 

After hearing comments from the floor, the Committee believes this item has merit and is fully developed. 

The Committee recommends this item for a Voting status. 

Central Weights and Measures Association 

During the CWMA 2021 Interim Meeting, the CWMA heard comments from the floor. Ms. Diane Lee

(NIST OWM) commented about this item in the NCWM Annual report. Mr. Charles Stutesman (Kansas)

asked if the intent of this item was for vehicle motor fuel or for all items such as home heating oil.

CWMA S&T Committee recommended item as a Developing Item.

During the 2022 CWMA Annual Meeting, the CWMA heard no comments from the floor and 

recommended this item remain a Voting item.

During the 2022 CWMA Interim Meeting Mr. Dmitri Karimov – Liquid Controls noted that some of these 

systems contain one meter and two hoses. This would not apply to those. Believe the intent was to refer to 

a single meter instead of a single hose. 

The CWMA S&T Committee believes this item is fully developed and recommends Voting status.

VTM-20.2 A Table T.2. Tolerances for Vehicle Mounted Milk Meters.

(Note: This item was revised based on changes that were made by the Committee at the 2021 Interim 

Meeting.)

(Note: The Item Under Consideration was removed from the voting consent calendar at the 2021 Annual 

Meeting and the S&T Committee made this a Developing Item.)

Source: POUL TARP A/S

Submitter’s Purpose and Justification:

Change tolerances to accommodate more efficient milk-metering systems.

OWM Executive Summary for VTM-20.2 – Table T.2. Tolerances for Vehicle Mounted Milk 

Meters.

OWM Recommendation: OWM supports the Assigned status for this item and encourages the task 

group to continue its review of the proposed OIML tolerances for Vehicle Tank Milk Meters.

• One of the questions raised concerning the current proposal that includes the OIML tolerances is that 

the proposal includes tolerances for the system and a separate tolerance for the meter. 
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• NIST OWM observed that a separate tolerance for the meter would apply during OIML type 

evaluation. However, NIST HB 44 only includes requirements for the entire measurement system 

and not separate main elements nor does it have separate tolerances for main elements known to be 

metrologically significant. 

• NIST OWM will look forward to more discussion of this item during task group meetings.

Table 3. Summary of Recommendations

VTM-20.2 Table T.2. Tolerances for Vehicle Mounted Milk Meters.

V D W A I Notes* Comments

Submitter/Task 

Group 

Task Group Documents:

• Milk Meter Tolerance Spreadsheet (01-14-

2021)

• Milk Meter Tolerance Report (Task 

Group, 07-19-21)

• Proposed Tolerance Tables (01-10-2022)

• Milk Meter NTEP CC Data (01-10-2022)

OWM

WWMA 

SWMA 

NEWMA 

CWMA 

NCWM

Letters of Support Letters of Opposition Notes

Industry

Agri-Mark (01-13-20)

Dean Foods (01-14-20)

Dairy Farmers of America 

(01-14-20)

Danone North America 

(01-15-20)

Manufacturers

Retailers and Consumers

*Notes Key:

1 − Submitted modified language

2 − Item not discussed

3 − No meeting held

4 − Not submitted on agenda

5 − No recommendation or not considered
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Item Under Consideration:

Amend Handbook 44, Vehicle-Tank Meters Code as follows: 

T.2. Tolerance Values. – Tolerances shall be as shown in Table 1. Accuracy Classes and Tolerances for 

Vehicle-Tank Meters Other Than Vehicle-Mounted Milk Meters and Table 2. Tolerances for VehicleMounted Milk Meters.

(Amended 1995, 20XX) 

Table 2. 

Tolerances for Vehicle-Mounted Milk Meters

Indication

(gallons)

Maintenance Tolerance

(gallons)

Acceptance Tolerance

(gallons)

100 0.5 0.3

200 0.7 0.4

300 0.9 0.5

400 1.1 0.6

500 1.3 0.7

Over 500 Add 0.002 gallon per indicated 

gallon over 500

Add 0.001 gallon per indicated gallon 

over 500

 (Added 1989)

Table 2. 

Tolerances for Vehicle-Mounted Milk Meters

Acceptance Tolerance Maintenance Tolerance

Complete Measuring System 0.5 % 0.5 %

Meter Only 0.3 % 0.3 %

(Amended 20XX) 

NIST OWM Detailed Technical Analysis:

A Milk Meter Task Group Meeting last met on January 3, 2022 to further discussed the proposed tolerances 

for Milk Meters. This is a proposal to increase the tolerances for vehicle mounted pump metering systems 

that measure milk and the proposed tolerance are those used in OIML for milk measuring systems.

Proposed 

Tolerance

Current NIST 

Tolerance

Proposed 

Tolerance

Current NIST 

Tolerance

Collected volume Maintenance Maintenance Acceptance Acceptance

Gallon Percent % Gallon Percent % Gallon Percent % Gallon Percent %

50 Gallon 0.25 0.5 % 0.25 0.5 %

100 Gallon 0.5 0.5 % 0.5 0.50 % 0.5 0.5 % 0.3 0.30 %
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200 Gallon 1 0.5 % 0.7 0.35 % 1 0.5 % 0.4 0.20 %

300 Gallon 1.5 0.5 % 0.9 0.30 % 1.5 0.5 % 0.5 0.17 %

400 Gallon 2 0.5 % 1.1 0.275 % 2 0.5 % 0.6 0.15 %

500 Gallon 2.5 0.5 % 1.3 0.26 % 2.5 0.5 % 0.7 0.14 %

The submitter (Poul Tarp) explained that use of vehicle mounted pump metering systems to measure milk 

reduces the amount of time needed to collect and process the milk which reduces the cost and loss of product 

that would occur with a slower measurement process. But, with the use of vehicle mounted pump 

measuring systems, entrained air is produced that cannot be removed and this air is measured as product. 

As such, with the use of a pump metering system there is an inherit loss to the buyer. Although the system 

has means for air elimination, not all entrained air can be removed and this is the submitter’s reason for 

requesting that the tolerances currently in the HB be increased. 

Poul Tarp also noted that it is recognized by the European Standardization Agencies: Measuring Instrument 

Directive (MID) and Organization of Legal Metrology (OIML) Recommendation (R) 117 Dynamic 

measuring systems for liquids other than water and the dairy industry in general that it is not possible to 

remove all the air from milk before measuring it. Poul Tarp notes that the MID and OIML (R) 117 standards 

specify that measurements of a vehicle mounted milk metering system must not result in inaccuracy of 

more than 0.5 % at any given amount being collected from a minimum of 50 gallons and up to +500 gallons. 

NIST HB 44 Section 3.31.has a designated tolerance table in volume for vehicle-mounted milk meters that 

was added to the code in 1989 with an acceptance tolerance of 0.3 and maintenance tolerance of 0.5 gallons 

for the first 100 gals and these tolerances decrease in percent tolerance as the indicated volume increases, 

as was reported in a presentation from Poul Tarp: 

NIST OWM’s initial points to consider as the Committee began to deliberate on the proposal were:

- Are there other methods that can be employed to remove entrained air from the milk? 

- Can the amount of error introduced from entrained air be determined? 

- Should NIST HB 44 tolerances be aligned with OIML R 117 less stringent tolerances, as 

recommended by the submitter.

- Should there be a separate tolerance table to address vehicle mounted pump metering systems? 

During the 2019 Interim Meeting another company stated that they met the current tolerances in HB 44 and 

were issued an NTEP certificate and believe that the current tolerances are appropriate. Other State 

regulators commented that the current certificate was limited to testing up to 300 gallons. At that time the 

S&T Committee assigned a task group to this item and NIST OWM expressed interest in working with the 

task group. 

Mr. Charlie Stutesman (Kansas), Chair of the Task Group, sent an email to the Milk Meter Tolerance Task 

Group (TG) providing a list of the TG members and the TG’s mission. Mr. Stutesman also informed the 

Task Group that most communication will be conducted via e-mail and that face-to-face meetings will be 

planned at Interim and Annual Meetings. 
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The following list contains the names of members on the Milk Meter Tolerance TG:

Chair – Mr. Charlie Stutesman (Kansas) 

NEWMA Representative – Mr. Jim Willis (New York) 

SWMA Representative – TBD

WWMA Representative – Mr. Jeff Cambies (California) 

NTEP Technical Advisor – Mr. Mike Manheim

NIST Technical Advisor – Ms. Diane Lee

Measurement Canada Technical Advisor – Mr. Luciano Burtini 

Industry Representative – Mr. Carey McMahon (Poul Tarp)

Industry Representative – Ms. Leigh Hamilton (Piper Systems)

Industry Representative – Mr. Brandon Meiwes (Dairy Farmers of America)

Industry Representative – Mr. Bob Fradette (Agri-Mark)

Mr. Mitch Marsalis (Los Angeles County, California) has agreed to be the SWMA representative. I am 

just waiting on formal assignment by the NCWM Chair for Mitch.

Milk Meter TG Mission:

The mission of the Task Group is to review and possibly recommend changes to the tolerances that apply 

to milk meters, which may include milk measuring systems, in Sections 3.31. Vehicle Tank Meters, Section 

3.35. Milk Meters, Section 3.37. Mass Flow Meters, and Section 4.42. Farm Milk Tanks. This TG will 

consider the tolerances proposed in S&T item VTM-20.2 and the tolerances in OIML R 117-2 “Dynamic 

measuring systems for liquids other than water” in their discussion.” 

Mr. Stutesman provided the Task Group with milk meter tolerances and requirements from OIML-R117-

2: 2007, NIST HB 44 Tolerances for Milk Meters that are located in the VTM Code Section 3.31, the Mass 

Flow Meter Code Section 3.37, and the Farm Milk Code Section 4.42 and Measurement Canada’s 

tolerances for milk meters and requested feedback from the task group on appropriate tolerances to apply. 

A Task Group member from Poul Tarp, the original submitter of the item, recommended that the proposal 

be changed to align NIST HB 44 with the tolerances for milk meters in OIML R-117-2. Mr. Stutesman 

circulated a proposal for consideration by the task group that would aligns the tolerances in NIST HB 44 

Section 3.31 Table 2 with OIML to tolerances. OIML Tolerances seem to apply two different tolerances. 

0.5 % tolerance for milk meters in a system and 0.3 % tolerance for a meter outside of a system that is used 

to measure milk. The proposed tolerances and changes to NIST HB 44 are provided below: 

Table 2. 

Tolerances for Vehicle-Mounted Milk Meters

Indication

(gallons)

Maintenance Tolerance

(gallons)

Acceptance Tolerance 

(gallons)

100 0.5 0.3

200 0.7 0.4

300 0.9 0.5

400 1.1 0.6

500 1.3 0.7

Over 500 Add 0.002 gallon per indicated 

gallon over 500

Add 0.001 gallon per indicated gallon 

over 500
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Table 2.

Tolerances for Vehicle-Mounted Milk Meters

Indication 

(gallons) Acceptance Tolerance Maintenance Tolerance

Complete Measuring System 0.5 % 0.5 %

Meter Only 0.3 % 0.3 %

Proposed change to Handbook 44- Simple rewrite of table 2 and paragraph T.4. in 3.31 VTM Code and 

Table 1 in 3.35 Milk Meter Code.

3.31 Vehicle Tank Meters 

T.2. Tolerance Values. – Tolerances shall be as shown in Table 1. Accuracy Classes and Tolerances for 

Vehicle-Tank Meters Other Than Vehicle-Mounted Milk Meters and Table 2. Tolerances for VehicleMounted Milk Meters.

(Amended 1995, 20XX)

If changes to the product depletion test tolerances in Handbook 44 are made to match OIML R117-1 

paragraph 2.10.1: 

T.4. Product Depletion Test. – The difference between the test result for any normal test and the 

product depletion test shall not exceed 0.5 % of the volume delivered in one minute at the maximum 

flow rate marked on the meter for meters rated higher than 380 Lpm (100 gpm) or 0.6 % of the volume 

delivered in one minute at the maximum flow rate marked on the meter for meters rated 380 Lpm (100 

gpm) or lower. Test drafts shall be of the same size and run at approximately the same flow rate. For 

vehicle tank meter measuring systems used to measure milk, the effect due to the influence of the 

air or gases on the measuring result shall not exceed 1.0 % of the quantity measured.

Mr. Charlie Stutesman also asked the Task Group if consideration should be given to updating all of the 

codes pertaining to milk metering devices in NIST HB 44 and if all milk metering requirements should be 

included in a single code. 

The NCWM Milk Meter Tolerance Task Group met virtually on January 7, 2020. During this meeting the 

Task Group discussed:

- the system of milk collection from farm to processer (seller to buyer), 

- the operation of metering systems that measure milk to include discussion of air elimination 

systems,

- review of the milk measuring tolerances in NIST HB 44 from 1919 to 2020, 

- review of the proposal to harmonize the NIST HB 44 VTM code milk metering tolerances with 

OIML tolerances for single milk meters and milk meter measuring systems, and

- whether or not the task group wanted to consider expanding its scope to include combining all milk 

metering requirements in NIST HB 44 to a single code. 
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By consensus the Task Group agreed with harmonizing the VTM milk metering tolerance with OIML R 

117 tolerances and that those tolerance be presented during the NCWM 2021 Interim Meeting for 

discussion. The Task Group also agreed that a request should be made to the S&T Committee to expand 

the scope of the Task Group to include combining milk meter requirements in NIST HB 44 to a single code.

Mr. Stutesman (TG Chair) proposed the TG visit a location to review Milk Measuring systems in use as its 

next step. The Task Group last met on July 1, 2021. 

NIST OWM is looking forward to gaining additional information on the various systems for milk metering 

and their capabilities and believes the task groups plans to visit a site will be helpful in determining the best 

approach for acceptable solution for milk metering systems. In the meantime, harmonizing with OIML 

tolerances may be an acceptable path forward. OWM reiterates its original questions concerning the 

operation of milk metering systems. OWM encourages the task group to continue its investigation of these 

systems.

Summary of Discussions and Actions:

A Milk Meter Tolerance Task Group was formed and assigned to this item. Please contact the Task Group 

Chair for more information:

Mr. Charlie Stutesman

Kansas Department of Agriculture

(785) 564-6681, charles.stutesman@ks.gov

Existing tolerances are based on the accuracy of the Flow meter itself. The proposed Tolerances are based 

on Milk Metering Systems where the magnetic flow meter is a part of the Milk Metering system handling 

milk containing air.

The accuracy of the Flow meter will always be influenced by the way it is used. The only way you can 

obtain the accuracy described by the manufacture is when the flow meter is operating as a “stand alone” 

unit and, equally important, only if the product passing through the flow meter is complete air-free.

The submitter provided the following:

During the past 20 years, the need for improved efficiency in the collection of milk has resulted in the 

use of milk pumping equipment being installed on milk tankers. 

One of the most obvious places for a modern Dairy to optimize is the amount of time that the milk 

tanker uses to make a collection. If you can reduce the collection time at each farmer, the Dairy will be 

able to get a significant reduction in collection and transport cost for the benefit of the Farmer, 

Consumer and the Dairy itself. At the same time, you will get an environmental benefit as a result of 

reduced CO2 in the milk collection process. 

The consequence of introducing pump systems on milk tankers is that it causes air to be mixed with the 

milk which again will influence the accuracy of the magnetic flow-meter mounted in the system. Milk 

entrains air unlike petroleum liquids which do not. As you know, the flow meter will count anything 

that passes through the meter – liquid as well as air – and it is therefore essential that as much air as 

possible is removed from the milk before it reaches the flow-meter. However, it is widely recognized 

that it is not possible to remove all the air from the milk, which will result in an inaccuracy. 
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It is therefore essential that the tolerances for vehicle mounted milk pump systems using magnetic flowmeters for determining milk volume reflects todays way of collecting milk. This means that existing 

Tolerance for milk meters cannot be used when the milk meter is a part of a system where different

system parts will influence the accuracy of the count. Such milk metering systems will need to be 

classified with their own tolerances.

Based on our 25 years of experience as a manufacturer of these systems and more than 3000 

installations on milk trucks operating in more than 15 countries, we would like to propose that the 

Tolerance for Vehicle Mounted Milk Metering Systems is changed from 0.3 % to 0.5 % and that the 

tolerances will be listed and classified separately and not be associated with products from the oil 

industry. Our proposal is consistent with Weights & Measures tolerances accepted around the world.

We hope that the NCWM will consider our proposal and we will be more than happy to meet with you 

and answer any questions you may have. We believe that a change of Tolerance is necessary in order 

for the Handbook 44 to reflect today ́s milk collection and the technical progress within milk collection.

Yours sincerely

Poul Tarp

President POUL TARP A/S 

The POUL TARP milk pump system holds an MID approval which is recognized and in accordance with 

guidelines and standards described in the OIML - INTERNATIONAL ORGANIZATION OF LEGAL 

METROLOGY
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FLOW COMPUTERS REGULATION IN THE US:
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The standards related to metrological aspects come from OIML R117-1 for liquids (Dynamic measuring 

systems for liquids other than water, part 1: Metrological and technical requirements) and documents D11 

(General requirements for electronic measuring instruments) and D31 (General requirements for softwarecontrolled measuring instruments) from OIML.

At the NCWM 2020 Interim Meeting Mr. Carey McMahon (Poul Tarp) provided a presentation on his 

company’s VTM milk metering system advocating for expanding tolerances for these systems.

Ms. Leigh Hamilton (Piper) provided a presentation concerning the piper system and stated in her 

presentation that piper currently has an approved NTEP certificate for their device that is in service in the 

U.S. Ms. Leigh opposes this item to increase the tolerances for milk meters and noted in her presentation 

that there may not be a need to increase the tolerances in order to move forward in allowing innovation in 

milk measurements. 

Mr. Charles Stutesman (Kansas) provided a presentation on research that KDA has done on the history of 

3 HB 44 Codes (3.31. VTMs, 3.35. Milk Meters, and 4.42. Farm Milk Tanks) and the issue of Piper’s NTEP 

Certificate. Mr. Stutesman discussed complications involved in measurement of product using various 

methods and potential shortcomings of Piper’s NTEP Certificate.

Mr. Doug Musick (Kansas) stated that he does not believe there is enough information presented to change 

existing tolerances and noted that the Piper system was only evaluated for accuracy up to a measurement 

of 300 gallons. He also noted that he believes that Piper’s certificate should be amended to qualify the 

system for draft sizes up to 300 gallons. Mr. Mike Keilty (Endress + Hauser) commented that he had 

concerns with Piper’s certificate. Ms. Hamilton noted that Piper followed and followed guidelines as 
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provided during the NTEP evaluation. Ms. Diane Lee (NIST OWM) stated that the Committee may want 

to consider a Developing status for this item and that more information is needed concerning air elimination 

methods for milk metering systems.

A representative from the Dairy Farmers of America stated that they oppose the increase in tolerance but 

supports the use of VTM metering systems. Mr. Carey McMahon (Poul Tarp) pointed out that the Poul 

Tarp system can be accurate for any size measurement, but the beginning and end of the measurement 

would not be accurate measures (within tolerance) due to entrained air in the product when the flow is not 

uniform. Mr. Dmitri Karimov (MMA) stated that the proposal should be further developed and pointed out 

that due to the tolerance structure becoming more stringent as the volume of the measurement increases, 

the acceptance tolerance at 500 gallons is unreasonable. Mr. Hal Prince (Florida) stated that he does not 

agree with expanding the tolerances. Mr. Prince believes that air elimination should be the focus and that 

the proposal should be assigned to a task group. Mrs. Tina Butcher (NIST OWM) noted that testing should 

be performed using multiple quantities and flowrates. Mr. Charles Stutesman (Kansas) pointed out that 

confusion is generated by multiple HB 44 codes addressing the measurement of milk and that the proposal 

should be assigned to a TG to sort this out. Mr. Stutesman also pointed out there is no requirements in HB 

44 for air elimination pertaining to milk metering in these codes. Mrs. Butcher noted that the current HB 

44 requirements may not be flexible enough for this new technology and that the existing codes may need 

to be reviewed and updated.

Ms. Leigh Hamilton (Piper) stated that this is not simply a consideration of only a change in tolerances. 

There are other requirements (currently in the OIML standard) that should also be considered in making 

any changes to the existing HB 44 requirements. Mr. Mike Keilty (Endress+Hauser) stated that air 

elimination is a difficult problem to mitigate and noted that he is not sure if it is necessary to expand the 

existing tolerances or make other amendments. Mr. Carey McMahon (Poul Tarp) stated that using the 

existing HB 44 tolerances in the VTM Code, at a draft of 5000 gallons, the tolerance value is highly 

unreasonable. Mr. Charles Stutesman (Kansas) noted that the type evaluation performed on the Piper 

system was limited to a draft of 300 gallons. If evaluation had included other draft sizes, the Piper system 

mat have failed the testing.

Mr. Ken Ramsburg (Maryland) stated that the proposal should be given a developing status. Mr. Ramsburg 

agreed that there is no existing requirement for this type of system addressing air elimination and stated 

that the flow meter, air eliminator, plumbing, and pumps all need to be considered during evaluation and 

the evaluation should be conducted on the system. 

Mr. Tim Chesser (Arkansas) questioned whether the flow meter used in the system is appropriate and noted 

that there are many unanswered questions surrounding this issue. Mr. Jim Willis (New York) recommended 

a Developing status for this item. Mr. Kevin Schnepp (California) stated that although he is opposed to 

relaxing existing tolerances, he supports the development of this proposal by an assigned task group.

During the Committee’s work session, the Committee agreed that this item has merit and should be given 

an Assigned status. The charge to the assigned task group will be to address three HB 44 codes (VTM, 

Farm Milk Tanks and Milk meters) to review the requirements and tolerances found in these codes and 

assess the need for changes.

The NCWM 2020 Annual Meeting, due to the 2020 COVID-19 pandemic, was adjourned to January 2021, 

at which time it was held as a virtual meeting. Due to constraint of time, only those items designated as 

2020 Voting Items were addressed. All other items were addressed in the subsequent 2021 NCWM Interim 

Meeting.
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At the NCWM 2021 Interim Meeting, the Committee heard from Mr. Stutesman (who gave an update on 

the task group activities. Mr. Stutesman reported that the Milk Meter TG worked via e-mail communication 

and reviewed and discussed the proposed Milk Meter Tolerances in Agenda item VTM-20.2. The Milk 

Meter Task Group also discussed the tolerances that are included in NIST HB 44 for Milk meters in various 

parts of HB 44 which include the VTM, Section 3.31, Farm Milk Tanks, Section 4.42., Mass Flow Meters, 

Section 3.37, and Milk Meters, Section 3.35. Mr. Stutesman also reported that the TG reviewed OIML 

tolerances for milk meters. Mr. Stutesman stated that after a review of the various tolerances, the Task 

Group agreed that the OIML tolerances provide tolerances that encompassed the system of measuring milk 

and not just a tolerance for the performance of the meter. The Milk Meter TG agreed with proposing the 

use of the OIML milk meter tolerance as the milk meter tolerances in the VTM code. Mr. Stutesman 

provided a copy of the proposed changes to VTM-20.2. The proposed tolerances will align the tolerances 

in the VTM Code for Milk Meters with OIML Milk Meter Tolerances. Mr. Stutesman requested that this 

item move forward as a Voting item. The Committee also heard from Mr. Clark Cooney who noted that 

he supported the items as Developing because one company mentioned meeting the existing tolerances. It 

was mentioned that the company’s testing was only performed over a limited range of volumes.

During the Committee’s work session, the Committee agreed with the proposal from the Milk Meter Task 

Group to adopt OIML tolerances for milk meters in the VTM code, that this item be given a Voting status, 

and that the Item Under Consideration be replaced with the work group’s proposal to adopt OIML 

tolerances. The Committee also agreed with expanding the Task Group to address other milk meter codes 

in HB 44. The Item Under Consideration above are the tolerances agreed to by the Milk Meter TG and that 

align with OIML tolerances. 

At the NCWM 2021 Annual Meeting Mr. Stutesman provided an update on the Milk Meter Task Group 

activities. Mr. Stutesman noted that there was a field trip to observe milk metering systems. He noted that 

the proposed tolerances will align the milk tolerances with the OIML tolerances for milk meters and Mr. 

Stutesman noted that the OIML tolerances provides one tolerance for the meter and another tolerance for a 

milk metering system. He also noted that it may be impractical to perform an air eliminator test on these 

devices due to comingling of product. 

During the Committee’s work session, the Committee agreed to a Voting Status for this item and added it 

to its voting consent calendar.

During the voting session, Mr. Stutesman asked that consideration be given to adding a non-retroactive date 

to the proposed tolerances. It was questioned during the discussion that if a non-retroactive date was added 

to the tolerances, then, what tolerances would apply to existing meters that had been manufactured and 

tested prior to the non-retroactive date. One of the concerns expressed with having a new tolerance table 

without a nonretroactive date was whether or not existing devices would be required to be reevaluated in 

the NTEP. The conference voted against adding the nonretroactive requirement to the proposed tolerance 

table and the Item Under Consideration to change the tolerances failed to receive the 27 votes from the 

House of State Representatives, so the item failed and went back to the S&T Committee. The S&T 

Committee agreed to a Developing status for this item. 

Note: For reference, the Item Under Consideration that was included in the 2021 NCWM Interim 

Meeting Agenda is provided below: 

Table 2.

Tolerances for Vehicle-Mounted Milk Meters

Indication

(gallons)

Maintenance Tolerance

(gallons)

Acceptance Tolerance

(gallons)
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Table 2.

Tolerances for Vehicle-Mounted Milk Meters

100 0.5 0.6 0.3 0.5

200 0.7 1.2 0.4 1.0

300 0.9 1.8 0.5 1.5

400 1.1 2.4 0.6 2.0

500 1.3 3.0 0.7 2.5

At the NCWM 2022 Interim Meeting Mr. Stutesman (Kansas) spoke as Chair of the Milk Meter TG. He 

requested that this item be assigned back to the Task Group for further development. Mr. Stutesman

provided an update on the Task Group meeting in January 2022 in which they discussed tolerances in both 

3.31 Vehicle Tank Meters and 3.35 Milk Meters and the need to have the tolerance be applied to both 

vehicle mounted and station meters as the manufacturers are developing meters that will be capable of being 

installed in either application. The tolerance tables can be found in the supporting documents. Mr. 

Stutesman also renewed the Task Group’s request to expand its scope to include possibly creating a new 

code that contains requirements of both vehicle mounted and stationary milk meters and metering systems 

due to the unique properties of milk as a liquid. Speaking on behalf of himself, Mr. Stutesman (Kansas) 

stated that he has provided a document in the supporting documents that outlines the four active and five 

inactive NTEP certified meters and metering systems in terms of test draft size and applicable tolerances. 

He noted that the active four have a range of 0.12 %-0.6 %. He also noted that milk meters are the only 

liquid measuring device where the volume tolerance decreases as the draft size increases and suggests 

percentages more in line with OIML tolerance would be more appropriate. Mr. Ramsburg suggested 

combining the two tolerances to be used for field evaluations. Ms. Lee commented that the Task Group 

should work toward making all test methods uniform. Ms. Lee also suggested that the Task Group and 

Committee look at the comments from various companies concerning different tolerance along the 

distribution line for milk. Mr. Musick and Mr. Matt Douglas (California) supported assigning this item to 

the Task Group for further development. During Committee work sessions, the Committee agreed to assign 

this item back to the Milk Meter TG so they may continue to ascertain data. In addition, the Committee 

agreed to request that NCWM Chairman Hankins expand the scope of the TG to include all reference to 

milk meters, meter systems and related test methods, specifications and tolerance in an effort to harmonize 

the codes. 

The Committee agreed to an Assigned status for the item.

At the NCWM 2022 Annual Meeting the Milk Meter TG Chair Stutesman, provided a status update of the 

milk meter task group activities. He mentioned that the task group continues to support proposed tolerances 

as provided in the Item Under Consideration. He also noted that the goal is consistency of the tolerances 

for milk meter measuring. He also noted that another representative from the Western is need on the Milk 

Meter Task group. 

At the Committee’s work session, the Committee agreed to keep an Assign status for this item.

Regional Association Reporting:

Western Weights and Measures Association

During the 2021 Annual Meeting Open Hearings the following comments were heard:
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Ms. e Lee put forth by TG working on milk meters. They are still in process of reviewing. It was put forth 

to vote but last-minute change to make it non retroactive. This put it back to Developing. What would 

happen to devices that are currently in the field? During the Annual Meeting this was returned back to 

Developing and NIST supports Developing. 

The WWMA S&T Committee recommended the status remain Developmental. During the 2021 S&T 

Work Session Ms. Lee was asked for further clarification on her testimony. She provided the following 

clarification: “During the Annual Meeting a proposal was made to add a non-retroactive date. Because 

questions were raised as to how this would affect existing devices the item was moved from Voting to 

Developing.” The Committee looks forward to hearing from the working group.

During the WWMA 2022 Annual Meeting the submitter was not present, and no comments were heard. 

During open hearings, due to timing constraints, the Committee did not take comments on Assigned Items. 

The Committee did allow the source to provide updates on these items. No update was provided. The 

WWMA S&T Committee recommended that this item remain Assigned. 

Southern Weights and Measures Association

During the 2021 Annual Meeting Open Hearing no comments were received on this item. 

This Committee would like to see more evidence and reasoning on why these devices should not have to 

meet the existing tolerances, and why the tolerances listed are appropriate.

This Committee recommended the item remain Developing so that the submitters can gather more evidence 

about the accuracy of these devices. 

The following comments were received during the 2022 SWMA Annual Meeting: 

Dr. Curran (Florida) stated he was concerned about increasing the tolerance for new technology. 

No comments were received from the Milk Meter Tolerance Task Group. 

The SWMA S&T Committee recommended this item remain as an Assigned Item. 

Northeastern Weights and Measures Association

During the 2021 Interim Meeting Open Hearing the following comments were heard.

Mr. Jim Willis (New York) commented as a member of the Task Group about the field trip that was taken 

in Rochester New York just prior to the NCWM meeting in July to witness the truck mounted Milk Meters 

in action. The Task Group is asking for recommendations in regard to a tolerance value that people would 

be comfortable with. Mr. Willis commented that the tolerance of 0.5 % is considered too large by some, 

but we have 0.4 % in the handbook now in-regards to checking a milk tank with a meter. 

Mr. Jimmy Cassidy (Massachusetts) asked if any systems currently meet the requirements in the handbook 

and Mr. Willis replied that currently there is one milk meter system on tank trucks that meets the 

requirements currently in the handbook. 

The NEWMA Specifications and Tolerances Committee recommended that this item remain in Developing 

Status.
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During the 2022 Annual Meeting Open Hearing Mr. Willis commented as a member of the Milk Meter 

Task Group. He indicated that the Task Group has made strides and hopes for ability to perform additional 

work on the item.

After hearing comments from the floor, the Committee recognized the need for further development of the item and 

recommended that the item retain an Assigned status. The Committee recommended the NCWM Milk Meter Task 

Group continue to work with stakeholders to further develop this item.

During the 2022 NEWMA Interim Meeting, no comments were heard from the floor, however the 

Committee recommended that this item retain an Assigned status with the Milk Meter Tolerance Task 

Group. 

Central Weights and Measures Association 

During the 2021 Interim Meeting Open Hearing, the Committee heard comments from the floor. Mr. 

Charles Stutesman (Kansas) would like to see item be returned to Task Group.

CWMA S&T Committee recommended that the item be assigned to Milk Meter Tolerance Task Group and 

be an Assigned Item.

During the 2022 Annual Meeting Open Hearing Mr. Stutesman (following 2022 NCWM Interim Meeting, 

this item was sent back to the MMTTG. Moving forward with staying with original tolerances that were 

proposed. Request to expand scope has been submitted. There will be a MMTTG meeting prior to the July 

annual meeting. Hoping to move forward and elevate to Voting status for next cycle.

The CWMA S&T Committee recommended this item to remain an Assigned Item.

During the 2022 CWMA Interim Meeting, no comments were heard from the floor. 

The CWMA S&T Committee recommended this item to remain as Assigned status. 

LPG – Liquified Petroleum Gas and Anhydrous Liquid-Measuring Devices

LPG-15.1 D N.3. Test Drafts.

(Note: Previously LPG-4)

(Note: In 2019 this item was combined with Block 1 “Terminology For Testing Standards” and other items 

that addressed terminology for standards and the use of “master meters.” Based on comments heard during 

the 2021 Annual Meeting, the S&T Committee recommended that all items that were combined with Block 

1 “Terminology For Testing Standards” that originally appeared as a separate item or a separate block of 

items on the S&T agenda prior to 2019, be removed from Block 1 “Terminology For Testing Standards” 

and appear as originally presented.

Item LPG-15.1 was removed from Block 1 “Terminology For Testing Standards” and now appears as a 

separate item on the 2022 Interim Meeting agenda.)

Source: Endress + Hauser Flowtec AG USA
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Submitter’s Purpose and Justification:

Amend Handbook 44 to allow field reference standards meters to be used to test and place into service 

dispensers and delivery system flow meters. 

This item has been assigned to the submitter for further development. For more information or to provide 

comment, please contact:

Mr. Michael Keilty

Endress + Hauser Flowtec AG

(970) 586-2122, michael.keilty@us.endress.com

The use of transfer standards is recognized in Code sections 3.34 Cryogenic Liquid-Measuring Devices 

Code and 3.38 Carbon Dioxide Liquid-Measuring Devices Code and 3.39 Hydrogen Gas-Measuring 

Devices – Tentative Code. Transfer standard is only defined for testing cryogenic liquid measuring devices. 

It has been pointed out that the term transfer standard is not correct and that field reference standard meters 

may be more appropriate. See new the Item Under Consideration, updated on September 8, 2017. 

Field evaluation of LPG meters and CNG dispensers and LNG dispensers is very difficult using volumetric 

and gravimetric field standards and methods. The tolerances for these applications are such that using field 

reference standard meters are more efficient and safer. With CNG and LNG and LPG applications, the 

field reference standard meters are placed in-line with the delivery system as it is used to fill tanks and 

vehicles. The use of field reference standard meters eliminates return to storage issues. The use of field 

reference standard meters is easier and faster compared to the use of traditional field standards. The cost 

of using field reference standard meters and transporting them is much less than the cost of traditional field 

provers and standards. 

Recognition in Handbook 44 will enable States to allow field reference standard meters to place systems 

into service and for field enforcement.

Volumetric field provers and gravimetric field proving are susceptible to environmental influences. The 

State of Colorado uses a field reference standard meter to test propane delivery truck meters. The State of 

Nebraska has used a field reference standard meter to test agricultural chemical meters. Other States have 

asked that there be recognition in HB44 in order for their State to allow the use of field reference standard 

meters.

In some applications, field reference standard meters are not more accurate than the meters used in the 

application. For that reason, longer test drafts and possibly more tests may need to be run. 

The State of California is purported to have conducted a short study of field reference standard meters in 

the past. The conclusion did not lead to wide adoption of the practice. 

Section 3.37 Mass Flow Meters user requirement U.R.3.8. Return of Product to Storage, Retail Compressed 

Natural Gas Dispensers requires that the natural gas which is delivered into the test container must be 

returned to storage. This is difficult and most often not complied with when the test vessel contents are 

released to atmosphere. States often have difficulties in remote locations finding suitable field reference 

equipment.

OWM Executive Summary for LPG-15.1 – N.3. Test Drafts.

OWM Recommendation: OWM believes that the purpose for this item, as specified by the submitter, 

is better addressed from a technical standpoint in Items GEN-23.1 and Block 8.
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OWM Executive Summary for LPG-15.1 – N.3. Test Drafts.

• State and industry have a need to use various types of field test standards to evaluate commercial 

devices installed in the marketplace. NIST OWM recognizes the need to use various standards to 

test commercial devices and support the use of these standards when test data supports its use.

• NIST OWM is also supporting the use of various types of field test standards through the purchase 

of several meters and the collection of data throughout the U.S. 

• The purpose statement for Items LPG-15.1 (LPG & Anhydrous Ammonia Liquid-Measuring 

Devices Code) indicates the goal of this items is:

“to amend Handbook 44 to allow field reference standard meters to be used to test and place into 

service dispensers and delivery system flow meters.”

• The proposed changes in Items LPG-15.1 suggest changes to the test draft criteria for devices 

covered under this code, which is not necessary to allow field reference standard meters to be used 

to test and place into service dispensers and delivery system flow meters. 

• Amongst the concerns raised to the S&T Committee over the proposed changes for LPG-15.1 is 

that it conflicts with existing test draft criteria and confusion over the application of the proposed 

requirement.

• As such, given the long debate over multiple iterations of the proposals, OWM proposes that since 

the purpose of the proposal is to allow field reference standard meters to be used to test and place 

into service dispensers and delivery system, and the responsibility for allowance of these field test 

standards are already addressed in the NIST Handbook 44 Fundamental Considerations and Items 

GEN-23.1 and Block 8 clarifies these responsibilities, that Consideration be given to the proposal 

in Items GEN-23.1 and Block 8 which clearly states the responsibility for allowance of field 

standards. 

• Block 8 clarifies what has long been recognized in NIST HB 44 concerning the responsibility for 

acceptance of a standard, making changes to specific codes such as those references in LPG-15.1 

unnecessary and confusing. 

o GEN-23.1 provides a requirement for all devices to avoid the need to specifically reference 

individual test methods in each specific code, it avoids the potential of implying that test methods 

not specifically referenced in a code would not be appropriate.

Table 3. Summary of Recommendations

LPG-15.1 – N.3. Test Drafts

V D W A I Notes* Comments

Submitter 

OWM

WWMA 
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Table 3. Summary of Recommendations

LPG-15.1 – N.3. Test Drafts

V D W A I Notes* Comments

SWMA 

NEWMA 

CWMA 

NCWM

Letters of Support Letters of Opposition Notes

Industry

Manufacturers

Endress+Hauser 10-07-2021

Endress+Hauser 01-11-2022

Endress+Hauser 05-12-2022

Seraphin 09-27-2016

Seraphin 06-23-2017

Seraphin 07-02-2018

Seraphin 06-17-2022

Retailers and Consumers

*Notes Key:

1 - Submitted modified language

2 - Item not discussed

3 - No meeting held

4 - Not submitted on agenda

5 - No recommendation or not considered

Item Under Consideration:

Amend Handbook 44, LPG and Anhydrous Ammonia Liquid-Measuring Devices as follows: 

N.3. Test Drafts. 

N.3.1. Minimum Test - Test drafts should be equal to at least the amount delivered by the device 

in 1 minute at its normal discharge rate. 

(Amended 1982) 

N.3.2. Field Reference Standard Meter Test. – The minimum quantity for any test draft 

shall be equal to or greater than the amount delivered in one minute at the flow rate being 

tested.

(Added 20XX)

NIST OWM Detailed Technical Analysis:

• Although this item has been on the agenda for a number of years, this item was grouped in a block of 

other similar items then removed from the block and placed back on the NCWM agenda as it originally 

appeared on the agenda. 
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• NIST OWM is working with States using Coriolis meters to collect data on the use of these meters as 

standards to test liquid measuring devices. This data will be shared with all regulatory officials to assist 

them with their approval of meters as standards.

• This purpose indicates its intent is to permit the use of field reference standard meters in field testing 

of commercial measuring systems.

• It is not necessary to reference “field reference standards” in a specific NIST HB 44 code in order to 

permit their use.

• Criteria for assessing the use of a given type of test standard are outlined in NIST HB 44 Appendix A 

Fundamental Considerations and clarified Items GEN-23.1 and Block 8 and OWM believes that the 

purpose for this item, as specified by the submitter, is better addressed from a technical standpoint in 

Items GEN-23.1 and Block 8.

• The decision on whether or not to accept a particular test method for use in testing commercial weighing 

and measuring equipment ultimately rests with the regulatory authority.

• NIST OWM and Seraphin developed Block 8 items (GEN-19.1 and OTH-22.1) on the 2022 Annual 

Meeting Report to help clarify and provide additional information on field standard traceability and 

specifications, and the regulatory authority’s responsibility for approval of field standards. 

• Item GEN-23.1 along with Block 8 on the 2023 Interim Meeting agenda clearly references the 

Director’s authority as outlined in the Fundamental Considerations. This not only avoids the need to 

specifically reference individual test methods in each specific code, it avoids the potential of implying 

that test methods not specifically referenced in a code would not be appropriate. 

• With regard to the proposed addition of a paragraph N.3.2. Field Reference Standard Meter Test., no 

information or data has been provided to justify that:

 a different test draft size than that specified in N.3.1. Test Draft is necessary in order to use a “Field 

Reference Standard Meter.” 

 the specific criteria of a minimum quantity of “equal to or greater than the amount delivered in one 

minute at the flow rate being tested” is appropriate.

NIST OWM believes this item is not supported with data, in that it lacks data to show that one minute of 

flow would be appropriate. We believe that this data can be collected as data is collected across the country 

to assess field standard meters or the submitter can provide additional data. Also, since the authority to 

accept or reject a meter as a field standard is the responsibility of the regulatory authority, this item is 

inappropriate for its purpose. 

Summary of Discussions and Actions:

The Committee initially considered a proposal to modify paragraph N.3. Test Drafts and to add a new 

paragraph N.3.2. Transfer Standard Test as shown below. Note that, in Fall 2016, Mr. Keilty provided an 

update to this proposal as shown in the Item Under Consideration above. 
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N.3. Test Drafts. – 

N.3.1. Minimum Test - Test drafts should be equal to at least the amount delivered by the device 

in one minute at its normal discharge rate. 

(Amended 1982)

N.3.2. Transfer Standard Test. – When comparing a meter with a calibrated transfer 

standard, the test draft shall be equal to at least the amount delivered by the device in 2 

minutes at its maximum discharge rate. 

The submitter recommended that NIST update EPO 28 for CNG dispensers and EPO 26 for LPG Liquid 

Measuring Systems to include transfer standard meter tests. NIST Handbook 105-4 should also be revised 

to specifically address the transfer standard meter and the requirements for use.

The S&T Committee might also consider amending Sections 3.30 Liquid-Measuring Devices Code and 

3.31 Vehicle-Tank Meters Code to allow transfer standard meters.

The Committee received written comments on all items in Block 4 and Block 5, as well as LPG-4 and 

MFM-2 emphasizing the need for there to be more study and discussion of the issues to assess the 

ramifications of all the proposed changes. The Committee also received written comments from the SMA 

that it looks forward to further information on these items and stating that it is important to be consistent in 

our use of terms across multiple sections of NIST Handbook 44. The Committee agreed to carryover this 

group of items on its 2019 agenda to allow for further discussion and development of these proposals. 

At the 2019 NCWM Interim Meeting the Committee decided to combine the items on the agenda dealing 

with the issue of transfer standard (including items already combined into blocks) into one block. Block 1 

(New) of the Interim Meeting report now includes Gen-3, Block 1 (original items from the 2019 interim 

agenda that appeared under Block 1), Block 2, LPG-3 and MFM-5, which were all separate items and 

blocks of items on the S&T Committee’s 2019 Interim Meeting agenda (NCWM Publication 15). Agenda 

items Gen-3, Block 1, Block 2, LPG-3, and MFM-5 are listed separately on the Interim agenda with a note 

added beneath each individual item referring the reader to the New B1 items. All items under this New B1 

have retained the same numbering system for ease in referring to the appendix for discussion on each item.

At the 2019 NCWM Annual Meeting: Mr. Brett Gurney (NCWM Chair) commented regarding the 

formation of a Task Group assigned to further develop this block proposal. The TG is charged with 

providing definitions for various types of standards (transfer, field, reference, etc.) as well as the criteria to 

be met by these types of standards. The completion date given to the TG is July 2021. The Committee 

agreed to the Assigned status for this block of items and looks forward to hearing updates from the TG. the 

Chair of the Task Group was: 

Mr. Jason Glass

Kentucky Department of Agriculture 

(502) 573-0282, jason.glass@ky.gov

At the 2020 NCWM Interim Meeting the Field Standard TG Chair Glass reported that the Task Group met 

prior to the Interim Meeting and has begun discussion of the items under Block 1. Mr. Glass stated that biweekly teleconference meetings were scheduled and that the group was optimistic but had significant work 

to accomplish. 

Mr. Russ Vires (SMA) supports the Scale item, SCL 18.1; in this block, Mr. Dimitri Karimov (Meter

Manufacturers Association) supports the Task Group activities, Mrs. Tina Butcher (NIST OWM) was 
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encouraged with the progress on terminology and provided an update on the Mass Flow Meter testing 

reporting that field testing was conducted October 28 to November 1, 2019 and that State and Industry 

participation included Colorado, Florida, Oregon, Emerson, and Tulsa Gas Technology. 

Mr. Kurt Floren (Los Angeles County, California) raised concerns with GEN-19.1. regarding the definition 

of “Standard, Field” and its reference to “stable” standards and how long a standard is expected to be stable, 

which is typically 1-year, for which he believes should be longer. Mr. Floren also questioned the statement 

in the definition “tested over a range of environmental and operational conditions that the measuring devices 

is used...” Mr. Floren noted that he was unsure if all laboratories will have the capabilities to test over this 

wide range of conditions. Mr. Floren also expressed concerns with the definition “Standard, Transfer” 

citing that this standard may not meet the fundamental considerations requirement for standards over a long 

period of time or wide range of environmental conditions. 

Mr. Steve Harrington (Oregon) echoed Mr. Floren’s comments. Field Standard TG Chair Glass responded 

that these are concerns of the TG and these issues will be discussed and considered as the TG develops 

these items. 

During the Committee’s work session, the Committee agreed that this item should remain an Assigned 

Item.

At the 2021 NCWM Interim Meeting the NCWM Field Standard TG Chair Glass provided an update on 

the Task Group activities. Mr. Glass reported that the Field Standard Task Group is following the activities 

of the NIST Master Meter Project and that the Task Group reviewed API specifications for use of master 

meters as a standard and a test protocol that will be used to ensure uniformity in collecting data on master 

meters used as field standards. He also reported that the TG does not have a recommendation for this item. 

Mr. Glass also reported that he would be stepping down as the TG Chair. Mr. Mike Keilty (Endress+Hauser 

AG) thanked Chair Glass and the TG for their work and requested that Block 1, LPG-15.1, N.3. and Block 

1 MFM-15.1, N.3 be removed from Block 1 items and to allow those items to move forward separate from 

the other Block 1 Items. Mr. Keilty stated that similar language was added to the Hydrogen code and that 

the proposed language in LPG-15.1 N.3. and MFM-15.1, N.3 will allow for the recognition of master meters 

as field standards. Mr. Henry Oppermann (WM-Consulting), stated that data is needed to ensure that master 

meters can be used over a range of conditions. Mr. Bob Murnane (Seraphin) stated that jurisdictions have 

the ability to use meters and that Block 1 LPG-15.1, N.3 and Block 1 MM-15.1, N.3 should remain in Block 

1 until data is available to support the use of master meters as a standard. Mr. Keilty mentioned that there 

has been useful dialog regarding master meters in the TG, but that he is concerned that the TG is not close 

to deciding and he expressed concerns with the TG’s focus on the NIST Master Meter Project. Mrs. Tina 

Butcher (NIST OWM) provided an update on the NIST Master Meter Project and noted that States have 

the regulatory powers to accept or reject a standard. She also mentioned that NIST is working with States 

to collect data needed to assess master meters and preliminary testing was conducted and data was collected 

on CNG at Tulsa Gas Technology’s facility in fall 2019. Ms. Diane Lee (NIST OWM) noted that NIST 

OWM feels that it is premature to add more language to the NIST Handbook 44 on master meters without 

data to support its use.

During the Committee’s work session, the Committee agreed to keeps all items in Block 1 and that this 

item should remain with an Assigned status.

At the 2021 NCWM Annual Meeting Mr. Glass reported that he would be stepping down as the Field 

Standard TG Chair. The Committee heard updates from members of the Task Group during open hearings. 

Mr. Mike Keilty (Endress+Hauser AG) noted that two of the items had been on the agenda since 2015 and 

requested that they be removed from the block and recommended recognizing the use of master meters. 

Other comments were to keep the items together until data is analyzed from the NIST Field Reference 
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Standard Work Group to support the use of master meters but that if some items were removed from the 

block, all items should be removed from the block. Based on comments heard during the 2021 Annual 

Meeting, the S&T Committee recommended that all items that were included in Block 1 “Terminology For 

Testing Standards” that originally appeared as a separate item or a separate block of items on the S&T 

agenda in and prior to 2019, be removed from Block 1 “Terminology For Testing Standards” and appear 

as originally presented. 

At the 2021 Committee work session, the Committee recognized that the Task Group has accomplished all 

it is able to at this point and is recommending the Task Group be disbanded and will make said 

recommendation to the NCWM Chairman. The Committee agreed to break all items in Block 1 into 

individual items and designate them all as Developing. The Committee thanks the Task Group and its 

members for their work. 

At the 2022 NCWM Interim meeting, the Item Under Consideration is provided below: 

N.3. Test Drafts. 

N.3.1. Minimum Test - Test drafts should be equal to at least the amount delivered by the device 

in 1 minute at its normal discharge rate. 

(Amended 1982) 

N.3.2. Field Reference Standard Meter Test. – The minimum quantity for any test draft 

shall be equal to or greater than the amount delivered in one minute at the flow rate being 

tested.

(Added 20XX)

Mr. Keilty shared a presentation on field standard meters during open hearings relevant to both LPG 15.1 

and MFM 15.1. The intent of the presentation was to describe initial and ongoing calibration traceability, 

compare OIML tolerances vs NIST Handbook 44, describe the benefits and show examples of master 

meters. An abbreviated copy of the presentation is available on the NCWM website in the interim meeting 

documents archive. Mr. Keilty commented that he believes LPG 15.1 and MFM 15.1 are fully developed 

and should receive Voting status for the annual meeting. He has updated the proposal to exclude the term 

“reference” from “field reference standard meter test”, as shown above. He requests that the Committee 

provide specific guidance if a Developing status is assigned. A comment from industry (Mr. Murnane – 

Seraphin) stated that N.3.2 in the proposal conflicts with the current code which states normal test drafts 

must be at least one minute at the maximum discharge flow rate of installation conditions. The current 

wording allows for a test to be conducted at any flow rate for one minute. There was concern from a 

regulator (Mr. Charles Stutesman, Kansas) echoing these concerns. Ms. Diane Lee (NIST) requested that 

more data be made available so that NIST is able to compare worldwide data against test data compiled 

within the U.S. by NIST. Mr. Mahesh Albuquerque (Colorado) expressed support for this item to receive 

Voting status. Mr. Marc Butler (Emerson Micro Motion) expressed confusion at the two notes, thinking 

that perhaps they conflicted with each other; are they both needed or are they independent? Mrs. Tina 

Butcher (NIST OWM) expressed that she recognizes the use and importance of master meters but is 

concerned with the purpose of this item. Mrs. Butcher suggested that the statement for use be reworked as 

test draft criteria is so critical. Mrs. Butcher recommended and offered NIST OWM assistance on this item.

During the S&T Committee work session, the Committee recognized the submitters desire that a Voting 

status be recommended but determined that there were too many concerns and confusion expressed. The 

Committee recommends that the submitter develop the item further by aligning language to existing 
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language in Handbook 44, clarifying the purpose to help avoid confusion of the new code on new 

equipment, and reaching out to NIST OWM or other industry or regulatory officials for feedback.

During the 2022 Annual Meeting Ms. Tina Butcher provided the NIST OWM Technical Analysis for this 

item and as addressed in this report she pointed out that a new general code requirement will be proposed 

for the new 2023 cycle that not only avoids the need to specifically reference individual test methods in 

each specific code, it avoids the potential of implying that test methods not specifically referenced in a code 

would not be appropriate.

Further comments were provided that OWM believes the purpose for this item, as specified by the 

submitter, is better addressed from a technical standpoint in Item Block 8. OWM proposes that since the 

purpose of the proposal is to allow field standard meters to be used to test and place into service dispensers 

and delivery systems, and the responsibility for allowance of these field test standards are already addressed 

in the NIST Handbook 44 Fundamental Considerations, and Item Block 8 clarifies these responsibilities, 

Consideration be given to the proposal in Item Block 8 which clearly states the responsibility for allowance 

of field standards along with a 2023 new proposal to add a general code requirement. 

Ms. Butcher also noted that State and industry have a need to use various types of field test standards to 

evaluate commercial devices installed in the marketplace and that NIST OWM recognizes the need to use 

various standards to test commercial devices and support the use of these standards when test data supports 

its use. But, the proposed addition of another paragraph N.3.2 in the LPG Code that specifically references

test draft for an individual test method (Field Standard Meter Test), potentially implies that test methods 

not specifically referenced in a code would not be appropriate.

The submitter of the item pointed out that the CWMA recommended that the item move forward as a vote 

and noted that a presentation was given at the CWMA about using meters to test devices. Also during open 

hearings a weights and measures official spoke on the ease of use of meters to test device. Although NIST, 

OWM provided comments in support of the use of various standards to test commercial devices when data 

supports their use, and that the proposed paragraph N.3.2 in the LPG Code for this item would potentially

imply that test methods not specifically referenced in a code would not be appropriate, the submitter of this 

item noted that he failed to understand why there was opposition the use of meters to test in use commercial 

meters and asked States to support the item. 

During the Committee’s work session, the committee agreed to a Developing status for this item based on 

the comments heard on this item.

Regional Association Reporting:

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting the following comments were received. Mr. Michael Keilty

(Endress+Hauser) - Clarified that the Joint source of the item with “Flow USA, Inc.” has changed its 

company name from Flowtec AG USA. An update was provided on this. Mr. Keilty recapped that last year 

WWMA S&T Committee recommended that these items (LPG-15.1 & MFM-15.1) remain Developing, 

and this was forwarded to the NCWM. At the Southern, the S&T Committee proposed these items for a 

vote, both passed at the Southern. The Central heard comments that this should be moved for voting. At 

the NCWM Interim Meeting Mr. Keilty asked the S&T Committee to revise the titles to provide clarity; 

that revised language is now before us. Mr. Keilty continued to note that the NCWM Interim & Annual 

Committee comments are found in the S&T agenda before you. There is an error in the notes for the 2022 

NCWM Annual Meeting; Mrs. Tina Butcher (NIST OWM) is not a submitter of this item. I will provide 
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my comments to the Committee by email. In conjunction with this item Mr. Keilty is now proposing to 

amend LMD-23.1, VTM-23.1 and MLK-23.1 (see Block 1, 2022 WWMA S&T agenda). These field 

standards will be traceable and will increase productivity. I ask the committee to accept LPG-15.1. Please 

move these items forward as a Voting Item. 

Mr. Robert Murnane (Seraphin Test Measure Company) stated he is not opposed to these meters in any 

way. Questions for the Committee: the purpose is to amend HB44, what does the language in section N.3.2 

have to do with the purpose statement? Will Weights and Measures Officials enforce section N.3 or N.3.2 

when testing? How will we know which meters are acceptable and which are not? Request that this item 

be withdrawn and proposes harmonizing the drafts between the two (N.3.1. & N.3.2.). Change N.3. to read 

that test drafts should be equal to at least the amount delivered by the device in one minute at the flow rate 

being tested. Then there is not any need for N.3.2., this is already addressed in the fundamental 

considerations. 

Mr. Matt Douglas (California, Division of Measurement Standards) stated he did not think this language 

was helpful and that this item has been on the agenda for 8 years. Mr. Douglas recommended this item for 

withdrawal. 

During open hearings, the Committee heard conflicting comments including that the purpose of this item 

is better addressed in Block 8. 

The WWMA S&T Committee recommended this item for withdrawal along with the recommendation that 

the submitter combine their efforts with the submitters of Block 8.

During the voting session, comments were received from membership. The submitter of LPG-15.1 

requested that the Committee reconsider the recommended Withdrawal status and to please leave the item 

with the current Developing status. 

Mr. Brent Ricks (Montana Department of Labor and Industry Weights and Measures) spoke not to a 

technical comment on this item but to agenda items that may be fully developed could be voted upon and 

for the committee to consider this when recommending a status for this item. 

Based on the comments heard from the body, the Committee entered deliberations. During deliberations, 

it was determined that the item was fully developed, and the submitter had nothing further to add. The 

Committee recommended a Voting status for the item. 

Upon returning to the voting session, the recommended status was changed from withdrawal to voting. A 

vote was put forward to the body resulting in no “yea” votes and 1 “nay” vote. 

Mr. Kurt Floren (Los Angeles County, California) put forward a motion of reconsideration for the vote due 

to the lack of response from membership during the vote. The motion passed and the vote for LPG-15.1 

was recalled, opening the floor for comments on the item. 

Mr. Keilty recommended a Developing status. 

Mr. Ed Williams (Ventura County, California) supported the recommendation for a Developing status. 

Mr. Austin Shepherd (San Diego County, California) requested clarification on the reasoning for the 

Committee’s position. 
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Clarification from the S&T Committee Chair was provided; the Committee recognized that there is 

language in the history of the item stating that the item may have merit for other jurisdictions. 

Mr. Floren recommended that the Committee consider the needs of other regions when recommending a 

status. 

The Committee entered a second deliberation session to assign a status for LPG-15.1. Taking note of the 

limited participation from the body during the vote to recommend a Voting status and along with the 

consideration of all the comments heard from the floor during the voting session, and all the previous 

comments and discussions regarding LPG-15.1, the Committee concluded that the item should return to the 

originally proposed recommendation of a Withdrawal status. 

The S&T Committee returned to the voting session with the Committee’s decision to recommend a 

Withdrawal status, the item was included and presented for a vote in the 2022 WWMA Committee’s final 

report. 

Southern Weights and Measures Association

The following comments were received during the 2022 SWMA Annual Meeting:

Mr. Keilty (Endress+Hauser), the submitter of this item, recommended it move forward as a Voting Item 

with the new language.

The SWMA S&T Committee recommended this item move forward as a Voting Item.

Northeastern Weights and Measures Association

At the 2022 Interim Meeting Mr. Michael Keilty (Endress Hauser) commented that he introduced this item 

in 2014 and there has been much documentation and discussion. The goal was to introduce field standard 

meters and small draft size benefit. Mr. Kielty indicated that he polled some states and he believes that 

having language in HB44 would enable those states to use field standard meters. Mr. Kielty also noted that 

he has submitted a letter to the NEWAM S&T Chair with changes to the purpose statement and other 

modifications to the language and recommends a Voting status. 

Mr. Bob Murnane (Seraphin Test Measure) asked what changed in the purpose statement and it was shared 

with the body. Mr. Murnane commented that he believes the Fundamental Considerations already allows 

State Directors to use field standards and pointed to language in Block 8 that would reinforce that. Mr. 

Murnane also believes there is an issue with a 1-minute test. Mr. Murnane does not believe this item is 

needed and urged that submitter to work with submitters of Block 8. Mr. Keilty stated that whenever new 

technology is available, the conference allows them to be used. He believes the language in this item 

facilitates the testing of systems already in place and allows 1 minute test to be sufficient. He pointed out 

that SWMA has voted twice to pass, as has CWMA. 

Mr. Henry Opperman (W&M Consulting) commented that the Fundamental Considerations allows 

recognition of other standards that perform at the level of field standards. He questions how we prove that 

a field standard meets the requirements in the Fundamental Considerations. Even if used, it is still not clear 

how the states determined they meet the requirements. 

Ms. Diane Lee (NIST OWM) commented that NIST is doing additional research on test draft paragraphs. 

If the purpose of this item is that master meters can be used, it’s always been addressed in Fundamental 
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Considerations that State Directors can accept anything. Ms. Lee noted that Block 8 is just clarifying what

I needed for selection of appropriate standards. 

Mr. Murnane indicated that he also called states referenced by Keilty and they are using the Fundamental 

Considerations for field standards. 

Mr. Jim Willis (New York) believes this item is redundant, noted that as a Director, he already has the 

authority through Fundamental Consideration, and recommended withdrawal. 

Mr. John Mcguire (New Jersey), Mr. Walt Remert (Pennsylvania), Mr. James Cassidy (Massachusetts) and 

Mr. Lou Sakin (Holliston, Massachusetts) all recommended withdrawal of this item.

After hearing comments from the body, the Committee agreed with the commenters that this item does not 

have merit and is redundant in nature. The Committee is recommending that this item be Withdrawn.

Central Weights and Measures Association 

At the 2022 Interim Meeting, Michael Keilty recalled that the CWMA recommended this as a Voting Item 

for the 2022 NCWM. In May CWMA voted and approved this item. Larger drafts than 1 minute can be 

used. 

Mr. Murnane noted that the purpose statement does not align with proposed change to N.3. 

Numerous meters are already approved under fundamental considerations, i.e.: the authority lies with the 

Director to approve devices. Why is the test draft being changed? Regulators must be able to choose 

whatever draft size they want, specifically for Mass Flow Meters. 

If the Minimum Measured Quantity is greater than one minute of flow, then some mass flow meters would 

require larger draft sizes. Several NTEP CCs were referenced in which the MMQ is less than one minute 

of flow, which would conflict with testing the MMQ. 

Craig VanBuren (Michigan): Suggest change in verbiage to address the MMQ / one minute of flow conflict. 

The CWMA S&T Committee believes this item is fully developed and recommends Voting status. The 

Committee also believes this should be added to Block 1. 

LPG-22.3 W S.2.5. Zero-Set-Back Interlock., S.2.5.2. Zero -Set-Back Interlock for 

Stationary Customer -Operated Electronic Retail Motor-Fuel Devices.

(Note: The Item Under Consideration has been updated since the 2022 Interim Meeting. The current item 

is a combined effort of the National Propane Gas Association and U-Haul International, Inc.

Note: At the 2022 Annual Meeting this item was designated as Developing. During the 2022 Fall Regional 

Meetings, the submitter requested that this item be Withdrawn and that consideration be given to Item LPG23.)

Source: National Propane Gas Association
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Submitter’s Purpose and Justification:

The proposal will address practical issues that propane marketers encounter when trying to comply with 

the zero setback requirements for propane stationary and truck-mounted meters in NIST Handbook 44. 

National Propane Gas Association:

This proposal was developed by the National Propane Gas Association’s Technology, Standards and Safety 

Committee, a volunteer organization comprised of 2500+ members, including propane retail marketers and 

others providing products or services to the propane industry. 

In S.2.5, the removal of the vehicle mounted meters from this two-minute requirement is necessary as the 

initiation of a vehicle mounted meter is performed at the truck prior to moving the delivery hose to the 

customer tank, sometimes as far as 150 feet from the meter, or in installations with multiple containers that 

may require continued adjustment of containers or delivery hose to complete a delivery. This configuration 

can lead to periods of up to 5 minutes between initial meter engagement and first container filling or 

between containers being filled on a single delivery. 

In revised S.2.6, we are proposing that vehicle mounted meters be allowed periods between meter 

engagement and product flow of greater than 2 minutes prior to automated time out initiation. A fiveminute period is more practical as the initiation of a vehicle mounted meter is performed at the truck prior 

to moving the delivery hose to the customer tank, sometimes as far as 150 feet from the meter, or in 

installations with multiple containers that may require continued adjustment of containers or delivery hose 

to complete a delivery. The configuration on a typical bobtail can lead to periods of up to 5 minutes between 

initial meter engagement and first container filling or additionally periods of greater than two minutes can 

transpire between containers being filled on a single delivery.

Addressing proposed new S.2.7, motor fuel, within the context of NFPA 58, refers to any container that has 

the potential to provide propane to fuel an engine. This can include a multitude of DOT cylinders and 

ASME containers that are not for the propulsion of an automobile. Current mechanical meter technology 

utilized in a standard propane dispenser for the filling of portable containers, such as those utilized in NFPA 

58 for motor fuel applications or those that do power automobiles, are not capable of being equipped with 

a zero-set-back interlock and the technology will not be potentially available until 2022, per meter 

manufacturers.

NFPA 58 does not currently explicitly allow the public to refuel its automobiles. All automobiles or other 

containers must be filled by a specially trained employee. A proposed change has been introduced for 

consideration in the 2023 edition of NFPA 58 that would permit public refueling of automobiles as long as 

the dispensing system meets very specific safety requirements, including a specialized nozzle, and is 

furnished with visible instructions. Upon the acceptance of this new public refueling allowance the propane 

industry agrees that Zero-Setback-interlocks are needed. These public self-service automotive dispensing 

systems will be listed to Underwriters Laboratories Standard 495 and will be dedicated to the filling of 

motor vehicles. 

In view of the above information, existing dispenser systems that may only be utilized by qualified trained 

employees should be permitted to continue operations with the existing meter technology and should not 

be required to include Zero-Set-Back Interlocks. This should include when the dispenser is removed from 

one location and installed in another, as long as the original meter remains functional. Existing cabinetry 

and controls utilized in a standard dispenser cabinet generally include non-digital meters and no electronic 

controls with the exception of a single switch that operates the pump. These simplistic designs are still 

effective and should not be prohibited from use in future (new) installations in which the transfer process 

is attended by trained personnel. Limiting the scope of this section will allow attended dispenser operations 
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which are primarily utilized for filling of portable containers to remain consistent in design and 

construction. Current use of this technology has not resulted in any known impact to the consumer or overcharge situations. The term “self-operated” is used in other locations in Handbook 44 and would include 

electronic dispensing devices and meters, which would then be consistent with the prior two sections that 

are limited to electronic meters. 

It is difficult to counter the arguments above. The sheer difficulties that a service person can encounter 

when a wet hose must be carried over terrain fairly long distances between receiving containers should be 

sufficient justification to approve this proposal. The counter argument to new S.2.7 would be that the 

customer may not be able to view the meter to ensure it is set back to zero. The submitter requested that 

this be a Voting Item in 2022. 

U-Haul International, Inc. 

Motor fuel, within the context of NFPA 58, refers to any container that has the potential to provide propane 

to fuel an engine. This can include a multitude of DOT cylinders and ASME containers that are not for the 

propulsion of an automobile. Current mechanical meter technology utilized in a standard propane dispenser 

for the filling of portable containers, such as those utilized in NFPA 58 for motor fuel applications or those 

that do power automobiles, are not capable of being equipped with a zero-set-back interlock and the 

technology will not be potentially available until 2022, per meter manufacturers. 

NFPA 58 currently does not allow the public to refuel its automobiles. All automobiles or other containers 

must be filled by a specially trained employee. A proposed change has been introduced for consideration 

in the 2023 edition of NFPA 58 that would permit public refueling of automobiles as long as the dispensing 

system meets very specific safety requirements, including a specialized nozzle, and is furnished with visible 

instructions. Upon the acceptance of this new public refueling allowance the propane industry agrees that 

Zero-Setback-interlocks are needed. These public self-service automotive dispensing systems will be listed 

to Underwriters Laboratories Standard 495 and will be dedicated to the filling of motor vehicles. 

Most propane dispensed is for purposes other than motor-fuel. Pursuant to NFPA 58, this is accomplished 

by a trained and certified employee dispensing propane, typically using mechanical meters, into cylinders 

and tanks. The employee is trained and required to manually reset the meter to zero after each transaction 

and verify the meter is reset prior to initiating a subsequent transaction. This has been and remains an 

accepted practice for dispensing propane. This process is the industry standard for approximately 97 % of 

all propane used in the United States. See U.S. Department of Energy, Alternative Fuels Data Center 

https://afdc.energy.gov/fuels/propane_basics.html. 

Unlike traditional motor-fuel, such as gasoline or diesel, customers cannot currently dispense propane into 

their vehicles. If NFPA 58 is amended to allow customers to dispense their own propane into their vehicles 

and the demand for propane as motor-fuel increases, the market will drive retailers to provide electronic 

customer-operated retail motor-fuel devices to meet the demand and customer expectations for efficient 

and expedient fueling transactions. At that time, the electronic customer-operated motor-fuel devices will 

certainly need to incorporate an automatic zero-set-back interlock. It is simply too early in the process to 

effectively force mechanical retail motor-fuel devices out of the market for such a small percentage of the 

retail propane market (approximately 3 %).
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OWM Executive Summary for LPG-22.3 – S.2.5. Zero-Set-Back Interlock., S.2.5.2. Zero -Set-Back 

Interlock for Stationary Customer -Operated Electronic Retail Motor-Fuel Devices.

OWM Recommendation: This item was withdrawn by the submitter and all regions supported the 

withdraw of this item. The original OWM comments are maintained in this analysis.

NIST OWM is not in support of this proposal to change S.2.5.2 requirements in the LPG Code and feel 

that this creates different requirements for retail motor fuel devices used for other products. Also, a 

proposal is needed for consideration of changes to timeout for LPG. The submitter requested that this 

item be withdrawn during the 2022 Regional Meetings, and that consideration be given to Item, LPG23.1. NIST Supports the submitters decision to withdraw this item. 

• The submitters explained in their justification that only trained operators can dispense propane into 

a vehicle and that these propane retail motor fuel dispensers do not meet the requirements for ZeroSet Back Interlock for Stationary Retail Motor-Fuel Devices. As such, the submitters are proposing 

that since these are not customer operated dispensers, and that the dispensers are operated by trained 

staff, the requirements in S.2.5.2 Zero-Set-Back Interlock for Stationary Retail Motor Fuel Devices 

should be revised to only apply to Customer Operated Electronic Retail Motor Fuel Devices. The 

following are NIST OWM comments to this proposed change.

• If a dispenser is operating as a retail motor fuel device the current requirements for zero-set-back 

interlock apply whether or not it is operated by the customer or trained staff. 

• The purpose of the Zero-Set-back Interlock is to ensure that an automatic interlock prevents 

subsequent delivery until the indicating element is returned to zero. 

• With the changes proposed, any propane retail motor fuel device that is operated by trained staff 

could possibly not be returned to zero at the start the next transaction. 

• Propane retail motor fuel devices, that are not customer operated, would not be required to meet S. 

2.5.2. in the LPG Code. 

Table 3. Summary of Recommendations

LPG-22.3 – S.2.5. Zero-Set-Back Interlock., S.2.5.2. Zero -Set-Back Interlock for Stationary 

Customer -Operated Electronic Retail Motor-Fuel Devices.

V D W A I Notes* Comments

Submitter 

OWM

WWMA 

SWMA 

NEWMA 

CWMA 

NCWM

Letters of Support Letters of Opposition Notes
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Table 3. Summary of Recommendations

LPG-22.3 – S.2.5. Zero-Set-Back Interlock., S.2.5.2. Zero -Set-Back Interlock for Stationary 

Customer -Operated Electronic Retail Motor-Fuel Devices.

V D W A I Notes* Comments

Industry

Manufacturers

Retailers and Consumers

*Notes Key:

1 - Submitted modified language

2 - Item not discussed

3 - No meeting held

4 - Not submitted on agenda

5 - No recommendation or not considered

Item Under Consideration:

Amend Handbook 44, Liquefied Petroleum Gas and Anhydrous Ammonia Liquid-Measuring Devices Cod 

as follows: 

S.2.5. Zero-Set-Back Interlock. 

S.2.5.1. Zero-Set-Back Interlock, Electronic Stationary Meters (Other than Stationary Retail 

Motor-Fuel Dispensers) and Electronic Vehicle-Mounted Meters. − A device shall be constructed 

so that after an individual delivery or multiple deliveries at one location have been completed, an 

automatic interlock system shall engage to prevent a subsequent delivery until the indicating 

element and, if equipped, recording element have been returned to their zero positions.

[Nonretroactive as January 1, 2021] 

(Added 2019) 

(Amended 2021) 

S.2.5.2. Zero-Set-Back Interlock for Stationary Customer-Operated Electronic Retail MotorFuel Devices. – A device shall be constructed so that: 

(a) after a delivery cycle has been completed by moving the starting lever to any position that 

shuts off the device, an automatic interlock prevents a subsequent delivery until the 

indicating elements and recording elements, if the device is equipped and activated to 

record, have been returned to their zero positions; 

(b) the discharge nozzle cannot be returned to its designed hanging position (that is, any 

position where the tip of the nozzle is placed in its designed receptacle and the lock can be 

inserted) until the starting lever is in its designed shut-off position and the zero-set-back 

interlock has been engaged; and 
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(c) in a system with more than one dispenser supplied by a single pump, an effective automatic 

control valve in each dispenser prevents product from being delivered until the indicating 

elements on that dispenser are in a correct zero position. 

[Nonretroactive as of January 1, 2017] 

(Added 2016)

NIST OWM Detailed Technical Analysis:

A similar proposal LPG-22.2, submitter U-Haul International, Inc. was withdrawn and both U-Haul 

International, Inc. and National Propane Gas Association collaborated to further develop LPG-22.3. 

Initially, the proposed changes, were made to an older version of the handbook. The current Item Under 

Consideration has been edited and changes are being proposed to the current version of NIST HB 44. 

Per review of the discussion provided by the submitter, propane dispensed into a vehicle requires a trained 

operator to dispense the propane. From other proposals on the 2022 Interim Meeting report, it is NIST 

OWM understanding that some stationary propane dispensers have been retrofitted to dispense propane as 

fuel for vehicles. As such these dispensers are now retail motor fuel dispensers and must meet the 

requirements for these devices in the LPG code.

The submitters explained in their justification that only trained operators can dispense propane into a vehicle 

and that these propane retail motor fuel dispensers do not meet the requirements for Zero-Set Back Interlock 

for Stationary Retail Motor-Fuel Devices. As such, the submitter is proposing that since these are not 

customer operated dispensers, and that the dispensers are operated by trained staff, the requirements in 

S.2.5.2. Zero-Set-Back Interlock for Stationary Retail Motor Fuel Devices should be revised to only apply 

to Customer Operated Electronic Retail Motor Fuel Devices The following are NIST OWM comments to 

this proposed change.

• If a dispenser is operating as a retail motor fuel device the current requirements for zero-set-back 

interlock apply whether or not it is operated by the customer or trained staff. 

• The purpose of the Zero-Set-back Interlock is to ensure that an automatic interlock prevents 

subsequent delivery until the indicating element is returned to zero. 

• With the proposed changes, any propane retail motor fuel device that is operated by trained staff 

could possibly not be returned to zero at the start the next transaction.

 

• Retail motor fuel dispenser such as gasoline dispensers are required to meet these requirements in 

a self-serve (Customer operated) or full Service (Trained staff operated) locations.

• Propane retail motor fuel devices, that are not customer operated, would not be required to meet S. 

2.5.2. in the LPG Code. 

• The title of the proposal will need to be updated with the current handbook paragraphs.

• In reference to requirements for a 5-minute timeout, the timeout was discussed by the conference 

in 2021. During those discussions 2, 3 and 5 minutes were discussed. The conference adopted a 

3- minute timeout which was added to NIST HB 44 in 2021. Although timeout was discussed in 

the submitter’s justification, the revised Item Under Consideration did not include a proposal for a 

change to the timeout requirements for LPG. 
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• NIST OWM is not in support of this proposal to change S.2.5.2 requirements in the LPG Code and 

feel that this creates different requirements for retail motor fuel devices used for other products. 

Also, a proposal is needed for consideration of changes to timeout for LPG. 

Summary of Discussions and Actions:

During the 2022 NCWM Interim Meeting, Mr. Bruce Swiecicki (National Propane Gas Association), 

working in collaboration with U-Haul International, requested the Committee replace the proposal in its 

2022 Interim Meeting agenda for this item with the following revised version: 

Amend Handbook 44, Liquefied Petroleum Gas and Anhydrous Ammonia Liquid-Measuring Devices Code 

as follows: 

S.2.6. Automatic Timeout. 

S.2.6.1. Electronic Stationary (Other than Stationary Retail Motor-Fuel Dispensers) and 

Electronic Vehicle-Mounted Meters. – For individual deliveries, if there is no product flow for 

three minutes the transaction must be completed before additional product flow is allowed. The 

three-minute timeout shall be a sealable feature on an indicator. 

[Nonretroactive as of January 1, 2021] 

(Added 2021) 

S.2.6.2. Zero-Set-Back Interlock, Electronic Vehicle Mounted Meters. - A device shall be so 

constructed that after an individual delivery or multiple deliveries at one location have been 

completed, an automatic interlock system shall engage to prevent a subsequent delivery until the 

indicating element and, if equipped, recording element have been returned to their zero position. 

For individual deliveries, if there is no product flow for a maximum of five minutes the 

transaction must be completed before additional product flow is allowed. The 5-minute timeout 

shall be a sealable feature on an indicator.

[Nonretroactive as of January 1, 2021] 

During Committee open hearings, Mr. Swiecicki acknowledge the proposal was based on an earlier version 

of NIST Handbook 44 and the paragraph numbering had changed. Consequently, the proposal needed 

modification to correspond to the 2022 version of the handbook. Mr. Swiecicki reported a two-minute time 

out was difficult to accomplish and suggested this be changed to five minutes. 

During the Committee’s work session, members of the Committee reviewed the revised proposal, which 

includes updated language and paragraph numbering, however, members of the Committee concluded the 

proposal was still not fully developed. The Committee agreed to amend the proposal as requested by the 

submitter. The Committee recommended the submitter of this item work with the submitter of LPG-22.2 

(U-Haul International) to harmonize the two proposals. 

Two officials supported Mr. Swiecicki’s comments and were also in favor of a five-minute time out. 

Ms. Diane Lee (NIST OWM) commented the proposal needed to be cleaned up to match the 2022 version 

of NIST Handbook 44. There was also a suggestion for the submitter to work with NIST OWM to further 

develop the proposal. 

No comments were heard in opposition to the continued development of this item. 
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Following the 2022 NCWM Interim Meeting, the submitter of this item and Item LPG-22.2 collaborated 

on a joint proposal as requested and submitted it to the Committee in time that it could be added to the 

Committee’s agenda for the 2022 NCWM Annual Meeting. See the Item Under Consideration for the new 

joint proposal. Because the submitters combined the two items into one, the Committee was able to 

withdraw LPG 22.2. from its agenda. 

Based on limited notes, during the 2022 NCWM Annual Meeting, comments were heard from the 

submitters of this item that they opposed the changes as currently written in the Item Under Consideration 

because when LPG is dispensed it should be dispensed by a trained operator not customer operated. The 

submitters expressed that they do not believe separate requirements are needed for bottle filling and vehicle 

fueling. The submitters argued that that LPG dispensed as motor fuel is currently only 3% of the market 

and that emphasis should be placed on the predominate use of these dispensers. The updated version that 

appears in the Item Under Consideration is the updated version provided by the submitters to correct the 

item to the current NIST HB 44 code numbering. The S&T Committee informed the submitters that they 

can submit updated language to the regions since they have opposed what is currently in the Item Under 

Consideration.

During the Committee working session the Committee agreed that this item would retain a Developing 

status. 

Editor Note 2: Although the submitter of this item appears to have proposed new language at the 2022 

Interim Meeting, the language that appears in Interim Meeting write-up combines automatic timeout and 

zero setback interlock language under the section for Automatic Timeout. A new proposal was submitted 

separately for the 2023 NCWM review cycle that is the same proposal with the same structure errors (See 

the 2023 Interim Meeting agenda LPG-23.2). In addition, another proposal was submitted for the 2023 

NCWM review cycle that appears to be a replacement for this item LPG-22.3 (See 2023 Interim Meeting 

agenda item LPG-23.1). If the submitters intend to withdraw LPG-22.3 and replace it with LPG-23.1 they 

can request that LPG-22.3 be withdrawn.

Regional Association Reporting:

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting the following comments were received: 

Mr. Konrad Philatowicz (U-Haul International, Inc.) – Mr. Philatowicz commented that the submitter 

intends to withdraw this item in favor of LPG-23.1. 

During open hearings, the submitter confirmed their intention to withdraw this item in preference of LPG23.1. 

The WWMA S&T Committee recommended that this item be withdrawn. 

Southern Weights and Measures Association

No comments were received on this item during the 2022 SWMA Annual Meeting. This item has been 

replaced with LPG 23.1. 

The SWMA S&T Committee recommended this item be Withdrawn. 
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Northeastern Weights and Measures Association

During the 2022 Interim Meeting, Mr. Steve Timar (New York), pointed out that the submitter requested 

to withdraw this item at the WWMA Meeting in favor of LPG-23.1. The Committee did not hear any other 

comments from the floor, nor the submitter. 

The Committee is recommending that this item be Withdrawn. 

Central Weights and Measures Association

During the 2022 Interim Meeting there were no comments from the floor.

The CWMA S&T Committee recommended this remain a Developing Item.

LPG-23.1 S.2.5. Zero-Set-Back Interlock

Source: National Propane Gas Association and U-Haul International

Submitter’s Purpose and Justification:

Address practical issues that propane retailers encounter when trying to comply with the zero setback 

requirements for propane stationary meters in Handbook 44.

This proposal reflects the intent of U-Haul International, Inc. and the National Propane Gas Association’s 

Technology, Standards and Safety Committee, a volunteer organization comprised of 2500+ members, 

including propane retail marketers and others providing products or services to the propane industry.

The intent behind enacting the current version of S.2.5.2 was to create consistency among motor-fuel 

devices used for all products. This proposal strikes a balance between a consistent standard for retail motorfuel devices and the diverse applications and industry standard for dispensing LP-Gas. To that end, this 

proposal addresses only those devices used exclusively for retail motor-fuel transfer. Multi-use LP-Gas 

devices that are used for the filling motor-fuel and other containers, including grill cylinders, forklift 

cylinders, cylinders used on recreational vehicles and even motor fuel containers, are covered by S.2.5.1. 

Most LP-Gas dispensed is for purposes other than motor-fuel. (Less than 3% of all LP-Gas used in the 

United States is used for transportation. See U.S. Department of Energy, Alternative Fuels Data Center

https://afdc.energy.gov/fuels/propane_basics.html.) Pursuant to NFPA 58, this is accomplished by a 

trained and certified employee dispensing LP-Gas, typically using analog (mechanical) meters, into 

cylinders and tanks. The analog (mechanical) meters are safe and effective, and most notably exempt from 

the zero-set-back requirement because S.2.5.1 only applies to electronic devices. Clearly, Handbook 44 

recognizes this reality as S.2.5.1 does not require that all LP-Gas dispensers have zero-set-back interlocks, 

only electronic devices. S2.5.1 is most appropriate because currently there is no readily available 

technology that can be used to retrofit an analog device. When looked at from a cost/benefit perspective, 

one has to question the expense of replacing an analog device with an electronic device at a location that 

mostly serves portable cylinders and not motor vehicle tanks when LP-Gas’s use is so limited in 

transportation. 

Furthermore, NFPA 58 currently does not allow the public to refuel its LP-Gas powered motor vehicles. 

All motor vehicles or other containers must be filled by a specially trained employee. A proposed change 

has been introduced for consideration in the 2023 edition of NFPA 58 that would permit public refueling 

of motor vehicles as long as the dispensing system meets very specific safety requirements, including a 
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specialized nozzle, and is furnished with visible instructions. Upon the acceptance of this new public 

refueling allowance, the LP-Gas industry agrees that Zero-Setback-interlocks are needed. These public 

self-service motor vehicle dispensing systems will be listed to Underwriters Laboratories Standard 495 and 

will be dedicated to the filling of motor vehicles. 

For the minimal amount of retail motor fuel customers that a typical LP-Gas dispenser serves, both U-Haul 

and NPGA feel that this proposal represents the most equitable approach to date for balancing the need to 

ensure fair transactions and consistent standards with how the LP-Gas industry currently dispenses LP-Gas 

and LP-Gas’s future transportation applications as envisioned by the proposed changes to NFPA 58 without 

conducting costly industry-wide retrofits of existing, functioning multi-use equipment. Handbook 44 needs 

to work with industry to make technical standards economically feasible lest it risk the advancement of LPGas as a viable and clean motor-fuel.

One continually occurring objection is that there would be no protection for the consumer without a zeroset-back feature on retail motor fuel devices. That really isn’t the case, however, as the customer always 

has the option to check the dispenser and meter before the filling process begins to verify that it is starting 

at zero.

The submitter requested that this be a Voting item.

OWM Executive Summary for LPG-23.1 – S.2.5. Zero-Set-Back Interlock

OWM Recommendation: NIST OWM believes additional discussion is need concerning this item and 

how it will be enforced when other LPG devices are in use that require zero-setback interlock and also 

the impact of the proposed requirement on other retail motor fuel devices of other products used to fuel 

vehicles.

• Zero set-back interlock ensures that a device is returned to zero before another customer or services 

person uses the device for another transaction (to ensure that an automatic interlock prevents 

subsequent delivery until the indicating element is returned to zero). 

• The LPG Code paragraphs S.2.5.1 and S.2.5.2 address electronic stationary and other stationary 

devices because the process for zero-set-back interlock operates differently for electronic stationary 

than stationary retail motor fuel device as described in S.2.5.2. but both devices are required to 

return to zero before another transaction is made.

• The submitter states that only a few transactions for LPG dispenser are for fueling vehicles and they 

are limited to use by trained staff. Paragraphs S.2.5.1 and S.2.5.2 are not dependent on who is 

dispensing the product or how often the device is used as a retail motor dispenser; the paragraphs 

are intended to ensure that the device is so designed that each new transaction starts at zero. What 

happens when they are used more frequently for use in fueling vehicles? 

• Both electronic stationary and stationary retail motor fuel dispensers according to the current 

requirements must have a zero-setback interlock.

 

• The proposed language added to both S.1.5.1 and S.1.5.2 is “Devices Used Exclusively as”

Stationary Retail Motor-Fuel Devices. As such, the zero-setback interlock requirement would only 

applies to those devices that are used exclusively to fueling vehicles. 
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OWM Executive Summary for LPG-23.1 – S.2.5. Zero-Set-Back Interlock

• Is this equitable to other products dispensed, such as gasoline dispensers. Gasoline dispensers are 

required to have a zero-setback interlock, and some are used to fill containers used for gasolinepowered equipment. Granted, the majority of gasoline dispensers are used to fill vehicles; but does 

this create an unfair market situation where some fueling dispensers are required to have zero setback interlock and others are not? 

• The submitter also stated that proposed changes were introduced for consideration in 2023 to allow 

public refueling of LP Gas with safety precautions and with these new requirements zero-setback 

interlock is needed. How will LPG devices with and without zero-setback interlock be fairlyregulated? 

Table 3. Summary of Recommendations

LPG-23.1 – S.2.5. Zero-Set-Back Interlock

V D W A I Notes* Comments

Submitter 

OWM

WWMA 

SWMA 

NEWMA 5

CWMA 

NCWM

Letters of Support Letters of Opposition Notes

Industry

Manufacturers

Retailers and 

Consumers

Regulators

*Notes Key:

1 − Submitted modified language

2 − Item not discussed

3 − No meeting held

4 − Not submitted on agenda

5 − No recommendation or not considered

Item Under Consideration:

Amend Handbook 44, Liquefied Petroleum Gas and Anhydrous Ammonia Liquid-Measuring Devices Code 

as follows: 

S.2.5. Zero-Set-Back Interlock.
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S.2.5.1. Zero-Set-Back Interlock, Electronic Stationary Meters (Other than Devices used 

Exclusively as Stationary Retail Motor- Fuel Dispensers) and Electronic Vehicle-Mounted Meters. 

− A device shall be constructed so that after an individual delivery or multiple deliveries at one location 

have been completed, an automatic interlock system shall engage to prevent a subsequent delivery until 

the indicating element and, if equipped, recording element have been returned to their zero positions.

[Nonretroactive as January 1, 2021]

(Added 2019) (Amended 2021) 

S.2.5.2. Zero-Set-Back Interlock for Devices Used Exclusively as Stationary Retail MotorFuel Devices. – A device shall be constructed so that:

(a) after a delivery cycle has been completed by moving the starting lever to any position that shuts 

off the device, an automatic interlock prevents a subsequent delivery until the indicating 

elements and recording elements, if the device is equipped and activated to record, have been 

returned to their zero positions;

(b) the discharge nozzle cannot be returned to its designed hanging position (that is, any position 

where the tip of the nozzle is placed in its designed receptacle and the lock can be inserted) 

until the starting lever is in its designed shut-off position and the zero-set-back interlock has 

been engaged; and

(c) in a system with more than one dispenser supplied by a single pump, an effective automatic 

control valve in each dispenser prevents product from being delivered until the indicating 

elements on that dispenser are in a correct zero position.

[Nonretroactive as of January 1, 2017]

(Added 2016) 

NIST OWM Detailed Technical Analysis: 

Zero set-back Interlock ensures that a device is returned to zero before another customer or services person 

uses the device for another transaction (to ensure that an automatic interlock prevents subsequent delivery 

until the indicating element is returned to zero). The LPG Code paragraphs S.2.5.1 and S.2.5.2 address 

electronic stationary and other stationary device because the process for zero-set-back interlock operates 

differently for electronic stationary than stationary retail motor fuel device as described in S.2.5.2. but both 

devices are required to return to zero before another transactions is made.

The submitter states that only a few transactions for LPG dispenser are for fueling vehicles and they are 

limited to use by trained staff. These paragraphs are not dependent on who is dispensing the product or 

how often the device is used as a retail motor dispenser; the paragraphs are intended to ensure that the 

device is so designed that each new transaction starts at zero. What happens when they are used more 

frequently for use in fueling vehicles?

Both electronic stationary and stationary retail motor fuel dispensers according to the current requirements 

must have a zero-setback interlock. The proposed language added to both S.1.5.1 and S.1.5.2 is “Devices 

Used Exclusively as” Stationary Retail Motor-Fuel Devices. As such the zero-setback interlock 

requirement would only apply to those devices that are used exclusively to fueling vehicles. Is this equitable 

to other products dispensed, such as gasoline dispensers. Gasoline dispensers are required to have a zerosetback interlock, and some are used to fill containers used for gasoline-powered equipment. Granted, the 
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majority of gasoline dispensers are used to fill vehicles, but does this create an unfair market situation where 

some fueling dispensers are required to have zero set-back interlock and others are not? 

The submitter also stated that proposed changes were introduced for consideration in 2023 to allow public 

refueling of LP Gas with safety precautions and with these new requirements zero setback interlock is 

needed. How will LPG devices with and without Zero-Setback Interlock be fairly-regulated?

NIST OWM believes additional discussion is need concerning this item and how it will be enforced when 

other LPG devices are in use that require zero-setback interlock and also the impact of the proposed 

requirement on other retail motor fuel devices of other products used to fuel vehicles.

Regional Association Reporting:

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting the following comments were received: 

Mr. Konrad Philatowicz (U-Haul International, Inc.) stated that Section 2.5.1 gives the general rule 

regarding the zero set back interlocks and that allows for manual and electronic meters to not meet the same 

standard which makes perfect sense. Section 2.5.2 refers to motor fuel dispensing devices and the word 

electronic is missing from the title. The changes address NIST and industry concerns. He asked that this 

be a voting item at the National meeting. 

Mr. Scott Simmons (Colorado Division of Oil and Public Safety) was in support of this item for voting. 

During open hearings, comments were heard supporting a Voting status. The WWMA S&T Committee 

believes that this item has merit, is fully developed, and recommended that this item be assigned a Voting 

status. 

Southern Weights and Measures Association

No comments were received on this item during the 2022 SWMA Annual Meeting. 

The SWMA S&T Committee recommended this item move forward as a Voting Item. 

Northeastern Weights and Measures Association

No comments. No comments were heard from the floor. The Committee does not have a recommendation 

as to the status of this item. 

Central Weights and Measures Association

No comments were heard from the floor. 

The CWMA S&T Committee recommended this as a Developing Item. The Committee has concerns 

regarding a consumer/customer starting a delivery when the device is not on zero.

LPG-23.2 S.2.6. Automatic Timeout.

Source: National Propane Gas Association
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Submitter’s Purpose and Justification:

Address practical issues that propane marketers encounter when trying to comply with the zero setback 

requirements for propane stationary and truck-mounted meters in Handbook 44.

This proposal was developed by the National Propane Gas Association’s Technology, Standards and Safety 

Committee, a volunteer organization comprised of 2500+ members, including propane retail marketers and 

others providing products or services to the propane industry. 

In S.2.6.1, the removal of the vehicle mounted meters from this three-minute requirement is necessary as 

the initiation of a vehicle mounted meter is performed at the truck prior to moving the delivery hose to the 

customer tank, sometimes as far as 150 feet from the meter, or in installations with multiple containers that 

may require continued adjustment of containers or delivery hose to complete a delivery. This configuration 

can lead to periods of up to 5 minutes between initial meter engagement and first container filling or 

between containers being filled on a single delivery. 

In revised S.2.6, we are proposing that vehicle mounted meters be allowed periods between meter 

engagement and product flow of greater than 2 minutes prior to automated time out initiation. A fiveminute period is more practical as the initiation of a vehicle mounted meter is performed at the truck prior 

to moving the delivery hose to the customer tank, sometimes as far as 150 feet from the meter, or in 

installations with multiple containers that may require continued adjustments of containers or delivery hose 

to complete a delivery. The configuration on a typical bobtail can lead to periods of up to 5 minutes between 

initial meter engagement and first container filling or additionally periods of greater than two minutes can 

transpire between containers being filled on a single delivery.

The submitter acknowledged that the opposition may feel that the change enacted from two to three minutes 

for the timeout is sufficient. However, it is not. Some sources say the average age of drivers in the propane 

industry is mid-50’s. Those folks do not move as quickly or nimbly as much younger drivers.

The submitter requested that this be a Voting Item.

OWM Executive Summary for LPG-23.2 – S.2.6. Automatic Timeout.

OWM Recommendation: Different device types may require varying timeouts; as such, if 5 minutes 

is deemed appropriate for electronic vehicle tank meters NIST OWM supports this change.

• The Automatic time-out feature helps to prevents the use the device by another customer when the 

preceding customer completes the transaction. This is achieved by requiring that the device 

automatically time-out after a specified time.

• The submitter is requesting that the automatic time out that is currently specified as 3 minutes for 

electronic vehicle mounted meters in the LPG code be removed from S.2.6.1 in the LPG code and 

another paragraph be created, S.2.6.3 for electronic vehicle tank meters and,

• The submitter is requesting that the automatic time out be extended to 5 minutes for electronic 

vehicle tank meters to account for the initiation time at the truck and moving the discharge hose to 

the customer tank which can exceed 150 feet. 

• Discussion may be needed to determine how this will impact the VTM code requirements with

Timeout requirements of three-minutes.
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OWM Executive Summary for LPG-23.2 – S.2.6. Automatic Timeout.

• Different device types will require varying timeout. As such, if the 5 minutes suggested is the 

appropriate industry standard for this device, NIST OWM supports this change.

Table 3. Summary of Recommendations

LPG-23.2 – S.2.6. Automatic Timeout.

V D W A I Notes* Comments

Submitter 

OWM

WWMA 

SWMA 

NEWMA 5

CWMA 

NCWM

Letters of Support Letters of Opposition Notes

Industry

Manufacturers

Retailers and 

Consumers

Regulators

*Notes Key:

1 − Submitted modified language

2 − Item not discussed

3 − No meeting held

4 − Not submitted on agenda

5 − No recommendation or not considered

Item Under Consideration:

Amend Handbook 44, LPG and Anhydrous Ammonia Liquid-Measuring Devices as follows:

S.2.6. Automatic Timeout. 

S.2.6.1. Electronic Stationary (Other than Stationary Retail Motor-Fuel Dispensers) and 

Electronic Vehicle-Mounted Meters. – For individual deliveries, if there is no product flow for 

three minutes the transaction must be completed before additional product flow is allowed. The 

three-minute timeout shall be a sealable feature on an indicator. 

[Nonretroactive as of January 1, 2021] 

(Added 2021) (Amended 20XX) 

S.2.6.2. Automatic Timeout Pay-at-Pump Retail Motor-Fuel Devices – Once a device has 

been authorized, it must deauthorize within three minutes if not activated. Reauthorization of the 
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device must be performed before any product can be dispensed. If the time limit to deauthorize 

the device is programmable, it shall not accept an entry greater than three minutes. 

[Nonretroactive as of January 1, 2022] 

(Added 2021) 

S.2.6.3. Electronic Vehicle-Mounted Meters. – For individual deliveries, if there is no 

product flow for five minutes the transaction must be completed before additional product 

flow is allowed. The five-minute timeout shall be a sealable feature on an indicator.

(Added 20XX)

NIST OWM Detailed Technical Analysis: 

The Automatic time-out feature helps to prevents the use the device by another customer, when the 

preceding customer completes the transaction. This is achieved by requiring that the device automatically 

time-out after a specified time. The submitter is requesting that the automatic time out that is currently 

specified as 3 minutes for electronic vehicle mounted meters in the LPG code be removed from S.2.6.1 in 

the LPG code and another paragraph be created, S.2.6.3 for electronic vehicle tank meters and, the 

submitter is requesting that the automatic time out be extended to 5 minutes for electronic vehicle tank 

meters to account for the initiation time at the truck and moving the discharge hose to the customer tank 

which can exceed 150 feet. 

Discussion may be needed to determine how this will impact the VTM code requirements with Timeout 

requirements of three-minutes, but different device types will require varying timeout. As such, if the 5 

minutes suggested is the appropriate industry standard for this device, NIST OWM supports this change. 

Regional Association Reporting:

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting the following comments were received: 

Mr. Scott Simmons (Colorado Division of Oil and Public Safety) was in support of this item for voting. 

From the bobtail delivery driver perspective this makes sense. The automatic timeout will be beneficial. 

He did not see any detriment. 

Mr. Kevin Schnepp (California Division of Measurement Standards) agreed with Mr. Simmons’ comments.

During open hearings, comments were heard supporting a Voting status. The WWMA S&T Committee 

believes that this item has merit, is fully developed, and recommended that this item be assigned a Voting 

status.

Southern Weights and Measures Association

No comments were received on this item during the 2022 SWMA Annual Meeting. 

The SWMA S&T Committee recommended this item move forward as a Voting Item. 

Northeastern Weights and Measures Association
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At the 2022 Interim Meeting no comments were heard from the floor. The Committee does not have a 

recommendation as to the status of this item.

Central Weights and Measures Association

At the 2022 Interim Meeting, there were no comments from the floor. The CWMA S&T Committee 

recommends this item be withdrawn. 

MLK – Milk Meters

MLK-23.2 Table T.1. Tolerances for Milk Meters

Source: Milk Meter Tolerances Task Group

Submitter’s Purpose and Justification:

Eliminate the current tolerance structure of a decreasing permissible tolerance allowance as the size of the 

test draft increases.

This is a companion item to VTM-20.2 [Vehicle Mounted Milk Meters] currently being considered. It 

would be logical to block these two items as the data and discussion for changes to both Handbook 44 

sections will be identical. This proposal is being made to eliminate the current tolerance structure of a 

decreasing permissible tolerance allowance as the size of the test draft increases. The proposed changes 

are identical to the current tolerance structure in the international community that follow OIML R-117. 

Without the changes to the tolerances, it would be possible for a device to be within tolerance at small test 

drafts and be out of tolerance for larger test drafts that are more representative of a typical delivery.

If OIML tolerances are adopted, the tolerances that are currently in place may increase at larger test drafts.

The Submitter requested a Voting status for this Item.

OWM Executive Summary for MLK-23.2 – Table T.1. Tolerances for Milk Meters

OWM Recommendation: A review of this item by the Milk Meter Task Group when a new chair is 

appointed may be useful. We agree with other regionals that this item be assigned to the Milk Meter 

Task Group. 

• The Milk Meter Task Group reviewed all the varying tolerances in HB 44 for Milk meters. Instead 

of keeping a decreasing tolerance as the test draft increases, as the tolerance in the Milk meters code, 

the Task Group is proposing that the tolerances as included in the 2023 interim Meeting Agenda for 

VTM-20.2 for milk meter also be adopted in the Milk Meter code. 

• With the Task Group Chair currently not assigned since Mr. Charlie Stutesman no longer works 

with Kansas Weights and Measures and is no longer Chair of the Milk Meter Task Group, a review 

of the item by the Task Group when a new chair is appointed may be useful. We agree with other 

regionals that this item be assigned to the Milk Meter Task Group when a new task group chair is 

assigned.
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Table 3. Summary of Recommendations

MLK-23.2 – Table T.1. Tolerances for Milk Meters

V D W A I Notes* Comments

Submitter 

OWM

WWMA 

SWMA 

NEWMA 5

CWMA 

NCWM

Letters of Support Letters of Opposition Notes

Industry

Manufacturers

Retailers and 

Consumers

Regulators

*Notes Key:

1 − Submitted modified language

2 − Item not discussed

3 − No meeting held

4 − Not submitted on agenda

5 − No recommendation or not considered

Item Under Consideration:

Amend Handbook 44, Milk Meters Code, as follows: 

T.2. Tolerance Values. – Tolerances shall be as shown in Table 1. Tolerances for Milk Meters.

(Amended 1989, 20XX) 
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Table 1. 

Tolerances for Milk Meters

Indication

(gallons)

Maintenance Tolerance

(gallons)

Acceptance Tolerance

(gallons)

100 0.5 0.3

200 0.7 0.4

300 0.9 0.5

400 1.1 0.6

500 1.3 0.7

Over 500 Add 0.002 gallon per indicated 

gallon over 500

Add 0.001 gallon per indicated gallon 

over 500

(Added 1989)

Table 1. 

Tolerances for Milk Meters

Acceptance Tolerance Maintenance Tolerance

Complete Measuring 

System 0.5% 0.5%

Meter Only 0.3% 0.3%

(Amended 20XX)

NIST OWM Detailed Technical Analysis:

The Milk Meter Task Group reviewed all the varying tolerances in HB 44 for Milk meters. Instead of 

keeping a decreasing tolerance as the test draft increases, as the tolerance in the Milk meters code, the Task 

Group is proposing that the tolerances as included in the 2023 Interim Meeting Agenda for VTM-20.2 for 

milk meter also be adopted in the Milk Meter code. 

With the Task Group Chair currently not assigned since Mr. Stutesman no longer works with Kansas 

Weights and Measures and is no longer Chair of the Milk Meter Task Group, a review of the item by the 

Task Group when a new chair is appointed may be useful. We agree with other regionals that this item be 

assigned to the Milk Meter Task Group when a new Task Group Chair is assigned.

Regional Association Reporting:

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting the following comments were received: Mr. Michael Keilty 

(Endress+Hauser) alerted the Committee that the Chairman of the Task Group no longer works for the State 

of Kansas, leaving a vacancy for the Chair position. Mr. Matt Douglas (California Division of Measurement 

Standards) recommended that this be combined with VTM-20.2 and recommended assignment to the Milk 

Meter Tolerance Task Group. In the original justification, the submitter recommended that this item be 

blocked with VTM-20.2. The WWMA S&T Committee recommended that this item be assigned to the 

Milk Meter Tolerance Task Group and that this item be blocked with VTM-20.2. 
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Southern Weights and Measures Association

The following comments were received during the 2022 SWMA Annual Meeting: Dr. Curran (Florida)

stated that he opposed raising the tolerances to accommodate this new device. No comments were received 

from the Milk Meter Tolerance Task Group. 

The SWMA S&T Committee recommended this item be Assigned to the Milk Meter Tolerance Task Group. 

Northeastern Weights and Measures Association

At the 2022 Interim Meeting, no comments were heard from the floor. The Committee does not have a 

recommendation as to the status of this item.

Central Weights and Measures Association

At the 2022 Interim Meeting, Mr. Doug Musick (Kansas) stated the current tolerance table has a specified 

tolerance for a specified draft size. The percentage calculations for them do not match. The percentage 

tolerance changes for the same meter based on draft size. Updating the tolerance will make it uniform with 

other liquid tolerance tables.

Mr. Michael Keilty (Endress+Hauser) stated that the sizes of provers for this testing are not common. They 

are difficult to find. 

The CWMA S&T Committee believes this item is fully developed and recommends Voting status.

MFM – Mass Flow Meters

MFM-15.1 D N.3. Test Drafts.

Previously MFM-2

(Note: In 2019 this item was combined with Block 1 “Terminology For Testing Standards” and other items 

that addressed terminology for standards and the use of “master meters.” Based on comments heard during 

the 2021 Annual Meeting, the S&T Committee recommended that all items that were combined with Block 

1 “Terminology For Testing Standards” that originally appeared as a separate item or a separate block of 

items on the S&T agenda prior to 2019, be removed from Block 1 “Terminology For Testing Standards” 

and appear as originally presented.

Item MFM-15.1 was removed from Block 1 “Terminology For Testing Standards” and now appears as a 

separate item on the 2022 Interim Meeting agenda.)

Source: Endress + Hauser Flowtec AG USA

Submitter’s Purpose and Justification:

Amend Handbook 44 to allow field reference standard meters to be used to test and place into service 

dispensers and delivery system flow meters. This item has been assigned to the submitter for further 

development. For more information or to provide comment, please contact:

Mr. Michael Keilty

Endress + Hauser Flowtec AG USA
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(970) 586-2122, michael.keilty@us.endress.com

The use of transfer standards is recognized in Code sections 3.34 Cryogenic Liquid-Measuring Devices 

Code and 3.38 Carbon Dioxide Liquid-Measuring Devices Code and 3.39 Hydrogen Gas-Measuring 

Devices – Tentative Code. Transfer standard is only defined for testing cryogenic liquid measuring devices. 

It has been pointed out that the term transfer standard is not correct and that field reference standard meters 

may be more appropriate. See new the Item Under Consideration, updated on September 8, 2017.

Field evaluation of LPG meters and CNG dispensers and LNG dispensers is very difficult using volumetric 

and gravimetric field standards and methods. The tolerances for these applications are such that using field 

reference standard meters are more efficient and safer. With CNG and LNG and LPG applications, the 

field reference standard meters are placed in-line with the delivery system as it is used to fill tanks and 

vehicles. The use of field reference standard meters eliminates return to storage issues. The use of field 

reference standard meters is easier and faster compared to the use of traditional field standards. The cost 

of using field reference standard meters and transporting them is much less than the cost of traditional field 

provers and standards.

Recognition in Handbook 44 will enable States to allow field reference standard meters to place systems 

into service and for field enforcement.

Volumetric field provers and gravimetric field proving are susceptible to environmental influences. The 

State of Colorado uses a field reference standard meter to test propane delivery truck meters. The State of 

Nebraska has used a field reference standard meter to test agricultural chemical meters. Other States have 

asked that there be recognition in HB 44 in order for their State to allow the use of field reference standard 

meters.

In some applications, field reference standard meters are not more accurate than the meters used in the 

application. For that reason, longer test drafts and possibly more tests may need to be run.

The State of California is purported to have conducted a short study of field reference standard meters in 

the past. The conclusion did not lead to wide adoption of the practice. 

Section 3.37 Mass Flow Meters user requirement U.R.3.8. Return of Product to Storage, Retail Compressed 

Natural Gas Dispensers requires that the natural gas which is delivered into the test container must be 

returned to storage. This is difficult and most often not complied with when the test vessel contents are 

released to atmosphere. States often have difficulties in remote locations finding suitable field reference 

equipment.

OWM Executive Summary for MFM-15.1 – N.3. Test Drafts.

OWM Recommendation: OWM believes that the purpose for this item, as specified by the submitter, 

is better addressed from a technical standpoint in Items GEN-23.1 and Block 8.

• State and industry have a need to use various types of field test standards to evaluate commercial 

devices installed in the marketplace. NIST OWM recognizes the need to use various standards to 

test commercial devices and support the use of these standards when test data supports its use.

• The NIST OWM is also supporting the use of field test standards through the purchase of several 

meters and the collection of data throughout the U.S.
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OWM Executive Summary for MFM-15.1 – N.3. Test Drafts.

• The purpose statement for Item MFM-15.1 (Mass Flow Meters Code) indicates the goal of this item 

is:

“to amend Handbook 44 to allow field reference standard meters to be used to test and place into 

service dispensers and delivery system flow meters.”

• The proposed changes in Items MFM-15.1 suggest changes to the test draft criteria for devices 

covered under this code, which is not necessary to allow field reference standard meters to be used 

to test and place into service dispensers and delivery system flow meters.

• Amongst the concerns raised to the S&T Committee over the proposed changes for MFM-15.1, is 

the inability for an inspector or service company to test devices under their conditions of use and as 

required elsewhere in the MFM code.

o Specifically, with the proposed addition of a paragraph N.3.2. Field Reference Standard Meter 

Test., no information or data has been provided to justify that:

 a different test draft size than that specified in N.3.1. or the current Mass Flow Meter, NIST 

HB 44 paragraph N.3 Test Draft is necessary in order to use a “Field Reference Standard 

Meter.” 

 the current requirements for test draft “one test draft at the maximum flow rate of the 

installation and one test draft at the minimum flow rate” is appropriate for use when testing 

with a meter or volume prover.

o This proposal creates two test draft paragraphs in NIST HB 44. It retains the existing criteria for 

the test draft and adds a proposal for a second test draft paragraph that states “the test draft shall 

be equal to or greater than the amount delivered in one minute” 

 It has been observed when testing CNG that some draft will take far less time than one 

minute. If the proposed test draft paragraph is added the test draft will not be achievable and 

as stated unable to test under conditions of use.

 Since this proposal adds another test draft paragraph with the existing paragraph for test draft 

it also creates confusion as to what paragraph the inspector should apply.

As such, given the long debate over multiple iterations of the proposals, OWM proposes that 

since the purpose of the proposal is to allow field reference standard meters to be used to test

and place into service dispensers and delivery system, and the responsibility for allowance of 

these field test standards are already addressed in the NIST Handbook 44 Fundamental 

Considerations and Item Block 8 clarifies these responsibilities, that Consideration be given to 

the proposal in Item Block 8 which clearly states the responsibility for allowance of field 

standards along with a new proposal to add a general code requirement. 

• Note that GEN-23.1 and Block 8 items clarify what has long been recognized in NIST HB 44 

concerning the responsibility for acceptance of a standard making changes to specific codes such as 

those references in MFM-15.1 and is better addressed in GEN-23.1 and Block 8.
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OWM Executive Summary for MFM-15.1 – N.3. Test Drafts.

• GEN-23.1 not only avoids the need to specifically reference individual test methods in each specific 

code, it avoids the potential of implying that test methods not specifically referenced in a code would 

not be appropriate. 

Table 3. Summary of Recommendations

MFM-15.1 – N.3. Test Drafts

V D W A I Notes* Comments

Submitter 

OWM

WWMA 

SWMA 

NEWMA 

CWMA 

NCWM

Letters of Support Letters of Opposition Notes

Industry

• Letter from 

Endress+Hauser (10-

07-2021)

• Endress+Hauser Slides 

(01-11-2022)

• Endress+Hauser Letter 

to CWMA (05-12-

2022)

• Comments from 

Seraphin (09-27-2016)

• Comments from 

Seraphin (06-23-2017)

• Comments from 

Seraphin (07-02-2018)

• Comments from 

Seraphin Test Measure 

Co. (06-17-2022)

Manufacturers

Retailers and Consumers

*Notes Key:

1 − Submitted modified language

2 − Item not discussed

3 - No meeting held

4 - Not submitted on agenda

 5 - No recommendation or not considered

Item Under Consideration:

Amend Handbook 44, Mass Flow Meters Code as follows: 

N.3. Test Drafts. 
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N.3.1. Minimum Test - The minimum test shall be one test draft at the maximum flow rate of the 

installation and one test draft at the minimum flow rate. More tests may be performed at these or 

other flow rates. (See T.3. Repeatability.) 

(Amended 1982 and 20XX)) 

N.3.2. Field Reference Standard Meter Test. – The minimum quantity for any test draft 

shall be equal to or greater than the amount delivered in one minute at the flow rate being 

tested.

(Added 20XX)

NIST OWM Detailed Technical Analysis:

• Although this item has been on the agenda for a number of years, this item was group in a block of 

other similar items then removed from the block and placed back on the NCWM agenda as it originally 

appeared on the agenda. 

• NIST OWM is working with States using Coriolis meters to collect data on the use of these meters as 

standards to test liquid measuring devices. This data will be shared with all regulatory officials to assist 

them with their approval of meters as standards.

• This purpose indicates its intent is to permit the use of field reference standard meters in field testing 

of commercial measuring systems.

• It is not necessary to reference “field reference standards” in a specific NIST HB 44 code in order to 

permit their use.

• Criteria for assessing the use of a given type of test standard are outlined in NIST HB 44 Appendix A 

Fundamental Considerations. 

• The decision on whether or not to accept a particular test method for use in testing commercial weighing 

and measuring equipment ultimately rests with the regulatory authority.

• NIST OWM and Seraphin developed Block 8 items (GEN-19.1 and OTH-22.1) on the 2022 Annual 

Meeting Report to help clarify and provide additional information on field standard traceability and 

specifications, and the regulatory authority’s responsibility for approval of field standards. 

• Specifically, with regard to the proposed addition of a paragraph N.3.2. Field Reference Standard Meter 

Test, no information or data has been provided to justify that: 

 a different test draft size than that specified in N.3.1. or the current Mass Flow Meter, NIST HB 44 

paragraph N.3 Test Draft is necessary in order to use a “Field Reference Standard Meter.” 

 The current requirements for test draft “one test draft at the maximum flow rate of the installation 

and one test draft at the minimum flow rate” is appropriate is for use when testing with a meter or 

volume prover. 

• This proposal creates two test draft paragraphs in NIST HB 44. It retains the existing criteria for the 

test draft and adds a proposal for a second test draft paragraph that states “the test draft shall be equal 

to or greater than the amount delivered in one minute”. 

• It has been observed when testing CNG that some draft will take far less time than one minute. If 

the proposed test draft paragraph is added the test draft will not be achievable. 
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• Since this proposal adds another test draft paragraph with the existing paragraph for test draft it 

also creates confusion as to what paragraph the inspector should apply.

As such, given the long debate over multiple iterations of the proposals, OWM proposes that since the 

purpose of the proposal is to allow field reference standard meters to be used to test and place into service 

dispensers and delivery system, and the responsibility for allowance of these field test standards are already 

addressed in the NIST Handbook 44 Fundamental Considerations and Items GEN-23.1 and Block 8 clarifies 

these responsibilities, that Consideration be given to the proposal in Items GEN-23.1 and Block 8 which 

clearly states the responsibility for allowance of field standards along with the proposal to add a general 

code requirement. 

Summary of Discussions and Actions:

In the fall of 2016, Mr. Keilty provided an update to the Item Under Consideration. That update appears in 

the agenda. The previous proposed Item Under Consideration was as follows: 

N.3. Test Drafts. – 

N.3.1. Minimum Test - Test drafts should be equal to at least the amount delivered by the device 

in one minute at its normal discharge rate. 

(Amended 1982) 

N.3.2. Transfer Standard Test. – When comparing a meter with a calibrated transfer 

standard, the test draft shall be equal to at least the amount delivered by the device in 2 

minutes at its maximum discharge rate. 

The submitter recommends that NIST update EPO 28 for CNG dispensers and EPO 26 for LPG Liquid 

Measuring Systems to include transfer standard meter tests. NIST Publication R 105-4 should also be 

revised to specifically address the transfer standard meter and the requirements for use.

The S&T Committee might also consider amending Sections 3.30 Liquid-Measuring Devices Code and 

3.31 Vehicle-Tank Meters Code to allow transfer standard meters.

The Committee received written comments on all items in Block 4 and Block 5, as well as LPG-4 and 

MFM-2 emphasizing the need for there to be more study and discussion of the issues to assess the 

ramifications of all the proposed changes. The Committee also received written comments from the SMA 

that it looks forward to further information on these items and stating that it is important to be consistent in 

our use of terms across multiple sections of Handbook 44. The Committee agreed to carryover this group 

of items on its 2019 agenda to allow for further discussion and development of these proposals. 

At the 2019 NCWM Interim Meeting, the S&T Committee decided to combine the items on the agenda 

dealing with the issue of transfer standard (including items already combined into blocks) into one block. 

Block 1 (New) of the Interim Meeting report now includes GEN-3, Block 1 (original items from the 2019 

interim agenda that appeared under Block 1), Block 2, LPG-3, and MFM-5, which were all separate items 

and blocks of items on the S&T Committee’s 2019 Interim Meeting agenda (NCWM Publication 15). 

Agenda items GEN-3, Block 1, Block 2, LPG-3, and MFM-5 are listed separately on the Interim agenda 

with a note added beneath each individual item referring the reader to the New B1 items. All items under 

this New B1 have retained the same numbering system for ease in referring to the appendix for discussion 

on each item. 
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At the 2019 NCWM Annual Meeting, Mr. Brett Gurney (NCWM Chair) commented regarding the 

formation of a Task Group assigned to further develop this block proposal. The TG is charged with 

providing definitions for various types of standards (transfer, field, reference, etc.) as well as the criteria to 

be met by these types of standards. The completion date given to the TG is July 2021. The Committee 

agreed to the Assigned status for this block of items and looks forward to hearing updates from the TG. 

The Chair of the Task Group was:

Mr. Jason Glass

Kentucky Department of Agriculture

(502) 573-0282, jason.glass@ky.gov

At the 2020 NCWM Interim Meeting Field Standard TG Chair Glass reported that the TG met prior to the 

NCWM Interim Meeting and has begun discussion of the items under Block 1. Mr. Glass stated that biweekly teleconference meetings were scheduled and that the group was optimistic but had significant work 

to accomplish. 

Mr. Russ Vires (SMA) supports the Scale item, SCL 18.1; in this block, Mr. Dimitri Karimov (Meter 

Manufacturers Association) supports the Task Group activities, Mrs. Tina Butcher (NIST OWM) was 

encouraged with the progress on terminology and provided an update on the Mass Flow Meter testing 

reporting that field testing was conducted October 28 to November 1, 2019, and that State and Industry 

participation included Colorado, Florida, Oregon, Emerson, and Tulsa Gas Technology. 

Mr. Kurt Floren (Los Angeles County, California) raised concerns with GEN-19.1. regarding the definition 

of “Standard, Field” and its reference to “stable” standards and how long a standard is expected to be stable, 

which is typically 1-year, for which he believes should be longer. Mr. Floren also questioned the statement 

in the definition “tested over a range of environmental and operational conditions that the measuring devices 

is used...”. Mr. Floren noted that he was unsure if all laboratories will have the capabilities to test over this 

wide range of conditions. Mr. Floren also expressed concerns with the definition “Standard, Transfer” 

citing that this standard may not meet the fundamental considerations requirement for standards over a long 

period of time or wide range of environmental conditions. 

Mr. Steve Harrington (Oregon) echoed Mr. Floren’s comments. Field Standard TG Chair Glass responded 

that these are concerns of the TG and these issues will be discussed and considered as the TG develops 

these items. 

During the Committee’s work session, the Committee agreed that this item should remain an Assigned 

Item.

At the 2021 NCWM Interim Meeting, the NCWM Field Standard TG Chair Glass provided an update on 

the Task Group activities. Mr. Glass reported that the field standard Task Group is following the activities 

of the NIST Master Meter Project and that the Task Group reviewed API specifications for use of master 

meters as a standard and a test protocol that will be used to ensure uniformity in collecting data on master 

meters used as field standards. Mr. Glass also reported that the TG does not have a recommendation for 

this item. Mr. Glass also reported that he would be stepping down as the TG Chair. Mr. Mike Keilty 

(Endress+Hauser AG) thanked Chair Glass and the TG for their work and requested that Block 1, LPG15.1, N.3. and Block 1 MFM-15.1, N.3 be removed from Block 1 items and to allow those items to move 

forward separate from the other Block 1 Items. Mr. Keilty stated that similar language was added to the 

Hydrogen code and that the proposed language in LPG-15.1 N.3. and MFM-15.1, N.3 will allow for the 

recognition of master meters as field standards. Mr. Henry Oppermann (W&M Consulting) stated that data 

is needed to ensure that master meters can be used over a range of conditions. Mr. Bob Murnane (Seraphin) 

stated that jurisdictions have the ability to use meters and that Block 1 LPG-15.1, N.3 and Block 1 MM-
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15.1, N.3 should remain in Block 1 until data is available to support the use of master meters as a standard. 

Mr. Keilty mentioned that there has been useful dialog regarding master meters in the TG, but that he is 

concerned that the TG is not close to deciding and he expressed concerns with the TG’s focus on the NIST 

Master Meter Project. Mrs. Tina Butcher (NIST OWM) provided an update on the NIST Master Meter 

Project and noted that States have the regulatory powers to accept or reject a standard. She also mentioned 

that NIST is working with States to collect data needed to assess master meters and preliminary testing was 

conducted and data was collected on CNG at Tulsa Gas Technology’s facility in fall 2019. Ms. Diane Lee 

(NIST OWM) noted that NIST OWM feels that it is premature to add more language to the NIST Handbook 

44 on master meters without data to support its use. 

During the Committee’s work session, the Committee agreed to keeps all items in Block 1 and that this 

item should remain with an Assigned status. 

At the 2021 NCWM Annual Meeting, Mr. Glass reported that he would be stepping down as the Field 

Standard TG Chair. The Committee heard updates from members of the Task Group during open hearings. 

Mr. Keilty noted that two of the items had been on the agenda since 2015 and requested that they be removed 

from the block and recommended recognizing the use of master meters. Other comments were to keep the 

items together until data is analyzed from the NIST Field Reference Standard Work Group to support the 

use of master meters but that if some items were removed from the block, all items should be removed from 

the block. Based on comments heard during the 2021 Annual Meeting, the S&T Committee recommended 

that all items that were included in Block 1 “Terminology For Testing Standards” that originally appeared 

as a separate item or a separate block of items on the S&T agenda in and prior to 2019, be removed from 

Block 1 “Terminology For Testing Standards” and appear as originally presented. 

During the 2021 Committee work session the Committee recognized that the Task Group has accomplished 

all it is able to at this point and is recommending the Task Group be disbanded and will make said 

recommendation to the NCWM Chair. The Committee agreed to break all items in Block 1 into individual 

items and designate them all as Developing. The Committee thanks the Task Group and its members for 

their work. 

At the 2022 NCWM Interim Meeting the Item Under Consideration presented at this meeting is provided 

below. 

N.3. Test Drafts. 

N.3.1. Minimum Test - The minimum test shall be one test draft at the maximum flow rate of the 

installation and one test draft at the minimum flow rate. More tests may be performed at these or 

other flow rates. (See T.3. Repeatability.) 

(Amended 1982 and 20XX) 

N.3.2. Field Reference Standard Meter Test. – The minimum quantity for any test draft 

shall be equal to or greater than the amount delivered in one minute at the flow rate being 

tested.

(Added 20XX)

Mr. Keilty shared a presentation on field standard meters during open hearings relevant to both MFM 15.1 

and LPG 15.1. The intent of the presentation was to describe initial and ongoing calibration traceability, 

compare OIML tolerances vs NIST Handbook 44, describe the benefits and show example. An abbreviated 

copy of the presentation is available on the NCWM website in the interim meeting documents archive. Mr. 

Keilty commented that he believes MFM 15.1 and LPG 15.1 are fully developed and should receive Voting 

status for the annual meeting. He has updated the proposal to exclude the term “reference” from “field 
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reference standard meter test”, as shown above. He requested that the Committee provide specific guidance 

if a Developing status is assigned. A comment from industry (Mr. Bob Murnane [Seraphin]) stated that 

N.3.2 in the proposal conflicts with the current code which states normal test drafts must be at least one 

minute at the maximum discharge flow rate of installation conditions. The current wording allows for a 

test to be conducted at any flow rate for one minute. There was concern from a regulator (Mr. Charles 

Stutesman, Kansas) echoing these concerns. Ms. Diane Lee (NIST OWM) requested that more data be 

made available so that NIST is able to compare worldwide data against test data compiled within the U.S.

by NIST. Mr. Mahesh Albuquerque (Colorado) expressed support for this item to receive Voting status. 

Mr. Marc Butler (Emerson Micro Motion) expressed confusion at the two notes, thinking that perhaps they 

conflicted with each other; are they both needed or are they independent? Mrs. Tina Butcher (NIST OWM) 

expressed that she recognizes the use and importance of master meters, but is concerned with the purpose 

of this item. Mrs. Butcher suggested that the statement for use be reworked as test draft criteria is so critical. 

Mrs. Butcher recommended and offered NIST OWM assistance on this item.

During the S&T Committee work session, the Committee recognized the submitters desire that a Voting 

status be recommended but determined that there were too many concerns and confusion expressed. The 

Committee recommended that the submitter develop the item further by aligning language to existing 

language in Handbook 44, clarifying the purpose to help avoid confusion of the new code on new 

equipment, and reaching out to NIST OWM or other industry or regulatory officials for feedback.

During the 2022 Annual Meeting, S&T Committee open hearings Mrs. Tina Butcher provided the NIST 

OWM technical analysis for this items when she address NIST OWM comments to LPG-15.1 and as 

addressed in this report she pointed out that a new general code requirement will be proposed for the new 

2023 cycle that would not only avoid the need to specifically reference individual test methods in each 

specific code, it avoids the potential of implying that test methods not specifically referenced in a code 

would not be appropriate.

Further comments were provided that OWM believes that the purpose for this item, as specified by the 

submitter, is better addressed from a technical standpoint in Item Block 8 and that OWM proposes that 

since the purpose of the proposal is to allow field standard meters to be used to test and place into service 

dispensers and delivery systems, and the responsibility for allowance of these field test standards are already 

addressed in the NIST Handbook 44 Fundamental Considerations and Item Block 8 clarifies these 

responsibilities, that Consideration be given to the proposal in Item Block 8 which clearly states the 

responsibility for allowance of field standards along with a 2023 new proposal to add a general code 

requirement. 

Mrs. Butcher also noted that State and industry have a need to use various types of field test standards to 

evaluate commercial devices installed in the marketplace and that NIST OWM recognizes the need to use 

various standards to test commercial devices and support the use of these standards when test data supports 

its use. But the proposed addition of another paragraph N.3.2 in the MFM Code that specifically references 

test draft for an individual test method (Field Standard Meter Test), potentially implies that test methods 

not specifically referenced in a code would not be appropriate.

The submitter of the item pointed out that the Central Weights and Measures Association recommended 

that the item move forward as a vote and noted that a presentation was given at the CWMA about using 

meters to test devices. Also, during open hearings, a weights and measures official spoke on the ease of 

use of meters to test device. Although NIST, OWM provided comments in support of the use of various 

standards to test commercial devices when data supports their use, and that the proposed paragraph N.3.2 

in the MFM Code for this item would potentially imply that test methods not specifically referenced in a 

code would not be appropriate, the submitter of this item noted that he failed to understand why there was 

in opposition and asked States to support the item. 
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During the 2022 Annual Meeting, Committee work session, the Committee agreed to a Developing status 

for this item based on the comments heard on this item.

Regional Association Reporting:

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting the following comments were received:

Mr. Robert Murnane (Seraphin Test Measure Company) - asked what does adding the language do? What 

data has been provided to support the change to 1 minute? Is it acceptable for Weights and Measures 

Officials to be prohibited from testing mass flow meters using any draft size equal to or greater than the 

MMQ over the range of flow rates? Currently code allows for conducting tests specified by the manufacture 

of the meter. This proposal would increase the size of the drafts. Will HB44 have to be changed every 

time a new field standard is introduced? The proposed item is not necessary and requests that this item be 

withdrawn from consideration.

Mr. Jan Konijnenburg (NIST Associate) stated the position of NIST OWM: the purpose of this item (and 

LPG-15.1) is better addressed in Block 8 and opposes this item as it is written.

Mr. Michael Keilty (Endress+Hauser) commented on Mr. Murnane’s comments. Mr. Murnane has 

submitted comments in June and Mr. Keilty wants to respond to those comments. Whenever there is a new 

technology, we must write codes. It is appropriate to make changes to HB44. You have to refer to HB44 

to see if a meter is acceptable. These devices will be traceable and vetted by the director or meteorologist. 

The MMQ test is not done normally. I looked at the certificates that were issued and three of the certificates 

are for the same meter, used by two companies in the U.S. it is impractical and unsafe to try to collect an 

MMQ sample at the maximum flow rate. I will forward my comments to the committee in an email. 

Recommends that this item move forward as a Voting Item.

Mr. Scott Wagner (State of Colorado) commented on Section N.3.2. transfer test, the concern is that the 2-

minute test draft might affect the EPO for testing CNG meters and would make it restrictive.

Mr. Murnane stated: how does the item support the purpose? An MMQ test would be prohibited by this 

code amendment. The test equipment available will change the volume of the test draft.

Mr. Matt Douglas (California Division of Measurement Standards) stated, “I do not think this language is 

helpful. This item has been on the agenda for 8 years and recommends this item be withdrawn.”

During open hearings, the Committee heard conflicting comments including that the purpose of this item 

is better addressed in Block 8. WWMA S&T Committee recommended this item for withdrawal, along 

with the recommendation that the submitter combine their efforts with the submitters of Block 8.

During the voting session comments were received from membership. The submitter requested that the 

committee reconsider the recommended Withdrawal status and to please leave the item with the current 

Developing status.

Based on the comments heard, the Committee entered deliberations. During deliberations, it was 

determined that the item was fully developed, and the submitter had nothing further to add. The Committee 

concluded that the item should remain with the recommendation for withdrawal.
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Southern Weights and Measures Association 

The following comments were received during the 2022 SWMA Annual Meeting: 

Mr. Keilty stated that the purpose statement was left out of the proposal when it moved from Block 8. It 

has now been added. He also submitted new language for N.3.2. 

N.3.2. Field Standard Meter Test.-The minimum quantity for any test draft shall be equal to or 

greater than the amount delivered in one minute at the flow rate being tested except for tests of 

the minimum measured quantity specified for the meter.

The SWMA S&T Committee recommended this item move forward as a Voting Item with the language 

above included. 

Northeastern Weights and Measures Association

At the 2022 Interim Meeting Mr. Keilty commented that he introduced this item in 2014 and there has been 

much documentation and discussion. The goal was to introduce field standard meters and small draft size 

benefit. Mr. Kielty indicated that he polled some states and he believes that having language in HB44 

would enable those states to use field standard meters. Mr. Kielty also noted that he has submitted a letter 

to the NEWAM S&T Chair with changes to the purpose statement and other modifications to the language 

and recommends a Voting status. Mr. Murnane asked what changed in the purpose statement and it was 

shared with the body. Mr. Murnane commented that he believes the Fundamental Considerations already 

allows State Directors to use field standards and pointed to language in Block 8 that would reinforce that. 

Mr. Murnane also believes there is an issue with a 1-minute test. Mr. Murnane does not believe this item 

is needed and urged that submitter to work with submitters of Block 8. Mr. Keilty stated that whenever 

new technology is available, the conference allows them to be used. He believes the language in this item 

facilitates the testing of systems already in place and allows 1 minute test to be sufficient. He pointed out 

that SWMA has voted twice to pass, as has CWMA. Mr. Henry Opperman (W&M Consulting) commented 

that the Fundamental Considerations allows recognition of other standards that perform at the level of field 

standards. He questions how we prove that a field standard meets the requirements in the Fundamental 

Considerations. Even if used, it is still not clear how the states determined they meet the requirements. Ms. 

Diane Lee (NIST OWM) commented that NIST is doing additional research on test draft paragraphs. If the 

purpose of this item is that master meters can be used, it’s always been addressed in Fundamental 

Considerations that State Directors can accept anything. Ms. Lee noted that Block 8 is just clarifying what 

is needed for selection of appropriate standards. Mr. Murnane indicated that he also called states referenced 

by Keilty and they are using the Fundamental Considerations for field standards. Mr. Jim Willis (New 

York) believes this item is redundant, noted that as a Director, he already has the authority through 

Fundamental Consideration, and recommends withdrawal. Mr. John Mcguire (New Jersey), Mr. Walt 

Remert (Pennsylvania), Mr. James Cassidy (Massachusetts) and Mr. Lou Sakin (Holliston, Massachusetts) 

all recommended withdrawal of this item. 

After hearing comments from the body, the Committee agreed with the commenters that this item does not 

have merit and is redundant in nature. The Committee is recommending that this item be Withdrawn. 

Central Weights and Measures Association 

At the 2022 Interim Meeting Mr. Keilty recalled that the CWMA recommended this as a Voting Item for 

the 2022 NCWM. In May CWMA voted and approved this item. Larger drafts than 1 minute can be used. 

Mr. Murnane stated that the purpose statement does not align with proposed change to N.3. Numerous 

meters are already approved under fundamental considerations, i.e.: the authority lies with the Director to 
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approve devices. Why is the test draft being changed? Regulators must be able to choose whatever draft 

size they want, specifically for Mass Flow Meters. 

If the Minimum Measured Quantity is greater than one minute of flow, then some mass flow meters would 

require larger draft sizes. Several NTEP CCs were referenced in which the MMQ is less than one minute 

of flow, which would conflict with testing the MMQ. 

Mr. Craig VanBuren (Michigan) suggested changes in verbiage to address the MMQ / one minute of flow 

conflict.

The CWMA S&T Committee believes this item is fully developed and recommends Voting status. The 

Committee also believes this should be added to Block 1.

HGM – Hydrogen Gas-Measuring Devices

HGM-23.1 UR.3.8. Safety Requirement

Source: Quong and Associates, Inc.

Submitter’s Purpose and Justification: 

Add safety requirement for hydrogen gas measuring devices. The proper fueling of hydrogen vehicles is 

critical to ensure that the vehicle and high-pressure tank is not damaged. Unlike other gases, such as 

compressed natural gas, hydrogen heats as a vehicle is fueled due to the reverse Joule-Thompson effect.

This means that the fueling rate and temperature of the hydrogen must be carefully controlled, or damage 

can occur to the vehicle hydrogen tanks. The hydrogen industry has done considerable work in developing

standard fueling protocols in SAE.

J2601 (https://www.sae.org/standards/content/j2601_202005/) and validation methods in 

ANSI/CSA HGV 4.3

(https://www.csagroup.org/store/product/CSA%25100ANSI%20HGV%204.3%3A22/) to 

ensure that the vehicles are fueledcorrectly and safely.

The validation of SAE J2601 using ANSI/CSA HGV 4.3 has been performed on the 50+ hydrogen

stations in California by the Air Resources Board (ARB) 

(https://ww2.arb.ca.gov/resources/documents/annual-hydrogen-evaluation). The proposed

requirement provides assurances that dispensers have been verified to the proper fueling protocol 

which will protect the dispenser, vehicle, and consumer.

While the California Department of Food and Agriculture is discussing submitting the same language for 

the California Code of Regulations, adding the same language of Handbook 44 would allow other states to 

understand and adopt the key hydrogenfueling protocol standards, thereby expanding the use of hydrogen

throughout the United States.

The submitter acknowledged that some may argue that the equipment to validate stations is not available

except in California.

The submitter’s response would be that, first, there are other private companies who have the equipment

to test dispensers outside of California, includingstations in the northeast US. Second, HGV 4.3 allows 

for factory acceptance testing of dispensers prior to installation and an abbreviated Site Acceptance Test.

This approach shortens the time and equipment necessary to verify a station meets SAE J2601. Third, 
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the design and software of the Hydrogen Station Equipment Performance (HyStEP) Device used byARB

is publicly available. (https://h2tools.org/hystep-hydrogen-station-equipment-performance-device)

The submitter provided the following links: 

• SAE J2601: https://www.sae.org/standards/content/j2601_202005/ (copyrighted) 

• ANSI/CSA HGV 4.3 

(https://www.csagroup.org/store/product/CSA%25100ANSI%20HGV%204.3%3A22/) 

(copyrighted) 

• California Air Resources Board: Annual Evaluation of Fuel Cell Electric Vehicle Deployment & 

Hydrogen Fuel Station Network Development 

• https://ww2.arb.ca.gov/resources/documents/annual-hydrogen-evaluation (many reports

available, latest is too large to attach)

• EVSE Pre_Rule Wkshop Shared Deck.pdf 

The submitter requested that this be a Voting Item in 2023.

OWM Executive Summary for HGM-23.1 – UR.3.8. Safety Requirement

OWM Recommendation:

• It has not been part of the weights and measures standards development process to include 

prescriptive safety requirements into handbook legal metrology standards.

• The dispenser’s design features regardless of their function should not affect the metrological 

integrity of the equipment.

• Traditional fueling applications have established mechanisms to address the safety features of 

dispenser installations not typically within in the scope of the weights and measures authority.

• Groundwork not outlined in the proposal must be laid to establish an SAE J2601 verification 

program.

Table 3. Summary of Recommendations

HGM-23.1 – UR.3.8. Safety Requirement

V D W A I Notes* Comments

Submitter 

OWM 5

WWMA 

SWMA 

NEWMA 

CWMA 
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Table 3. Summary of Recommendations

HGM-23.1 – UR.3.8. Safety Requirement

V D W A I Notes* Comments

NCWM

Letters of Support Letters of Opposition Notes

Industry

Manufacturers

Retailers and 

Consumers

Regulators

*Notes Key:

1 - Submitted modified language

2 - Item not discussed

3 - No meeting held

4 - Not submitted on agenda

5 - No recommendation or not considered

Item Under Consideration:

Amend Handbook 44 Hydrogen Gas-Metering Devices Code as follows:

UR 3.8. Safety Requirement –All hydrogen gas-measuring devices subject to this code shall 

maintain verification of testingdemonstrating conformance with the latest version of SAE J2601 

Fuel Protocols for Light Duty Gaseous Hydrogen SurfaceVehicles, as determined by the latest 

version of ANSI/CSA HGV 4.3 “Test Methods for Hydrogen Fueling Parameter Evaluation. 

(Nonretroactive as of January 1, 10XX)

NIST OWM Detailed Technical Analysis: 

The proposal will essentially require weights and measures officials to assess compliance with an SAE and 

ANSI standards. The official will be required to verify the owner is operating dispensing equipment that 

holds fueling safety protocol certification to SAE J2601 which can involve the performance of the 

dispenser, its programing, communications capability, and the station’s hydrogen storage system as well as 

a suitable test apparatus for use in the verification procedure. It has not been part of the weights and 

measures standards development process to include prescriptive safety requirements into handbook legal 

metrology standards. The dispenser’s design features regardless of their function should not affect the 

metrological integrity of the equipment.

If it is just an inspection for possession of current documentation, that may be more palatable; however, 

that is not really clear from the proposal and weights and measures programs do not typically enforce safety 

standards. Will compliance with safety standards keep coming up as an issue with alternative fuel vehicle 

refueling applications? This is unlike traditional fueling applications which have established mechanisms 

to address the safety features of dispenser installations. How does each jurisdiction ensure that equipment 

has met safety standards without putting weights and measures programs in the position of having to verify 
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the equipment complies with standards other than HB44, since that’s not typically within the scope of their 

authority (other than a limited number of programs which do regulate safety requirements)? 

Safety is always first priority; however, has the groundwork been laid to provide all the key components to 

weights and measures jurisdictions to properly address existing and new installations of equipment. The 

safety community should be approached on lessons learned in similar applications and to determine all 

other options and possible opportunities to make stakeholders in the up-and-coming hydrogen marketplace 

aware of recommended practices for safe fueling protocols. 

Regional Association Reporting:

Central Weights and Measures Association

No comments from the floor. The CWMA S&T Committee recommended this as a Developing Item. 

Clarification regarding the term “verification” is needed.

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting the following comments were received:

Mr. Kevin Schnepp (California Division of Measurement Standards) stated that he has worked with the 

submitter. J-2601 is a requirement for operating in the state of California. This is a safety protocol. This 

is both a standard and a test method. The design parameters for the equipment meet the standard. This is 

not a type evaluation requirement; it is a user requirement. He supported this item.

The WWMA S&T Committee feels that this item has merit and recommended that this item be assigned a 

Developing status with consideration to the concerns identified during open hearings.

Southern Weights and Measures Association

The following comments were received during the 2022 SWMA Annual Meeting:

Dr. Curran (Florida) questioned whether this was the proper venue for this item. Mr. Floyd (Louisiana)

also commented that this was not the proper venue for this item. This Committee would like the NCWM 

S&T Committee to consider whether this type of item is within the scope of weights and measures. 

The SWMA S&T Committee recommended this item move forward as a Developing Item.

Northeastern Weights and Measures Association

Mr. Spencer Quong (Quong and Associates representing Toyota Motors North America) explained the 

requirements for validation of fueling protocol through SAE. Mr. Quong indicated that if hydrogen vehicles 

filled too quickly, it will overheat and if the fueling protocol is performed significantly different, it may 

affect accuracy. Ms. Juana Williams (NIST OWM) noted that safety is first and foremost however, this 

proposal would require that the owner of the device be trained in fueling safety, which is not typical to put 

in HB44. Mr. Jason Flint (New Jersey) commented that the language in this item may be more suited for 

other standard setting organizations such as NFPA.

After hearing comments from the floor, the Committee recommended that this item be given a Developing 

status.
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EVF – Electric Vehicle Fueling Systems

EVF-21.1 D A.1. General

Source: ABB, BTCPower, Electrify America, Edison Electric Institute, EVConnect, EVgo, Greenlots, 

Rivian, Siemens, Tesla, Tritium

Submitter’s Purpose and Justification:

To provide clarity on how Handbook 44, Sec. 3.4 tentative code will apply to existing EVSE that are in the 

ground before it becomes effective by identifying which elements are non-retroactive.

While it is important to ensure that consumers are receiving accurate and transparent information regarding 

the accuracy of EV charging stations, the cost to retrofit existing stations that often do not include an 

integrated meter, especially DCFC where commercial DC metering technology is not readily available 

today, will be cost prohibitive. In California Initial Statement of Reasons (ISOR) for adopting 

specifications and tolerances requirement for commercial EVSE, California estimated that it costs 

approximately $4,500 to upgrade existing Level 2 stations and $20,000 to upgrade existing DCFC. To put 

this into context, California DMS utilized 2015 DOE data stating that the average commercial Level 2 

EVSE costs between $3,000-$6,000 and the average DCFC up to $40,000 or more. The retrofit costs would 

represent a significant investment amount that does not seem warranted. The ISOR is available here: 

https://www.cdfa.ca.gov/dms/pdfs/regulations/EVSE_ISOR.pdf. According to DOE AFDC station 

locator there are 23,000 level 2 station with 66,000 connectors in the U.S. and 3,700 DCFC stations with 

14,000 connectors. Being conservative and utilizing just the number of stations, it would cost $92M to 

upgrade the existing Level 2 station in the U.S. today and $74M to upgrade the existing DCFC stations, a 

number that is expected to grow as more stations are deployed. Placing this excessive upgrade burden on 

manufacturers and network operators is not feasible and an alternative pathway needs to be explored to 

ensure consumer transparency and EVSE accuracy for existing stations without requiring extensive 

retrofits. This number also does not include the amount of public funding across various states that has 

been invested in these EVSE that would prematurely potentially be ripped out and replaced. It could also 

have the unintended consequence that the EV industry stops charging for charging services at existing sites 

or shut them down if the investment in retrofits is greater than the benefit of continuing to operate. Stranded 

assets across the country are a valid concern and should not be taken lightly. It is important to not 

prematurely replace EVSE in the field until the useful life of the system has been obtained. Spending a 

significant amount of capital to upgrade existing stations rather than investing in new infrastructure does 

not appear aligned with EV deployment goals. Therefore, it is recommended that there is consideration for 

making sure requirements are non-retroactive and there is a phase in timeline for existing stations. The 

language utilized above is similar to what CA DMS implemented, which was the first state to adopt a 

version of Handbook 44 Sec 3.4 for EVSE. The date for DC EVSE is set at January 1, 2023 to match 

California’s timeline but also because this is when DC metering technology is expected to be commercially 

available in the market and integrated into DC EVSE by most EVSE manufacturers that are either working 

on their own product or with third party meter manufacturers.

In general, it appears that there is some openness to considering how legacy EVSE that are in the ground 

today should be treated when considering that DC metering technology integrated into the EVSE was not 

commercially available when many of these stations were developed. The main concern that has been 

raised is regarding whether there should be an overall exemption for existing EVSE to the measurement 

provisions in HB 44 Sec 3.4 or whether existing EVSE should be exempt from certain requirements in the 

subsections of Sec 3.4 that are not feasible to attain. In reviewing the subsections of Sec 3.4, the proposal 

submitters determined that it would not be feasible to meet most subsections of Sec 3.4 with equipment that 

is in the ground with the exception of S.5 Marking (except S.5.2) and S.6 printing requirements. To ensure 
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there is not confusion between which stations were in the ground prior to dates referenced above, EVSE 

owners and operators will need to work with local weights and measures officials on a self-reporting 

mechanisms or some other mechanism for tracking station service dates. California will be the first state 

that will need to determine how this process will operate in the field given it has already adopted the 

exemption noted above and compliance for new AC stations is effective January 1, 2021. On the consumer 

side, EVSE operators and owners today can provide certain provisions to ensure the accuracy of the 

commercial transaction that can be facilitated outside of having a meter integrated into the EVSE. For 

instance, some owners and operators may be able to utilize the accuracy that is traceable via the 

measurement technology in the EV that accounts for any losses and ensure the consumer is being accurately 

and fairly billed for what he or she is receiving.

The submitter requested Voting status for this item in 2021.

OWM Executive Summary for EVF-21.1 – A.1. General

OWM Recommendation: 

• OWM believes this item should not be revisited because as written in the Item Under Consideration 

it requires considerable further development. Rather than proposing an exemption from all 

requirements in Section 3.40, OWM recommends the submitters not revisit this proposal and for 

those problematic areas of compliance they should propose modifications to specific requirements 

that result in a suitable alternative means to achieve conformity. 

• OWM acknowledges the submitters have been diligently working with the NIST USNWG EVFE 

Subgroup. The EVFE Subgroup has held 16 meetings since 2020 where the submitters presented 

possible alternatives for the group to review prior to presenting those alternatives to the community 

for consideration. The EVFE Subgroup only reached a consensus in June 2022 for a proposal that 

does not delay fundamental requirements for accuracy of commercial systems. The EVFE 

Subgroup’s proposal recommends a wider DC tolerance (5 percent) for EVSEs installed prior to 

2024 and specifies that must include accuracy markings for transparency to the EV driver about the 

conditions for the sale of electrical energy and in fairness to competing businesses. The EVFE 

Subgroup offers that proposal for consideration as an alternative to Agenda Items EVF-23.5 and 

EVF-23.6 with notable differences. 

• NIST OWM is aware of the submitters’ November 15, 2022 email sent to the Committee where the 

submitters recommend withdrawing EVF 21.1 and EVF-21.5 given new proposal EVF-23.6 reflects 

feedback on these 2021 proposals and the significant changes to the proposals since August 2020 

(as well as the EVSE code becoming permanent). The submitters are also supportive of designating 

EVF-23.6 as a Voting Item.

• The proposal, if adopted as written, would mean an entire generation of devices will be permitted 

to operate for a 10-year period without having to comply with any HB 44 Section 3.40 requirements 

for indications, receipts, accuracy, security for metrological features, specific code markings, etc. 

for what may well be the lifetime of the device. 

• To allow such a blanket exemption does a disservice to the electric vehicle refueling industry and 

would be viewed as competitively unfair to traditional and other alternative vehicle fueling 

applications which are required to comply with similar requirements or EVSE manufacturers who 

are spending money to comply with current requirements. The fairness issue has surfaced in several 

2023 proposals. 
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OWM Executive Summary for EVF-21.1 – A.1. General

• The submitters need to consider that, even if an effective date is added to a device-specific code, 

Section 1.10 General Code requirements will still apply. 

• The submitters made alternate proposals available to the EVFE Subgroup for their review in January 

2022 and April 2022. These alternate proposals do not include any modifications to paragraph A.1. 

General as shown in the Item Under Consideration. 

• The EVFE Subgroup’s discussions have been ongoing in their review of the submitters latest 

proposals which are intended to replace S&T Agenda Items EVF-21.1 and EVF-21.5. The EVFE 

Subgroup has not reached a consensus on the submitters’ latest proposals which were revised to 

address specific features such as the indicating element, identification/marking information, as well 

as general and type evaluation tolerances. 

Table 3. Summary of Recommendations

EVF-21.1 – A.1. General

V D W A I Notes* Comments

Submitter 

See 9/28/20 industry presentation of the 

original proposal at WWMA. See also 

letters of 7/12/21 and 10/6/21 regarding 

proposed modifications to the original 

proposal.

OWM

 See also OWM’s letter of 9/28/20 

summarizing key points to consider.

WWMA 

SWMA 

NEWMA 

CWMA 

NCWM

Letters of Support Letters of Opposition Notes

Industry 1 In addition to submitters’ 

letters noted above.

Manufacturers

Retailers and Consumers

*Notes Key:

1 − Submitted modified language

2 − Item not discussed

3 − No meeting held

4 − Not submitted on agenda

5 − No recommendation or not considered
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Item Under Consideration:

A.1. General – This code applies to devices, accessories, and systems used for the measurement of 

electricity dispensed in vehicle fuel applications wherein a quantity determination or statement of 

measure is used wholly or partially as a basis for sale or upon which a charge for service is based.

A.1.1. Effective Dates for DC EVSE – All DC EVSE used for commercial purposes and put 

into service on or before January 1, 2023 are exempt from this standard for a period of 10 

years from the date put into service. comply 

A.1.2. Effective Dates for AC EVSE – All AC EVSE used for commercial purposes and put 

into service on or before January 1, 2022 are exempt from this standard for a period of 10 

years from the date put into service.

NIST OWM Detailed Technical Analysis: 

As the weights and measures community continues to consider proposed new paragraphs A.1.1 and A.1.2 

which would exempt EVSEs from all NIST HB 44 Section 3.40 requirements based on the dates these 

systems were placed into commercial use, NIST OWM would like to note the following concerns: 

As worded the proposal is: (1) unclear on the exact type of use that entitles an EVSE to an exemption from 

all code requirements and also (2) in conflict with General Code paragraph G-A.6. Nonretroactive 

Requirements. 

The proposal, if adopted, would mean an entire generation of devices will be permitted to operate for a 10-

year period without having to comply with any HB 44 Section 3.40 requirements for indications, receipts, 

accuracy, security for metrological features, specific code markings, etc. for what may well be the lifetime 

of the device. 

To allow such a blanket exemption does a disservice to the electric vehicle refueling industry and would be 

viewed as competitively unfair to traditional and other alternative vehicle fueling applications which are 

required to comply with similar requirements or EVSE manufacturers who are spending money to comply 

with current requirements. 

The submitter needs to consider that, even if an effective date is added to an entire device-specific code, 

Section 1.10. General Code requirements will still apply. 

For jurisdictions that don’t automatically adopt the current version on NIST Handbook 44, this window of 

time during which noncompliant devices can continue to be installed will be even longer. 

The USNWG EVF&S that developed the EVFS Code and modified the Timing Device Code (to recognize 

EVSEs) has been widely advertised and all stakeholders (including EVFS OEMs) encouraged to join. 

Many companies have been an integral part of the development of these requirements and have expended 

considerable funds to bring their equipment into compliance at a competitive disadvantage if a large group 

of competing devices were to be exempted from the requirements. 

The proposal describes the marketplace as having “existing stations that often do not include an integrated 

meter” which might be an indication that available EVSEs placed into commercial use before the proposed 

enforcement date will have limited or no legal metrology components. In this case a notice is necessary for 
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consumers that purchasing electricity from one site does not provide the same assurance of accuracy that is 

provided at another site. 

If there are concerns about specific provisions in the code, these need to be addressed by making specific 

sections “nonretroactive” with sunset dates, not by exempting the device from the requirements of the 

specific code in entirety. Factored into any enforcement dates should be the fact that the EVFS codes have 

been available for over seven years (and was under development by regulators and industry for three years 

prior to that).

Throughout 2021 up through June 2022 NIST OWM has recommended the submitters revise their 2021 

proposals to address concerns previously expressed by the USNWG EVF&S’s EVFE Subgroup and weights 

and measures community prior to submission of any alternate proposals for a review of the EVFE Subgroup.

The submitters provided updates to the community in July 2021 about their work to revise the proposals in 

NCWM S&T Committee Agenda Items EVF-21.1 A.1. General and EVF-21.5 T.2. Load Test Tolerances. 

Their work was completed in early November 2021.

On November 20, 2021, NIST OWM provided input on the submitter’s alternate proposal. This revised 

proposal modifies five NIST Handbook 44 Section 3.40 EVFS requirements (that address indicating 

elements, sealing, identification/marking, and tolerances). The submitters and NIST OWM met on 

December 7, 2021 to discuss NIST OWM’s preliminary review and adjustments suggested for the alternate 

proposal. Subsequent revisions by the submitters of their alternate proposals were also made available to 

the EVFE Subgroup in January 2022 and April 2022. These alternate proposals do not include any 

modifications to paragraph A.1. General. The EVFE Subgroup’s discussions have been ongoing in their 

review of the submitters latest proposals which are intended to replace S&T Agenda Items EVF-21.1 and 

EVF-21.5. The EVFE has not reached a consensus on the submitters’ latest proposals.

NIST OWM is aware of the submitters’ November 15, 2022 email sent to the Committee where the 

submitters recommend withdrawing EVF 21.1 and EVF-21.5 given new proposal EVF-23.6 reflects 

feedback on these 2021 proposals and the significant changes to the proposals since August 2020 (as well 

as the EVSE code becoming permanent). The submitters are also supportive of designating EVF-23.6 as a 

voting item. At this stage, given the lengthy deliberations over the course of the past three years by the 

EVFE Subgroup on EVF-21.1 and other alternative proposals developed by the submitters, as well as the 

significant differences between the enforcement dates and conditions applicable to DC Systems in 

EVF-23.6 in contrast to and the Subgroup’s June 2022 alternate proposal for DC tolerances and 

corresponding marking requirements to be applicable based simply on a 2024 installation date; nor the 

proposed conditions in EVF-21.1 for a blanket exemption from the entire code for ten years being replaced 

by EVF-23.6 where DC system’s compliance involves certification/installation/multiple enforcement dates 

would any of these options be conducive to a straightforward and orderly implementation of the EVFS 

Code. Possibly the EVFE Subgroup’s alternate proposal with some refinement is the most viable option.
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Summary of Discussions and Actions:

During the NCWM 2021 Interim Meeting the Committee assigned Developing status for this item. For 

more information or to provide comment, please contact:

Ms. Francesca Wahl

Tesla

(650) 435-0422, fwahl@tesla.com 

NCWM 2022 Annual Meeting

Ms. Francesca Wahl (Tesla) representing the submitters of this proposal indicated the developers of the 

agenda item are working to address problems encountered with the requirements by the upcoming standards 

development cycle and before the code gains permanent status. Mr. Kurt Floren (Los Angeles County, 

California) had a question regarding whether amendments to the code would be entertained prior to the 

code becoming permanent. A priority item (EVF-22.1) recommending the EVFS Code be upgraded to 

permanent status was approved late June 2022 and included as a Voting Item on the July 2022 S&T 

Committee’s Agenda. There is already a Voting Item (EVF-20.1), this proposal (EVF-21.1), and a second 

unresolved proposal (EVF-21.5) as well as ongoing work and deliberations in the community to further 

refine specific tentative EVFS code requirements. The July 2022 adoption of the priority item resulted in 

amending NIST Handbook 44 Section 3.40 Electric Vehicle Fueling Systems – Tentative Code to: (1) 

change the code’s status to permanent effective January 1, 2023 and (2) modify paragraphs S.2.7. 

Indications of Delivery, N.5.2.(b) Accuracy Testing; For DC systems, and T.2.1. EVSE Load Test 

Tolerances to include a statement that makes these three requirements applicable to DC systems on or after 

January 1, 2028. This agenda item (EVF-21.1) remained unchanged and carried over to the 2023 standards 

develop cycle under the development of the submitters.

Submitter’s Update: The 11 Submitters’ sent a November 15, 2022 email to the NCWM S&T Committee 

outlining their history with EVF-21.1 (a proposal for a 10 year EVSE code exemption) and EVF-21.5 (a 

proposal for DC systems installed before 2033 to be permitted 2.5 times wider tolerances and after 2033 a 

1 percent/2 percent tolerance already applied to AC systems applies to all EVSEs), the items introduction 

into the 2021 cycle and the proposals achieving Developmental status and subsequent work to address input 

on these items. The submitters noted their unanticipated July 2022 change in the code’s status to become 

enforceable in 2023 and acknowledged at that same time the NCWM also modified the code to make certain 

elements not enforceable until 2028 implying it was not possible today to enforce these elements. For the 

submitters these actions accelerated the need to incorporate the concepts in the proposals and other 

handbook modifications to ensure the EVFS code is ready for implementation. However, a new 2023 

proposal EVF 23.6 (for DC systems installed prior to 2024 when bearing accuracy markings are permitted 

a 5 percent tolerance which sunsets in 2034 although all DC tolerances don’t apply until 2028) replaces the 

need to continue maintaining EVF-21.1 and EVF-21.5 as Developing Items. 

The submitters noted their diligence in their work and are appreciative of the feedback and guidance from 

the community. The submitters recommend withdrawing EVF 21.1 and EVF-21.5 given new proposal 

EVF-23.6 reflects feedback on these 2021 proposals and the significant changes to the proposals since 

August 2020 (to include the EVSE code becoming permanent). The submitters are also supportive of 

designating EVF-23.6 as a voting item. The submitters plan to speak to both recommendations during the 

January 2023 NCWM Interim Meeting and are happy to answer questions.
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Regional Association Reporting:

Central Weights and Measures Association

Francesca Wahl (Tesla): EVF-23.6 is a resubmittal of this item. Request this remains Developing.

The CWMA S&T Committee recommended this item remains as Developing.

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting the following comments were received:

Ms. Francesca Wahl (TESLA) – Ms. Wahl commented the USNWG has been making progress on the 

subject. She noted the group has made some significant modifications along with submitting item EVF23.6. A formal vote on the item was not taken by the workgroup. Ms. Wahl noted the comments expressed 

apply to both EVF 21.1 and EVF-21.5. A recommendation for items EVF-21.1 and EVF-21.5 to remain 

developing was made by the Ms. Wahl. 

Mr. Kurt Floren (County of Los Angeles, California) questioned the justification of this item, including the 

10-year exemption. He opposed the item and encouraged the Committee to propose nothing more than to 

keep it developmental. 

Mr. Kevin Schnepp (California Division of Measurement Standards) recommended the item be withdrawn 

for the reasons mentioned. He further commentated that a 10-year exemption is not warranted, is not 

applicable for these devices, and does not belong in the handbook.

Southern Weights and Measures Association

The following comments were received during the 2022 SWMA Annual Meeting:

Ms. Scheleese Goudy (Electrify America and submitter) requested that it be withdrawn.

The SWMA S&T Committee recommended this item be Withdrawn.

Northeastern Weights and Measures Association

Ms. Wahl commented that there is no status update from the group of submitters and requested to keep the 

item as developing. Ms. Juana Williams (NIST OWM) pointed out that this proposal as worded grants a 

10-year exemption for both AC and DC systems. The EVSE Subgroup is aware there are multiple alternate 

proposals addressing this item. Ms. Williams asks submitters to work with the EVSE Subgroup. Mr. John 

McGuire (New Jersey) stated that a 10-year exemption is too long and unnecessary and recommend 

withdrawal or developing. Mr. Jim Willis (New York) requested that this item be withdrawn. 

After hearing comments from the floor, the Committee does not believe this item has merit. The Committee 

agreed that a blanket 10-year exemption for devices is not appropriate and recommended that this item be 

Withdrawn.
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EVF-21.5 D T.2. Load Test Tolerances.

Source: ABB, BTCPower, Electrify America, Edison Electric Institute, EVConnect, EVgo, Greenlots, 

Rivian, Siemens, Tesla, Tritium

Submitter’s Purpose and Justification:

To create separate metering requirements for DC EVSE due to significant technology differences and 

challenges between AC and DC systems.

Proposed changes to the text to differentiate alternating current (AC) EVSE from direct current (DC) EVSE. 

Metering for DC architected systems is considerably more complicated and in ways that the original 

drafting of this provision never contemplated. For example, the tentative code when initially written never 

contemplated 350kW EVSE or liquid cooled cabling from the charging post to the connector. As such, it 

is necessary to separate the implementation dates of some of the specifications, tolerances, and other 

technical requirements. DC metering solutions are still being researched and developed and are not yet 

commercially available to be integrated into DC chargers at scale and at reasonable cost. While the supply 

chain for the physical meters themselves is slowly catching up, the metering system in a DC EVSE, 

particularly high-power DC EVSE that utilize liquid-cooled cables, goes beyond the physical meter itself 

which is incorporated in the main housing of the EVSE. For example, measurements may also need to be 

taken at the connector end of the dispenser and software and algorithms must be developed, validated, and 

integrated into the EVSE system to allow for accurate metering of kWh delivered to the vehicle. 

Implementing more complex metering systems needed for DCFC requires significant design and 

manufacturing changes to DC EVSE. 

The proposed tolerances account for the fact that these systems are still in development and are untested. 

The proposed timeline provides the industry with enough time to develop, test, validate, and deploy reliable 

DC metering system technology. This timeline is also consistent with the timeline approved by the State 

of California which accounts for the vast majority of the EVSE market. EVSE manufacturers are working 

diligently to meet the California timeline and are confident that it can be met.

While it is important to ensure that consumers are receiving accurate and transparent information regarding 

the accuracy of EV charging stations, it is also important that the technology to deliver high accuracy is 

available and reliable.

There is concern about both the proposed timeline and the accuracy requirement. Some are concerned that 

the accuracy specification of 2.5% acceptance and 5% maintenance is too high and does not provide 

sufficient consumer confidence that all charge sessions are equal regardless of provider and station. The 

proposers would note that this is a new and evolving technology where charging providers place a premium 

on customer experience as they compete for this growing market. Thus far, customers have not registered 

complaints about lack of transparency. Some are concerned that the timeline for instituting a metering 

regime is too far into the future. The proposers acknowledge the few years it will take to have reliable DC 

metering systems commercially available at scale but are working as quickly as possible to develop and 

integrate these systems into their chargers. Some are also concerned that the metering requirements have 

been in a place for several years already and therefore the EVSE community should not need more years to 

develop solutions. The proposers note that current DC EVSE technology was never contemplated by the 

existing metering regime and DC technology, particularly high-power DC EVSE, were not in existence at 

the time the original specifications were set. For example, the first 350kWh EVSE with liquid cooled cables 

weren’t deployed in the US until 2018.

The submitter requested Voting status for this item in 2021.
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OWM Executive Summary for EVF-21.5 – T.2. Load Test Tolerances

OWM Recommendation: OWM believes this item requires further development. 

• The submitters made alternate proposals available to the EVFE Subgroup for their review in January 

2022 and April 2022. These alternate proposals did include modifications to paragraph T.2. Load 

Test Tolerance to become a nonretroactive requirement enforceable in 2024 initially with a 4 percent 

overregistration/6 percent underregistration tolerance which then became 5 percent for DC systems 

that would also require accuracy markings if the device “is not subject to 1 percent Acceptance/2 

percent Maintenance tolerance.” 

• The EVFE Subgroup’s discussions have been ongoing in their review of the submitters 2022 

proposals which are intended to replace S&T Agenda Items EVF-21.1 and EVF-21.5. The EVFE 

Subgroup did not reach a consensus on the submitters' latest proposals which were revised to address 

specific features such as the indicating element, identification/marking information, as well as 

general and type evaluation tolerances.

• The EVFE Subgroup was balloted June 17, 2022 on its proposal to recognize a separate new 5 % 

tolerance for DC EVSEs installed prior to 2024 and a corresponding new requirement for marking 

the accuracy of pre-2024 equipment.

o The final outcome of this ballot resulted in the EVFE Subgroup being in favor of the proposal. 

The results were provided to the submitters in October 2022 to enable them to assess how and if 

to modify their original proposal to the S&T Committee.

• OWM notes that a sunset date (retroactive enforcement date) ending a dual tolerance structure 

would encourage uniformity in equipment performance in the marketplace; facilitate value 

comparisons by consumers; and phase out less accurate equipment.

• According to information provided to the USNWG by the submitters, not all DC chargers (including 

those manufactured in recent years) manufactured prior to 2024 can be readily or inexpensively 

upgraded to meet the existing (1 % and 2 %) tolerances. 

o Of the DC chargers manufactured prior to 2024, including those manufactured in recent years, 

some are capable of being upgraded to meet the existing (1 % and 2 % tolerances) and some are 

not.

o Of those DC chargers that can be upgraded, the cost for such upgrades can vary across a rather 

wide spectrum.

o While some estimates of impact have been provided, the details seem to represent the broad 

spectrum of capabilities and cost, making it difficult to assess the impact on manufacturers, 

businesses, and consumers as a whole.

o Details regarding the percentage of equipment that falls into these categories would be helpful 

to the community in assessing the need for a sunset date and, if a sunset date is deemed 

appropriate, what represents a reasonable time frame for phasing out the less accurate 

equipment.
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OWM Executive Summary for EVF-21.5 – T.2. Load Test Tolerances

o Information has also been provided to suggest that newer DC devices being manufactured 

(including those manufactured today) are more robust than older equipment, extending the 

lifespan beyond that originally reported in past discussions. 

• OWM acknowledges the submitters have been diligently working with the NIST USNWG EVFE 

Subgroup. The EVFE Subgroup has held 16 meetings since 2020 where the submitters presented 

possible alternatives for the group to review prior to presenting those alternatives to the community 

for consideration. The EVFE Subgroup reached a consensus the group’s June 2022 proposal. The 

EVFE Subgroup proposal does not delay fundamental requirements for accuracy of commercial 

systems. The EVFE Subgroup’s proposal recommends a wider DC tolerance (5 percent) for EVSEs 

installed prior to 2024 and specifies that must include accuracy markings for transparency to the EV 

driver about the conditions for the sale of electrical energy and in fairness to competing businesses. 

NIST OWM notes that the group’s proposal does require additional editing for clarity about the 

application of the marking requirement. The EVFE Subgroup offers that proposal for consideration 

as an alternative to Agenda Items EVF-23.5 and EVF-23.6. NIST OWM finds there are notable 

differences in the EVFE Subgroup proposal and EVF-23.6 proposal for DC systems installed prior 

to 2024 when bearing accuracy markings are permitted a 5 percent tolerance which sunsets in 2034 

although all DC tolerances don’t apply until 2028. 

• NIST OWM is aware of the submitters’ November 15, 2022 email sent to the Committee where the 

submitters recommend withdrawing EVF 21.1 and EVF-21.5 given new proposal EVF-23.6 reflects 

feedback on these 2021 proposals and the significant changes to the proposals since August 2020 

(as well as the EVSE code becoming permanent). The submitters also indicated they are supportive 

of designating EVF-23.6 as a Voting Item.

• The submitters need to consider that, even if an effective date is added to a device-specific code, 

Section 1.10 General Code requirements will still apply. 

Table 3. Summary of Recommendations

EVF-21.5 – T.2. Load Test Tolerances.

V D W A I Notes* Comments

Submitter 

See also letters of 7/12/21 and 10/6/21 

regarding proposed modifications to the 

original proposal.

See 11/15/22 email asking Committee to 

withdraw as submitters move to endorse 

EVF-23.6.

OWM

 See also OWM’s letter of 9/28/20 

summarizing key points to consider.

WWMA 

SWMA 

NEWMA 

CWMA 

NCWM
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Table 3. Summary of Recommendations

EVF-21.5 – T.2. Load Test Tolerances.

V D W A I Notes* Comments

Letters of Support Letters of Opposition Notes

Industry 1 In addition to submitters’ 

letters noted above.

Manufacturers

Retailers and Consumers

*Notes Key:

1 - Submitted modified language

2 - Item not discussed

3 - No meeting held

4 - Not submitted on agenda

5 - No recommendation or not considered

Item Under Consideration:

T.2. Load Test Tolerances.

T.2.1. AC EVSE Load Test Tolerances. – The tolerances for AC EVSE load tests are:

(a) Acceptance Tolerance: 1.0 %; and 

(b) Maintenance Tolerance: 2.0 %.

T.2.2. DC EVSE Load Test Tolerances. – The tolerances for DC EVSE load tests:

(a) Devices installed prior to January 1, 2033

(1) Acceptance Tolerance: 2.5 %; and 

(2) Maintenance Tolerance: 5.0 % 

(b) Devices installed January 1, 2033 or later 

(1) Acceptance Tolerance: 1.0 %; and 

(2) Maintenance Tolerance: 2.0 % 

NIST OWM Detailed Technical Analysis:

Should the weights and measures community continue to consider proposed new paragraph T.2.2 which 

would widen the tolerances for DC systems “installed” prior to January 1, 2033, NIST OWM asks are there 

existing devices that can meet the current requirements? Justifications for proposing the relaxing of the 

tolerances to this degree, particularly without a sunset date (i.e., a retroactive date) are not being received 

from all manufacturers?
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From a technical standpoint accuracy is fundamental to determining a basic property of a measuring system 

in its use to establish a fee. Manufacturers and at least one jurisdiction are evaluating the performance of 

DC equipment as of December 2022. If the existing HB 44 requirement for a 1 percent Acceptance and 2 

percent Maintenance Tolerances for all systems are modified then OWM would be less reluctant to seeing 

the adoption of a phase-in date to meet the tighter tolerances that includes an accompanying sunset date 

(i.e., a retroactive date). Those dates should be established from multiple factors looking at the overall 

impact which may not be well understood by many members of the community. OWM asks what concrete 

issues can be cited by the submitters to counter any opposing arguments for a phase in period for DC 

systems? It would be important to have statistics on the population of devices not in compliance with 

requirements as discussion moves forward on this proposal.

This is not a typical practice to be done on an unlimited basis. This would be more palatable from both a 

competitive and enforcement standpoint if there are specific technical issues, that necessitate and justify 

relaxing equipment tolerances on an industrywide basis. An additional concern is that companies are 

spending money to comply with the existing NIST HB section 3.40 tentative code yet are competing with 

a population of existing equipment. An additional question is: how big is that population exactly?

NIST OWM also would ask how many devices are out there that would be put into use and competing with 

AC devices, thus creating a competitive advantage for DC devices? 

Lately multiple stakeholders in the community have either brought forward or indicated less reluctance in 

opposing a dual tolerance structure. There will be concerns about a dual tolerance structure if this proposal 

moves forward since it still does not include a corresponding marking or some other type of information 

requirement to alert consumers that purchasing electricity from one fueling device does not provide the 

same accuracy assurance as it does from another fueling device. Bottom line multiple tolerance tiers 

frustrate value comparisons. There is not a lot of data being made available on the accuracy of DC devices. 

Comments from the EVFE Subgroup representatives from industry and national laboratory indicate the 

current 1 % acceptance and 2 % maintenance tolerances are achievable by existing DC systems. NIST 

OWM was made aware in June 2022 that at least one jurisdiction is in possession of a DC test standard that 

has traceability, but that date has been extended several times. Several EVFE Subgroup members indicate 

there is a confidentiality issue that prevents release of any data. 

Throughout 2021 up through mid-2022 NIST OWM has recommended the submitters revise their 2021 

proposals to address concerns previously expressed by the USNWG EVF&S’s EVFE Subgroup and weights 

and measures community prior to submission of any alternate proposals for a review of the EVFE Subgroup.

The submitters provided updates to the community in July 2021 about their work to revise the proposals in 

NCWM S&T Committee Agenda Items EVF-21.1 A.1. General and EVF-21.5 T.2. Load Test Tolerances. 

Their work was completed in early November 2021. 

On November 20, 2021, NIST OWM provided input on the submitter’s alternate proposal. This revised 

proposal modified five NIST Handbook 44 Section 3.40 EVFS requirements (that address indicating 

elements, sealing, identification/marking, and tolerances). The submitters and NIST OWM met on 

December 7, 2021 to discuss NIST OWM’s preliminary review and adjustments suggested for the alternate 

proposal. Subsequent revisions by the submitters of their alternate proposals were also made available to 

the EVFE Subgroup in January 2022 and April 2022. The EVFE Subgroup’s discussions have been 

ongoing in their review of the submitters proposals for expanding tolerances to 5 % for older equipment in 

commercial operation and EVSE marking requirements if a dual tier tolerance structure exists. The EVFE 

Subgroup was balloted June 17, 2022 on a proposed new 5 % tolerance for DC EVSEs installed prior to 

2024 and a corresponding new requirement for marking the accuracy of pre-2024 equipment. The EVFE 
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Subgroup will offer this proposal as an alternative to two new 2023 proposals (EVF-23.5 and EVF-23.6 

both are proposals to require new accuracy markings and widen DC systems tolerances but warrant careful 

review of the conditions and enforcement dates in these proposals).

NIST OWM is aware of the submitters’ November 15, 2022 email sent to the Committee where the 

submitters recommend withdrawing EVF 21.1 and EVF-21.5 given new proposal EVF-23.6 reflects 

feedback on these 2021 proposals and the significant changes to the proposals since August 2020 (as well 

as the EVSE code becoming permanent). The submitters are also supportive of designating EVF-23.6 as a 

voting item. At this stage, given the lengthy deliberations over the course of the past three years by the 

EVFE Subgroup on EVF-21.1 and other alternative proposals developed by the submitters, as well as the 

significant differences between the enforcement dates and conditions applicable to DC Systems in 

EVF-23.6 in contrast to and the Subgroup’s June 2022 alternate proposal for DC tolerances and 

corresponding marking requirements to be applicable based simply on a 2024 installation date; nor the 

proposed conditions in EVF-21.1 for a blanket exemption from the entire code for ten years being replaced 

by EVF-23.6 where DC system’s compliance involves certification/installation/multiple enforcement dates 

would any of these options be conducive to a straightforward and orderly implementation of the EVFS 

Code. Possibly the EVFE Subgroup’s alternate proposal with some refinement is the most viable option.

Summary of Discussions and Actions:

During the NCWM 2021 Interim Meeting the Committee assigned Developing status for this item. For 

more information or to provide comment, please contact:

Mr. Asaf Nagler

ABB

202-639-4075, asaf.nagler@us.abb.com

At the NCWM 2022 Annual Meeting a priority item (EVF-22.1) recommending the EVFS Code be 

upgraded to permanent status was approved late June 2022 to be included as a voting item on the July 2022 

S&T Committee’s Agenda. There was already a voting item (EVF-20.1), this proposal (EVF-21.5) and a 

second unresolved proposal (EVF-21.1) as well as work and deliberations in the community to further refine 

specific tentative EVFS code requirements. Adoption of the priority item did occur resulting in 

amendments to the NIST Handbook 44 Section 3.40 Electric Vehicle Fueling Systems – Tentative Code to: 

(1) change the code’s status to permanent effective January 1, 2023 and (2) modify paragraphs S.2.7. 

Indications of Delivery, N.5.2.(b) Accuracy Testing; For DC systems, and T.2.1. EVSE Load Test 

Tolerances to include a statement that makes these three requirements applicable to DC systems on or after 

January 1, 2028. This agenda item (EVF-21.5) remained unchanged and carried over to the 2023 standards 

develop cycle under the development of the submitters. This item should be updated to include the new 

statement that passed adoption July 2022 to reflect the retroactive enforcement date of January 1, 2028 for 

paragraph T.2.1, that will be applicable to DC systems.

Submitter’s Update: the 11 Submitters’ sent a November 15, 2022 email to the NCWM S&T Committee 

outlining their history with EVF-21.1 (a proposal for a 10 year EVSE code exemption) and EVF-21.5 (a 

proposal for DC systems installed before 2033 to be permitted 2.5 times wider tolerances and after 2033 a 

1 percent/2 percent tolerance already applied to AC systems applies to all EVSEs), the items introduction 

into the 2021 cycle and the proposals achieving Developmental status and subsequent work to address input 

on these items. The submitters noted their unanticipated July 2022 change in the code’s status to become 

enforceable in 2023 and acknowledged at that same time the NCWM also modified the code to make certain 

elements not enforceable until 2028 implying it was not possible today to enforce these elements. For the 

submitters these actions accelerated the need to incorporate the concepts in the proposals and other 
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handbook modifications to ensure the EVFS code is ready for implementation. However, a new 2023 

proposal EVF 23.6 (for DC systems installed prior to 2024 when bearing accuracy markings are permitted 

a 5 percent tolerance which sunsets in 2034 although all DC tolerances don’t apply until 2028) replaces the 

need to continue maintaining EVF-21.1 and EVF-21.5 as Developing Items. 

The submitters noted their diligence in their work and are appreciative of the feedback and guidance from 

the community. The submitters recommended withdrawing EVF 21.1 and EVF-21.5 given new proposal 

EVF-23.6 reflects feedback on these 2021 proposals and the significant changes to the proposals since 

August 2020 (to include the EVSE code becoming permanent). The submitters are also supportive of 

designating EVF-23.6 as a voting item. The submitters plan to speak to both recommendations during the 

January 2023 NCWM Interim Meeting and are happy to answer questions.

Regional Association Reporting:

Central Weights and Measures Association

Ms. Francesca Wahl (Tesla): EVF-23.6 is a resubmittal of this item. Requested this remain Developing.

The CWMA S&T Committee recommended this item remains as Developing.

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting the following comments were received:

Ms. Francesca Wahl (TESLA): Ms. Wahl commented the USNWG has been making progress on the 

subject. She noted the group has made some significant modifications along with submitting EVF-23.6. A 

formal vote on the item was not taken by the workgroup. Ms. Wahl noted the comments expressed apply 

to both EVF-21.1 and EVF-21.5. A recommendation for items EVF-21.1 and EVF-21.5 to remain 

developing was made by Ms. Wahl. 

Mr. Kevin Schnepp (California Division of Measurement Standards): Mr. Schnepp commented the item 

does not have merit, given the state of current technology. Mr. Schnepp recommended the item be 

withdrawn.

Mr. Kurt Floren (County of Los Angeles, California): Mr. Floren agreed with Mr. Schnepp’s comments.

During open hearings comments were heard the item was outdated and not applicable given the state of 

current technology. The WWMA S&T Committee recommended that this item be withdrawn.

Southern Weights and Measures Association

The following comments were received during the 2022 SWMA Annual Meeting:

Ms. Scheleese Goudy (Electrify America), the submitter of this item, requested that it be withdrawn.

The SWMA S&T Committee recommended this item be withdrawn.

Northeastern Weights and Measures Association

Ms. Francesca Wahl (Tesla), on behalf of the submitters, indicated there has been no movement on this 

item and noted there are new proposals as part of the EVSE Subgroup. Mr. Keith Bradley (Electrify 
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America) recommended this item be withdrawn. Ms. Juana Williams (NIST OWM) indicated that devices 

already can meet requirements in this paragraph, but EVSE Subgroup has reviewed proposal and did not 

reach a consensus. Mr. Jason Flint (New Jersey) and Mr. Jim Willis (New York) recommended that the 

item be withdrawn. 

After hearing comments from the floor, the Committee does not believe this item has merit and there are 

other proposals that deal with this subject. The Committee is requesting that this item be withdrawn.

EVF-23.1 S.2.5.1. Money-Value Divisions Digital, S.8.(a) Minimum Measured Quantity, 

S.5.3.(d) Abbreviations and Symbols; Joule, N.1. No Load Test, T.5. No Load 

Test, N.2. Starting Load Test, T.6. Starting Load, Appendix D–megajoule

Source: NIST USNWG EVF&S-EVFE Subgroup

Submitter’s Purpose and Justification:

Further refine electrical vehicle fueling systems code requirements in NIST Handbook 44 Specifications, 

Tolerances, and Other Technical Requirements for Weighing and Measuring Devices Section 3.40 Electric 

Vehicle Fueling Systems Code to: (1) remove the “megajoule” unit of measurement definition and all 

references to the term cited in the design specifications; (2) base the computation of the total sales price on 

a more appropriate quantity interval that does not exceed 0.01 kWh rather than a 0.1 kWh; (3) decrease the 

permissible sizes of the minimum measured quantity (MMQ) to those that are more appropriate quantities 

for AC and DC systems deliveries and result in a shorter duration for the light load test procedure; and (4) 

no longer require an accuracy test and the applicable test tolerances at no load and at starting load.

The EVFE Subgroup proposes deleting all references to the “megajoule” unit of measurement in the method 

of sale regulation for retail sales of electrical energy as a vehicle fuel. This modification will align the unit 

of measurement recognized for electrical energy vehicle fueling equipment (i.e., the kilowatt-hour) in 

corresponding legal metrology requirements in NIST Handbook 44 Specifications, Tolerances, and Other 

Technical Requirements for Weighing and Measuring Devices Section 3.40 Electric Vehicle Fueling 

Systems Code and corresponding international documentary standards.

While objections to the proposed modifications may surface the group is not currently aware of any and 

these matters would be brought to light during the August through October 2022 comment period. The 

EVFE Subgroup also notes that the additional paragraphs it has recommended for modification are not 

recent developments but are the result of information gathered through testing carried out over the past six 

years and input from OEMs on EVSEs and from jurisdictions conducting tests and type evaluation of 

devices in field installations and laboratory environments; therefore, this proposal is the result of advances 

in the operating capacity of EVSEs which indicate that modifications to multiple paragraphs are warranted. 

Removing the “megajoule (MJ)” unit of measurement from the handbook does not conform to the practice 

in place for applying the concept of primary use of SI (metric) measurements recommended in the Omnibus 

Trade and Competitiveness Act of 1988. Although it appears that trade practice is limited to use of the 

kilowatt-hour unit of measurement for electrical energy deliveries to an EV battery; if that practice were 

to change the “joule” could be placed back into the handbook.
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The submitter requested that this be a Voting Item in 2023.

OWM Executive Summary for EVF-23.1 – S.2.5.1., S.8., S.5.3.(d), N.1., T.5., N.2., T.6., Appendix D 

– Definitions; megajoule (MJ)

OWM Recommendation:

• NIST OWM agrees with this EVFE Subgroup’s proposal that further refines the electrical vehicle 

fueling systems code requirements in NIST HB 44. 

• NIST OWM also notes there is a related method of sale proposal on the L&R Committee Agenda 

(MOS-23.4) that updates the unit of measurement terminology for the EVSE application in NIST 

HB 130.

• NIST OWM concurs with the EVFE Subgroup’s late fall 2022 proposed changes to the EVFS Code 

in S&T Agenda Item 23.1 to include: 

o further modification to paragraph S.2.5.1. Money-Value Divisions Digital to clarify that it is at 

the “end of the transaction when mathematical agreement shall occur. 

o proposed new modifications to: 

- paragraph S.5.2. EVSE Identification and Marking Information to ensure continuity across 

the EVFS Code in all references to the EVSE’s current level; and 

- further amending paragraph S.5.3. Abbreviations and Symbols to recognize the term 

“kilowatt-hour” 

The additional modifications would read:

S.2.5.1. Money-Value Divisions Digital. – An EVSE with digital indications shall 

comply with the requirements of paragraph G-S.5.5. Money-Values, Mathematical 

Agreement, and the total price computation at the end of a transaction shall be based 

on quantities not exceeding 0.5 MJ or 0.01 kWh.”

S.5.2. EVSE Identification and Marking Information.

(b) maximum current deliverable amperes; 

S.5.3. Abbreviations and Symbols.

(d) JkWh = joulekilowatt hour. 

Table 3. Summary of Recommendations

EVF-23.1 – S.2.5.1., S.8., S.5.3.(d), N.1., T.5., N.2., T.6., Appendix D – Definitions; megajoule (MJ)

V D W A I Notes* Comments

Submitter 
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Table 3. Summary of Recommendations

EVF-23.1 – S.2.5.1., S.8., S.5.3.(d), N.1., T.5., N.2., T.6., Appendix D – Definitions; megajoule (MJ)

V D W A I Notes* Comments

OWM 

WWMA 

SWMA 

NEWMA 

CWMA 

NCWM

Letters of Support Letters of Opposition Notes

Industry 1 26AUG2022 input on S.2.5.1. 

Manufacturers

Retailers and 

Consumers

Regulators

*Notes Key:

1 - Submitted modified language

2 - Item not discussed

3 - No meeting held

4 - Not submitted on agenda

5 - No recommendation or not considered

Item Under Consideration:

Amend Handbook 44, Electric Vehicle Fueling Systems Code Sections as follows: 

The EVFE Subgroup developed recommendations for modifying the code by removing the definition of 

the unit of measurement for the “megajoule” from the handbook:

megajoule (MJ). – An SI unit of energy equal to 1 000 000 joules (J). [3.40] 

The computed total price for the sale of electrical energy shall be based on an EVSE using a quantity interval 

that does not exceed 0.01 kWh rather than 0.1 kWh or in units of the megajoule. The EVFE Subgroup also 

recommends removing the megajoule unit of measurement from paragraph S.2.5.1. Money-Value Divisions 

Digital. During its December 8, 2022 meeting the group agreed to further amend the requirement in 

response industry concerns about systems’ delays in relaying transaction information and for clarify that it 

is at the “end of the transaction” when mathematical agreement shall occur as shown below: 

S.2.5.1. Money-Value Divisions Digital. – An EVSE with digital indications shall comply with the 

requirements of paragraph G-S.5.5. Money-Values, Mathematical Agreement, and the total price 

computation at the end of a transaction shall be based on quantities not exceeding 0.5 MJ or

0.01 kWh.

(Amended 202X) 
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The EVFE Subgroup recommends modifying paragraph S.8. Minimum Measured Quantity (MMQ) to 

recognize an MMQ of 0.1 kWh which is very common among EVSE that have already been type approved. 

For ANSI C12 American National Standard for Electricity Meters—0.1, 0.2, and 0.5 Accuracy Classes 

compliant meters meter constants of 0.001 kWh are common. In these meters the meter is expected to be 

fully accurate at deliveries of only a single watthour (i.e., 0.001 kWh). Dispensing a larger amount of energy 

to determine accuracy is not needed. Additionally, the EVFE Subgroup recommends paragraph S.8 specify 

an MMQ not to exceed 1.0 kWh as a more appropriate quantity for DC systems and include a new note to 

encourage a smaller MMQ for EVSEs which in the case of AC systems will result in a shorter time to 

conduct a test by a factor of five. 

S.8. Minimum Measured Quantity (MMQ). – The minimum measured quantity shall satisfy the 

conditions of use of the measuring system as follows:

(a) Measuring systems shall have a minimum measured quantity not exceeding 2.5 MJ or:

(1) 0.5 kWh for AC EVSE; and

(2) 1.0 kWh for DC EVSE. 

Note: To minimize the duration of required testing, manufacturers may want to consider limiting the declared MMQ 

to the level of 0.1 kWh for AC EVSE. 

(Amended 202X) 

The EVFE Subgroup also recommends removing the term and abbreviation for the “joule” unit of 

measurement, the No Load Test and Starting Load Test notes and their corresponding tolerances from the 

code requirements because these conditions are never encountered by a customer. An EVSE never operates 

at no load for any significant time. The Starting Load Test should not be required because the EVSE never 

operates at 0.5A. Also, during its December 8, 2022 meeting the group agreed to amend paragraph S.5.2. 

EVSE Identification and Marking Information to ensure continuity across the EVFS Code in all references 

to the EVSE’s current level and further amend paragraph S.5.3. Abbreviations and Symbols to recognize 

the term “kilowatt-hour” and its corresponding abbreviation and after reviewing a similar proposal in 

Agenda Item EVF-23.4. Consequently, also modify the relevant handbook requirements as follows: 

S.5.2. EVSE Identification and Marking Information.

(b) maximum current deliverable amperes; 

S.5.3. Abbreviations and Symbols.

(d) J = joule.

N.1. No Load Test. – A no load test may be conducted on an EVSE measuring system by applying 

rated voltage to the system under test and no load applied.

T.5. No Load Test. – An EVSE measuring system shall not register when no load is applied. 

N.2. Starting Load Test. – A system starting load test may be conducted by applying rated 

voltage and 0.5-ampere load.

T.6. Starting Load. – An EVSE measuring system shall register a starting load test at a 

0.5 ampere (A) load.
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Renumber paragraph N.3. Minimum Test Draft (Size) through N.6. Repeatability Tests to become N.1. 

through N.4., respectively.

NIST OWM Detailed Technical Analysis: 

NIST OWM acknowledges the EVFE Subgroup’s proposal was developed to further refine the electrical 

vehicle fueling systems code requirements in NIST Handbook 44 Specifications, Tolerances, and Other 

Technical Requirements for Weighing and Measuring Devices Section 3.40 Electric Vehicle Fueling 

Systems Code and agrees with the proposal. NIST OWM also notes there is a related method of sale 

proposal on the L&R Committee Agenda (MOS-23.4) that updates the unit of measurement terminology 

for the EVSE application in NIST HB 130 Uniform Laws and Regulations in the Areas of Legal Metrology 

and Fuel Quality.

NIST OWM concurs with the EVFE Subgroup’s late fall 2022 proposed changes to the EVFS Code in S&T 

Agenda Item 23.1 to include the alternate proposed modifications to paragraph S.2.5.1. Money-Value 

Divisions Digital. The EVFE Subgroup agreed at its December 8, 2022 meeting that further modification 

to paragraph S.2.5.1. was appropriate to clarify that it is at the “end of the transaction when mathematical 

agreement shall occur. NIST OWM agrees with the proposed new modifications to paragraph S.5.2. EVSE 

Identification and Marking Information to ensure continuity across the EVFS Code in all references to the 

EVSE’s current level and further amending paragraph S.5.3. Abbreviations and Symbols to recognize the 

term “kilowatt-hour” and its corresponding abbreviation which the EVFE Subgroup recommended after 

reviewing similar proposals in Agenda Item EVF-23.4. These additional modifications are shown below: 

S.2.5.1. Money-Value Divisions Digital. – An EVSE with digital indications shall comply 

with the requirements of paragraph G-S.5.5. Money-Values, Mathematical Agreement, and 

the total price computation at the end of a transaction shall be based on quantities not 

exceeding 0.5 MJ or 0.01 kWh.”

S.5.2. EVSE Identification and Marking Information.

(b) maximum current deliverable amperes; 

S.5.3. Abbreviations and Symbols.

(d) JkWh = joulekilowatt hour. 

U.S. National Work Group’s Electric Vehicle Fueling Equipment Subgroup (EVFE SG)

• The SG asks the S&T Committee to replace its recommended changes to paragraph S.2.5.1. 

Money-Value Divisions Digital to further clarify the point in the process when mathematical 

agreement occurs with the following:

S.2.5.1. Money-Value Divisions Digital. – An EVSE with digital indications shall comply 

with the requirements of paragraph G-S.5.5. Money-Values, Mathematical Agreement, and the 

total price computation at the end of the transaction shall be based on quantities not 

exceeding 0.5 MJ or 0.01 kWh.

(Amended 202X) 

• The SG considered recommending a definition for the term “transaction” that would be specifically 

applicable to Section 3.40 possibly based on the definition published September 2022 in OIML G 
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22 the corresponding international EVSE guide. The SG did not reach a conclusion on a proposed 

definition; however, the SG may come back with a recommendation at some point in the future as 

part of a separate proposal. Two points to consider should the SG revisit the proposed definition is 

whether the term should apply to the 14 other NIST HB 44 codes where the term is also cited and 

further clarify whether it is the customer, the electric vehicle fueling system, or some other 

intelligence that provides acknowledgement of receipt of information relevant to the transaction 

process. 

• The SG agrees with the proposed changes in S&T Agenda Item 23.4 to: (1) paragraph S.5.2.(b) 

EVSE Identification and Marking Requirements for clarity and consistency in the expression of 

current values across the EVFS Code and to properly identify the highest current value or level at 

which the manufacturer has specified for the operation of the EVSE, the EVFE SG supports 

identifying this marking information as the “maximum deliverable ampere” rather than the 

currently stated “maximum current deliverable”, and (2) paragraph S.5.3.(d) Abbreviations and 

Symbols which removes the “joule” unit of measurement and its corresponding abbreviation and 

further modifies that subparagraph to include the “kilowatt-hour” as well as recognize that unit’s 

abbreviation “kWh”.

The EVFE SG believes it has addressed all questions about the interpretation and applicability of 

code requirements in this proposal and is not aware of any further requests that the group revisit 

requirements or definitions in Agenda Item EVF-23.1. 

Summary of Discussions and Actions:

A letter dated August 26, 2022 from industry representing Electrify America was sent to the NCWM S&T 

Committee. Electrify America “offered a revision to this proposal that is narrowly tailored and necessary 

to avoid significant interference with the ordinary operation of electric vehicle chargers. Electrify America, 

LLC, is the country’s largest open network of fast DC electric vehicle chargers operating over 3,000 

chargers in most states. Electrify America has a serious concern about the proposed revision to paragraph 

S.2.5.1, “Money-Value Divisions Digital,” where the total price computation must be based on quantities 

not exceeding 0.01 kWh. Measurements of energy delivery are carried out locally, but the price calculation 

is carried out by the centralized server and reported back, repeatedly through the transaction, for display to 

the customer. For a charger operating at 350 kW (a capability that is now quite common) to ensure that the 

total cost is updated with each 0.01 kWh would require an update every 50 milliseconds. Lags in 

communications (Internet service to the device) for fast chargers will be not uncommon to be more than 

0.01 kWh late in updating the rolling cost display, even after operators incur the heavy bandwidth penalty 

to even attempt these updates. It would be impossible for even the swiftest humans to make a choice, and 

stop a charging session, based on a change in information occurring in 100 milliseconds. The system in 

which cost information is calculated and communicated by a central server uses the Open Charge Point 

Protocol (OCPP) the emerging industry standard. These central server calculations are important for 

chargers to be able to operate flexibly with multiple pricing structures. 

Electrify America asks why this requirement should be imposed and was not aware that this 0.01-kWh issue 

was brought up and deliberated in the EVFE Subgroup promptly alerting NIST. As Electrify America 

understands the code, the obligation to present a running, continually-updated cost would come from the 

reference to paragraph G-S.5.5. Money-Values, Mathematical Agreement. So, proposal EVF-23.1 could 

be revised to separate the 0.01-kWh requirement, as follows:

S.2.5.1. Money-Value Divisions Digital. – An EVSE with digital indications shall comply 

with the requirements of paragraph G-S.5.5. Money-Values, Mathematical Agreement, and 
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the total computed price of the energy sale, presented at the completion of a 

transaction, computation presented shall be based on quantities not exceeding 0.5 MJ or 

0.01 kWh. 

In this proposed revision, Electrify America used the term “total computed price” instead of “price 

computation” to remain consistent with existing paragraph S.2.6. EVSE Recorded Representation, which 

describes the information that must be provided at the end of the transaction. “The completion of a 

transaction” is also the same term that is used in paragraph S.2.6. 

Electrify America asks the Committee to recommend this change. The remainder of EVF-23.1 is sensible 

and appropriate.” 

The following background information was excerpted from the abbreviated summary on Agenda Item 3.a 

of the EVFE Subgroup’s October 6, 2022 virtual meeting. The following discussion by the EVFE Subgroup 

in an effort to address Electrify America’s concerns regarding the group’s proposed modification to 

paragraph S.2.5.1. Money-Value Divisions. 

The group identified S&T Agenda Item EVF 23.1 as needing further modification to its proposed changes 

to paragraph S.2.5.1. Money-Value Divisions Digital to specify at what point in the delivery to apply this 

requirement. The EVFE Subgroup also agreed to recommend a new definition of “transaction” drawn from 

OIML Guide 22 Electrical Vehicle Supply Equipment be included in NIST Handbook 44 Appendix D – 

Definitions to further clarify what constitutes the purchase or transaction process. 

The proposal to modify paragraph S.2.5.1. to no longer include the megajoule unit of measurement when 

expressing the electrical energy quantity value that is used to calculate the total price for refueling was 

developed in May 2022 by the EVFE Subgroup. An industry representative who agrees with the group’s 

recommendation cautions the group on the second part of its proposal to reduce the maximum interval value 

permissible for quantities expressed in the kilowatt-hour (kWh) from 0.1 to 0.01. The proposed change 

was made in anticipation that the unit price of electrical energy for vehicle refueling would reach $1.00 per 

kWh or more. The group acknowledges that the maximum quantity value should be revisited to keep pace 

with the average national price per kilowatt hour for an EV charging session. 

One industry member has concern that the recommended modification of the kWh value would result in 

the relay (“pinging”) of information would result in a delay in the device’s processing transaction 

information from what currently takes place in the system. Several in the group indicated that some delay 

might occur (e.g., a minimal number of milliseconds); however, with digital indications the consumer most 

likely would not detect the lag during refueling. Additionally, paragraph S.1.2. EVSE Indicating Elements 

specifies that an EVSE shall include an indicating element that continuously accumulates transaction 

information. During the processing of that information a very minimal lag might occur while the electrical 

energy delivery is taking place, but at the conclusion of the delivery there would be agreement between 

indications. Therefore, the EVSE Subgroup agreed further modification is necessary to paragraph S.2.5.1. 

Money-Value Divisions Digital for clarity and to specify this requirement applies “at the end of a 

transaction.” 

The EVFE Subgroup concluded that the interpretation of what process occurs to constitute a “transaction” 

is not defined in the handbook and therefore, a new definition of “transaction” which will be drawn from 

OIML Guide 22 Electrical Vehicle Supply Equipment should be included in NIST Handbook 44 Appendix 

D – Definitions. These latest alternate modification to the code and proposed new definition for Appendix 

D were distributed to the Subgroup membership on October 7th for input at the upcoming meeting on 

October 18th. At this time the group is not recommending other than the EVFS Code [3.40] be referenced 

in the proposed new definition. 
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Regional Association Reporting:

Central Weights and Measures Association

Ms. Scheleese Goudy (Electrify America) opposed to the 0.01 kWh statement of S.2.5.1. This is 

unreasonable for the communication network system which would have to work in the background to 

“ping” at this rate.

Ms. Francesca Wahl (Tesla) requested to remove the 0.01 kWh change and move everything else forward 

as Voting. 

Mr. Craig VanBuren (Michigan) stated the difference between 0.1 kWh and 0.01 kWh is not significant: 

approximately 0.4 cents. Supports moving forward with that change. 

The CWMA S&T Committee believes this item is fully developed and recommended Voting status with 

the following changes:

S.2.5.1. Money-Value Divisions Digital. – An EVSE with digital indications shall comply with the 

requirements of paragraph G-S.5.5. Money-Values, Mathematical Agreement, and the total price

computation shall be based on quantities not exceeding 0.5 MJ or 0.01 kWh.

(Amended 202X) 

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting the following comments were received: 

Ms. Goudy stated: generally okay with this item. She doesn’t recall if there was a consensus on the 0.01 

kWh. The pinging of the back-end system could go past the capabilities of the charger and there is no 

added benefit to the customer. We suggest that the 0.01-kilowatt hour be removed. 

Mr. Kevin Schnepp (California Division of Measurement Standards) commented: DMS can stand in 

support of the item and recommended that the 0.01 kWh issue be addressed.

Ms. Wahl seconded the comments regarding the 0.01 recommendation.

Mr. Chris King (Siemens) agreed with TESLA.

During open hearings, comments were heard supporting a Voting status with exception of the “0.01 kWh” 

edit in the section S.2.5.1. portion of the proposal. The WWMA S&T Committee believes that this item 

has merit, and recommends that this item be assigned a Voting status with the following edit: 

S.2.5.1. Money-Value Divisions Digital. – An EVSE with digital indications shall comply with the 

requirements of paragraph G-S.5.5. Money-Values, Mathematical Agreement, and the total price 

computation shall be based on quantities not exceeding 0.5 MJ or 0.01 kWh0.1 kWh. 

(Amended 202X) 

The WWMA S&T Committee requested the submitter address the formatting of their proposal to meet 

NCWM standard editing requirements. 
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Southern Weights and Measures Association

The following comments were received during the 2022 SWMA Annual Meeting: 

Ms. Goudy submitted the updated wording, which is newly adopted by the NIST workgroup as of October 

2022. She recommended moving this item forward as a Voting Item with the following wording:

S.2.5.1. Money-Value Divisions Digital. – An EVSE with digital indications shall comply with the

requirements of paragraph G-S.5.5. Money-Values, Mathematical Agreement, and the total price 

computation at the end of a transaction shall be based on quantities not exceeding 0.5 MJ or 0.01 

kWh. 

The SWMA S&T Committee recommended this item move forward as a Voting Item with the above 

wording. 

Northeastern Weights and Measures Association

Mr. Keith Bradley (Electrify America) explained that 0.1kWh for DC could be an issue due to 

communication speeds. Mr. Bradley suggested modifying the language to “...total price computation at 

the end of the transaction”. Ms. Juana Williams (NIST OWM) indicated that the EVSE Subgroup is making 

further modifications to this item. Ms. Wahl agreed with the language modification suggested by Mr. 

Bradley. Mr. Lou Sakin (Holliston, Massachusetts) recommended that this item be Developing. 

After hearing comments from the floor, the Committee believes the item has merit. The Committee 

recommended that the item be given a Developing status.

EVF-23.2 S.2.7. Indication of Delivery

Source: Siemens Industry Inc., Smart Infrastructure eMobility

Submitter’s Purpose and Justification:

Provide consistent treatment of AC and DC chargers on the topic of Indication of Delivery. 

People have argued that retrofitting DC EVSE with displays would be extremely expensive. First 

manufacturers have had seven years to comply with the display requirement. All but one have complied. 

Non-compliance was a conscious business decision to ignore the requirement. Second, Tesla generally 

places multiple chargers at each location and at each location has a data/control device for the entire 

installation. Since HB44 allows a single information kiosk for multiple EVSE it would be quite economical 

to put in a single display pedestal for all EVSE installed at a single location.

Tesla has an elegant customer experience where the charging transaction is authorized and all of the 

information desired by the customer is displayed on the vehicle’s display. That provides a good driver 

experience but does not allow testing of the EVSE as per the Handbook. Tesla has recently announced that 

it intends to begin offering charging to non-Tesla EVSE. Those vehicles will not have access to the data 

provided on a Tesla display.

The submitter requested that this be a Voting item in 2023.
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OWM Executive Summary for EVF-23.2 – S.2.7. Indication of Delivery

OWM Recommendation:

• The effective date was placed under this specific paragraph that addresses indications and therefore 

applies only to this paragraph while there are multiple other code paragraphs that include 

requirements for indication of that same transaction information throughout the charging session. 

• An important question for the community is that as the enforcement date draws closer will 

compliance be delayed further by extending the effective date or granting a permanent exemption 

to equipment.

• An EVFS may have its own integral display indication or multiple devices being interfaced to a 

single display capable of clearly providing each device’s associated information. NIST Handbook 

44 Section 1.10 General Code requirements under G.S.5. Indicating and Recording Elements and 

where applicable Section 5.55 Timing Devices Code also include indication requirements that apply 

to EVFSs.

• The proposal should be analyzed from the standpoint of its effect on the consumer, operator, 

competing businesses, and regulatory authority. One thing that is missing from that part of the 

argument is that simply eliminating the indications requirement doesn’t ensure that all vehicle 

displays provide the same clear and understandable alternative in the vehicle, nor explain how 

W&M officials will regulate/ensure that clear and legible indication for all vehicle types.

• The State of California has type approved AC systems based on their meeting indication 

requirement in the Electric Vehicle Fueling Systems Code.

• This is a continuance of the case where consideration has not been given to similar work by multiple 

stakeholders from the weights and measures and electrical energy community on the USNWG 

EVFE SG over the past three years to reach a consensus that is clear, comprehensive, fair from a 

competitive standpoint, and takes place before submitting a proposal that effects the fundamental 

weights and measures component of transparency.

Table 3. Summary of Recommendations

EVF-23.2 – S.2.7. Indication of Delivery

V D W A I Notes* Comments

Submitter 

OWM 

WWMA 

SWMA 

NEWMA 

CWMA 

NCWM

Letters of Support Letters of Opposition Notes
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Table 3. Summary of Recommendations

EVF-23.2 – S.2.7. Indication of Delivery

V D W A I Notes* Comments

NO LETTERS/NOTES AS OF 13:30 09NOV2022JW

Industry

Manufacturers

Retailers and 

Consumers

Regulators

*Notes Key:

1 − Submitted modified language

2 − Item not discussed

3 − No meeting held

4 − Not submitted on agenda

5 − No recommendation or not considered

Item Under Consideration:

Amend Handbook 44, Electric Vehicle Fueling Systems as follows: 

S.2.7. Indication of Delivery. – The EVSE shall automatically show on its face the initial zero condition 

and the quantity delivered (up to the capacity of the indicating elements). All AC and DC EVSE are 

exempt from this requirement until January 1, 2028. 

NIST OWM Detailed Technical Analysis: 

The effective date was placed under this specific paragraph that addresses indications and therefore applies 

only to this paragraph while there are multiple other code paragraphs that include requirements for 

indication of that same transaction information throughout the charging session. An important question for 

the community is that as the enforcement date draws closer will compliance be delayed further by extending 

the effective date or granting a permanent exemption to equipment. 

Indications are the means by which transaction and other related information is read from the device itself, 

although a device may have additional auxiliary indicating elements for the convenience of the 

owner/operator as long as they are not confusing or misleading. Electric Vehicle Fueling Systems have the 

option of each device having its own integral display indication or multiple devices being interfaced to a 

single display capable of clearly providing each device’s associated information. NIST Handbook 44 

Section 1.10 General Code requirements under G.S.5. Indicating and Recording Elements and where 

applicable Section 5.55 Timing Devices Code also include indication requirements that apply to EVFSs. 

Proposals which alter, further delay the enforcement date, or eliminate any requirement for making basic 

transaction information available should be analyzed from the standpoint of their effect on the consumer, 

operator, competing businesses, and regulatory authority. Consideration should be given to transparency, 

value comparison across competing installations, confidence in the marketplace, etc., given the projected 

expansion of commercial devices also competing with traditional and other alternative fueling applications 

in the marketplace. What if other vehicle refueling industries request a similar exemption? 
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It should be noted that the State of California has type approved AC systems based on their meeting 

indication requirement in the Electric Vehicle Fueling Systems Code.

There is limited justification for this proposal, and it appears that it follows on the heels of the NCWM’s 

actions in July 2022 to delay the application for DC systems until 2028. This is a continuance of the case 

where consideration has not been given to similar work by multiple stakeholders from the weights and 

measures and electrical energy community on the USNWG EVFE SG over the past three years to reach a 

consensus that is clear, comprehensive, fair from a competitive standpoint, and takes place before 

submitting a proposal that effects the fundamental component of transparency, knowing what has been 

transacted whether buying or selling and being able to make value comparisons in the marketplace. Given 

that the earliest this proposal could become effective is 2024, and the rapidly expanding marketplace it is 

uncertain what point there is to implementing the latest proposed modifications for AC systems in the 

paragraph. It’s likely that once a device has been “approved” without an indication, there will be argument 

that it should then be grandfathered.

Regional Association Reporting:

Central Weights and Measures Association

Ms. Francesca Wahl (Tesla) indicated no direct position. Generally supportive of the consistency. The 

justification section for this item in the agenda is not accurate. The current version is online.

Mr. Craig VanBuren (Michigan) recommended Developing status.

The CWMA S&T Committee recommended this as a Developing Item.

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting the following comments were received. Mr. Chris King 

(Siemens) stated the voting item was approved at the NCWM. It all comes down to customer choice as 

well as cost. Most models do not have this indicator. All of them provide the info to the customer through 

an app and it has worked well for years. We support extending this exemption to the face of all AC and 

DC EVSE. The models that do have this are 2 to 3 times more expensive. Allowing this change would 

reduce costs for customers buying this EVSE. Ms. Wahl agreed with Siemens.

Mr. Kevin Schnepp (California Division of Measurement Standards) stated California already has this 

requirement for AC EVSE’s. Mr. Schnepp cautioned the body; they are proposing a device that puts the 

onus on the customer. This is wrong. There are 16 devices already approved that meet the requirements. 

I recommend withdrawal. 

During open hearings, comments were heard that there are AC EVSE devices approved and in use that meet 

the current requirement. The WWMA S&T Committee recommended withdrawal of this item.

Southern Weights and Measures Association

The following comments were received during the 2022 SWMA Annual Meeting. Mr. Prince (Florida) 

stated that this has been addressed and the item should be withdrawn. Ms. Goudy (Electrify America)

stated that this would modify a brand-new proposal and should be withdrawn. The SWMA S&T Committee 

recommended this item be Withdrawn.
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Northeastern Weights and Measures Association

Ms. Francesca Wahl (Tesla) stated that she believes there is merit for discussion, but additional details 

would be helpful. Ms. Juana Williams (NIST OWM) pointed out there are AC systems that meet this 

requirement and are already type-approved in California. Mr. Jason Flint (New Jersey) and Mr. Jim Willis 

(New York) suggested that this item be given a Developing status.

After hearing comments from the floor, the Committee believes that this item has merit. The Committee 

recommended that this item be given a Developing status.

EVF-23.3 S.2.7. Indication of Delivery 

Source: Power Measurements LLC

Submitter’s Purpose and Justification:

Reduce the exemption for DC EVSE from 2028 to 2025.

The requirement for a display has been in the code since its inception in 2016. On December 31, 2015 (just 

before HB44 3.4 was published with tentative status) there were only 2,377 DC EVSE installed. Of these 

1,790 were from a single provider, Tesla. By December 31, 2017 (two years after the code was published) 

there were only 3,708 DC EVSE of which 2,883 were Tesla. At that point in time the only manufacturer 

not producing EVSE which complied with the display requirement in S.2.7 was Tesla. They remain the 

only noncompliant supplier today, seven years after the code was initially published. There is no 

technological reason for Tesla not to provide a display on their EVSE.

People have argued that retrofitting DC EVSE with displays would be extremely expensive. First 

manufacturers have had seven years to comply with the display requirement. All but one have complied. 

Non-compliance was a conscious business decision to ignore the requirement. Second, Tesla generally 

places multiple chargers at each location and at each location has a data/control device for the entire 

installation. Since HB44 allows a single information kiosk for multiple EVSE it would be quite economical 

to put in a single display pedestal for all EVSE installed at a single location.

Tesla has an elegant customer experience where the charging transaction is authorized, and all of the 

information desired by the customer is displayed on the vehicle’s display. That provides a good driver 

experience but does not allow testing of the EVSE as per the Handbook. Tesla has recently announced that 

it intends to begin offering charging to non-Tesla EVSE. Those vehicles will not have access to the data 

provided on a Tesla display.

The submitter requested that this be a Voting item in 2023.

OWM Executive Summary for EVF-23.3 – S.2.7. Indication of Delivery

OWM Recommendation:

• The effective date was placed under this specific paragraph that addresses indications and therefore 

applies only to this paragraph while there are multiple other code paragraphs that include 

requirements for indication of that same transaction information throughout the charging session.
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OWM Executive Summary for EVF-23.3 – S.2.7. Indication of Delivery

• An important question for the community is that as the enforcement date draws closer will 

compliance be delayed further by extending the effective date or granting a permanent exemption 

to equipment.

• An EVFS may have its own integral display indication or multiple devices being interfaced to a 

single display capable of clearly providing each device’s associated information. NIST Handbook 

44 Section 1.10 General Code requirements under G.S.5. Indicating and Recording Elements and 

where applicable Section 5.55. Timing Devices Code also include indication requirements that 

apply to EVFSs.

• The proposal should be analyzed from the standpoint of its effect on the equipment manufacturer, 

consumer, operator, competing businesses, and regulatory authority as to how it will be interpreted, 

applied, and enforced because of other indication requirements across the codes. 

• The State of California has type approved AC systems based on their meeting indication 

requirement in the Electric Vehicle Fueling Systems Code.

Table 3. Summary of Recommendations

EVF-23.3 – S.2.7. Indication of Delivery

V D W A I Notes* Comments

Submitter 

OWM

WWMA 

SWMA 

NEWMA 

CWMA 

NCWM

Letters of Support Letters of Opposition Notes

Industry

Manufacturers

Retailers and 

Consumers

Regulators

*Notes Key:

1 − Submitted modified language

2 − Item not discussed

3 − No meeting held

4 − Not submitted on agenda

5 − No recommendation or not considered
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Item Under Consideration:

Amend Handbook 44, Electric Vehicle Fueling Systems as follows: 

S.2.7. Indication of Delivery. – The EVSE shall automatically show on its face the initial zero condition 

and the quantity delivered (up to the capacity of the indicating elements). All DC EVSE are exempt from 

this requirement until January 1, 20282025. 

NIST OWM Detailed Technical Analysis: 

Although the proposal modifies the 2028 effective date to become 2025, that effective date was placed 

under this specific paragraph that addresses indications and therefore applies only to this paragraph. There 

are multiple other code paragraphs that include requirements for indication of that same transaction 

information throughout the charging session. An important question for the community is that as the 

enforcement date draws closer will compliance be delayed further by extending the effective date or 

granting a permanent exemption to equipment. 

Indications are the means by which transaction and other related information is read from the device itself, 

although a device may have additional auxiliary indicating elements for the convenience of the 

owner/operator as long as they are not confusing or misleading. Electric Vehicle Fueling Systems have the 

option of each device having its own integral display indication or multiple devices being interfaced to a 

single display capable of clearly providing each device’s associated information. NIST Handbook 44 

Section 1.10 General Code requirements under G.S.5. Indicating and Recording Elements and where 

applicable Section 5.55 Timing Devices Code also include indication requirements that apply to EVFSs.

Proposals which alter, further delay the enforcement date, or eliminate any requirement for making basic 

transaction information available should be analyzed from the standpoint of their effect on the consumer, 

operator, competing businesses, and regulatory authority. Consideration should be given to transparency, 

value comparison across competing installations, confidence in the marketplace, etc., given the projected 

expansion of commercial devices also competing with traditional and other alternative fueling applications 

in the marketplace. What if other vehicle refueling industries request a similar exemption? 

Regional Association Reporting:

Central Weights and Measures Association

Ms. Francesca Wahl (Tesla) requested this be Withdrawn. No additional justification as to why the date 

should be changed. No supporting data. 

Mr. Craig VanBuren (Michigan) also requested this be Withdrawn. Both industry and regulators worked 

in good faith to come to this consensus of a 5-year time allowance. Federal administration has indicated 

that this would be contended if it passed.

Ms. Scheleese Goudy (Electrify America) requested this be Withdrawn. 

The CWMA S&T Committee recommended this item be Withdrawn. 

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting the following comments were received: 
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Ms. Wahl commented, we believe this item should be withdrawn. Two months ago, the 2028 date was 

adopted. There is no real merit in moving up to the 2025 date.

Ms. Goudy agreed with TESLA.

Mr. Kevin Schnepp (California Division of Measurement Standards) stood to support this item. DMS 

thinks that 2028 exemption is too long, technology can already meet the requirements and supports a Voting 

status.

Mr. Chris King (Siemens) supported the comments of TESLA.

During open hearings comments were heard that there are already devices which meet the current 

requirement. The WWMA S&T Committee believes that this item has merit, is fully developed, and 

recommended that this item be assigned a Voting status.

Southern Weights and Measures Association

The following comments were received during the 2022 SWMA Annual Meeting:

Mr. Prince (Florida) stated that this has been addressed and the item should be withdrawn. 

Ms. Goudy stated that this item would modify a brand-new proposal and it should be 

withdrawn.

The SWMA S&T Committee recommended this item be withdrawn.

Northeastern Weights and Measures Association

Ms. Juana Williams (NIST OWM) stated that the EVSE Subgroup has no recommendation at this time.

Ms. Wahl recommends withdrawal. She noted that at the 2022 NCWM Annual Meeting, the EVSE code 

was fully adopted as enforceable, and no justification was made within this proposal to roll back the date 

to 2025. Mr. Keith Bradley (Electrify America), Marc Paquette (Vermont), Mr. James Cassidy 

(Massachusetts), and Mr. Jim Willis (New York) all agreed with the statements of Ms. Wahl and agree with 

a Withdrawal status.

After hearing comments from the floor, the Committee does not believe this item has merit. The submitter 

did no provide reasoning to roll back the date to 2025. The Committee is recommending that this item be 

withdrawn.

EVF-23.4 S.5. Markings, and N.5. Test of an EVSE System.

Source: Power Measurements LLC

Submitter’s Purpose and Justification:

Update the details of the recommended tests in HB44 3.40 to better conform to current practice and Pub 14 

instructions.
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S.5.2

• Change (b) to maximum deliverable amperes because that is the term to be used throughout the 

document. Previously both terms had been used interchangeably.

S.5.3

• Joule is no longer used in the document. Replace with the abbreviation for kilowatt hours.

N.5

• When the HB44 code was originally written there had been no real experience in EVSE testing. 

Additionally, DC EVSE were quite new and power levels were low (typically 50kW) by today’s 

standards where 350 kW systems are already deployed, and megawatt systems are in discussion. 

The test points chosen at that time have been proven to be less than optimum to verify performance 

of the EVSE. Publication 14, which was developed later than HB44 adopted a set of test points 

similar to those proposed here. The tests proposed here have been extensively discussed in the 

NIST EVSE Working Group. However, that Work Group ran out of time for a formal vote to 

approve these proposals.

As background, the NIST WG is submitting Form 15s to start the restructuring of the test process. In those 

Form 15s the No Load and Starting load tests are removed from Section 3.4. This proposal completes the 

restructuring of the EVSE testing.

Detailed review of proposed changes:

Logically Section 5.2.1 should follow Section 5.2.2 so both sections have been renumbered.

New 5.2.1

In the new 5.2.1 (formerly 5.2.2) the word Laboratory was added to the title. As the power of both AC and 

DC EVSE has grown rapidly the equipment to test them at full power has become both large and expensive. 

It is perfectly reasonable for NTEP or a manufacturer to have this type of equipment but not reasonable for 

the average Weights and Measures inspector to have it available in the field. For that reason, this proposal 

breaks testing into two types: (1) testing for type verification done in a laboratory or at a manufacturer and 

(2) testing in the field for verification.

For testing AC systems in the laboratory three test points are proposed: 

(i) A point between 10 % and 20 % of the maximum deliverable amperes, but not exceeding 8A,

(ii) A point between 45 % and 55 % of the maximum deliverable amperes,

(iii)A point between 70 % and 100 % of the maximum deliverable amperes.

All test points are expressed in terms of a percent of the maximum deliverable amperes of the EVSE. For 

point (i) of the test a restriction has been added to ensure that high current chargers are tested near the 

nominal 6 A load that is the minimum charging current for most vehicles.

Today AC Level 2 chargers typically have maximum currents of 30 A to 80 A. Chargers with currents 

above 32 A were generally unavailable at the time HB44 3.4 was written. Several vehicles have recently 
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been introduced that charge at 48 A. There is only one vehicle currently available that charges at 80 A. 

This test regime can be performed quickly. It can be performed on any AC Level 2 EVSE with test 

equipment commercially available and in the hands of multiple Weights and Measures authorities.

New 5.2.2

Since HB44 3.40 was initially written a whole new generation of DC chargers have been developed. At 

that time the maximum power delivery was approximately 100 kW at 400 VDC. Today we have 350 kW 

systems operating at both 400 VDC and 800 VDC. The CCS EVSE standards have already been updated 

to allow chargers up to 1000 VDC and 800 A (800 kW). Because there are now two broad classes of DC 

EVSE; 400 VDC and 800VDC two voltage test points are included. Both voltage classes are capable of 

charging at 400V so a point between 350 VDC and 400VDC is required for both. For systems that can also 

operate at 800VDC a second point between 700 VDC and 800 VDC is required. Current points are to be 

tested at both voltages if they are appropriate for the EVSE.

For DC systems three test points are proposed: 

(i) A point at less than 30 A

(ii) A point between 45 % and 55 % of the maximum deliverable amperes

(iii) A point between 70 % and 100 % of the maximum deliverable amperes

This approach provides a test point at the lower end of the power transfer range where older vehicles may 

charge or where more modern EVs charge when topping off. The other two points are intended to bracket 

the power levels where most EV transfer most of their energy. 

The power levels of DC EVSE are rapidly evolving to ever higher levels. For that reason, this change 

provides for flexibility in field testing of DC EVSE at the high power point. The high current point is 

revised to 20% to 100% of the maximum deliverable current with guidance to test at the maximum power 

level that is possible using the test equipment available. The new code also provides for using a vehicle 

as the test load providing it meets the 20% of maximum deliverable current requirement.

One objection might be the creation of a field testing regime for DC EVSE that is less rigorous than that 

applied in the laboratory. For many decades ANSI C12 meter testing has applied testing over the full range 

of voltage and current for meters during type testing but only done validation testing at two current values. 

For example, class 320 meters (320 A maximum current) are tested for accuracy at 11 points between 3 A 

and 320 A during type evaluation. However, for verification typically only two current points are used 5 

A and 50 A.

Another objection might be the requirement to test 800 VDC EVSE at both 400 VDC and 800 VDC. Only 

a very few electric vehicles (three at this time) are capable of using 800 VDC charging. Therefore, even 

though an EVSE may be capable of 800 VDC operation because most EV operate at 400 VDC testing at 

400 VDC on an 800 VDC capable system is appropriate.

The submitter requested that this be a Voting Item in 2023.
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OWM Executive Summary for EVF-23.4 S.5. – Markings and N.5. Test of an EVSE System.

OWM Recommendation:

• The proposed modifications to subparagraph S.5.2. (b) to specify EVSEs must be marked with the 

“maximum deliverable amperes” will clarify the appropriate terminology for specifying the 

amperage load rating for the equipment’s operation and to be marked on the device. 

• At this time the “joule” unit of measurement is not used for expressing electrical energy quantity 

values in commercial EVSE applications. For continuity across EVSE NIST Handbook codes and 

regulations the term and its abbreviation (J) should also be removed from subparagraph S.5.3.(d). 

The kilowatt-hour unit of measurement and its corresponding abbreviation should be recognized in 

the EVFS Code.

• There does not seem to be a general consensus on the minimum test criteria to apply to AC and DC 

systems. There may be test criteria that cannot be applied in both the laboratory and in the field 

because there are factors the examiner cannot control or adequately correct for. Tests should be 

conducted over the range of operating conditions for which the device is designed. 

• The 2023 proposal creates a new separate test requirement specifically for laboratory evaluations; 

therefore a 2028 exemption would also be new text that requires being underscored to clearly 

designate the 2028 effective date as new language. 

• The 2028 effective date is confusing, is the intent that no testing at an approved brick and motor 

facility nor type evaluations can be carried out until January 1, 2028?

• A slight change is recommended for the agenda item’s title to include missing paragraphs S.5.2.(b) 

EVSE Identification and Marking Requirements and S.5.3.(d) Abbreviations and Symbols; joule 

and striking S.5. Markings to clarify these units of measurement are a part of this proposal. This 

would also assist the community in distinguishing this item from multiple others 2023 proposals 

that address EVFS marking requirements.

Table 3. Summary of Recommendations

EVF-23.4 – S.5. Markings and N.5. Test of an EVSE System.

V D W A I Notes* Comments

Submitter 

OWM

WWMA 

SWMA 

NEWMA 

CWMA No recommendation for this item.

NCWM

Letters of Support Letters of Opposition Notes

Industry
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Table 3. Summary of Recommendations

EVF-23.4 – S.5. Markings and N.5. Test of an EVSE System.

V D W A I Notes* Comments

Manufacturers

Retailers and 

Consumers

Regulators

*Notes Key:

1 - Submitted modified language

2 - Item not discussed

3 - No meeting held

4 - Not submitted on agenda

5 - No recommendation or not considered

Item Under Consideration:

Amend Handbook 44, Electric Vehicle Fueling Systems as follows: 

S.5. Markings. – The following identification and marking requirements are in addition to the

requirements of Section 1.10. General Code, paragraph G-S.1. Identification. 

S.5.1. Location of Marking Information; EVSE. – The marking information required in 

General Code, paragraph G-S.1. Identification shall appear as follows:

(a) within 60 cm (24 in) to 150 cm (60 in) from ground level; and

(b) on a portion of the EVSE that cannot be readily removed or interchanged (e.g., not on a 

service accesspanel).

S.5.2. EVSE Identification and Marking Requirements. – In addition to all the marking 

requirements of Section 1.10. General Code, paragraph G-S.1. Identification, each EVSE shall have 

the following information conspicuously, legibly, and indelibly marked:

(a) voltage rating;

(b) maximum current deliverable amperes; 

(c) type of current (AC or DC or, if capable of both, both shall be listed);

(d) minimum measured quantity (MMQ); and 

(e) temperature limits, if narrower than and within – 40 °C to + 85 °C (− 40 °F to + 185 °F). 

(Amended 2021) 

S.5.3. Abbreviations and Symbols. – The following abbreviations or symbols may appear on an 

EVSE system.

(a) VAC = volts alternating current; 
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(b) VDC = volts direct current;

(c) MDA = maximum deliverable amperes;

(d) J = joulekWh – kilowatt hours. 

And

N.5. Test of an EVSE System.

N.5.12. Performance Verification in the Field. – Testing in the field is intended to validate the 

transactional accuracy of the EVSE system. Provided the EVSE under test has a valid type 

approval certificate, then tThe following testing is deemed sufficient for a field validation. 

(a) For AC EVSE

(1) A point between 10 % and 20 % of the maximum deliverable amperes, but not 

exceeding 8 A;

(2) A point between 45 % and 55 % of the maximum deliverable amperes; and 

(3) A point between 70 % and 100 % of the maximum deliverable amperes. 

(b) For DC EVSE

(1) A point at less than 30 A

(2) A point between 20 % and 100 % of the maximum deliverable amperes with 

guidance to test at the maximum power level that is possible using the test 

equipment available. 

For DC systems it is anticipated that an electric vehicle may be used as the test load. Under that 

circumstance, testing at the load presented by the vehicle shall be sufficient provided that it is 

greater than 20 % of the maximum deliverable amperes.

All DC EVSE are exempt from this requirement until January 1, 2028. 

(Amended 2023) 

N.5.21. Laboratory Accuracy Testing. – The testing methodology compares the total energy 

delivered in a transaction and the total cost charged as displayed/reported by the EVSE with that 

measured by the measurement standard. Each test shall be performed for at least the minimum 

measured quantity (MMQ).

(a) For AC systems:

(1) Accuracy tests of the EVSE system at a load of not less than 85 % of the maximum 

deliverable amperes (expressed as MDA) as determined from the pilot signal for a 

total energy delivered of at least twice the minimum measured quantity (MMQ). If 

the MDA would result in maximum deliverable power of greater than 7.2 kW, then 

the test may be performed at 7.2 kW. Shall be performed at the following current 

levels:
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(i) A point between 10 % and 20 % of the maximum deliverable amperes, but not 

exceeding 8A;

(ii) A point between 45 % and 55 % of the maximum deliverable amperes; and 

(iii) A point between 70 % and 100 % of the maximum deliverable amperes. 

(2) Accuracy test of the EVSE system at a load of not greater than 10 % of the maximum 

deliverable amperes (expressed as MDA) as determined from the pilot signal for a 

total energy delivered of at least the minimum measured quantity (MMQ).

(b) For DC systems (see note)tests shall be performed at two voltage points one between 350 

VDC and 400 VDC and if supported by the EVSE a second at between 700 VDC and 800 

VDC: 

(1) Accuracy tests of the EVSE system at a load of not less than 85 % of the maximum 

deliverable amperes current (expressed as MDA) as determined from the digital 

communication message from the DC EVSE to the test standard for a total energy 

delivered of at least twice the minimum measured quantity (MMQ).shall be 

performed at the following current levels:

(i) A point at less than 30A; 

(ii) A point between 45 % and 55 % of the maximum deliverable amperes; and 

(iii) A point between 70 % and 100 % of the maximum deliverable amperes. 

(2) Accuracy test of the EVSE system at a load of not more than 10 % of the maximum 

deliverable amperes (expressed as MDA) as determined from the digital 

communication message from the DC EVSE to the test standard for a total energy 

delivered of at least the minimum measured quantity (MMQ). (2) Accuracy test of the 

EVSE system at a load of not more than 10 % of the maximum deliverable amperes 

(expressed as MDA) as determined from the digital communication message from the 

DC EVSE to the test standard for a total energy delivered of at least the minimum 

measured quantity (MMQ).

All DC EVSE are exempt from this requirement until January 1, 2028. 

(Amended 2022 and 2023) 

Note: For DC systems it is anticipated that an electric vehicle may be used as the test load. Under 

that circumstance, testing at the load presented by the vehicle shall be sufficient. Circumstance, 

testing at the load presented by the vehicle shall be sufficient

NIST OWM Detailed Technical Analysis: 

The submitter’s proposed modifications to subparagraph S.5.2. (b) EVSE Identification and Marking 

Requirements will clarify throughout the EVFS code the appropriate terminology for specifying the 

amperage load the EVSE’s manufacturer has rated the equipment at for its operation and as a required 

marking on the device. 
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The unit of measurement “joule” is not presently in use for expressing electrical energy quantity values in 

commercial EVSE applications. Therefore, to ensure continuity across all relevant EVSE NIST Handbook 

codes and regulations the term “joule,” to include its abbreviation (J), should not be included in 

subparagraph S.5.3.(d) or any other legal metrology requirements at this time. The kilowatt-hour unit of 

measurement and its corresponding abbreviation should be recognized in the EVFS Code. 

Although the community has more knowledge on the operations of EVFSs, test equipment, and installation 

sites there does not seem to be a general consensus on the minimum test criteria to apply to AC and DC 

systems. Variability in test processes and procedures arise from factors that are inherent in the device under 

test, in the test itself, or in test equipment. There may be test criteria that cannot be applied in both the 

laboratory and in the field because there are factors the examiner cannot control or adequately correct for. 

Tests should be conducted over the range of operating conditions for which the device is designed. 

The 2028 exemption included in the DC system test procedure as part of the July 2022 priority item 

amended paragraph N.5.2 a general set of test procedures. S&T Agenda Item EVF-23.4, a 2023 proposal, 

adds a separate set of test procedures for type evaluation that did not previously exist and would be a 

substantive change to the 2023 edition of the handbook. The 2023 proposal creates a new separate test 

requirement specifically for laboratory evaluations; therefore a 2028 exemption, if appropriate, would also 

be new text that requires being underscored to clearly designate the 2028 effective date as new language. 

The 2028 effective date is confusing, is the intent that no testing at an approved brick and motor facility 

nor type evaluations can be carried out until January 1, 2028? 

A slight change is recommended for the agenda item’s title to include missing paragraphs S.5.2.(b) EVSE 

Identification and Marking Requirements and S.5.3.(d) Abbreviations and Symbols and striking S.5. 

Markings to clarify the appropriate terminology for the EVSE current level and unit of measurement are 

also under consideration in this proposal. This would also assist the community in distinguishing this item 

from multiple other 2023 proposals that address other types of EVFS marking information. 

U.S. National Work Group’s Electric Vehicle Fueling Equipment Subgroup (EVFE SG)

• The SG agrees with the proposed changes to: (1) paragraph S.5.2.(b) EVSE Identification and 

Marking Requirements for clarity and consistency in the expression of current values across the 

EVFS Code and to properly identify the highest current value or level at which the manufacturer 

has specified for the operation of the EVSE, the EVFE SG supports identifying this marking 

information as the “maximum deliverable ampere” rather than the currently stated “maximum 

current deliverable”, and (2) paragraph S.5.3.(d) Abbreviations and Symbols which removes the 

“joule” unit of measurement and its corresponding abbreviation and further modifies that 

subparagraph to include the “kilowatt-hour” as well as recognize that unit’s abbreviation “kWh”. 

• The SG agrees with the proposed changes to N.5.1. Performance Verification in the Field and N.5.2. 

Accuracy Testing in concept, but the SG is not in concurrence with specific recommendations in 

the proposal. The SG would like to share the following points from its discussions of these items.

o Some members of the SG would like to take a closer look at the test points. 

o The SG would like to ask the SG’s Test Procedures Subcommittee to take a look at the 

criteria and provide feedback to the SG and the S&T Committee before the item moves 

ahead.
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o There are concerns about the limitations of available test standards and how the proposed 

test criteria might impact this.

o Regarding N.5.2. Accuracy Testing (Field) subparagraph (2)(i), the SG has concerns about 

testing to less than 10% of maximum current or maximum deliverable amperes which could 

be significantly below typical levels of operation.

o There were some questions about whether type evaluation criteria should be included in 

Handbook 44.

o Specifying field test criteria that only apply if a device holds type evaluation certification. 

Exactly what test criteria apply to devices that do not have a certificate? Must those devices 

first undergo the proposed more stringent test criteria specified to be performed under 

laboratory conditions?

Regional Association Reporting:

Central Weights and Measures Association

Ms. Scheleese Goudy (Electrify America): Ms. Goudy stated the NIST USNWG discussed this and had 

consensus of doing the opposite of this proposal. This makes it unnecessarily difficult for testing. 

Ms. Francesca Wahl (Tesla): Opposes. The high-end testing as written may be challenging for systems 

with higher power levels such as heavy-duty trucks and other high-power systems.

CWMA S&T 2022 Interim Meeting Report

Mr. Craig VanBuren (Michigan): Requested developing. Send to the NIST USNWG for consideration.

The CWMA S&T Committee has no recommendation for this item.

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting the following comments were received:

Ms. Scheleese Goudy (Electrify America): Ms. Goudy stated Electrify America opposes this proposal. 

Ms. Goudy suggested the 30 amps is too small and too low for the 10% accuracy testing. Ms. Goudy 

recommended a Withdrawal status.

Mr. Chris King (Siemens) stated Siemens supports and agrees with Electrify America's comments. Mr. 

King proposed this item would add significantly to the expense of setting up and running an operation. Mr. 

King recommended a Withdrawal status.

Ms. Francesca Wahl (TESLA) stated TESLA supports the previous comments by Electrify America and 

Siemens. Ms. Wahl proposed the item can be developed, that there is merit, but is not consistent with the 

working group. Ms. Wahl suggested the item is not fully developed. 

Mr. Kevin Schnepp (California Division of Measurement Standards) commented there is some concern 

about the language for specifications and tolerances. Mr. Schnepp recommended this item be assigned to 

a work group. Mr. Schnepp recommended a Developing status.
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During open hearings, comments were heard that contents in this item were previously discussed in the 

USNWG, but no official position has been taken by the USNWG. There were also comments during open 

hearing taking the position the item is not fully developed. The WWMA S&T Committee recommended

the submitters work with USNWG to address the comments heard during open hearings and that they work 

to develop one proposal by combining language from EVF-23.7. 

The WWMA S&T Committee recommended that this item be blocked with item EVF-23.7. The WWMA 

S&T Committee recommended the new blocked items be assigned a Developing status.

Southern Weights and Measures Association

The following comments were received during the 2022 SWMA Annual Meeting:

Ms. Goudy stated that the test current is too low and recommended withdrawal.

Dr. Curran (Florida) stated that line 17 on page 238 should read N.5.1.

The SWMA S&T Committee recommended that this item be withdrawn.

Northeastern Weights and Measures Association

Mr. Keith Bradley (Electrify America) addressed challenges in testing DC meters in that low current is the 

hardest and perhaps the least important thing to test in the system. 

After hearing comments from the floor, the Committee believes this item has merit and requests that the 

EVSE Subgroup continue work on this item. The Committee recommended this item be given a Developing 

status.

EVF-23.5 S.5.2. EVSE Identifications and Marking Requirements and T.2. Load 

Accuracy Test tolerances

Source: Power Measurements LLC

Submitter’s Purpose and Justification:

Update the tolerances for DC EVSE and change the effective date to January 1, 2024. Make the new 

tolerance retroactive effective January 1, 2025.

This topic has been discussed in the NIST Working Group numerous times. Most recently it appeared that 

the group was obtaining consensus on the language presented here. Industry has reported that their testing 

of existing systems suggests that they would comply with the proposed error limits of +/- 5% without 

requiring any infield upgrades. Since thousands of new DC EVSE are planned under current Federal 

programs it is very important to have some known level of accuracy for all EVSE in the field. The 5% 

level for all systems installed prior to January 1, 2025 is a reasonable approach that should have no negative 

effects on the industry. Delaying a specified accuracy to 2028 opens the market up to inequities and fraud.

This proposal has significant financial advantage to industry. Under it all systems installed before January 

1, 2025 would be permanently grandfathered in at the +/- 5% tolerance levels until they were retired or had 

a repair which required recertification.
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The time frame discussed most recently in the NIST WG was for this change to be effective January 2024. 

That was to some extent predicated on getting this change into the code in 2023. In this submission the 

date has been delayed to January 1, 2025 to allow everyone to be fully prepared for its implementation.

The principal argument made against this requirement has been that systems cannot be made to comply in 

a reasonable time or for a reasonable amount of investment. More recent testing of existing systems has 

shown that with the relaxed tolerance of +/- 5% the vast majority of systems already installed would qualify.

The submitter requested that this be a Voting Item in 2023.

OWM Executive Summary for EVF-23.5 – S.5.2. EVSE Identifications and Marking Requirements 

and T.2. Load Accuracy Test Tolerances

OWM Recommendation:

• Items EVF-23.5 and EVF-23.6 both propose changes to marking and accuracy requirements in 

NIST Handbook 44.

• OWM has given thought to how we might assist the Committee and the Community in addressing 

these items and arriving at a single proposal that would meet the needs of the submitters of both 

items and other stakeholders.

• OWM believes this proposal (Item EVF-23.5) and the alternative recommended in Item EVF 23.6 

both require more work and vetting as suggested by two of the four regional associations.

o We believe this work would most appropriately be done in the USNWG SG as recommended 

during the WWMA meeting and recommend the Committee designate these items as 

Developing and ask the SG for assistance in vetting the proposals.

• Should the Committee believe there is an urgent need to move one of these proposals forward, we 

encourage the Committee to use the proposed language in Item EVF-23.5 as a starting point to 

ensure clarity and understanding of the final language.

o Having well-defined tolerances with clear and understandable effective dates is essential.

o Defining tolerances in the specific device codes is also preferable to the alternative of having 

jurisdictions use the provisions of the General Code to implement tolerances suitable for the 

application since this has the potential for non-uniform application across the country.

• OWM has included comments on Item EVF-23.6 as part of its analysis of that item.

• Regarding Item EVF-23.5, OWM is mindful of the comments made in some of the regions and by 

other stakeholders through written comments submitted to the Committee that the specifics of this 

proposal (Item EVF-23.5) may not meet the needs of all stakeholders.

o See the letter on the Committee’s website in opposition to EVF-23.5 (Colorado, Michigan, 

Florida, Vermont and Electrify America, Tesla, and EVGo) and recommends the community 

work to modify the code to appropriately address the marketplace and provide a comprehensive 

uniform set of requirements needed by regulators and equipment manufacturers (EVSE and 
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OWM Executive Summary for EVF-23.5 – S.5.2. EVSE Identifications and Marking Requirements 

and T.2. Load Accuracy Test Tolerances

test apparatus). What has been done in the development stage and over the last seven years to 

verify EVSEs in commercial (for fee) applications.

• However, the proposed changes in Item EVF-23.5 are much clearer in language, format, and 

application and are closer to language agreed to by the USNWG SG in June 2022 than are the 

proposed changes in Item EVF-23.6.

o The NIST USNWG EVFE Subgroup reached a consensus through a June 2022 ballot in which 

the group agreed to move forward to recommend a wider tolerance of 5 percent only for DC 

systems installed before 2024 that must bear accuracy markings while maintaining for AC 

systems a 1 percent Acceptance Tolerance/2 percent Maintenance Tolerance and the tighter 

tolerance would also apply to post 2024 DC systems.

o The language from that June 2022 ballot is included in OWM’s detailed analysis below and in 

Item EVF-23.6.

o OWM has included specific comments regarding changes needed to the proposed language in 

Item EVF-23.6 as part of OWM’s analysis of that item.

• Below are some additional comments for the Committee and other stakeholders to consider in 

reviewing Items EVF-23.5 and EVF-23.6.

• Proposed accuracy markings need to be separate from the markings of electrical energy levels and 

required temperature ranges, therefore OWM recommends the “Notice” be included as a separate,

new subparagraph S.5.2.1.

• Adoption should occur only after fully vetting proposals to modify fundamental requirements such 

as those that impact accuracy, transparency, or that ensure fair competition to:

• avoid unforeseen consequences;

• ensure stakeholders have the tools needed for this new device application;

• discourage nonuniformity which can have a disruptive impact on the marketplace; and

• take corrective action on discovering any gaps/oversight in modifications to the seven-yearold legal metrology requirements. 

• NIST OWM encourages the community's participation in the USNWG EVFE Subgroup which 

began its work in 2012 and whose work resulted in NIST HB 44 3.40. EVFS Code's adoption in 

2015. The Subgroup is reviewing the four paragraphs that appear in multiple 2023 proposals that 

address: (1) dual EVSE tolerances (2.0 percent or 5.0 percent [DC EVSEs]); (2) new EVSE 

markings required for the wider tolerance in the marketplace; and (3) corresponding accuracy test 

procedures.

• The EVFE Subgroup last met on December 8, 2022, to address proposals under consideration for 

the 2023 cycle and will provide a clear statement in writing of its exact position on agenda items.
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Table 3. Summary of Recommendations

EVF-23.5 – S.5.2. EVSE Identifications and Marking Requirements, and T.2. Load Accuracy Test 

tolerances.

V D W A I Notes* Comments

Submitter 

OWM USNWG EVFE SG’s position is 

available.

WWMA 

SWMA 

NEWMA 

CWMA 

NCWM

Letters of Support Letters of Opposition Notes

Industry

 Co-authors and sent October 

18, 2022.

Manufacturers

Retailers and 

Consumers

Regulators

 Co-authors and sent October 

18, 2022.

*Notes Key:

1 - Submitted modified language

2 - Item not discussed

3 - No meeting held

4 - Not submitted on agenda

5 - No recommendation or not considered

Item Under Consideration:

Amend Handbook 44, Electric Vehicle Fueling Systems as follows: 

S.5.1. EVSE Identification and Marking Requirements. – In addition to all the marking 

requirements of Section 1.10. General Code, paragraph G-S.1. Identification, each EVSE shall have 

the following information conspicuously, legibly, and indelibly marked:

(a) voltage rating;

(b) maximum current deliverable;

(c) type of current (AC or DC or, if capable of both, both shall be listed);

(d) minimum measured quantity (MMQ); and 
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(e) temperature limits, if narrower than and within – 40 °C to + 85 °C (− 40 °F to + 185 °F).

(Amended 2021) 

(f) For EVSEs subject to a tolerance of 5% (see paragraph T.2.1.) a notice shall be 

conspicuously, legibly, and indelibly displayed, in a position plainly visible to a person 

accessing a charging port of the EVSE which states:

NOTICE:

“This charger operates at a tolerance of 5 percent versus chargers 

which operate at a tolerance of 2 percent.” 

EVSEs subject to a tolerance of 1 % Acceptance and 2% Maintenance Tolerance are not 

required to be marked with such a statement.

And

N.5.2. Accuracy Testing. – The testing methodology compares the total energy delivered in a 

transaction and the total cost charged as displayed/reported by the EVSE with that measured by the 

measurement standard.

(b) For DC systems (see note):

(1) Accuracy test of the EVSE system at a load of not less than 85 % of the maximum 

deliverable amperes current (expressed as MDA) as determined from the digital

communication message from the DC EVSE to the test standard for a total energy 

delivered of at least twice the minimum measured quantity (MMQ).

(2) Accuracy test of the EVSE system at a load of not more than 10 % of the maximum 

deliverable amperes (expressed as MDA) as determined from the digital

communication message from the DC EVSE to the test standard for a total energy 

delivered of at least the minimum measured quantity (MMQ).

All DC EVSE are exempt from this requirement until January 1, 2028.

And

T.2. Load Accuracy Test Tolerances.

T.2.1. EVSE Load Accuracy Test Tolerances. – The tolerances for EVSE load accuracy tests

for all AC EVSE and for DC EVSE installed on or after January 1, 2025 are:

(a) Acceptance Tolerance: 1.0 %; and 

(b) Maintenance Tolerance: 2.0 %.

For DC EVSE installed prior to January 1, 2025 tolerances for the accuracy tests are:

(a) Acceptance Tolerance: 5.0 %; and 

(b) Maintenance Tolerance: 5.0 %. 
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All DC EVSE are exempt from this requirement until January 1, 2028. 

(Amended 2022)

NIST OWM Detailed Technical Analysis: 

Moving forward with adoption before fully vetting proposals to modify fundamental requirements such as 

accuracy, transparency, or that ensure fair competition which are the foundation of every weighing and 

measuring device code can have unforeseen consequences. To delay or eliminate these basic guidelines 

(tools needed for this new device application) encourages nonuniformity (from state to state) which can be 

disruptive and impact the level of confidence in the marketplace. Proposals should be evaluated based on 

their impact on all stakeholders in the community. Time and again the community has moved to take 

corrective action on discovering an oversight that resulted from either the modification of existing or 

adoption of a new legal metrology requirement. In the interim prior to a code’s publication or the first type 

evaluation, jurisdictions maintain their regulatory authority over new commercial device applications and 

emerging technological advances in weighing and measuring equipment through provisions offer 

alternative means of achieving a provisional status of compliance that encourages commerce is not 

overburdensome while still allowing for their program’s oversight. Some do admit this path can be a more 

complex process but when well thought out it works. So, there are options such as General Code provisions, 

the Fundamental Considerations, and provisional status for devices for stakeholders during that interim 

period until all components of the weights and measures infrastructure are in place. 

The proposal outlined in agenda item EVF-23.5 is not exactly the same as an alternative proposal agreed to 

in a June 2022 ballot of the EVFE Subgroup. In the case of the EVFE Subgroup, the wider tolerance of 5 

% for DC systems installed before 2024 was identified by several OEMs as achievable, and the less than 

ideal existence of dual tolerances in the marketplace would be addressed by marking the accuracy 

achievable by devices which met only the wider tolerance. Granted some refining of the requirement text 

would be necessary the group’s alternate proposal addressed many concerns expressed by both OEMs and 

regulators when the Subgroup’s discussions on this topic first began in 2020. 

NIST OWM is aware of a letter from the State Weights and Measures Directors of Colorado, Michigan, 

Florida, Vermont and industry representative from Electrify America, Tesla, and EVGo. If as the coauthors of the letter indicate that jurisdictions have not up through October 2022 regulated these systems, 

then all work to modify the code to appropriately address the marketplace and provide a comprehensive 

uniform set of tools/requirements needed by regulators and equipment manufacturers (EVSE and test 

apparatus) can be accomplished. And this includes expediting changes to any oversights or other gaps in 

the requirements. 

Since the proposed accuracy marking applies only to systems capable of meeting the wider 5 percent 

tolerance, thus not applicable to all systems, and is separate information from the required marking of 

electrical energy levels and temperature range for the operation of the equipment, we therefore recommend 

the “Notice” be included as a separate new subparagraph S.5.2.1. 

NIST OWM encourages the community’s participation in the USNWG which began work in 2012 as a 

forum for stakeholders and other interested parties in establishing legal metrology standards (also the 

weights and measures infrastructure) for electrical energy measurements. That effort resulted in NIST HB 

44 3.40 EVFS Code’s adoption in 2015. The four paragraphs that appear in multiple 2023 proposals address 

(1) dual EVSE tolerances (2.0 percent or 5.0 percent [DC EVSEs]); (2) new EVSE markings required for 

the wider tolerance in the marketplace (proposed new 5.0 percent accuracy for DC systems); and (3) 

corresponding accuracy test procedures are part of the EVFE SG’s meeting discussions. The EVFE 

Subgroup’s work continues up through today having met October 6, 18, and December 8, 2022 to address 
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proposals under consideration for the 2023 cycle. It should be noted that the EVFE SG has worked to 

further refine the code as more is learned about these systems and since January 2020 met 16 times to 

consider the proposals the group submitted to the S&T Committee as well as those developed or under 

development outside of its forum to provide their input. The EVFE SG will provide a clear statement of its 

exact position on agenda proposals when it reaches a consensus and provides this information in writing 

(as shown below). The EVFE SG reached a consensus in July 2022 which the group agreed to move 

forward to recommend a wider tolerance of 5 percent only for DC systems installed before 2024 that must 

bear accuracy markings while maintaining for AC systems a 1 percent Acceptance Tolerance/2 percent 

Maintenance Tolerance and the tighter tolerance would also apply to post 2024 DC systems. 

U.S. National Work Group’s Electric Vehicle Fueling Equipment Subgroup (EVFE SG)

• The SG agreed to forward the results of its June 2022 ballot (in which it proposed changes to the 

tolerances and the addition of marking requirements) to the S&T Committee and recommended the 

Committee consider these recommendations as it considers Items EVF-23.5 and EVF-23.6. 

• In a June 2022 ballot, the SG agreed to recommend the following changes to the tolerances and 

marking requirements in Section 3.40. The SG asks that the Committee consider the SG’s 

recommendations presented below as it deliberates on S&T Agenda Items EVF-23.5 and EVF-23.6 

which include proposed changes to these same handbook code paragraphs. The changes agreed to 

by the SG in its June 2022 ballot are shown below.

o Additionally, some device users on the SG indicated that there remains a desire to recognize 

and then maintain a 5% tolerance for DC legacy (i.e., installed prior to 2024) equipment.

T.2. Load Accuracy Test Tolerances.

T.2.1. EVSE Load Accuracy Test Tolerances for AC Systems. – The tolerances for 

EVSE load tests for AC systems areshall be as follows: 

(a) Acceptance Tolerance: 1.0 %; and 

(b) Maintenance Tolerance: 2.0 %.

(Amended 202X) 

T.2.2. EVSE Accuracy Test Tolerances for DC Systems. – The tolerances for EVSE 

load tests on DC systems shall be as follows: 

(a) For DC systems installed prior to 2024 and that bear the notice specified in 

paragraph S.5.2.1. Marking of Accuracy Limits, DC EVSEs Installed Prior to 

2024, acceptance and maintenance tolerances are: 5.0 %. 

(b) For DC systems installed on or after January 1, 2024 or that do not bear the 

notice specified in paragraph S.5.2.1. Marking of Accuracy Limits, DC 

EVSEs Installed Prior to 2024 tolerances are:

(1) Acceptance Tolerance: 1.0 %; and 

(2) Maintenance Tolerance: 2.0 %. 

(Added 202X) 
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S.5.2. EVSE Identification and Marking Requirements. – In addition to all the 

marking requirements of Section 1.10. General Code, paragraph G-S.1. Identification, each 

EVSE shall have the following information conspicuously, legibly, and indelibly marked: 

(a) voltage rating;

(b) maximum current deliverable;

(c) type of current (AC or DC or, if capable of both, both shall be listed); 

(d) minimum measured quantity (MMQ); and

(e) temperature limits, if narrower than and within – 40 °C to + 85 °C (− 40 °F to + 

185 °F). 

S.5.2.1. Marking of Accuracy Limits, DC EVSEs Installed Prior to 2024. - DC 

EVSEs installed prior to 2024 shall be marked with the following:

NOTICE:

“This charger operates at a tolerance of ± 5 percent versus newer chargers 

which operate at a maximum tolerance of ± 2 percent.”

This marking shall be conspicuously, legibly, and indelibly marked, in a 

position plainly visible to a person accessing a charging port of the EVSE. 

This marking requirement does not apply to DC EVSEs that are capable of 

meeting an acceptance tolerance of 1 % and a maintenance tolerance of 2 %.

(Added 202X)

(Amended 2021) 

Summary of Discussions and Actions:

A letter dated October 18, 2022 from the State Weights and Measures Directors of Colorado, Michigan, 

Florida, Vermont, and industry representatives from Electrify America, Tesla, and EVGo was sent to the 

NCWM S&T Committee. The co-authors of the letter remind the Committee that it accepted their July 

2022 recommendations for exempting DC systems from “accuracy tolerances and testing until 2028” citing 

this as a “solution that enables regulators to inspect and test to the accuracy of chargers for which 

appropriate testing equipment in available.” Further indicating that an “inspector or service agent cannot 

certify a DC fast charger because what is needed is equipment that they can bring to a site of a range up to 

350 kW and 600 amps or more and that has NIST-traceable calibration for the energy delivered.” Also, the 

letter states the “NCWM should not reduce the exemption that it adopted in July 2022 until the Committee 

has evidence test equipment is reasonably available.”
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Regional Association Reporting:

Central Weights and Measures Association

Ms. Francesca Wahl (Tesla) requested it be Withdrawn. This is already covered in EVF-23.6. The NIST 

USNWG does not agree with this. This is another proposal to try to move up the already agreed upon 2028 

date.

Mr. Craig VanBuren (Michigan) and Ms. Scheleese Goudy (Electrify America) requested it be Withdrawn.

The CWMA S&T Committee recommended this item be Withdrawn.

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting the following comments were received:

Ms. Wahl commented TESLA opposes this item and proposed this item looks to moving up the date that 

was recently adopted at the July 2022 NCWM, from 2028 to 2025. Ms. Wahl proposed this item be 

combined and harmonized with EVF-23.6. Ms. Wahl recommended a Withdrawal status.

Ms. Goudy commented Electrify America agrees with TESLA’s comments.

Mr. Chris King (Siemens) commented Siemens agrees with TESLA’s comments.

During open hearings, comments were heard that contents in this item were previously discussed in the 

USNWG, but no official position has been taken by the USNWG. There were also comments during open 

hearing taking the position the item is not fully developed. The WWMA S&T Committee recommended

the submitters work with the USNWG to develop one proposal by combining language from EVF-23.6.

The WWMA S&T Committee recommended that this item be blocked with item EVF-23.6. The WWMA 

S&T Committee recommended the new blocked items be assigned a Developing status.

Southern Weights and Measures Association

The following comments were received during the 2022 SWMA Annual Meeting:

Mr. Prince (Florida) stated that this issue has been addressed and that this item should be withdrawn.

Ms. Goudy stated that this item should be withdrawn.

The SWMA S&T Committee recommended that this item be withdrawn.

Northeastern Weights and Measures Association

Mr. Bradley and Ms. Wahl requested that this item be withdrawn. Ms. Juana Williams (NIST OWM) 

commented that the EVFE Subgroup has not had the time to vet this item and requested that it be 

developing. Mr. Marc Paquette (Vermont) noted that there are currently no traceable standards to test DC 

devices and requested a developing status. Mr. Lou Sakin (Holliston, Massachusetts), Mr. John McGuire 

(New Jersey), and Mr. Walt Remert (Pennsylvania) agreed with Mr. Paquette’s comments and also 

requested that the item have a Developing status.
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After hearing comments from the floor, the Committee believes that this item has merit. The Committee 

recognizes the current limitations in testing DC devices. The Committee is recommending that this item 

be assigned a Developing status.

EVF-23.6 S.5.2. EVSE Identification and Marking Requirements and T.2. Tolerances

Source: Florida Department of Agriculture and ConsumerServices; Electrify America; Tesla; EVGo, 

Siemens

Submitter’s Purpose and Justification:

The revised proposal would amend Handbook 44, Section 3.40 Tentative Code in the following ways:

1. Paragraph T.2.1. would be revised for DC chargers. The 1 % (acceptance) / 2 % (maintenance)

tolerances would apply to devices installed after January 1, 2024. For devicesinstalled before that

date, the tolerances would be 5% (acceptance and maintenance).

2. For the sake of clarity and transparency for customers and inspectors, a device subjectto the 5 %

tolerance would have to be marked as such. The proposal would require specific language for the

marking.

3. If a manufacturer has achieved 1 %-capable chargers earlier than the January 2024 timeframe,

users of those chargers might prefer not to mark the chargers as 5% chargers; and thenthose

chargers would be subject to the 1 %/2 % tolerance. The proposal includes language to establish

this treatment.

The 5 % tolerance for pre-2024 chargers would end on January 1, 2034. After that date, all DC chargers 

would be subject to the 1 % (acceptance) / 2 % (maintenance) tolerance.

A. The effect of the proposed revisions

The changes we propose would work as follows: all DC chargers would remain exempt from the accuracy

tolerances until January 1, 2028, as NCWM adopted at the 2022 Annual Meeting. When accuracy

tolerances come into force, a DC charger installed after January 1, 2024, would have to satisfy the 1%

(acceptance) / 2 % (maintenance) tolerance, the same levels as for AC chargers. But a DC charger installed

before January 1, 2024, would have to meet only a 5% accuracy tolerance. That 5% accuracy tolerance

would expire on January 1, 2034, at which point all the legacy chargers will have to have been retrofitted

or replaced.

The proposal would require a charger that is subject to the 5 % tolerance to display a marking, with

specified language, informing customers and inspectors of that fact. But the proposal leaves open the

possibility that a given manufacturer might achieve the 1 %/2 % tolerance earlier, and then would specify

that capability for a given model. Devices in that model would not have to bemarked as 5 % devices;

but if they are not marked that way, they would of course be subject to the 1 %/2 % level as for new

chargers.

B. The basic justification

DC and AC chargers are fundamentally different—in technology, in customer use, and in metering 

capabilities. AC charging technology, the older form, delivers energy in the same form—voltages and 

currents oscillating at 60 Hertz (in the United States) as utilities have provided it for a century.

Because a vehicle hasto convert AC energy to DC for charging the battery, AC charging stations operate
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at no more than 19.7 kW, and most no more than 6-7 kW. These charging rates will add 24-80 miles of

range in an hour of charging a typical car, and consequently AC charging involves extended sessions—

the median time that a customer uses an AC station is 22 hours.

1 The voltages delivered are no more

than 480 volts ac, and the current is no more than 50 amps ac (andmore typically 30 amps ac). By 

contrast, DC chargers deliver energy in the same form that a battery ultimate needs it. Using voltages 

of 400 to 950 volts dc and currents up to 500 amps dc (higher levels are coming in the future for

applications like charging heavy trucks), they are able todeliver 50kW, 150 kW, 350 kW, or higher 

charging rates. These stations will add 200-1400 milesof range in an hour of charging, or, more 

meaningfully, 400 miles of range in as little as 20 minutes. A customer at a DC station will arrive, 

charge briefly, and then depart. Customers incorporate AC chargers into their regular routines, such 

as by driving to work and charging there. DC chargers are more commonly used to support longdistance trips.2

For AC charging, manufacturers have been able to utilize metering technology that has been developed

over a century for electric utilities. When Handbook 44, section 3.40 was developed in 2015, that AC

metering technology was well understood. There have been long-established standards for AC revenue

meters—though those standards, in the utility sector, are not necessarily the same in every respect as how

a weights and measures standard would work. One indication ofthe relatively mature state of AC metering

is that NIST has long provided ordinary-course calibration services for AC watt-hour meters that operate

at 60 Hertz, within ranges of 69 to 480 volts and 0.5 to 30 amps (sufficient to cover typical AC chargers).3

DC metering technology, by contrast, has been “in research and development.”4 When section 3.40 was

adopted, the accuracy tolerances of 1.0% (acceptance) and 2.0% (maintenance) were predictive and

aspirational for DC chargers. As of November 2019, when California adopted its own regulation based

on section 3.40, meters and chargers meeting that standard were not yet generally commercially available.5

Meanwhile, NIST calibration services for DC watt-hour meters are non-standard, and are availableonly up

to 240 volts and 5 amps6

—far below the levels needed for testing DC chargers.

Argonne National Lab has studied the availability of DC metering technology. Our understanding is

that its draft report (not yet finalized,so far as we are aware) concludesthat thereare now on the market 

(at least in principle) meters for use in DC chargers that can meet a 1% acceptance / 2% maintenance 

tolerance. It is reasonable to conclude that the 1% / 2% tolerancewill be achievable in general. The

current proposal isfocused on how to handle the chargersthat are installed before that point. Previously

installed chargers will not in general be able to satisfy a 1% / 2% accuracy tolerance. To be clear, we do

not suggest that every existing charger would be more than 2% inaccurate. Indeed, it would not 

genuinely be possible to make that assessment, given the lack of NIST-traceable measurement

apparatusto test fast DC chargers in the field.

There is presumably a distribution of potential deviations among devices in the field. Given what

metering technology has been commercially available, a 2 % maintenance accuracy would lead to

inspection problems for a high proportion of devices.

1 Idaho National Laboratory, “Plugged In: How Americans Charge Their Electric Vehicles,” p.14, 

https://avt.inl.gov/sites/default/files/pdf/arra/PluggedInSummaryReport.pdf. 2 As the California Energy Commission has explained, “it is therefore useful to treat infrastructure for interregional travel 

(predominantly DCFCs) differently from infrastructure for intraregional travel (predominantly Level 1 and Level 2 chargers).”

https://efiling.energy.ca.gov/GetDocument.aspx?tn=233986&DocumentContentId=66805 at page 14. 3 https://shop.nist.gov/ccrz ProductDetails?sku=56200C&cclcl=en_US. 4 Cal. Dep’t of Food & Agriculture, Final Statement of Reasons on Electric Vehicle Fueling Systems, p.23 (Nov. 1, 2019).

5 Id.

6 https://shop.nist.gov/ccrz ProductDetails?sku=56110S&cclcl=en_US.
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The proposal would establish a tolerance of 5% for devices installed before January 1, 2024. The

justification for this particular choice of tolerance and timeline is as follows:

1. In 2019, California adopted a regulation that put a modified version of section 3.40 into force for

new devices. DC chargers installed before January 2023 are subject to no weights and measures

standards at all until 2033. DC chargers installed after January 2023 (and before January 2033)

are subject to a maintenance tolerance of 5.0% (and acceptance tolerance of 2.5%). Consequently,

in California, which represents roughly 30% of the currently-existing base of DC chargers, the

maintenance tolerance will be 5.0% for the coming decade. A maintenance tolerance of 5.0% for

legacy chargers in section 3.40 will be stricter overall than the California regulation (because it

will apply to all legacy chargers, whereas the California standard applies only to post-2023

chargers) but will align with the numerical tolerance used in California. Although a 5.0%

tolerance is among the larger tolerances used in Handbook 44, it is not unprecedented. And the

fact that newchargers in California will be subject to that standard will mean EV charging

customers have substantial experience with that chargers at that tolerance, and the 5.0% tolerance

we propose would be the same transactional experience as customers in California (the largest EV

charging market in the country) receive. It bears mention, too, that as Measurement Canada

prepares to implement standards for AC chargers, the tolerance (acceptance and maintenance) will

be 3.0%, not the 1% acceptance in Handbook 44. The cost of a typical charging session is $15

to $20. A 5.0% maintenance standard would mean a variation, beyond that, of an additional plus

or minus 40 cents. As with any tolerance, that variation could at any given charger be for or

against either side to the transaction.

2. The industry submitters have studied carefully their existing chargers, measurement devices and

existing models now available. They believe the 5% maintenance tolerance is achievable at a

manageable cost in the future, because it will generally not require extensive reconfiguring of

cabinets and the installation of four-wire cables.

3. The cost of bringing legacy chargers into line with the 1 %/2 % standard would be extreme. 

Although equipment is not available to test DC fast chargers in the field, some operators have found 

in tests of existing devices that they can be brought to a 5% tolerance but cannot meet the 1 %/2 % 

standard without replacing the meters or implementing an entirely new measurement system, which 

means a physical reconfiguration at each station and/or replacing the cables for delivering the 

energy to vehicles. Section 3.40. standards are based on the energy delivered at the connector to 

the car; in other words, a charger must account for losses in the cables. The most straightforward 

way to account for losses is to measure the voltage at the vehicle connector; that means the cable 

must have two additional high-voltage leads, to carry that voltage back to the meter7

. In 

California’s Initial Statement of Reasons (ISOR) for adopting specifications and tolerances 

requirement for commercial EVSE, California estimated that it costs approximately $20,000 to 

retrofit an existing DC charger.8

 We understand that cost to represent the cost (parts and labor) to 

replace the charging cable, and possibly to replace the meter if that task is simple. This cost may 

be a significant underestimate for some models of charger, because replacing the meter may not 

always be possible without physical reconfiguration of the space within the charger. Which charger 

models would require that sort of reconfiguration, and what proportion of the installed base they 

represent, is impossible to know without a detailed model-by-model study and detailed model-bymodel installation data across manufacturers. The upper end of cost would be simply the cost of 

7 Charging cables are themselves complex objects, with liquid coolant and high-voltage insulation. Cables for fast DC chargers 

that include additional high-voltage sensing leads were not available in 2015. 8 https://www.cdfa.ca.gov/dms/pdfs/regulations/EVSE_ISOR.pdf.
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replacing a charger, which many operators would find preferable to physical reconfiguration of 

charger internals anyway. The International Council on Clean Transportation (“ICCT”) reported 

in 2019 that fast DC chargers cost between $75,000 and $140,000 per charger, for the charger 

itself.9

 Installation costs range from $18,000 per charger (for six 150 kW chargers9 Michael 

Nicholas, “Estimating electric vehicle charging infrastructure costs across major U.S. metropolitan 

areas,” ICCT Working Paper 2019-14, p.2 tab. 2 (Aug. 2019, at a site) to $65,000 per charger (for 

one 350 kW charger at a site).10 The total cost (installation and equipment) for a 4-charger site 

would be roughly $720,000. That said, some amount of the installation cost represents upgrades 

to electrical supply lines and basic site construction, costs that would not be incurred anew to 

replace equipment. So, for a rough estimate, it is appropriate to use the lowest cost estimate from 

the ICCT, which is $17,692 (the cost per charger for a large site of 50 kW chargers). With that 

figure, replacing a 4-charger site of 350 kW chargers would cost roughly $630,000, or $157,000 

per charger.

4. Based on data on the existing charge base from the National Renewable Energy Laboratory’s

Alternative Fuels Data Center (“AFDC”), we can assume there will be about 36,000 “pre-2024” 

DCchargers.11 These are only a fraction of the overall chargers that will be installed nationwide

over the coming decade but bringing them into compliance with a 1%/2% tolerance will be highly

costly. Taking out the 30% that are in California (which already has regulations with a 5.0%

maintenance tolerance, for all post-2023 DC chargers), retrofitting all of those at the $20,000 cost

would total $720 million. If meter replacement is not possible and those chargers must all be

replaced, the total would be $5.6 billion. The actual cost of bringing the pre-2024 chargers to

compliance with a 2.0% maintenance tolerance would be somewhere between these numbers.12

5. The January 2024 date moves faster than the California regulation. Under the California

regulation, the 1% / 2% tolerance would not come into force until 2033. It appears that meters

capable of that tolerance are now available on the market. The submitters propose January 2024

as the date for distinguishing “legacy” from “new” chargers, because the existence of these meters

on the market is not all that is needed. Manufacturers have to access the meters, design products

incorporating them; revise production lines; test the new products to ensure they are safe and

reliable; and obtain third-party certifications (such as from Underwriters Laboratory) of the

revisedproducts. After those steps, a manufacturer can begin delivering a revised product to

operators. Installation of a charger is not simply a matter of placing it on a counter; charging

sites involve construction work, leading to the secure attachment of a charger to a specially built

concrete pad. In other words, from the first delivery of a new model of charger to the first

installations of thosechargers also takes time. The January 2024 date is appropriate for expecting

new chargers to incorporate meters that were available a few years before that date.

9 Michael Nicholas, “Estimating electric vehicle charging infrastructure costs across major U.S. metropolitan areas,” ICCT 

Working Paper 2019-14, p.2 tab. 2 (Aug. 2019), 

https://theicct.org/sites/default/files/publications/ICCT_EV_Charging_Cost_20190813.pdf. 10 Id. at 4 tab. 4. 11 According to the AFDC’s station locator database, there are 6,580 DC stations with 22,767 chargers. The AFDC also reports that 

the number of DC ports grew 29% year-on-year to the second quarter of 2021. 

https://afdc.energy.gov/files/u/publication/electric_vehicle_charging_infrastructure_trends_second_quarter_2021.pdf. 

With growth at this rate, about 6,600 additional DCFC stations will be installed in 2022 and 2023, leading to a total of about 36,000 

DC chargers that would be “pre-2024” chargers under the proposal. 12 A charger that is not qualified for a given tolerance level may well be within the bounds of the tolerance, because there is some 

distribution in metering performance. Even if devices are replaced only after inspection, a significant fraction would need 

replacement, thus incurring this scale of cost. Moreover, it might be most sensible for an operator to ensure all its devices are 

qualified, rather than waiting to see what the results of inspection might be for a given charger.
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6. The proposal focuses on installation before January 2024, rather than using the concept of 

retroactive/non-retroactive that is more common in Handbook 44, because non-retroactive is 

ordinarily based on when a device is placed in service. Many states do not yet regulate EV chargers 

and consequently have no placed-in-service process. In these states, “placed in service” would not 

be a well-defined concept, and regulators might not have good ways to determine when a device 

was placed in service. Installation is a reasonably well-defined process, and it should be possible 

to identify when a given charger was installed. California’s regulation has differing status for pre2023 and post-2023 chargers, and it bases that line on installation.

7. The proposal also specifies 5.0% as the acceptance tolerance, not just the maintenance tolerance. 

As a practical matter in field inspections, the acceptance tolerance for pre-2024 chargers will not 

be important. Section 3.40 (as amended at the 2022 NCWM meeting) exempts DC chargers from 

the accuracy tolerance until 2028. When they become subject to accuracy tolerances, no pre-2024 

charger will be at the point of acceptance. The proposal specifies an acceptance tolerance for clarity 

in type evaluations, which ordinarily evaluate device models against the applicable acceptance 

tolerance.

8. The exemption until 2028 adopted at the 2022 meeting does not eliminate the need for this proposal. 

When DC chargers are subject to accuracy tolerance requirements, pre-2024 chargers will still need 

to meet the applicable tolerance or be retrofitted or replaced. The 2028 time frame is unreasonably 

soon to do that, given the cost estimates above. California estimated that chargers have an effective 

10-year lifespan.13 This estimate is highly uncertain, in part because it was based in part on older 

AC chargers. Newer DC chargers, using more advanced technology for significantly more 

expensive equipment, are likely to have usable lifetimes greater than 10 years. The proposal 

recognizes that, nonetheless, there is a tradeoff between the cost of retrofitting or replacing devices, 

and the value of tighter tolerances. Some number of chargers will fail and need replacement earlier 

than 10 years, thus reducing the number that eventually need to be retrofitted or replaced to comply 

with tighter accuracy tolerances. Overall, the proposal uses the same 10-year period that several 

states have already adopted.14 Notably, the effect is significantly more stringent than in the 

California regulation. Under California’s rule, a charger installed before 2023 is subject to no 

standards for 10 years, and then becomes subject to standards in 2033; a replacement of the charger 

in 2032 would be subject to the 5.0% maintenance tolerance. A charger installed in 2023 (and that 

hypothetical 2032 installation) would be subject to the 5.0% tolerance indefinitely, with no end 

point. Our proposal, by contrast, would make a pre-2024 charger subject to the 5.0% tolerance 

once the 2028 compliance dates kicks in but only until 2034, at which point the charger would have 

to be retrofitted, replaced, or otherwise brought to the 1%/2% tolerance.

C. Potential objections

In response to the industry’s original proposal, some people commented that AC and DC chargersshould

be treated the same. As explained above, they are not the same, not only because of technology differences

but also because customers use them and view them differently. California and NTEP have distinguished

AC and DC chargers since at least 2021, and NCWM has alreadyrecognized important differences

between them, in Handbook 44.

Some have also commented that there should not be parallel accuracy classes for a given application. But

this approach is not unprecedented. In 1986, NCWM required new scales to be marked with an accuracy

class. Pre-1986 scales could remain unmarked, and those unmarked scales were subject to various

13 Cal. Dep’t of Food & Agriculture, Final Statement of Reasons, p.6. 14 4 Cal. Code of Regulations § 4002.11; Rev. Code Wash. § 19.94.190(6).
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accuracy tolerances (depending on application) that ranged up to 5.0 %, compared to the largest tolerance

for any marked scale at 2.0 %. For grain moisture meters, Handbook 44 has completely separate sections

for pre-1998 and post-1998 devices, with some different tolerance specifications for older and newer

devices. For both scales and grain moisture meters, there was no sunset date; the older devices have been

allowed to continue in use for as long as they operated. We do not suggest that the circumstances with

EV chargers are the same. Each of those past examples was based on justifications particular to that

situation. Nonetheless, these examples show that it has been done to maintain parallel tolerances for a

given application. In addition, there are already parallel, differing tolerances for EV chargers. If the

proposal is not adopted, pre-2023 chargers in California will have no tolerance at all until 2033; post2023 chargers will have a 5.0% maintenance tolerance for the indefinite future; and chargers elsewhere in

the country, including in states neighboring California, will have the existing Handbook 44 tolerances.

The proposal shifts the line between differing tolerances, but the situation of differingtolerances for the

same application is already in place without the proposal.

There have been claims that some manufacturers may be able to achieve 1% devices (DC chargers) before

January 2024, and one or more may already have done so. Even so, the proposal is still warranted.

Operators of EV chargers should not be forced to replace their existing chargers simply because they

could not get access to chargers made by a given manufacturer. It is generally agreed that when section

3.40 was adopted, the equipment to satisfy it did not exist for DC chargers. Reaching that point has

required research and development by meter manufacturers andcharger manufacturers. The goal of

regulation should be to handle the technology transition in a reasonable, fair manner, without prejudice

to operators that have made diligent efforts in procurement and operation of their chargers.

This proposal arrives without the formal approval of the U.S. National Work Group subgroup on EV

charging. But a similar proposal did have general consensus at the Work Group. NIST personnel solicited

views on the proposal through an email ballot at the end of June 2022. The resulting votes were 11 in

favor, and 1 opposed. As of this filing, NIST has not provided information on whether this vote was

sufficient for the subgroup to formally endorse the proposal. The one person voting “no” said that the

person would have voted yes if the proposal included a 10-year end date for the 5% tolerance. The current 

proposal has that feature and thus addresses the only concern expressed by the sole “no” vote. The current

proposal has that feature and thus addresses the only concern expressed by the sole “no” vote.

OWM Executive Summary for EVF-23.6 – S.5.2. EVSE Identification and Marking Requirements., 

and T.2. Tolerances.

OWM Recommendation:

• Items EVF-23.5 and EVF-23.6 both propose changes to marking and accuracy requirements in 

NIST Handbook 44.

• OWM has given thought to how we might assist the Committee and the Community in 

addressing these items and arriving at a single proposal that would meet the needs of the 

submitters of both items and other stakeholders.

• OWM believes this proposal (Item EVF-23.6) and the alternative recommended in Item EVF 

23.5 both require more work and vetting as suggested by two of the four regional associations.

• We believe this work would most appropriately be done in the USNWG SG as recommended 

during the WWMA meeting and recommend the Committee designate these items as Developing 

and ask the SG for assistance in vetting the proposals.
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OWM Executive Summary for EVF-23.6 – S.5.2. EVSE Identification and Marking Requirements., 

and T.2. Tolerances.

• Should the Committee believe there is an urgent need to move one of these proposals forward, 

OWM encourages the Committee to use the proposed language in Item EVF-23.5 as a starting 

point to ensure clarity and understanding of the final language.

o Having well-defined tolerances with clear and understandable effective dates is 

essential.

o Defining tolerances in the specific device codes is also preferable to the alternative of 

having jurisdictions use the provisions of the General Code to implement tolerances 

suitable for the application since this has the potential for non-uniform application across 

the country.

• Regarding Item EVF-23.6, OWM offers the following specific technical concerns and 

comments.

• OWM questions the reference to the phrase “certified to....” In the proposed EVF-23.6 

paragraph S.2.5.1. Marking.

o If the intent is to note the marking is not required for devices capable of meeting the 1 

% Acceptance and 2% Maintenance tolerance, then the language should clearly state 

this.

• OWM concurs that the markings need to be “conspicuously and legibly displayed.” Prior 

versions of similar language considered by the EVFE Subgroup also included the term 

“indelible” in recognition that the General Code requires all markings to be of a permanent 

nature. OWM recommends including the term “permanent” to align with the language used in 

the General Code.

• There are several dates referenced in proposed EVF-23.6 paragraph T.2.2. Tolerances that 

conflict and OWM believes will create confusion for those implementing the proposed 

requirements.

• The statement adopted by the NCWM in July 2022 exempting DC devices from any tolerance 

requirements until 2028 remains in the proposal, yet there is a date of 2024 in both the proposed 

paragraph T.2.2.(a) and paragraph T.2.2.(b) which specifies requirements for DC devices 

installed prior to 2024. This is confusing.

• Proposed paragraph T.2.2.(a) references a sunset date of 2034, yet there is still a statement 

referring to a 2028 date, creating a conflict. Additionally, the 2034 date is 6 years after the 2028 

date that was adopted by the NCWM in July 2022. The rationale for extending the sunset date 

is not clear. OWM also notes that a date of 2034 is eighteen years after the tentative code was 

first adopted by the NCWM.

• The rationale for the following statement in paragraph T.2.2.(b) is not clear and OWM believes 

this statement needs to be struck from the proposed new paragraph T.2.2.(b):
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OWM Executive Summary for EVF-23.6 – S.5.2. EVSE Identification and Marking Requirements., 

and T.2. Tolerances.

o “or that do not bear the notice specified in paragraph S.5.2.1. Marking of Accuracy 

Limits, DC EVSEs Installed Prior to 2024 tolerances are”

• Proposed accuracy markings need to be separate from the markings of electrical energy levels 

and required temperature ranges, therefore OWM agrees the “Notice” be included as a separate, 

new subparagraph S.5.2.1.

• As shared in its comments in Item EVF-23.5, OWM believes the proposed changes in Item EVF23.5 are much clearer in language, format, and application and are closer to language agreed to 

by the USNWG SG in June 2022 than are the proposed changes in Item EVF-23.6.

o The NIST USNWG EVFE Subgroup reached a consensus through a June 2022 ballot in 

which the group agreed to move forward to recommend a wider tolerance of 5 percent 

only for DC systems installed before 2024 that must bear accuracy markings while 

maintaining for AC systems a 1 percent Acceptance Tolerance/2 percent Maintenance 

Tolerance and the tighter tolerance would also apply to post 2024 DC systems.

o The language from the June 2022 ballot is included in OWM’s detailed analysis below 

and in Item EVF-23.5.

o As noted in its comments on Item EVF-23.5, OWM is aware of comments indicating 

EVF-23.5 may not meet the needs of all stakeholders as presently written and OWM 

believes additional changes would be needed to that item. However, the proposed 

changes in Item EVF-23.5 are much clearer in language, format, and application and are

closer to language previously agreed to by the USNWG SG in June 2022 than are the 

proposed changes in Item EVF-23.6.

• There are differences between the language recommended in that June 2022 SG ballot and that 

proposed in Item EVF-23.6. The language adopted in the June 2022 ballot:

o Permits DC devices installed before 2024 to have a wider tolerance if they were clearly 

marked to designate their accuracy.

o Includes a wider tolerance of 5 % for DC systems installed before 2024 when accuracy 

is marked, which several OEMs identified as achievable. Note: The SG’s language does 

not include an exemption for DC systems from accuracy tolerances up through 2028 to 

sunset in 2034.

o Acknowledges the less-than-ideal existence of dual tolerances in the marketplace would 

be addressed by marking systems to indicate when 5 percent is their achievable 

accuracy; and

o Recognizes the EVFE Subgroup would further refine the requirement’s text. 

• OWM is also aware of a Florida, Electrify America, Tesla, EVGo, and Siemens’ October 15, 

2022, letter sent to the S&T Committee regarding EVF-23.6 and a June balloted proposal of the 
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OWM Executive Summary for EVF-23.6 – S.5.2. EVSE Identification and Marking Requirements., 

and T.2. Tolerances.

USNWG EVFE Subgroup (SG). OWM submitted the following clarifications regarding this 

letter to the S&T Committee.

o NIST OWM, as convenors of the EVFE SG, sent a response to the Committee indicating 

that although the results of the Subgroup’s June 2022 ballot indicate the group’s support 

for modifications to tolerances and marking requirements this should not be construed 

as supporting the specific changes proposed in EVF-23.6.

o There are some key differences between the Subgroup’s June balloted proposal and 

EVF-23.6. Specifically, the Subgroup’s proposal does not include two different 

retroactive dates and differs in the magnitude of the tolerances and specific conditions 

under which they would apply, the permissible format required for markings (which are 

not indelible, do the submitters have a label or electronic only in mind?) and reference 

to certification. The convenors of the Subgroup will continue to provide written and 

verbal input as explicitly directed by the group. 

• Below are some additional comments for the Committee and other stakeholders to consider in 

reviewing Items EVF-23.5 and EVF-23.6.

• Adoption should occur only after fully vetting proposals to modify fundamental requirements 

such as those that impact accuracy, transparency, or that ensure fair competition to:

o avoid unforeseen consequences;

o ensure stakeholders have the tools needed for this new device application;

o discourage nonuniformity which can have a disruptive influence on the marketplace; 

and

o take corrective action on discovering any gaps/oversight in modifications to the sevenyear-old legal metrology requirements.

• NIST OWM encourages the community's participation in the USNWG EVFE Subgroup which 

began its work in 2012 and whose work resulted in NIST HB 44 3.40. EVFS Code's adoption in 

2015. The Subgroup is reviewing the four paragraphs that appear in multiple 2023 proposals 

that address: (1) dual EVSE tolerances (2.0 percent or 5.0 percent [DC EVSEs]); (2) new EVSE 

markings required for the wider tolerance in the marketplace; and (3) corresponding accuracy 

test procedures.

• The EVFE Subgroup last met on December 8, 2022, to address proposals under consideration 

for the 2023 cycle and will provide a clear statement in writing of its exact position on agenda 

items.
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Table 3. Summary of Recommendations

EVF-23.6 – S.5.2. EVSE Identification and Marking Requirements., and T.2. Tolerances.

V D W A I Notes* Comments

Submitter 

OWM

WWMA 

SWMA 

NEWMA 

CWMA 

NCWM

Letters of Support Letters of Opposition Notes

Industry  October 15, 2022 letter.

Manufacturers  October 15, 2022 letter.

OWM

Clarification on the June and 

December 2022 findings of 

the USNWG EVFE 

Subgroup.

Retailers and 

Consumers

Regulators  October 15, 2022 letter.

*Notes Key:

1 - Submitted modified language

2 - Item not discussed

3 - No meeting held

4 - Not submitted on agenda

5 - No recommendation or not considered

Item Under Consideration:

Amend Handbook 44, Electric Vehicle Fueling Systems as follows: 

S.5.2. EVSE Identification and Marking Requirements. – In addition to all the marking 

requirements of Section 1.10. General Code, paragraph G-S.1. Identification, each EVSE shall have the 

following information conspicuously, legibly, and indelibly marked:

(a) voltage rating;

(b) maximum current deliverable;

(c) type of current (AC or DC or, if capable of both, both shall be listed);

(d) minimum measured quantity (MMQ); and

(e) temperature limits, if narrower than and within – 40 °C to + 85 °C (40 °F to + 185 °F).
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S.5.2.1. Marking of Accuracy Limits, DC EVSEs Installed Prior to 2024. - A DC EVSE

installed prior to 2024 shall be marked with the following unless it is certified to the

tolerances of T.2.2(b): 

NOTICE:

“This charger operates at a tolerance of up to ± 5 percent versus other chargers which

operate at a tolerance of up to ± 2 percent.”

This marking shall be conspicuously and legibly displayed in a position plainly visible to a 

personaccessing a charging port of the EVSE.

(Added 202X) 

T.2. Test Tolerances

T.2.1. EVSE Load Accuracy Test Tolerances for AC Systems. – The tolerances for EVSE load 

tests for AC systems are:

(a) Acceptance Tolerance: 1.0 %; and

(b) Maintenance Tolerance: 2.0 %.

T.2.2. EVSE Load Accuracy Test Tolerances for DC Systems. -- The tolerances for EVSE 

load tests on DC systems shall be as follows:

(a) For DC systems installed prior to January 1, 2024, and that bear the notice

specified in paragraph S.5.2.1. Marking of Accuracy Limits, DC EVSEs Installed

Prior to 2024, acceptance and maintenance tolerances are: 5.0 %. This paragraph 

T.2.2(a) shall expire on January 1, 2034; after that date, all DC EVSEs shall be

subject to the tolerances of paragraph T.2.2(b). 

(b) For DC systems installed on or after January 1, 2024, or that do not bear the

notice specified in paragraph S.5.2.1. Marking of Accuracy Limits, DC EVSEs 

Installed Prior to 2024 tolerances are:

(1) Acceptance Tolerance: 1.0 %; and

(2) Maintenance Tolerance: 2.0 %. 

All DC EVSE are exempt from this requirement paragraph T.2.2 until January 1, 2028. 

NIST OWM Detailed Technical Analysis: 

The proposal outlined in agenda item EVF-23.6 is not exactly the same as an alternative proposal agreed to 

in a June 2022 ballot of the EVFE Subgroup. In the case of the EVFE Subgroup, the wider tolerance of 5

% for DC systems installed before 2024 was identified by several OEMs as achievable, and the less than 

ideal existence of dual tolerances in the marketplace would be addressed by marking the accuracy 

achievable by devices which met only the wider tolerance. Granted some refining of the requirement text 

would be necessary the group’s alternate proposal addressed many concerns expressed by both OEMs and 

regulators when the Subgroup’s discussions on this topic first began in 2020. 
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NIST OWM is aware of an October 15, 2022 letter from Florida and industry representatives from Electrify 

America, Tesla, EVGo, and Siemens sent to the NCWM S&T Committee. The co-authors of the letter 

summarized the EVF-23.6 proposal recommendations. The co-authors stated their beliefs about their 

comparison of EVF-23.6 to the Subgroup membership’s June 2022 balloted proposal and the subgroup’s 

position on EVF-23.6. On October 20th NIST OWM as convenors of the USNWG EVFE Subgroup sent to 

the NCWM S&T Committee a written response to the October 15th letter to clarify references made that 

imply the EVFE Subgroup’s approval or support of S&T Agenda Item EVF-23.6. Though the results of 

the Subgroup’s June 2022 ballot indicate the group’s support for modifications to tolerances and marking 

requirements this should not be construed as supporting the specific changes proposed in EVF-23.6. There 

are some key differences between the Subgroup’s June balloted proposal and EVF-23.6. Specifically, the 

Subgroup’s proposal does not include two different retroactive dates and differs in the magnitude of the 

tolerances and specific conditions under which they would apply, the permissible format required for 

markings, and reference to certification. The convenors also clarified that the Subgroup will provide written 

and verbal input as explicitly directed by the group (shown below under the subgroup heading). 

The proposal in EVF-23.6 to include a new paragraph T.2.2. to address DC systems tolerances as worded

permits a 5 percent tolerance for EVSEs installed pre- or post- 2024 on the condition this accuracy is 

declared in a “NOTICE”; however, if not bearing a notice then the expectation is that regardless of the 

installation date a DC system will still be permitted 5 percent accuracy. Device tolerances should not henge 

on the presence of a temporary label (i.e., the “Notice” for accuracy does not have to be indelible). 

Equipment has been permitted multiple accuracy classes; however, those devices bear an accuracy class 

marking permanently at all times and that determination is made during type evaluation of the device. In 

many device codes there is only a single accuracy class. 

Newly proposed subparagraph T.2.2.(a) specifies a 2034 sunset date for equipment with a 5 percent 

accuracy this is almost two decades after the EVFS Code was published and becomes the second 

enforcement date included in the tolerance specification. The DC tolerance requirement also includes a 

2028 enforcement date proposed in July 2022 and then adopted in July 2022 as part of a priority item. That 

2028 date appears as the current handbook edition as an applicable enforcement date in Agenda Item EVF23.6. This proposal attempts to address DC systems tolerances when they are exempt from handbook test 

tolerances until 2028. 

Agenda Item EVF-23.6 proposed new paragraph S.5.2.1., an accuracy marking requirement for DC systems 

installed before 2024, is not applicable if the EVSE is “certified.” Typically, references in the code to 

“certified” equipment are there to address requirements applicable to either test standards such as certified 

test weights or a reference scale, which are typically verified just prior to use and meet a performance level 

higher than that of the commercial device under test, or the device has undergone type evaluation and been 

issued a certificate. What would be the instructions for achieving this status given DC systems are not 

certified?

Moving forward with adoption before fully vetting proposals to modify fundamental requirements such as 

accuracy, transparency, or that ensure fair competition which are the foundation of every weighing and 

measuring device code can have unforeseen consequences. To delay or eliminate these basic guidelines 

(tools needed for this new device application) encourages nonuniformity (from state to state) which can be 

disruptive and impact the level of confidence in the marketplace. Proposals should be evaluated based on 

their impact on all stakeholders in the community. Time and again the community has moved to take 

corrective action on discovering an oversight that resulted from either the modification of existing or 

adoption of a new legal metrology requirement. 

NIST OWM encourages the community’s participation in the USNWG which began work in 2012 as a 

forum for stakeholders and other interested parties in establishing legal metrology standards (also the 
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weights and measures infrastructure) for electrical energy measurements. That effort resulted in NIST HB 

44 3.40 EVFS Code’s adoption in 2015. The four paragraphs that appear in multiple 2023 proposals address 

(1) dual EVSE tolerances (2.0 percent or 5.0 percent [DC EVSEs]); (2) new EVSE markings required for 

the wider tolerance in the marketplace (proposed new 5.0 percent accuracy for DC systems); and (3)

corresponding accuracy test procedures are part of the EVFE SG’s meeting discussions. The EVFE 

Subgroup’s work continues up through today having met October 6, 18, and December 8, 2022 to address 

proposals under consideration for the 2023 cycle. It should be noted that the EVFE SG has worked to 

further refine the code as more is learned about these systems and since January 2020 met 16 times to 

consider the proposals the group submitted to the S&T Committee as well as those developed or under 

development outside of its forum to provide the group’s input. The EVFE SG will provide a clear statement 

of its exact position on agenda proposals when it reaches a consensus and provides this information in 

writing (as shown below). The EVFE SG reached a consensus in July 2022 which the group agreed to 

move forward to recommend a wider tolerance of 5 percent only for DC systems installed before 2024 that 

must bear accuracy markings while maintaining for AC systems a 1 percent Acceptance Tolerance/2 

percent Maintenance Tolerance and the tighter tolerance would also apply to post 2024 DC systems. 

U.S. National Work Group’s Electric Vehicle Fueling Equipment Subgroup (EVFE SG)

• The SG agreed to forward the results of its June 2022 ballot (in which it proposed changes to the 

tolerances and the addition of marking requirements) to the S&T Committee and recommend the 

Committee consider these recommendations as it considers Items EVF-23.5 and EVF-23.6. 

• In a June 2022 ballot, the SG agreed to recommend the following changes to the tolerances and 

marking requirements in Section 3.40. The SG asks that the Committee consider the SG’s 

recommendations presented below as it deliberates on S&T Agenda Items EVF-23.5 and EVF-23.6 

which include proposed changes to these same handbook code paragraphs. The changes agreed to 

by the SG in its June 2022 ballot are shown below.

o Additionally, some device users on the SG indicated that there remains a desire to recognize 

and then maintain a 5% tolerance for DC legacy (i.e., installed prior to 2024) equipment. 

T.2. Load Accuracy Test Tolerances.

T.2.1. EVSE Load Accuracy Test Tolerances for AC Systems. – The tolerances for 

EVSE load tests for AC systems areshall be as follows: 

(a) Acceptance Tolerance: 1.0 %; and 

(b) Maintenance Tolerance: 2.0 %.

(Amended 202X) 

T.2.2. EVSE Accuracy Test Tolerances for DC Systems. – The tolerances for 

EVSE load tests on DC systems shall be as follows:

(a) For DC systems installed prior to 2024 and that bear the notice specified in 

paragraph S.5.2.1. Marking of Accuracy Limits, DC EVSEs Installed Prior to 

2024, acceptance and maintenance tolerances are: 5.0 %. 
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(b) For DC systems installed on or after January 1, 2024 or that do not bear the 

notice specified in paragraph S.5.2.1. Marking of Accuracy Limits, DC 

EVSEs Installed Prior to 2024 tolerances are:

(1) Acceptance Tolerance: 1.0 %; and 

(2) Maintenance Tolerance: 2.0 %. 

(Added 202X)

S.5.2. EVSE Identification and Marking Requirements. – In addition to all the 

marking requirements of Section 1.10. General Code, paragraph G-S.1. Identification, each 

EVSE shall have the following information conspicuously, legibly, and indelibly marked:

(a) voltage rating;

(b) maximum current deliverable;

(c) type of current (AC or DC or, if capable of both, both shall be listed); 

(d) minimum measured quantity (MMQ); and

(e) temperature limits, if narrower than and within – 40 °C to + 85 °C (− 40 °F to + 

185 °F). 

S.5.2.1. Marking of Accuracy Limits, DC EVSEs Installed Prior to 2024. - DC 

EVSEs installed prior to 2024 shall be marked with the following:

NOTICE:

“This charger operates at a tolerance of +/- 5 percent versus newer chargers 

which operate at a maximum tolerance of +/- 2 percent.”

This marking shall be conspicuously, legibly, and indelibly marked, in a 

position plainly visible to a person accessing a charging port of the EVSE. 

This marking requirement does not apply to DC EVSEs that are capable of 

meeting an acceptance tolerance of 1 % and a maintenance tolerance of 2 %. 

(Added 202X)

(Amended 2021) 

Summary of Discussions and Actions:

A letter dated October 15, 2022 from the State Weights and Measures Director of Florida and industry 

representatives from Electrify America, Tesla, EVGo, and Siemens was sent to the NCWM S&T 

Committee. The co-authors of the letter summarized the EVF-23.6 proposal recommendation for a 5

percent tolerance for DC systems installed before 2024 when so marked, if installed after 2024 or lacking 

the 5 percent DC systems are subject to 1 percent/2 percent tolerance. The co-authors noted the October 
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4th announcement by NIST of a general consensus on a June 2022 balloted proposal of the USNWG EVFE 

Subgroup (attached to the co-authors October 15th letter). The co-authors response to the Subgroup member 

opposing the June 2022 proposal was to include a new 2034 expiration on the 5 percent tolerance as part of 

the proposal in item EVF-23.6. The co-authors stated their beliefs about their comparison of EVF-23.6 to 

the Subgroup membership’s June 2022 balloted proposal and the subgroup’s position on EVF-23.6.

A letter dated October 20, 2022 from the NIST OWM as convenors of the USNWG EVFE Subgroup was 

sent to the NCWM S&T Committee in response to an October 15th letter co-authored by Florida, Electrify 

America, Tesla, EVGo, and Siemens. The letter was sent to clarify references made in the October 15th

letter that imply the EVFE Subgroup’s approval or support of S&T Agenda Item EVF-23.6. Though the 

results of the Subgroup’s June 2022 ballot indicate the group’s support for modifications to tolerances and 

marking requirements this should not be construed as supporting the specific changes proposed in EVF23.6. There are some key differences between the Subgroup’s June balloted proposal and EVF-23.6. 

Specifically, the Subgroup’s proposal does not include two different retroactive dates and differs in the 

magnitude of the tolerances and specific conditions under which they would apply, the permissible format 

required for markings, and reference to certification. The convenors of the Subgroup will continue to 

provide written and verbal input as explicitly directed by the group. 

NOTE: The EVFE Subgroup met on December 8, 2022, input based on the group’s discussions of S&T 

Item EVF-23.6 are provided above in the section of this analysis under the heading U.S. National Work 

Group’s Electric Vehicle Fueling Equipment Subgroup (EVFE SG).

Regional Association Reporting:

Central Weights and Measures Association

Ms. Scheleese Goudy (Electrify America): DC EVSE installed before 2024 will have 5 % accuracy until 

2034. When the tentative code was written in 2015, historical data for AC measurements were readily 

available. DC metering technology was still in R&D. Tolerances could not be formulated. Legacy devices 

could reasonably meet 5 %, but not 1%/2 %. This could require complete replacement of many legacy 

devices.

Ms. Francesca Wahl (Tesla): Rework of two above. Does not modify the 2028 date but provides a pathway 

forward. This proposal represents informal consensus of the NIST USNWG.

Mr. Craig VanBuren (Michigan): Move forward as Voting. Possible change: P 244, line 39. which “may” 

operate.

The CWMA S&T Committee believes this item is fully developed and recommend Voting status with the 

following changes:

S.5.2. EVSE Identification and Marking Requirements. – In addition to all the marking 

requirements of Section 1.10. General Code, paragraph G-S.1. Identification, each EVSE shall have the 

following information conspicuously, legibly, and indelibly marked:

(a) voltage rating;

(b) maximum current deliverable;

(c) type of current (AC or DC or, if capable of both, both shall be listed);
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(d) minimum measured quantity (MMQ); and

(e) temperature limits, if narrower than and within – 40 C to + 85 C ( 40 F to + 185 F). 

S.5.2.1. Marking of Accuracy Limits, DC EVSEs Installed Prior to 2024. - A DC EVSE 

installed prior to 2024 shall be marked with the following unless it is certified to the tolerances 

of T.2.2(b): 

NOTICE:

“This charger operates at a tolerance of up to ± 5 percent versus other chargers which may 

operate at a tolerance of up to ± 2 percent.”

This marking shall be conspicuously and legibly displayed in a position plainly visible to a 

person accessing a charging port of the EVSE.

(Added 202X)

T.2. Test Tolerances.

T.2.1. EVSE Load Accuracy Test Tolerances for AC Systems. – The tolerances for EVSE load 

tests for AC systems are:

(a) Acceptance Tolerance: 1.0 %; and

(b) Maintenance Tolerance: 2.0 %.

T.2.2. EVSE Load Accuracy Test Tolerances for DC Systems. -- The tolerances for EVSE load 

tests on DC systems shall be as follows:

(a) For DC systems installed prior to January 1, 2024, and that bear the notice specified in 

paragraph S.5.2.1. Marking of Accuracy Limits, DC EVSEs Installed Prior to 2024,

acceptance and maintenance tolerances are: 5.0 %. This paragraph T.2.2(a) shall expire 

on January 1, 2034; after that date, all DC EVSEs shall be subject to the tolerances of 

paragraph T.2.2(b). 

(b) For DC systems installed on or after January 1, 2024, or that do not bear the notice 

specified in paragraph S.5.2.1. Marking of Accuracy Limits, DC EVSEs Installed Prior

to 2024 tolerances are:

(1) Acceptance Tolerance: 1.0 %; and

(2) Maintenance Tolerance: 2.0 %. 

All DC EVSE are exempt from this requirement paragraph T.2.2 until January 1, 2028.

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting the following comments were received: 

Ms. Scheleese Goudy (Electrify America): Ms. Goudy commented on the metering technology for DC 

chargers are now becoming available as technology develops. Ms. Goudy proposed previously installed 
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devices will not be able to meet the 1 and 2% tolerances. Ms. Goudy commented the tolerances are being 

developed with separate tolerances for legacy devices that can’t meet the proposed requirements. Ms. 

Goudy stated there was a vote of 11-1 in favor of the item in the assigned work group. The 1 no vote said 

that it would have been a yes if there was a 10-year sunset. Ms. Goudy stated the changes to the item 

incorporated the change to include a 10-year sunset of legacy devices. Ms. Goudy commented devices 

would be marked for the public and inspectors with the required tolerances. Ms. Goudy recommended 

Voting status.

Mr. Kevin Schnepp (California Division of Measurement Standards) commented this was discussed in the 

national workgroup. Mr. Schnepp recommended that a task group be assigned to verify which items were 

in a consensus and which were not. Mr. Schnepp proposed a hard stop date for legacy devices is necessary 

and that there isn’t one with the current language. Mr. Schnepp commented on his disagreement with the 

"or" statement in the current language.

Ms. Francesca Wahl (TESLA) commented TESLA agrees with the comments made by Electrify America. 

Ms. Wahl commented the language is to include a hard stop date of legacy devices supports the removal of 

“or” from the language.

Mr. Chris King (Siemens) commented Siemens agrees with TESLA’s comments.

During open hearings, comments were heard that contents in this item were previously discussed in the 

USNWG, but no official position has been taken by the USNWG. There were also comments during open 

hearing taking the position the item is not fully developed. The WWMA S&T Committee recommended

the submitters work with the USNWG to develop one proposal by combining language from EVF -23.5.

The WWMA S&T Committee recommended that this item be blocked with item EVF-23.5. The WWMA 

S&T Committee recommended the new blocked items be assigned a Developing status.

Southern Weights and Measures Association

The following comments were received during the 2022 SWMA Annual Meeting:

Mr. Prince (Florida) spoke in favor of this item being a satisfactory compromise.

Mr. Floyd (Louisiana) stated that he would rather not have devices with warning labels for accuracy.

Ms. Goudy (Electrify America) the submitter of this item, recommended this move forward as a Voting 

Item.

Mr. Stokes (South Carolina) stated that he supported the use of warning labels for these devices and 

supported this item.

The SWMA S&T Committee recommended this item move forward as a Voting Item.

Northeastern Weights and Measures Association

Mr. Keith Bradley (Electrify America) recognizes that when the code was originally adopted there was 

questions about DC meters being able to meet a 1% and 2% tolerance. This item is to make sure devices 

are properly marked for the consumer as installed before 2024 and 5% tolerance. If devices are not marked 

this way, the 1% and 2% tolerances would apply. Installed devices would have the larger tolerance until 

2034, then revert. Ms. Francesca Wahl (Tesla) recommends Voting status. Ms. Juana Williams (NIST
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OWM) noted that there is a letter from NIST to indicate that a status update on this item is forthcoming and 

has info to address marking and tolerances for DC systems. In a June meeting by the EVSE Subgroup, 

there was no 2028 retroactive date being considered and the proposal they reviewed included different sets 

of tolerances and marking requirements based on install date. Mr. Jason Flint (New Jersey) requested that 

this item be given a Developing status as there is too much debate and too many questions. Mr. Flint 

suggested that the submitters of EVF-23.5 and EVF-23.6 work together to develop further.

After hearing comments from the floor, the Committee believes the item is not fully developed and several 

questions need to be answered. The Committee is recommending that this item be given a Developing 

status.

EVF-23.7 N.1. No Load Test, N.2. Starting Load Test, N.5.2. Accuracy Testing, and 

Appendix D: maximum deliverable amperes

Source: Electrify America

Submitter’s Purpose and Justification:

The proposal would have the testing conducted at the contemplated 10%. Because it is unlikely that tests 

would actually be at precisely 10%, the proposal would allow testing in a small range slightly above 10%. 

The accuracy tests in section 3.40 contemplate testing an EV charger at two points, one at relatively low 

current and power, and the other at relatively high current and power. The low point was evidently intended 

to be at 10% of a charger’s maximum current. It is likely that charger manufacturers have designed chargers 

with that 10% in mind as the “low” point of accuracy tests. But the code does not actually state that testing 

should be at 10%. It says testing can be at a current less than 10%. This formulation is problematic because 

it encompasses any current less than 10%. Zero is less than 10%, and 0.1 A is less than 10% even though 

it is less than the amount at which the code requires a charger to first register a load. Even currents larger 

than these, but less than 10%, would be unnecessarily difficult for an accuracy test. The problem is that 

low currents are an area where accuracy is particularly difficult. For example, one common metering 

configuration is to measure the current being delivered by means of a shunt resistor, which generates a 

voltage from the high current passing through it. These resistors necessarily have very low resistances 

because they are necessarily dissipating power in accordance with the resistance. A typical resistor in an 

EV charger metering setup might be 100 micro-ohms. For a 500 amps full-scale current in a DC charger, 

that resistor would be dissipating 25 watts of power - thus, a much larger resistor is not a practical option. 

At, say, 10 amps of delivered current, the voltage generated across the resistor would be 1 millivolt. A 1% 

measurement of that 1 millivolt would be 10 microvolts. At that level, a range of noise sources become 

quite significant, such as thermal EMF in the resistor itself and induced EMFs from the presence within the 

charger cabinet of voltages up to 480 volts ac or 950 volts dc, as well as any offsets or noise in the circuitry 

measuring the transduced voltage. The net result is that it is very challenging to achieve high accuracy at 

low currents in a device designed to handle and measure high currents. For reasons like these, the draft 

international (OIML) standard specifies that an accuracy test should be conducted at a given minimum 

current, rather than (like current Handbook 44) at any current up to that minimum. 

Meanwhile, low currents are the levels least significant for transactional accuracy. At low current, a charger 

is delivering energy at a relatively low rate. As a practical matter, an EV will charge at the maximum rate 

possible in the circumstances. As the battery reaches a higher state of charge, it will draw less power from 

the EV, but only a small proportion of the overall energy will be delivered at low rates, precisely because 

the rates are low. Suppose as a simplified example, an EV charges for 30 minutes at 300 amps and 30 

minutes at 15 amps (at a voltage of 400 volts). The EV will have received 60 kWh in the first part of the 
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session, and only 3 kWh in the second part. The low-current period of charging contributes relatively little 

to the accuracy/inaccuracy of the overall transaction. 

Thus, it is important for Handbook 44 to set a minimum current for accuracy tests. Because the point of 

10% of the maximum deliverable amperes is already in the code and has probably been used as a design 

basis for chargers, the proposal would keep that as the low-current point. The overall concept would be for 

testing to occur at 10% of maximum deliverable amperes, rather than at up to 10%. But it is impractical to 

specify a single point. An inspection that does not achieve a test at precisely the 10% should not, as a 

consequence, be an invalid inspection. To make this practical, the proposal would have the low-end test 

occur in a range of currents, namely 10% to 20% of the charger’s maximum. 

The code presents a similar problem for DC chargers tested using EVs as loads. The code allows an EV to 

be used as the load, rather than using a controlled load that draws the loads specified in the code. But the 

code provides no specifications about how to use an EV in this sort of test. So, it is possible that a tester 

could use an EV that is, say, at 95% state of charge in the battery, and that would arrive at the charger and 

draw very low levels of current (sometimes called a “trickle charge”). For the reasons discussed above, 

that sort of test would not be a productive test of the meaningful accuracy of the charger. The code should 

set a minimum current for an EV-based test to be usable. The proposal would have that minimum be 30% 

of the charger’s maximum. It is set at more than 10% because the EV-based test uses a single test point, 

which should therefore be somewhere in the middle of the charger’s range. 

The proposal would also add a definition of “maximum deliverable amperes.” This quantity is the same as 

used in the existing code as the basis for the 10% figure, but it is not currently defined. The definition 

would state that maximum deliverable amperes means the amount marked on the charger. (The code 

already requires that amount to be marked.) This amount might be less than the manufacturer’s 

specification for the potential maximum of the device, if for example the installation limits the charger to a 

particular amount, or the installer has selected a configuration with a lower maximum. But the maximum 

deliverable amount is a quantity that is fixed at installation and marked on the charger. The current code 

suggests that maximum deliverable amperes is the amount that the charger communicates to a vehicle or 

test apparatus. That approach is confusingly ambiguous, because the charger might for various reasons 

sometimes communicate a lower available current than its marked maximum. The proposal clarifies that 

for accuracy tests based on a percentage of maximum current, the “maximum” being used is the maximum 

marked on the device.

These concepts have been discussed in the U.S. National Work Group’s subgroup on EV charging. There 

is general consensus in favor of the proposal, but there has not been a quorum to vote formally in favor of 

it. 

Finally, the proposal would eliminate the no-load and starting-load tests. These tests take unnecessary time, 

because an inspector has to wait to verify that a load of zero genuinely produces no response and a starting 

load of just 0.5 amps produces a response. Meanwhile, these tests are not meaningful for the transactional 

accuracy of an EV charger. In the process of establishing a handshake that the EV charger is connected to 

a vehicle, the charger might provide minute test amounts of current, so that a truly zero load is not pertinent 

to any real transaction; and these minute test currents may well e above 0.5 amps, so that this threshold is 

also not pertinent to transactions. It would be possible to verify that a charger does not register an energy 

delivery when no transaction is started, but that test would be redundant of verifying that the charger starts 

at zero. Meanwhile, 0.001 kWh (the minimum resolution under Handbook 44) corresponds to roughly 3 to 

5 hundredths of a cent, so that verifying the registration of such tiny amounts given a tiny current is not 

helpful for the overall transactional accuracy.
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The submitter is not aware of objections that would be raised to this proposal. The concept is consistent 

with the discussions at the U.S. National Work Group based on information from testing over the past six 

years, and input from regulators and industry.

The submitter requested that this be a Voting Item in 2023.

OWM Executive Summary for EVF-23.7 – N.1. No Load Test, N.2. Starting Load Test N.5.2. 

Accuracy Testing, and Appendix D: maximum deliverable amperes

OWM Recommendation:

• Test procedures are not solely written to the operational characteristics or particular design of one 

test apparatus. Test procedures should encompass operational conditions over the course of the 

entire transactions in the marketplace. Test points should fall within the rated minimum up through 

the maximum operational ranges specified by the manufacturer for the EVFS under normal 

conditions of commercial use. 

• Observe this proposal removes any reference to the feature used to determine the MDA percentage 

level achieved during accuracy tests and establishes a new MDA range for performing the light load 

test and when a vehicle is the test load for verifying EVFSs; whereas other proposals recommend 

the establishment of a new laboratory test in addition to field test procedures.

• The EVFS test standard must be fit for purpose or appropriate and suitable (this might be 

demonstrated by data) in its design, capacity, and accuracy; and would allow for replication of the 

manner in which the EVSE is used in commerce. The test standard used to verify an EVSE must 

also meet the NIST HB 44 Appendix A Fundamental Considerations for a test apparatus. 

• Therefore, with a decade of experience with EVFSs having gone through type evaluation (i.e., 

CADMS) and test equipment designed to verify both AC and DC systems and the laboratory 

community closing in on filling the last gaps in the weights and measures infrastructure for EVFSs; 

it is important and necessary that all stakeholders (EVSE/test equipment manufacturers, type 

examiners, and regulators) reach a consensus on test procedures. 

• Is this a proposal to renumber paragraph N.5. Accuracy Testing to become N.5.2.1.? The proposal 

does not show paragraph N.5.2 in entirety, is the submitter proposing to remove the 2028 

enforcement date? 

• For clarity the “meaning portion” of a definition should not include the term or parts of the term it 

is defining nor cite one of the many code paragraphs where the term is used because the appearance 

can be the term is unique to that sole paragraph. Therefore, the term’s definition should include 

reference to the EVFS Code in brackets (i.e., [3.40] at the end of the definition rather cite a single 

code requirement or paragraph. The EVFS is a permanent code and definitions applicable to the 

code should be included in Appendix D—Definitions. 

• The proposal removes the No Load Test and Starting Load Test but does not do the same for the 

tolerances applicable to these tests in paragraphs T.5. and T.6, respectively. 
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Table 3. Summary of Recommendations

EVF-23.7 – N.1. No Load Test, N.2. Starting Load Test, N.5.2. Accuracy Testing, and Appendix D: 

maximum deliverable amperes

V D W A I Notes* Comments

Submitter 

OWM Work necessary to refine tests.

WWMA  Block with Item EVF-23.4.

SWMA 

NEWMA 

CWMA 

NCWM

Letters of Support Letters of Opposition Notes

Industry

Manufacturers

Retailers and 

Consumers

Regulators

*Notes Key:

1 - Submitted modified language

2 - Item not discussed

3 - No meeting held

4 - Not submitted on agenda

5 - No recommendation or not considered

Item Under Consideration:

Amend Handbook 44 Electric Vehicle Fueling Systems Code as follows: 

N.1. No Load Test.– A no load test may be conducted on an EVSE measuring system by applying

rated voltage tothe system under test and no load applied.

N.2. Starting Load Test. – A system starting load test may be conducted by applying rated

voltage and 0.5-ampereload.

... 

N.5.2.1. Accuracy Testing. – The testing methodology compares the total energy delivered in a 

transaction and the total cost charged as displayed/reported by the EVSE with that measured by the

measurement standard. 

(a) For AC systems:

(1) Accuracy test of the EVSE system at a load of not less than 85 % of the maximum 

deliverable amperes (expressed as MDA) as determined from the pilot signal for a 
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total energy delivered of at least twice the minimum measured quantity (MMQ). If the 

MDA would result in maximum deliverable power of greater than 7.2 kW, then the test 

may be performed at 7.2 kW.

(2) Accuracy test of the EVSE system at a load of not greater thanbetween 10 % and 

20%of the maximum deliverable amperes (expressed as MDA) as determined from 

the pilot signal for a total energy delivered of at least the minimum measured quantity 

(MMQ).

(b) For DC systems (see note): 

(1) Accuracy test of the EVSE system at a load of not less than 85 % of the maximum 

deliverable amperes current (expressed as MDA) as determined from the digital 

communication message fromthe DC EVSE to the test standard for a total energy

delivered of at least twice the minimum measured quantity (MMQ). 

(2) Accuracy test of the EVSE system at a load of not more than 10 % and 20% of the 

maximum deliverable amperes (expressed as MDA) as determined from the digital 

communication message from the DCEVSE to the test standard for a total energy 

delivered of at least the minimum measured quantity (MMQ).

Note: For DC systems it is anticipated that an electric vehicle may be used as the test load. Under that circumstance, 

testing at the load presented by the vehicle shall be sufficient provided that it is greater than 30% of the maximum

deliverable amperes of the EVSE system. 

And

Appendix D:

maximum deliverable amperes. - The value in amperes, marked on an EVSE pursuant to paragraph 

S.5.2. EVSE Identification and Marking Requirements, of the maximum current that the EVSE can

provide. 

NIST OWM Detailed Technical Analysis: 

There are other proposals on the S&T Committee agenda to modify the minimum light load and full load 

test procedures for AC and DC systems addressed in paragraph N.5.2. Accuracy Testing under 

consideration in the 2023 cycle. One reoccurring recommendation is for a separate new set of test 

procedures for type evaluation performed under laboratory conditions that did not previously exist and 

would be a substantive change to the 2023 edition of the HB 44. However, this proposal removes any 

reference to the feature used to determine the MDA percentage level achieved during accuracy tests and 

establishes a new MDA range for performing the light load test and when a vehicle is the test load for 

verifying EVFSs.

Test procedures are not solely written to the operational characteristics or particular design of one test 

apparatus. Test procedures should encompass operational conditions over the course of the entire 

transactions in the marketplace. Test points should fall within the rated minimum up through the maximum 

operational ranges specified by the manufacturer for the EVFS under normal conditions of commercial use. 

The USNWG developed the handbook AC and DC systems’ light load test and full load test procedures in 

part because they appeared to be the most likely conditions under which equipment would be used during 
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a charging session and based on existing test procedures and knowledge about watt-hour type electric 

meters. Watthour type electric meters were the only electrical energy device regulated by a U.S. weights 

and measures in the 2012 timeframe. For each gap in the EVSE infrastructure there have been stakeholders 

indicating a solution is possible. The community was advised to wait for completion of performance criteria 

for DC meters which became available in March 2021 in ANSI C 12.32-2021 American National Standard 

for Electricity Meters for the Measurement of DC Energy and would be an important reference document 

for DC type electricity metering in EVFSs. Therefore, with a decade of experience with EVFSs having 

gone through type evaluation (i.e., CADMS) and test equipment designed to verify both AC and DC 

systems and the laboratory community closing in on filling the last gaps in the weights and measures 

infrastructure for EVFSs it is important and necessary that all stakeholders (EVSE/test equipment 

manufacturers, type examiners, and regulators) reach a consensus on test procedures. 

The EVFS test standard must be fit for purpose or appropriate and suitable (this might be demonstrated by 

data) in its design, capacity, and accuracy; and would allow for replication of the manner in which the 

EVSE is used in commerce. The test standard used to verify an EVSE must also meet the NIST HB 44 

Appendix A Fundamental Considerations for a test apparatus. 

The term “maximum deliverable amperes” or abbreviated as “MDA” would be defined as “the highest 

current value or highest level of current or highest total current capacity at which the manufacturer has 

designed the EVFS to operate and meet accuracy.” Note: choose one of the three lead statements as the 

most appropriate description of the current level in the beginning of this alternative new definition. The 

current level at the installation site and for test equipment shall be suitable for the MDA rating of the EVFS. 

The term “maximum deliverable amperes” is cited in multiple requirements in the EVFS Code and is 

relevant to test conditions and is also required marking information on the EVFS. For clarity the “meaning 

portion” of a definition should not include the term or parts of the term it is defining nor cite one of the 

many code paragraphs where the term is used because the appearance can be the term is unique to that sole 

paragraph. Therefore, the term’s definition should include reference to the EVFS Code in brackets (i.e., 

[3.40] at the end of the definition rather cite a single code requirement or paragraph. The EVFS is a 

permanent code and definitions applicable to the code should be included in Appendix D—Definitions. 

Is this a proposal to renumber paragraph N.5. Accuracy Testing to become N.5.2.1.? The proposal does 

not show paragraph N.5.2 in entirety, is the submitter proposing to remove the 2028 enforcement date? 

Regional Association Reporting:

Central Weights and Measures Association

Ms. Scheleese Goudy (Electrify America) remarked that the low end test was meant to be at 10% but as 

written would allow anything less than 10 %. Less than 10 % is unnecessarily difficult. Little energy will 

be delivered at these low rates. Greater inaccuracies below 10 %. Move forward as voting. Note the 

change on N.5.2.1.(b)(2) to “between 10 % and 20%”. 

Ms. Francesca Wahl (Tesla) recommended this move forward as voting.

Mr. Loren Minich (Kansas) stated that page 252 Line 10, remove the “of” before the range.

Mr. Craig VanBuren (Michigan) agreed and remarked this isrReady for voting with recommended changes.

The CWMA S&T Committee believes this item is fully developed and recommended Voting status with 

the following changes:
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N.1. No Load Test. – A no load test may be conducted on an EVSE measuring system by 

applying rated voltage to the system under test and no load applied.

N.2. Starting Load Test. – A system starting load test may be conducted by applying rated 

voltage and 0.5-ampere load.

N.5.2.1. Accuracy Testing. – The testing methodology compares the total energy delivered in a 

transaction and the total cost charged as displayed/reported by the EVSE with that measured by the

measurement standard.

(a) For AC systems:

(1) Accuracy test of the EVSE system at a load of not less than 85 % of the maximum

deliverable amperes (expressed as MDA) as determined from the pilot signal for a 

total energy delivered of at least twice the minimum measured quantity (MMQ). If the 

MDA would result in maximum deliverable power of greater than 7.2 kW, then the 

test may be performed at 7.2 kW. 

(2) Accuracy test of the EVSE system at a load of not greater than between 10 % and 

20% of the maximum deliverable amperes (expressed as MDA) as determined from 

the pilot signal for a total energy delivered of at least the minimum measured quantity 

(MMQ).

(b) For DC systems (see note):

(1) Accuracy test of the EVSE system at a load of not less than 85 % of the maximum 

deliverable amperes current (expressed as MDA) as determined from the digital 

communication message from the DC EVSE to the test standard for a total energy

delivered of at least twice the minimum measured quantity (MMQ). 

(2) Accuracy test of the EVSE system at a load of not more than between 10 % and 20%

and 20 % of the maximum deliverable amperes (expressed as MDA) as determined 

from the digital communication message from the DC EVSE to the test standard

for a total energy delivered of at least the minimum measured quantity (MMQ).

Note: For DC systems it is anticipated that an electric vehicle may be used as the test load. 

Under that circumstance, testing at the load presented by the vehicle shall be sufficient 

provided that it is greater than 30% of the maximum deliverable amperes of the EVSE 

system. 

And

Appendix D:

maximum deliverable amperes. - The value in amperes, marked on an EVSE pursuant to paragraph 

S.5.2. EVSE Identification and Marking Requirements, of the maximum current that the EVSE can 

provide.

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting the following comments were received: 
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Ms. Scheleese Goudy (Electrify America) commented the item is written to allow testing at any current and 

the rate to charge is very low compared to the 10% accuracy. Ms. Goudy commented these tests make 

inspectors wait and are not meaningful for the accuracy of an EV charger. Ms. Goudy commented there 

was a broad consensus at the USNWG but no official vote was taken by the Work Group. Ms. Goudy 

recommended a Voting status.

Mr. King commented Siemens targets a 10% accuracy test. Mr. King commented Siemens is in favor of 

the change.

Ms. Wahl second the comments by Electrify America and Siemens. Ms. Wahl recommended a Voting 

status.

Mr. Kevin Schnepp (California Division of Measurement Standards commented in full support of 

recommendations to strike the no load and starting load tests. Mr. Schnepp commented he doesn’t think 

there is consensus from the Work Group. Mr. Schnepp recommended that this item be discussed with the 

U.S. National Working Group to make sure that it is highly agreed upon. Mr. Schnepp proposed if two 

vehicles are charging at once it cuts the 10% in half. Mr. Schnepp commented in favor the range between 

10 and 20%. Mr. Schnepp recommended a Developing status.

During open hearings, comments were heard that contents in this item were previously discussed in the 

USNWG, but no official position has been taken by the USNWG. There were also comments during open 

hearing taking the position the item is not fully developed. The WWMA S&T Committee recommended

the submitters work with the USNWG to develop one proposal by combining language from EVF-23.4.

The WWMA S&T Committee recommended that this item be blocked with item EVF-23.4. The WWMA 

S&T Committee recommended the new blocked items be assigned a Developing status.

Southern Weights and Measures Association

The following comments were received during the 2022 SWMA Annual Meeting:

Mr. Prince (Florida) supports this as a Voting Item.

Ms. Goudy (Electrify America) recommended this item move forward as a Voting Item.

The SWMA S&T Committee recommended this item move forward as a Voting Item.

Northeastern Weights and Measures Association

Mr. Keith Bradley (Electrify America) stated that the core problem is testing at low currents. Mr. Bradley 

believes that “10%-20%” is better than “up to 10%” as no currently installed charger will be able to do less 

than 10%. Currently, the HB doesn’t qualify what the test procedure is for testing device using an EV. Ms. 

Juana Williams (NIST OWM) indicated that the removal of “no load test” and “starting load test” is 

consistent with other proposals viewed by the EVFE Subgroup. Ms. Williams also questioned how an 

inspector will know they reached 10% and 85% if there is no pilot signal or information coming from digital 

communications with the system. Ms. Williams also noted that a definition being tied to marking 

requirement is not typically done. Mr. Keith Bradley (Electrify America) explained that an inspector would 

know max deliverable amps as it should be marked on the device, know the current as displayed by the 

testing apparatus, then compare. Mr. Jason Flint (New Jersey) recommended that the item be Developing.
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After hearing comments from the floor, the Committee believes the item has merit. The Committee is

recommending a Developing status. 

GMA – Grain Moisture Meters 5.56 (A)

GMA-19.1 D Table T.2.1. Acceptance and Maintenance Tolerances Air Oven Method 

for All Grains and Oil Seeds.

Source: NTEP Grain Analyzer Sector

Submitter’s Purpose and Justification:

Reduce the tolerances for the air oven reference method.

This item has been assigned to the submitter for further development. For more information or to provide 

comment, please contact:

Mr. Karl Cunningham 

Illinois Department of Agriculture

217-785-8301, karl.cunningham@illinois.gov 

AMS, FGIS request samples and list of grains from states to include in their ongoing calibration program. 

States and other interested parties wanted to verify that corn samples from their state were included in the 

calibration data for NTEP meters because of variations states reported between UGMA meter and other 

meter technologies on corn samples.

During the 2016 Grain Analyzer Sector Meeting, numerous instances of inconsistent moisture meter 

measurements involving grain shipments from U.S. interior facilities to U.S. export port facilities were 

reported. The Sector received a suggestion that if the UGMA can make better measurements, then the 

Sector should consider reducing the applicable tolerances in HB 44. At the 2016 and 2017 Grain Analyzer 

Sector meetings Mr. Charlie Hurburgh (Iowa State University) agreed to chair a GA Sector Task Group to 

review the current HB 44 tolerance with both UGMA meters and Non-UGMA meters. During the 2018 

meeting Mr. Hurburgh reported that based on data he analyzed from Iowa State Weights and Measures 

Grain Inspection reports, UGMA meters read closer to the reference air oven moisture results than nonUGMA meters.

It was also noted during the 2018 NTEP Grain Analyzer Sector meeting that the current tolerances were 

developed in 1991 and have not been changed to coincide with the change in technology for these devices; 

and this action is needed for grain industry risk management.

Prior to the 2019 NCWM Interim Meeting, all four regional weights and measures associations agreed to 

forward the proposal as a voting item on the Interim Agenda. However, following the regional meetings, 

additional data was submitted to the Sector which indicates a need to consider developing different 

tolerance for some grain types. Through a subsequent ballot, and a majority vote, the Sector agreed to 

recommend changing the status of the item to developing to provide the Sector time to consider additional 

data and changes to its original proposal. 
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OWM Executive Summary for GMA-19.1 – Table T.2.1. Acceptance and Maintenance Tolerances 

Air Oven Method for All Grains and Oil Seeds.

OWM Recommendation: NIST OWM supports the collection of data to verify that the proposed 

reduction in tolerances is appropriate for all grains. 

• During the NTEP Grain Analyzer (GA) Sector 2019 meeting, the Sector reviewed data from Arkansas 

for Long Grain Rough Rice (LGRR) and other grains. The data showed that the proposal to tighten 

the acceptance and maintenance tolerance may not be appropriate for all grain types. The original 

data presented and used as a basis for the proposal applied to corn and soybeans. After reviewing the 

data, the Sector decided to collect inspection data from across the country. An industry representative 

offered to assist with data analysis and along with the NIST representative will work in producing 

the inspection data needed for the analysis. A request for State participation will be sent to State 

weight and measures. The Sector requests that this remain a Developing Item as they move forward 

in evaluating additional data. 

• North Carolina submitted the requested grain data for review. Field meter inspection data from the 

state of North Carolina for years 2017 to 2019 was examined and comprised over 3300 records each 

usually averaged 3 commodity drops on UGMA and Non-UGMA meter types. While only one state’s 

data cannot be considered representative of all the other states, the results provide indications of 

trouble with decreased tolerances on both UGMA and Non-UGMA meter types.

• Additional data is expected from other States participating in the grain data submission.

Table 3. Summary of Recommendations

Item GMA-19.1–Table T.2.1. Acceptance and Maintenance Tolerances Air Oven Method for All 

Grains and Oil Seeds.

V D W A I Notes* Comments

Submitter 

OWM

WWMA 

SWMA 

NEWMA 

CWMA 

NCWM

Letters of Support Letters of Opposition Notes

Industry

Manufacturers

Retailers and Consumers
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Table 3. Summary of Recommendations

Item GMA-19.1–Table T.2.1. Acceptance and Maintenance Tolerances Air Oven Method for All 

Grains and Oil Seeds.

V D W A I Notes* Comments

*Notes Key:

1 - Submitted modified language

2 - Item not discussed

3 - No meeting held

4 - Not submitted on agenda

 5 - No recommendation or not considered

Item Under Consideration:

Amend Handbook 44, Grain Moister Meter Code 5.56 (a) as follows:

T.2.1. Air Oven Reference Method. – Maintenance and acceptance tolerances shall be as shown in 

Table T.2.1. Acceptance and Maintenance Tolerances Air Oven Reference Method. Tolerances are 

expressed as a fraction of the percent moisture content of the official grain sample, together with a 

minimum tolerance.

(Amended 2001) 

Table T.2.1. 

Acceptance and Maintenance Tolerances Air Oven Reference Method

Type of Grain, Class, or Seed Tolerance Minimum Tolerance

Corn, oats, rice, sorghum, 

sunflower

0.05 of the percent

moisture content

0.8 %

in moisture content

All other cereal grains and oil 

seeds

0.04 of the percent

moisture content

0.7 %

in moisture content

Table T.2.1. 

Acceptance and Maintenance Tolerances Air Oven Reference Method

for All Grains and Oil Seeds

Tolerance Minimum Tolerance

0.03 of the percent moisture content 0.5 % in moisture content

(Amended 2001 and 20XX) 

NIST OWM Detailed Technical Analysis: 

During the NTEP Grain Analyzer (GA) Sector 2019 meeting, the Sector reviewed data from Arkansas for 

Long Grain Rough Rice (LGRR) and other grains. The data showed that the proposal to tighten the 

acceptance and maintenance tolerance may not be appropriate for all grain types. The original data 
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presented and used as a basis for the proposal applied to corn and soybeans. After reviewing the data, the 

Sector decided to collect inspection data from across the country. An industry representative offered to 

assist with data analysis and along with the NIST representative will work in producing the inspection data 

needed for the analysis. A request for State participation will be sent to State weight and measures. The 

Sector requests that this remain a Developing Item as they move forward in evaluating additional data. 

At the 2020 Interim Meeting the S&T Committee agreed to retain this item as Developing in anticipation 

of additional data that is being collected to assess the proposed tolerances and the appropriateness of the 

change to tolerances for other grain types. The NIST Technical Advisor is working with the Grain Analyzer 

Sector and States to collect additional data on the proposed changes to the tolerances with plans to present 

data at the next NTEP GA Sector Meeting in August 2021. NIST OWM agrees with the S&T Committee 

that this item should be given a Developing status until additional data is examined.

Ms. Diane Lee (NIST) is working with the Sector to collect data on Unified Grain Moisture Algorithm 

(UGMA) grain moisture meters and non-UGMA grain moisture meters. North Carolina, Arizona, Illinois, 

and Iowa agreed to provide 2017-2019 inspection data on field meters. The participating States were 

requested to submit data by December 1, 2021. One state will be unable to participate, and North Carolina

has submitted their data.

During the 2022 Grain Analyzer Sector Meeting the Sector reviewed data from North Carolina. Regarding 

potential changes to “Handbook 44” tolerances for Grain Moisture Meters, field meter inspection data from 

the state of North Carolina for years 2017 to 2019 was examined. Only the one state provided data, but 

that comprised over 3300 records each usually averaging 3 commodity drops on UGMA and Non-UGMA 

meter types. While only one state’s data cannot be considered representative of all the other states, the 

results here provide indications of trouble with decreased tolerances on both UGMA and Non-UGMA meter 

types. The following provide a percentage of device that exceeded the current tolerance compared to the 

percentage of meters that would exceed the proposed tolerance.

The Sector has requested additional data from other States to gain a better perspective on the impact of 

lowering the tolerances for grain moisture meters. 

History

The GA Sector originally forwarded this proposal to the regional weights and measures associations with 

a proposed Voting status. All regional weights and measures associations agreed to forward the proposal 

as a voting item on the 2019 NCWM Interim Agenda and the Sector appreciates their review and support. 

However, following the regional meetings additional data was submitted to the sector which indicates a 

need to consider developing different tolerance for some grain types. Through a subsequent ballot, and a 

majority vote, the sector agreed to recommend changing the status of the item to developing to provide the 

Sector time to consider additional data and changes to its original proposal. OWM agrees with the Grain 

Analyzer (GA) Sector’s revised decision to change the status of this item to Developing.

This proposal to change the air-oven method tolerances was developed during the 2018 GA Sector meeting. 

During the 2018 GA Sector Meeting, Dr. Charlie Hurburgh provided the Sector with an analysis of data for 

2-corn and 1-soybeans samples which included the average error for UGMA grain moisture meter

Exceed current 

tolerance (UGMA)

Exceed current 

tolerance (NonUGMA) 

Exceed proposed 

tolerance (UGMA) 

Exceed proposed 

tolerance (NonUGMA) 

Count 10 18 54 263 

Records 1146 2208 1146 2208 

Fraction 0.87% 0.82% 4.71% 11.91% 
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technology and the average error of 2 MHz grain moisture meter technology from Iowa State weights and 

measures inspection data for years 2014-2017. Based on the Sectors review of the data, discussion of new 

tolerances, and the ability of the technologies to meet the new tolerances the Sector agreed to change the 

tolerances based on the data provided.

During additional discussion of what tolerances to apply to other grains, it was proposed that the same 

tolerances could apply to all grains, because corn is one of the more difficult grains to test and would likely 

have one of the largest variations when testing. No objections from States or meter manufacturers were 

provided during the discussion and voting to forward the item to the State regional weights and measures 

associations. Following the Sector meeting one State noted that there may be an issue with applying the 

tolerance to some grain types, specifically long grain rough rice. The GA Sector’s technical advisor 

requested that the State forward field data to review the grain moisture meter results for LGRR and other 

grains. After review of the data with the proposed tolerances it was determined that a high meter failure 

rate could result with a change to the tolerances for some grain types.

After the Sector’s Technical Advisor discussed the findings with the NTEP laboratory and the Sector 

members that originally proposed the tolerance change, they agreed with proposing a Developing status for 

this item, the Sector was officially balloted and also agreed to change the originally proposed Voting status 

to Developing to allow the Sector time to review additional data and make changes to its original proposal.

Summary of Discussions and Actions:

At the NCWM 2022 Interim Meeting, the Committee heard comments from Ms. Diane Lee (NIST OWM) 

who noted that additional data is needed to assess the proposed tolerances. Ms. Lee added that states would 

be submitting more data. Ms. Lee requested that this item remain Developing. During the Committee’s 

work session, the Committee agreed to a Developing status for this item.

At the NCWM 2022 Annual Meeting open hearings Mrs. Tina Butcher (NIST OWM) provided updates on 

the Grain Analyzer Sector’s proposal to reduce the tolerance for grain moisture meters. She informed the 

S&T Committee that the Grain Analyzer Sector had originally reviewed data for corn and soybeans. After 

the proposal for changes to the tolerances were submitted to the NCWM, information was received that 

reducing the tolerance may be problematic for other grains. As such the Grain Analyzer Sector is collecting 

additional data on other grain types and request a Developing status and additional time to collect the data.

At the NCWM 2022 Annual Meeting Committee meeting, the Committee agreed to a Developing status 

for this item. 

Regional Association Reporting:

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting no comments were heard on this item: 

No additional data or update was received by the Committee. The WWMA S&T Committee recommended

withdrawal and encouraged the submitter to reintroduce the item when sufficient data is available. 

Southern Weights and Measures Association

During the 2022 SWMA Annual Meeting open hearing the Committee heard no comments. 
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The SWMA S&T Committee recommended this item remain as a Developing Item. 

Northeastern Weights and Measures Association

During the 2022 Interim Meeting, Ms. Diane Lee (NIST OWM) indicated the need for more data on more 

grains. This proposal is seeking to lower tolerances due to better technologies of UGMA meters. 

However, according to data submitted by North Carolina, grains are failing at the proposed tolerances. 

Ms. Lee requests more time so more states can submit data. 

The Committee is recommending that this item retain a Developing status. 

Central Weights and Measures Association 

During the 2022 Interim Meeting Open Hearing Doug Musick, Kansas, recommended that item remain 

developing, while waiting on additional data. Mr. Ivan Hankins (Iowa) stated that 0.5% tolerance is fair 

and should move forward to Voting. 

The CWMA S&T Committee recommended this remains a Developing Item to allow time to collect 

additional data. 

GMA-23.1 N.1.3. Meter to Like-Type Meter Method Transfer Standards and Table T.2.2. 

Acceptance and Maintenance Tolerances Meter to Like-Type Meter 

Method

Source: NTEP Grain Analyzer Sector

Submitter’s Purpose and Justification:

Clarify what is meant by the term Meter to Like-Type Meter in the Grain Moisture Meter Code 5.56(a).

During the 2017 Grain Analyzer Sector meeting there was a discussion on Meter to like-type meter testing 

and the definition of a like-type meter. There was discussion on test procedures for meter to like-type meter 

testing. It was noted that there may be only about two states using this type of test method and that it may 

be due to the cost of obtaining like-type meters to perform the test. A question was raised as to what is 

considered a like-type meter and it was explained that like-type meant that the make and model were the 

same. Suggestions were made to include a definition for like-type in NIST HB 44 and to consider 

documenting test procedures for meter to like-type meter testing.

During the 2018 grain analyzer sector meeting, the sector discussed industry and State weights and measures 

programs that used meter to like-type meter testing and master meter test methods. Kansas reported that 

reference meters are used to collect moisture results on samples. The samples are then taken to the field to 

compare to commercial field moisture meters. It was also reported that most State weights and Measures 

that use a meter-to-meter test method for testing field meters do not use a meter to like-type meter testing 

program which is specified in NIST HB44. The Perten representative reported that Perten uses three layers 

of master meters when calibrating their devices. It was noted that an analysis of the failure rate for meterto-meter test methods should be investigated and an analysis of all the issues for meter-to-meter test methods 

is needed along with test methods for this type of field testing. 

During the 2022 grain analyzer sector meeting the GA sector reviewed data from States and the NTEP 

laboratory and discussed what was considered like-type for this test method. Data collected in the NTEP 

program shows a bias between meters of different type, therefore adding an error to the test results when a 
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meter of unlike type is used to test another meter. The GA sector agreed that like-type based on the current 

data available must be interpreted as the same model family, as defined by the National Type Evaluation 

Program Certificate of Conformance. As such the Sector agreed to add language to Section 5.56(a) 

paragraphs N.1.3 and T.2.2. to clarify the definition of like type. 

The submitter acknowledged that some states may be using a meter-to-meter test method that is not a meter 

to like-type meter method.

The submitter requested Voting status.

OWM Executive Summary for GMA-23.1 – N.1.3. Meter to Like-Type Meter Method Transfer 

Standards and Table T.2.2. Acceptance and Maintenance Tolerances Meter to Like-Type Meter 

Method

OWM Recommendation: NIST supports with the proposed changes with suggestions for editorial 

changes to the proposal. 

• The title of the item should include the word "type" to be consistent with the term used in NIST HB 

44. Thus, the title and references in the item should include the phrase "Meter to Like-Type Meter" 

rather than "Meter to Like-Meter." The title in our technical analysis and references in the body of 

the proposed item have been corrected to include the term "Like-Type."

• We suggest modifications to the changes made to the note in T.2.2. as follows: 

NOTE: Like-type as described in paragraph N.1.3. See definition for like-type meter in N.1.3. 

(Added 20XX)

Table 3. Summary of Recommendations

GMA-23.1 N.1.3. Meter to Like-Type Meter Method Transfer Standards and Table T.2.2. 

Acceptance and Maintenance Tolerances Meter to Like-Type Meter Method

V D W A I Notes* Comments

Submitter 

OWM

WWMA 

SWMA 

NEWMA 

CWMA 

NCWM

Letters of Support Letters of Opposition Notes

Industry

Manufacturers

Retailers and 

Consumers

Regulators
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Table 3. Summary of Recommendations

GMA-23.1 N.1.3. Meter to Like-Type Meter Method Transfer Standards and Table T.2.2. 

Acceptance and Maintenance Tolerances Meter to Like-Type Meter Method

V D W A I Notes* Comments

*Notes Key:

1 − Submitted modified language

2 − Item not discussed

3 − No meeting held

4 − Not submitted on agenda

5 − No recommendation or not considered

Item Under Consideration:

Amend NIST Handbook 44 Grain Moisture Meters Code as follows: 

N.1.3. Meter to Like-Type Meter Method Transfer Standards. – Properly standardized reference 

meters using National Type Evaluation Program approved calibrations shall be used as transfer 

standards. A reference meter shall be of the same type model family, as defined by the National Type 

Evaluation Program Certificate of Conformance, as the meter under test. Tests shall be conducted 

side-by-side using, as a comparison medium, grain samples that are clean and naturally moist, but 

not tempered (i.e., water not added). 

(Added 2001) (Amended 20XX)

And

T.2.2. Meter to Like-Type Meter Method. – Maintenance and acceptance tolerances shall be as 

shown in Table T.2.2. Acceptance and Maintenance Tolerances Meter to Like-Type Meter Method. 

The tolerances shall apply to all types of grain and seed.

(Added 2001) 

Table T.2.2. 

Acceptance and Maintenance Tolerances Meter to Like-Type Meter Method

Sample Reference Moisture Tolerance

Up to 22 % 0.5 %

in moisture content

(Added 2001)

NOTE: See definition for like-type meter in N.1.3.

(Added 20XX)

NIST OWM Detailed Technical Analysis: 

NIST supports with the proposed changes with suggestions for editorial changes to the proposal. These 

changes are provided below: 
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• The title of the item should include the word "type" to be consistent with the term used in NIST HB 44. 

Thus, the title and references in the item should include the phrase "Meter to Like-Type Meter" rather 

than "Meter to Like-Meter." The title in our technical analysis and references in the body of the proposed 

item have been corrected to include the term "Like-Type." 

• We suggest modifications to the changes made to the note in T.2.2. as follows: 

NOTE: Like-type as described in paragraph N.1.3. See definition for like-type meter in N.1.3.

(Added 20XX) 

Regional Association Reporting:

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting no comments were heard on this item. The WWMA S&T 

Committee believes that this item has merit and recommended this item remain Developing to allow for 

input and adjustments. The WWMA S&T Committee also requested the submitter address the formatting 

of their proposal to meet NCWM standard editing requirements. 

Southern Weights and Measures Association

No comments were received on this item during the 2022 SWMA Annual Meeting. The SWMA S&T 

Committee recommended this item move forward as a Voting Item. 

Northeastern Weights and Measures Association

Ms. Diane Lee (NIST OWM) noted that questions came up as to what is considered “like-type” and if 

inspectors could use any and all models of a device listed on a Certificate of Conformance. In this situation 

“like-type” would mean model family. NIST has not made a full assessment on this item. 

The Committee is recommending that this item be given a Developing status. 

Central Weights and Measures Association

Mr. Loren Minnich (Kansas) stated that this clarifies which meter can be used in this application. He 

supports this item as Voting. Mr. Ivan Hankins (Iowa) supported as Voting. 

The CWMA S&T Committee believes this item is fully developed and recommended Voting status.

MULTIPLE DIMENSION MEASURING DEVICES

MDM-22.1 D S.1.7. Minimum Measurement.

Source: Parceltool P/L

Submitter’s Purpose and Justification:

Exempt mobile tape based MDMD devices from the 12D minimum measurement.
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The 12 d minimum measurement is designed for instruments that use an internal rounding function to round 

the actual measurement up or down to the nearest value of d before being displayed. For measurement of 

12 d, or less, the potential error in the measurement is considered too large and therefore the specification 

of the 12 d minimum measurement is in place.

Measurements below 12 d are commonplace when using a mobile tape (tape measure) type of device for 

determining measurements. An accepted practice for this type of device is for the Measurement to be 

rounded up to the nearest whole unit of measurement (e.g., 1 inch) before being used to calculate any 

charges.

The submitter requested that this be a Voting Item in 2022.

OWM Executive Summary for MDM-22.1 – S.1.7. Minimum Measurement.

OWM Recommendation: Unless additional information to justify the proposed changes to the MDMD 

Code is provided to the Committee by the submitter (or submitter’s consultant), OWM recommends this 

item be withdrawn.

• This is the identical proposal that appeared in the S&T Committee’s 2019 agenda (as S&T Item 

MDM-2) and was withdrawn by the Committee in 2019.

• The NCWM MDMD Work Group also reviewed the MDM-2 proposal during its spring 2019 

meeting and recommended the item be withdrawn. 

• We have reviewed our comments and recommendations provided to the 2019 S&T Committee for 

S&T Item MDM-2 and still find them relevant today. Consequently, we provide them again with 

only few minor changes in our detailed analysis of this item included below. 

• There is no additional information provided in the justification section of this item in the 

Committee’s current agenda to explain the reason for resubmission or why the Committee should 

reconsider its earlier action to withdraw the item in 2019.

• We raised all of the above points during the 2022 NCWM Interim Meeting and recommended the 

Committee withdraw this item. During that same meeting, however, Mr. Darrell Flocken (NCWM) 

requested the Committee maintain a Developing status based upon a request he had received from 

the submitter’s consultant who indicated the submitter wished to resurrect the item.

Table 3. Summary of Recommendations

MDM-22.1 – S.1.7. Minimum Measurement.

V D W A I Notes* Comments

Submitter 

OWM 

WWMA 

SWMA 

NEWMA 
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Table 3. Summary of Recommendations

MDM-22.1 – S.1.7. Minimum Measurement.

V D W A I Notes* Comments

CWMA 

NCWM 

Letters of Support Letters of Opposition Notes

Industry • Letter from CubeTape 

(08-10-2021)

• Letter from Mr. Suiter

(06-27-2022)

Manufacturers • Letter from MettlerToledo (10-18-2022)

Retailers and Consumers

*Notes Key:

1 - Submitted modified language

2 - Item not discussed

3 - No meeting held

4 - Not submitted on agenda

 5 - No recommendation or not considered

Item Under Consideration:

Amend Handbook 44, Multiple Dimension Measuring Devices Code as follows:

S.1.7. Minimum Measurement. – Except for entries of tare and mobile tape based MDMD 

devices, the minimum measurement by a device is 12 d. The manufacturer may specify a longer 

minimum measurement. For multi-interval devices, this applies only to the first measuring range (or 

segment) of each measurement axis (length, width, and height). 

(Amended 2017 and 20XX) 

NIST OWM Detailed Technical Analysis:

The following was copied from OWM’s 2022 NCWM Annual Meeting analysis and remains unchanged for 

the 2023 NCWM Interim Meeting:

This very same proposal appeared in the S&T Committee’s 2019 agenda (as S&T Item MDM-2) and was 

withdrawn by the Committee in 2019. Additionally, the first two paragraphs included in the Committee’s 

current agenda beneath the heading “Original Justification,” are the very same two paragraphs contained in 

the Committee’s 2019 Interim Meeting Agenda in the Background Discussion section of the item. That is, 

there is no additional information provided in the justification section of this item in the Committee’s 

current agenda to explain the reason for resubmission or why the Committee should reconsider its earlier 

action to withdraw the item in 2019. OWM notes too that the NCWM MDMD work group also reviewed 

the MDM-2 proposal during its spring 2019 meeting and recommended the item be withdrawn. 

We have reviewed our comments and recommendations provided to the 2019 S&T Committee for S&T 

Item MDM2 and still find them relevant today. Consequently, we submit them again (shown in the box 
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below to include a few minor changes that we’ve made) to the Committee as our analysis for the item 

“MDM-22.1” in the Committee’s current agenda.

OWM recognizes there is a potential for introducing excessive error in measurements when they are 

performed using a process or instrument that does not provide a sufficient level of resolution in the 

measurement. Minimum measurement requirements are established in NIST Handbook 44 device codes 

based on the premise, “rounding of digital values and the allowable error in a device from the application 

of tolerance creates the potential for large errors at small measurements.” This effect decreases 

proportionately as the measurement size is increased along with the number of increments used in the 

measurement. To put this principle into perspective as it relates to multiple dimension measuring devices 

(MDMDs), NIST Handbook 44 maintenance and acceptance tolerances applicable to MDMDs are plus or 

minus 1 division (See paragraph T.3. Tolerance Values). Considering this tolerance in perspective with 

this proposal, a 1-division error within a 12division measurement (i.e., the minimum measurement currently 

permitted in accordance with paragraph S.1.7.) represents over 8 percent of the measurement value (1 ÷ 12 

= 0.083 ≃ 8.3 %). If the measurement were to include 50 divisions (or increments), that same 1-division 

error represents only 2 percent of the measurement value (1 ÷ 50 = 0.020 or 2 %).

Compounding the potential for even greater error is the fact that MDMDs are generally used to measure 

hexahedron-shaped objects by determining values for length, width, and height, and then multiplying these 

values together to determine the cubic volume occupied by the object. Since there are three measurements 

needed to determine the volume, the error effect of using a device to make small measurements is multiplied 

threefold. For example, a 1-division plus error at a 12-division measurement of length, width, and height 

would result in over a 27 percent error in the volume measurement of the object being measured as 

illustrated in the table below. 

Axis Measurement (+ 1 d error) Actual

Length 13 d 12 d

Width 13 d 12 d

Height 13 d 12 d

Volume 2197 x-unit3 1728 x-unit3

Difference:

Measurement minus Actual 

2197 x-unit3 – 1728 x-unit3 = 469 x-unit3

Percent error calculation (469 x-unit3 ÷ 1728 x-unit3

) x 100 = 27.1 %

Thus, given the potential that this proposal has for creating such very large measurement errors and the 

monetary impact those errors can have on commercial transactions, OWM does not believe this item should 

be advanced. 

In addition, OWM also points out the following concerns relating to this item:

• A guiding principle in the development of HB 44 requirements is that the same requirements should 

apply to devices used in the same application, regardless of technology or design. The proposed 

change in this item violates the principle by proposing there be an exemption to one of the 

requirements in the MDMD code for a particular type of MDMD.

• The background/discussion pertaining to this item includes the statement that it is not unusual for 

measurements to be made of less than 12 divisions. If this is in fact the case, those using these 
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devices commercially to take such measurements are violating the minimum measurement 

requirement in HB 44. OWM would hope that the submitter of this item, knowing this to be true, 

would take necessary steps to educate users so that accurate measurements can be ensured. OWM 

believes that there may also be a problem caused by the use of a device with too large a division 

size for use in measuring small objects rendering that device unsuitable for the purpose intended. 

Another potential problem may be created when two devices with different division values are 

needed due to the wide linear range of the different axes needing to be measured. 

• The background/discussion portion of this item also indicates an accepted practice for this type of 

device is for the measurement to be rounded up to the nearest whole division. OWM notes such 

rounding conflicts with the instructions provided on the Federal Express and United States Postal

Service websites for determining DIM weight, that specify the measurements are to be rounded to 

the nearest inch. 

The current 12 d minimum measurement specified in HB 44 is uniform with the same in OIML R 129. 

Thus, a change to HB 44 requirement would cause conflict with OIML requirements.

OWM’s Comments and Recommendation for Item MDM-22.1 Copied from its 2019 Analysis of 

MDM-2

Summary of Discussions and Actions:

During Committee open hearings at the 2022 NCWM Interim Meeting, Mr. Rick Harshman (NIST OWM) 

reported this very same proposal had appeared in the S&T Committee’s 2019 agenda (as S&T Item MDM2) and was withdrawn by the Committee in 2019. Additionally, the first two paragraphs included in the 

Committee’s current agenda beneath the heading “Original Justification,” are the very same two paragraphs 

contained in the Committee’s 2019 Interim Meeting Agenda in the Background Discussion section of the 

item. That is, there is no additional information provided in the justification section of this item in the 

Committee’s current agenda to explain the reason for resubmission or why the Committee should reconsider 

its earlier action to withdraw the item in 2019. Mr. Harshman noted too that the NCWM MDMD work 

group also reviewed the MDM-2 proposal during its spring 2019 meeting and recommended the item be 

withdrawn. For these reasons, OWM recommends the item be withdrawn.

Mr. Darrell Flocken (NCWM) acknowledged he too was aware that the proposal is identical to the one that 

the Committee had withdrawn in 2019. He noted, however, that he had been contacted by a representative 

of the submitter and that this person had advised him the submitter desired to further pursue adoption of the 

proposal. Mr. Flocken indicated he expected new information to be made available to Committee from the 

submitter to provide better justification for it. 

During the Committee’s work session members of the Committee agreed to maintain the item on the 

Committee’s agenda as a Developing Item to allow the submitter an opportunity to provide additional 

information that could justify the proposed changes. 

Regional Association Reporting:

Western Weights and Measures Association

During the 2021 Annual Meeting Open Hearings the following comments were heard:
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Mr. Russell Vires (Mettler Toledo) is opposed to the change proposed here. No reason to eliminate the 

minimum measurement.

The WWMA S&T Committee recommended that this item be assigned a Developmental status. The 

Committee recommended that the submitter provide data to support why the devices are unable to meet the 

12-division requirement. The Committee also recommended that the submitter consult the MDMD 

Working Group.

During open hearings, no comments were heard on this item. No additional data or update was received 

by the Committee.

The WWMA S&T Committee recommended that this item be withdrawn.

Southern Weights and Measures Association

During the 2021Annual Meeting Open Hearings, Mr. Russ Vires (Mettler Toledo) requested that this item 

be withdrawn because the justification was invalid. 

This Committee recommended this item be Withdrawn due to having no justification provided for the 

change. 

The following comments were received during the 2022 SWMA Annual Meeting:

Dr. Curran (Florida) stated that this item was not needed.

The SWMA S&T Committee recommended this item be Withdrawn.

Northeastern Weights and Measures Association

During the 2021 Interim Meeting Open Hearing the following comments were heard.

Mr. Rick Harshman (NIST OWM) commented that this is a new item and members of NIST OWM’s LMDP 

have not had opportunity to review/consider it. There’s little information provided in the 

background/discussion of this item. If the device has digital indication, by rounding all values up as is 

specified in the background/discussion, the device would fail to comply with HB 44 paragraph GS.5.2.2.(c). 

Mr. Lou Sakin (Hopkinton/Northbridge, Massachusetts) commented that this item is in-need of further 

development. 

The NEWMA Specifications and Tolerances Committee recommended that this item be given Developing 

Status. 

During the 2022 Annual Meeting Open Hearings the following comments were heard:

Mr. Russ Vires (SMA) rose to oppose the item. He commented that the justification provided by the 

submitter does not identify issue that is to be resolved. Mr. Vires suggested that the submitter work with 

MDM Work Group for a solution and referenced the Work Group meets in May and will be discussing this 

proposal.
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After hearing comments from the floor, the Committee recognized the need to further develop this item and 

recommended the item retain Developing status.

During the 2022 Interim Meeting Open Hearings the following comments were heard:

Ms. Diane Lee (NIST OWM) noted that this item has been on the agenda before and NIST OWM 

recommended withdrawing. 

Mr. Jason Flint (New Jersey) indicated that in the past, the submitter has not been available to answer 

questions regarding this proposal, and he recommended that the item be withdrawn.

After hearing comments from the floor, the Committee does not believe that this item has merit. The 

Committee is recommending that this item be Withdrawn.

Central Weights and Measures Association

During the 2021 Interim Meeting Open Hearing the Committee heard no comments from the floor. 

CWMA S&T Committee has no recommendation for this item.

During the 2022 Annual Meeting Open Hearings, the Committee received the following comments:

Mr. Russ Vires (SMA) - the SMA opposes this item. The justification provided by the submitter does not 

adequately identify the issue this item is attempting to resolve, and why mobile tape-based MDMD devices 

should be exempted compared to all other MDMD devices. The SMA recommended that the submitter 

work with the MDMD Work Group to develop a suitable solution to this issue.

The CWMA S&T Committee recommends this item to be withdrawn.

During the 2022 Interim Meeting Open Hearing the following comments were heard from the floor:

Mr. Loren Minich (Kansas): withdraw.

The CWMA S&T Committee recommended this item be withdrawn.

SMA 

During the 2021 Fall Meeting the SMA opposed this item. The justification provided by the submitter does 

not adequately identify the issue this item is attempting to resolve, and why mobile tape-based MDMD 

devices should be exempted compared to other MDMD devices. The SMA recommended that the submitter 

work with the MDMD Work Group to develop a suitable solution to this issue.

During the 2022 Spring Meeting the SMA opposed this item. The rationale was the same as during the 

2021 Fall Meeting.

During the 2021 Fall Meeting the SMA opposed this item. The rationale was the same as during the 2021 

Fall Meeting and the 2022 Spring Meeting. The SMA recommended that the submitter work with the 

MDMD Work Group to develop a suitable solution to this issue, otherwise remove it.
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OTH – Other Items

OTH-16.1 D Electric Watthour Meters Code under Development

Source: NIST Office of Weights and Measures

Submitter’s Purpose and Justification:

1) Make the weights and measures community aware of work being done within the NIST U.S. 

National Work Group (USNWG) on Electric Vehicle Fueling and Submetering to develop proposed 

requirements for electric watthour meters used in submeter applications in residences and 

businesses;

2) Encourage participation in this work by interested regulatory officials, manufacturers, and users of 

electric submeters.

3) Allow an opportunity for the USNWG to provide regular updates to the S&T Committee and the 

weights and measures community on the progress of this work;

4) Allow the USWNG to vet specific proposals as input is needed.

OWM Executive Summary for OTH-16.1 – Electric Watthour Meters Code Under Development

OWM Recommendation: Although, the EWG SG is open to discussion on points addressed in the 

OWM detailed technical analysis we agree with a Voting status for this item. 

• Over the past several years, has been developing a proposed NIST Handbook 44 code for EWHtype meters.

o The SG held eighteen meetings in 2021 and twelve meetings in 2022 in addition to meetings 

of small Task Groups focused on specific issues.

• This item has been on the S&T Committee’s agenda since 2016 as a Developing Item to allow the 

USNWG to inform the weights and measures community of progress on the draft code.

• The EWH SG appreciates the Committee’s willingness to maintain the item on the agenda as a 

mechanism for and to encouraging input and participation from those interested in the draft code 

and associated work. 

• The EWH SG is pleased to submit a draft NIST HB44 code for “Non-Utility Electricity Measuring 

Systems” for consideration at the 2023 NCWM Interim Meeting. 

• The EWH SG submitted a draft code to the S&T Committee Chair on November 12, 2022, and this 

draft appears in the Committee’s 2023 NCWM Publication 15 agenda.

• The EWH SG believes the draft code is ready for consideration as a voting item and asks the 

Committee to consider assigning this item Voting status.
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OWM Executive Summary for OTH-16.1 – Electric Watthour Meters Code Under Development

• As noted in OWM’s more detailed analysis below, there are several areas of the code in which the 

Subgroup is continuing to develop some additional language; however, this work need not delay 

consideration of the Code. These areas include the following paragraphs: 

o S.1.4.2. Test Output 

 The Subgroup would particularly like input on this paragraph. Though the majority of 

members supported the proposed language, regulatory members of the subgroup 

disagreed with the proposed language. 

o Table S.3.2.3.b., Note 7 

 The work group is considering a future proposal to add a corresponding User 

Requirement.

o N.3. Minimum Test Duration 

 The subgroup is considering alternative language to describe full and light load tests. 

o N.5.(a) Test of NUEMS 

 The subgroup is considering moving this paragraph from the Notes section and placing 

it into the User Requirement section.

• Although the most recent draft of the code was not available until after the Fall 2022 regional 

meetings, the regions and others will have adequate opportunity to review and comment on the draft 

in the period between the Interim and Annual Meetings.

• Thus, the EWH SG believes that designating this item with a Voting status is still an appropriate 

course of action. 

Table 3. Summary of Recommendations

OTH-16.1 – Electric Watthour Meters Code under Development

V D W A I Notes* Comments

Submitter 

• Initial Draft Code for Non-Utility

Electricity-Measuring Systems (09-01-

2021)

OWM

WWMA 

SWMA 

NEWMA 

CWMA 

NCWM
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Table 3. Summary of Recommendations

OTH-16.1 – Electric Watthour Meters Code under Development

V D W A I Notes* Comments

Letters of Support Letters of Opposition Notes

Industry

Manufacturers

Retailers and Consumers

*Notes Key:

1 - Submitted modified language

2 - Item not discussed

3 - No meeting held

4 - Not submitted on agenda

 5 - No recommendation or not considered

Item Under Consideration: 

This item was added to the NCWM S&T Committee’s agenda as a “Developing Item” to allow a forum in 

which progress of the USNWG can be reported as it develops legal metrology requirements for electric 

watthour meters and continues work to develop test procedures and test equipment standards.

Mrs. Tina Butcher (NIST OWM), Chair of the USNWG on Electric Refueling & Submetering, has 

continued to provide regular updates to the Committee on this work and to encourage input and participation 

from the weights and measures community since the addition of this item to the Committee’s agenda in 

2016. See the Committee’s 2016 through 2021 Final Reports and 2022 Interim Report for details. 

The SG is nearing completion of a draft NIST Handbook code for “Non-Utility Electricity-Measuring 

Systems.” Work continues on a few sections of the draft code; however, the SG would like to begin getting 

feedback from the weights and measures community on the draft code. The SG requested that the 

Committee post an early draft of the code on the NCWM website. 

The draft code was posted in Fall 2021 and is available for download at 

https://www.ncwm.com/publication-15. 

The Subgroup asks the NCWM S&T Committee to consider (and the regional associations to support) the 

following. 

1. Permitting the item to remain in a Developing status on its agenda to allow for further development 

and input on the draft Handbook 44 Code. 

2. Permitting the SG to post the draft code along with other supporting documents on the NCWM 

S&T Committee’s web page. Areas under review and development by the SG will be noted in 

yellow highlighted text.

3. Encouraging weights and measures officials and industry to study the draft code and provide input 

to the SG, including proposed changes along with rationale for such changes and any indication of 

support or opposition. 
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The SG requested comments be submitted to the SG Chair or Technical Advisor by the end of March 2022. 

The above approach was intended to allow the SG the opportunity to solicit input and incorporate comments 

from the weights and measures community on the draft code in advance of proposing it for a vote more 

broadly.

The SG has continued to meet and revise specific areas of the code and still hopes to finalize a draft for 

submission in the 2022-2023 NCWM cycle.

The Electric Watthour Meter Subgroup (EWH SG) of the USNWG on Electric Vehicle Fueling & 

Submetering has held multiple in-person and web meetings since the 2017 NCWM Annual Meeting. This 

SG has held 15 virtual meetings since January 2021 focused on finalizing a draft code on “Non-Utility 

Electricity-Measuring Systems.”

Those interested in participating in this work are asked to contact SG Chair, Ms. Lisa Warfield, or Technical 

Advisor, Mrs. Tina Butcher. Contact information is included in the “Background” section of this item.

NIST OWM Detailed Technical Analysis: 

• The USNWG on Electric Vehicle Fueling & Submetering is divided into two subgroups; one to address 

electric vehicle fueling and one to address utility-type watt hour meters.

• This item addresses work being done by the latter subgroup, the “Electric Watthour Meter Subgroup 

(EWH SG).

• Over the past several years, has been developing a proposed NIST Handbook 44 code for EWH-type 

meters.

o The SG held eighteen meetings in 2021 and twelve meetings in 2022 in addition to meetings 

of small Task Groups focused on specific issues.

• This item has been on the S&T Committee’s agenda since 2016 as a Developing Item to allow the 

USNWG to inform the weights and measures community of progress on the draft code.

• The EWH SG appreciates the Committee’s willingness to maintain the item on the agenda as a 

mechanism for and to encouraging input and participation from those interested in the draft code and 

associated work. 

• The EWH SG is pleased to submit a draft NIST HB44 code for “Non-Utility Electricity Measuring 

Systems” for consideration at the 2023 NCWM Interim Meeting. 

• The EWH SG submitted a draft code to the S&T Committee Chair on November 12, 2022, and this 

draft appears in the Committee’s 2023 NCWM Publication 15 agenda.

• The EWH SG believes the draft code is ready for consideration as a voting item and asks the Committee 

to consider assigning this item “Voting” status.

• There are some areas of the code in which the Subgroup is continuing to develop some additional 

language; however, this work need not delay consideration of the Code.
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• The Subgroup would also like to call attention to some specific areas of the Code as noted below and 

is open to suggested changes by the Committee as comments are received on this item.

o Paragraph S.1.4.2. Test Output.

 The Subgroup voted several times on the language in this paragraph and the majority 

of members supported this language. However, the regulatory members of the 

Subgroup disagreed with this language. Thus, the Subgroup would especially 

appreciate review and comments on this paragraph.

o Table S.3.2.3.b., Note 7:

 The Subgroup is considering the development of an accompanying new User 

Requirement related to the marking of the service voltage. This would be presented as 

a future recommendation to the draft code.

o N.3. Minimum Test Duration:

 The Subgroup is considering alternative language for this paragraph that would include 

more specificity regarding the full and light load tests. The Subgroup will offer any 

such recommendations for changes to the Committee to consider along with any other 

comments the Committee might receive from NCWM members.

o N.5.(a) Test of NUEMS:

 The Subgroup is considering moving N.5.(a) out of the Notes section and moving it to 

a User Requirement (with corresponding changes to present it as a User Requirement) 

as follows and is interested in input on this suggestion:

• UR.X.X. Each NUEMS submitted for testing shall have all necessary 

components assembled, connected, and configured as intended for use. 

Components may include, but are not limited to, meter, sensor(s), indicator(s), 

etc.

• All the regional associations reviewed this item at their fall meetings and recommended a Developing 

status; however, this assessment was based on the prior version of the draft code and comments 

received up to that point.

• Although the most recent draft of the code was not available until after the Fall 2022 regional meetings, 

the regions and others will have adequate opportunity to review and comment on the draft in the period 

between the Interim and Annual meetings.

• Thus, the EWH SG believes that designating this item with a Voting status is still an appropriate course 

of action.

• Those interested in participating in this work please contact:

o Subgroup Chair, Ms. Lisa Warfield (NIST OWM)

Email (lisa.warfield@nist.gov) or phone (301) 975-3308

o Technical Advisor, Mrs. Tina Butcher (NIST OWM)
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Email (tbutcher@nist.gov) or phone (301) 975-2196.

NCWM 2022 Interim Meeting

Mr. Matt Douglas (California – DMS) stated that California supports the development of this item but has 

concerns about identity marking requirements being on a separate document. Also, the devices should be 

easy to test before and after instillation. This device should allow for electronic data logger. Ms. Juana 

Williams (NIST OWM) commented that the subgroup had provided a draft code that is on the website. Ms. 

Williams requested comments be submitted to Mrs. Tina Butcher (NIST OWM) or Ms. Lisa Warfield 

(NIST OWM) by March 22, 2022. Ms. Williams stated these comments will be used to provide and updated 

draft for the 2022-2023 submission cycle and the item remain in developing status. The Committee agreed 

that the item be given a Developing status.

NCWM 2022 Annual Meeting

The Committee heard an update from Mrs. Tina Butcher (NIST OWM), Technical Advisor to the NIST 

USNWG Electric Watthour Meter Sub Group (SG), who highlighted the points in the Executive Summary 

to this item. Mrs. Butcher acknowledged this item has been on the agenda for several years, during which 

time the SG has been continually working to develop a draft code for submission to the NCWM for 

consideration. The SG shared a draft with the Committee in August 2021 and asked that it be posted to the 

NCWM website. The SG had identified specific sections of the draft code which was still being refined by 

the SG. The SG had asked that that those interested in this work review the remainder of the code and 

provide input that would allow the SG an opportunity to modify the draft to reflect their comments prior to 

submitting a final recommendation to the NCWM.

Mrs. Butcher reported that the SG is diligently continuing to work on this item, holding eighteen meetings 

in 2021 and seven meetings in 2022. She thanked those who provided comments during the regional and 

national meetings, noting in particular the Committee heard from California Division of Measurement 

Standards who noted that additional work is needed on the marking requirements. She noted that California

and others have raised questions about the provision that would allow required markings to appear on a 

separate document and asked for clarifications on how this would work. Other concerns raised included 

making sure that testing capabilities are readily achievable both before and after installation and refining 

requirements for audit trail requirements to ensure that hard copies of any event loggers are available to the 

inspector. The SG appreciates this input and is working to resolve the remaining areas of concern identified 

and hopes present a draft to the NCWM in the coming fall.

The Committee agreed to retain this item on its agenda with a Developing status while the SG continues its 

work.

Regional Association Reporting:

Western Weights and Measures Association

During the 2022 WWMA Annual Meeting no comments were heard on this item.

During open hearings, no comments were heard on this item. The WWMA S&T Committee recommended

that this item should remain Developing to allow the USNWG to continue development of the model code. 
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Southern Weights and Measures Association

The following comments were received during the 2022 SWMA Annual Meeting: 

Ms. Lisa Warfield (NIST OWM) stated the workgroup planned to have an item in NCWM Publication 15 

before the 2023 NCWM Interim Meeting. 

The SWMA S&T Committee recommended this item remain as a Developing Item. 

Northeastern Weights and Measures Association

At the 2022 Interim Meeting Ms. Lisa Warfield (NIST OWM) commented that NIST is still working on this item. An 

update will be available for the NCWM Interim Meeting. 

The Committee is recommending that this item retain a Developing status. After hearing comments from the floor, 

the Committee recognized the need to further develop this item and recommended the item retain 

Developing status.

Central Weights and Measures Association

At the 2022 Interim Meeting no comments were heard from the floor. 

The CWMA S&T Committee recommended this as a Developing Item.

Block 1 Items (B1) Minimum Draft Size When Using a Field Standard Meter

B1: LMD-23.1 N.3.5. Wholesale Devices

B1: VTM-23.1 N.3. Test Drafts

B1: MLK-23.1 N.3. Test Drafts

Source: Endress+Hauser Flow USA, Inc.

Submitter’s Purpose and Justification:

Define the minimum test draft size when using a field standard meter.

The proposal describes the minimum quantity test draft size, using a field standard meter, when testing a 

Liquid-Measuring Device. 

This proposal to amend the 3.30 Liquid-Measuring Devices Code, 3.31 Vehicle Tank Meters Code, 3.35 

Milk Meters Code, and provides a clear recommendation for the test draft size using a field standard meter 

which is significantly less than the draft size needed for fixed volume provers. The use of field standard 

meters offers accurate traceable commissioning and enforcement testing of metering systems in a fraction 

of the time needed when using fixed volume proving standards or scales. 

Test drafts recommendations using field standard meters (master meters) are presently described in code 

sections 3.34. Cryogenic Liquid-Measuring Devices, 3.38 Carbon Dioxide Liquid-Measuring Devices, and 

3.39. Hydrogen Gas-Measuring Devices. 

There are similar proposals to amend Mass Flow Meter and Liquefied Petroleum Gas codes to include field 

standard meters and describe the necessary test draft size.
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The devices used as field standard meters are calibrated to traceable national standards and the process and 

equipment used for the calibration has been audited by nationally accredited organizations. Documentation 

supporting the calibration and validation is supplied with the devices. 

The American Petroleum Institute and the American Gas Association have standard documents describing 

the use of master meters. 

State Directors have stated that the addition of language for field standard meters (master meters) is useful 

for them to support adoption in their jurisdictions.

There has been opposition to the proposed Mass Flow Meter and Liquid Petroleum Gas codes Test Draft 

amendments for field standard meters. Those cite that Appendix A gives the Director authority to choose 

testing standards. They have initiated several proposals to amend language in Appendix A. There is a 

proposal to add language to the General Code. They have remained silent regard to the description of test 

drafts and master meters in the other sections of Handbook 44 and the confusing references in Appendix D 

definitions. 

NIST has not written a 105 Series standard for field standard meters (master meters). In 2018, NIST began 

conducting a long-term test program of master meters.

Requested Status by Submitter: Voting Item

OWM Executive Summary for Block 1 Items (B1) – Minimum Draft Size When Using a Field 

Standard Meter

OWM Recommendation: NIST OWM believes that test draft criteria should be non-technology 

specific when addressed in NIST HB44. It is suggested that other proposal on the agenda may be a better 

approach for current changes to the test draft sections in Handbook 44. We encourage that future 

consideration be given to removing the test draft sections from the individual codes and placing them in 

the General Code as a suitability requirement with further guidance on selecting an appropriate test draft 

maybe in the Fundamental Considerations and/or EPOs.

• The submitter of this item is the same submitter of Items LPG-15.1 and MFM-15.1 which are 

changes to the test draft paragraphs in the LPG and MFM Codes. 

• The items in Block 1 are the same proposal made in Items LPG-15.1 and MFM-15.1, but the 

proposals are for the test draft paragraphs in different sections of the Handbook (LMD-23.1 N.3.5. 

Wholesale Device, VTM-23.1 N.3. Test Draft, MLK-23.1 N.3.Test Draft). 

• The purpose statement for Block 1 items which is “to define the minimum test draft size when using 

a field standard meter” are different than LPG-15.1 and MFM-15.1 likely due to comments received 

concerning these items.

• The test draft items on the 2022 Interim agenda are seeking to establish test draft criteria for various 

test methods in use for testing commercial devices. The Test draft items on the 2022 Interim Agenda 

are LMD-23.4, LPG-15.1, MFM-15.1, Block 1, and Block 5. 

• LPG-15.1, MFM-15.1, and Block 1 items are proposals to add a separate paragraph to the code to 

address the test method using field standard meters. As noted in other comments to these item,

NIST HB 44 was written to be non-technology specific so that requirements in the handbook would 
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OWM Executive Summary for Block 1 Items (B1) – Minimum Draft Size When Using a Field 

Standard Meter

apply to any device or method used to test a device. This prevents separate code requirements for 

the different test methods or devices under test.

• There are three items on the 2022 Interim agenda that are proposals to change the same LMD 

paragraph N.3.5 Wholesale Devices which are:

- LMD-23.4 N.3.5. Wholesale Devices, 

- B1: LMD-23.1 N.3.5 Wholesale Devices, and 

- B5: N.3.5. LMD-23.2 Wholesale Devices. 

Since two of the above items are not proposal to add another paragraph to N.3.5.and are in-line with 

creating requirements that are non-technology specific by editing the existing paragraph such that the 

paragraph is more encompassing of other test methods, we encourage that the submitters of these items, 

LMD-23.4 N.3.5.and B5: LMD-23.2 N.3.5. work together to combine the changes that are being 

proposed to the same paragraph, N.3.5. Wholesale Devices. If the submitters are in agreement with 

combining these changes a proposed change for the combined items LMD-23.4 N.3.5 Wholesale 

Device and B5: N.3.5. LMD-23.2 Wholesale Device is provided for consideration:

N.3.5. Wholesale Devices – The total delivered quantity for any required accuracy test should 

shall be equal to, or is recognized as being representative of, a volume equivalent to at least the 

amount delivered by the device in one minute at its the meter’s maximum discharge rate and shall 

in no case be less than 200 L (50 gal). 

(Amended 1987,and 1996, and 2023) 

• There are two items on the 2022 Interim Meeting Agenda that are proposals for changes to the same 

paragraph, VTM code N.3. Test draft which are: 

- B1: VTM-23.1 N.3. Test Drafts 

- B5: VTM-23.2 N.3. Test Draft 

Since B5 VTM-23.2. N.3. Test Drafts adds clarification to the existing paragraph we encourage the 

committee to look at the proposed change in B5: VTM-23.2. N.3. Test Draft 

• NIST OWM has similar comments for Block 1 items as is provided for LPG-15.1, MFM-15.1 since 

the proposals in Block 1 are the same proposals in LPG-15.1 and MFM-15.1, that add a separate 

paragraph for N.3 Test Drafts. As mentioned, in other comment although the purpose statement has 

changed for Block 1 items there are still concerns with providing different requirements for test 

draft based on different test method and confusion this may cause and number of paragraphs that 

will be added based on different technology.

• Technology will continue to change and evolve, and we will need to respond to the number of 

changes, such as the different standards that will be in use, and the factors associated with different 

technologies. We will need to ensure an appropriate test draft is selected so that the errors of test 

method and device under test do not contribute greatly to the test of the device. Coupled with what 

is already in the fundamental considerations for responsibility for selecting a test standard and what 

is being proposed in Items Gen-23.1 and Block 8, we believe a solution may be to add a general 

code requirement with additional guidance in the fundamental consideration or EPOs for Test draft 
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OWM Executive Summary for Block 1 Items (B1) – Minimum Draft Size When Using a Field 

Standard Meter

and consider removing Test Draft from the individual codes and addressing it in the general code in 

test notes as a suitability requirement. 

Table 3. Summary of Recommendations

Block 1 Items (B1) – Minimum Draft Size When Using a Field Standard Meter

V D W A I Notes* Comments

Submitter 

OWM

WWMA 

SWMA 

NEWMA 

CWMA 

NCWM

Letters of Support Letters of Opposition Notes

Industry

Manufacturers

Comments from Seraphin 

(06-29-2018)

Comments from Seraphin 

(07-31-2018)

Comments from Seraphin 

(07-31-2018)

Comments from Weights and 

Measures Consulting and Seraphin 

Test Measure Co. (01-13-2021)

Retailers and 

Consumers

Comments from 

Ross Andersen (12-

12-2018)

Regulators

*Notes Key:

1 − Submitted modified language

2 − Item not discussed

3 − No meeting held

4 − Not submitted on agenda

5 − No recommendation or not considered
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B1: LMD-23.1 N.3.5. Wholesale Devices

Item Under Consideration:

Amend Handbook 44, Liquid Measuring Devices Code as follows: 

N.3.5 Wholesale Devices 

N.3.5.1 Wholesale Devices – The delivered quantity should be equal to at least the amount 

delivered by the device in one minute at its maximum discharge rate and shall in no case be less 

than 200 L (50 gal). 

N.3.5.2. Field Standard Meter Test. – The minimum quantity for any test draft shall be equal to 

or greater than the amount delivered in one minute at the flow rate being tested. 

(Added 20XX, Nonretroactive as of January 1, 20XX)

B1: VTM-23.1 N.3. Test Drafts

Item Under Consideration:

Amend Handbook 44, Vehicle Tank Meters Code as follows: 

N.3. Test Drafts 

N.3.1. Test Drafts - The delivered quantity should be equal to at least the amount delivered by 

the device in 1 minute at its maximum discharge rate and shall in no case be less than 180 L (50 

gal) or 225 kg (500 lb). 

N.3.2. Field Standard Meter Test. – The minimum quantity for any test draft shall be equal to 

or greater than the amount delivered in one minute at the flow rate being tested. (Added 20XX) 

(Added 20XX, Nonretroactive as of January 1, 20XX)

B1: MLK-23.1 N.3. Test Drafts

Item Under Consideration:

Amend Handbook 44, Milk Meters Code as follows: 

N.3. Test Drafts 

N.3.1. Test Drafts - The delivered quantity should be equal to at least the amount delivered by 

the device in one minute at its maximum discharge rate, and shall in no case be less than 400 L or 

400 kg (100 gal or 1 000 lb). 

N.3.2. Field Standard Meter Test. – The minimum quantity for any test draft shall be equal to or 

greater than the amount delivered in one minute at the flow rate being tested. (Added 20XX) 

(Added 20XX, Nonretroactive as of January 1, 20XX)
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NIST OWM Detailed Technical Analysis: 

The submitter of this item is the same submitter of Items LPG-15.1 and MFM-15.1 which are changes to 

the test draft paragraphs in the LPG and MFM Codes. 

The items in Block 1 are the same proposal made in Items LPG-15.1 and MFM-15.1, but the proposal are 

to the test draft paragraphs in different sections of the Handbook which are LMD-23.1 N.3.5. Wholesale 

Device, VTM-23.1 N.3. Test Draft, MLK-23.1 N.3.Test Draft. The purpose statement for Block 1 items 

which is “ to define the minimum test draft size when using a field standard meter” are different than LPG15.1 and MFM-15.1 likely due to comments received concerning these items. 

The test draft items on the 2022 Interim agenda are seeking to establish test draft criteria for various test 

methods in use for testing commercial devices. The Test draft items on the 2022 Interim Agenda are LMD23.4, LPG-15.1, MFM-15.1, Block 1, and Block 5. 

• LPG-15.1, MFM-15.1, and Block 1 items are proposals to add a separate paragraph to the code to 

address the test method using field standard meters. As noted in other comments to these item, 

NIST HB 44 was written to be non-technology specific so that requirements in the handbook would 

apply to any device or method used to test a device. This prevents separate code requirements for 

the different test methods or devices under test.

• There are three items on the 2022 Interim agenda that are proposals to change the same LMD 

paragraph N.3.5 Wholesale Devices which are:

o LMD-23.4 N.3.5. Wholesale Devices, 

o B1: LMD-23.1 N.3.5 Wholesale Devices, and 

o B5: LMD-23.2 N.3.5. Wholesale Devices. 

Since two of the above items are not proposal to add another paragraph to N.3.5.and are in-line with 

creating requirements that are non-technology specific by editing the existing paragraph such that the 

paragraph is more encompassing of other test methods, we encourage that the submitters of these items, 

LMD-23.4 N.3.5.and B5: LMD-23.2 N.3.5. work together to combine the changes that are being 

proposed to the same paragraph, N.3.5. Wholesale Devices. If the submitters are in agreement with 

combining these changes a proposed change for the combined items LMD-23.4 N.3.5 Wholesale Device 

and B5: N.3.5. LMD-23.2 Wholesale Device is provided for consideration:

N.3.5. Wholesale Devices – The total delivered quantity for any required accuracy test should 

shall be equal to, or is recognized as being representative of, a volume equivalent to at least the 

amount delivered by the device in one minute at its the meter’s maximum discharge rate and shall 

in no case be less than 200 L (50 gal). 

(Amended 1987,and 1996, and 2023) 

• There are two items on the 2022 Interim Meeting Agenda that are proposals for changes to the same 

paragraph, VTM code N.3. Test draft which are: 

o B1: VTM-23.1 N.3. Test Drafts

o B5: VTM-23.2 N.3. Test Draft 

Since B5 VTM-23.2. N.3. Test Drafts adds clarification to the existing paragraph we encourage the 

Committee to look at the proposed change in B5: VTM-23.2. N.3. Test Draft. 
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• NIST OWM has similar comments for Block 1 items as is provided for LPG-15.1, MFM-15.1 since 

the proposals in Block 1 are the same proposals in LPG-15.1 and MFM-15.1, that add a separate 

paragraph for N.3 Test Drafts. As mentioned, in other comment although the purpose statement 

has changed for Block 1 items there are still concerns with providing different requirements for test 

draft based on different test method and confusion this may cause and number of paragraphs that 

will be added based on different technology.

Technology will continue to change and evolve, and we will need to respond to the number of changes, 

such as the different standards that will be in use, and the factors associated with different technologies. 

We will need to ensure an appropriate test draft is selected so that the errors of test method and device under 

test do not contribute greatly to the test of the device. Coupled with what is already in the fundamental 

considerations for responsibility for selecting a test standard and what is being proposed in Items Gen-23.1

and Block 8, we believe a solution may be to add a general code requirement with additional guidance in 

the fundamental consideration or EPOs for Test draft and consider removing Test Draft from the individual 

codes and addressing it in the general code in test notes as a suitability requirement.

Regional Association Reporting:

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting Mr. Michael Keilty (Endress+Hauser) referred to previous 

comments regarding LPG-15.1 and MFM-15.1 items. He stated that the language is similar to the test draft 

language. The goal is to aid the States and this one is good. This applies to fuels and neck provers. Many 

systems are going unchecked due to the rarity of dedicated provers for milk for example. He recommended 

that Block 1 items be passed forward as a Voting Item. 

Mr. Robert Murnane (Seraphin Test Measure Company) stated that he was opposed to this for the same 

reasons as stated in the discussion about LPG-15.1 and MFM-15.1 items. He did not think that we need a 

different code for a mass flow or LPG meter. He recommended changing N.3. to include test drafts “one 

minute at the flow rate being tested”. 

During open hearings, the Committee heard conflicting comments about these items. The Committee takes 

the positions that the purpose of this item is better addressed in Block 8. WWMA S&T Committee 

recommended that this item be withdrawn with the recommendation that the submitter combine their efforts 

with the submitters of Block 8. 

Southern Weights and Measures Association

The following comments were received during the 2022 SWMA Annual Meeting: Mr. Keilty, 

(Endress+Hauser) stated that this block contained the same changes as LPG 15.1, which has already been 

approved. He also stated that electronic devices have changed a lot since 1989, and they still comply with 

the Fundamental Considerations. 

Mr. Searles (American Petroleum Institute) stated that he supported this item moving forward as 

Developing, and that devices should not be pointed out separately. 

Mr. Murnane (Seraphin) stated that he supported this moving forward as a Developing Item. 

Mr. Nicholas Suemnick (Marathon Petroleum) stated that he supported this moving forward as Developing.
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Mr. Prince (Florida) stated that the membership needs to make a decision on how we want to handle this 

issue. 

The SWMA S&T Committee recommended this item move forward as a Voting Item. 

Northeastern Weights and Measures Association

During the 2022 Interim Meeting Mr. Michael Keilty (Endress Hauser) reported that the language in this 

item is similar to LPG-15.1 and MFM-15.1 Mr. Henry Opperman (Weights & Measures Consulting) has 

concerns that are related to the test notes that he believes have not been thought through. Will any meter 

that passes Fundamental Considerations be used? Mr. Opperman noted that a normal test of a LMD 

includes test of air eliminator and the test of a VTM includes a product depletion test, which would not be 

able to be performed. Any standard has to provide reproducible results under field conditions. Mr. Bob 

Murnane (Seraphin Test Measure) pointed out that some meters already meet 1/3 requirement and can 

already be used as a field standard. Ms. Diane Lee (NIST OWM) noted that the members have already 

withdrawn similar items that contain this same language. Ms. Tisha Arriaga (Marathon Petroleum) 

commented that she is not in favor of the proposal and doesn’t want to keep creating a list of test devices. 

Would like to see them in one simple statement. Mr. Michael Keilty (Endress Hauser) commented that 

fixed volume provers are different than master meters and SVP, with separate benefits or disadvantages. 

Mr. Keilty stated that it is more important and beneficial to list different types of technologies and 

performance requirements. Mr. Lou Sakin (Holliston, MA) requested that the item be withdrawn. Mr. 

Prentiss Searles (API) commented that he is not in favor of the proposal. Mr. Jason Flint (New Jersey) 

noted the language in this proposal mirrored LPG-15.1 and MFM-15.1, which were already recommended 

for withdrawal by the body. Mr. Flint suggested that those items be merged into this Block or this Block 

be withdrawn as well. 

After hearing comments from the floor, the Committee does not believe this item has merit. The Committee 

recognizes that the language in this item is the same as other items that have been previously recommended 

for withdrawal. The Committee recommended that this item be withdrawn. 

Central Weights and Measures Association

During the 2022 Interim Meeting Mr. Michael Keilty (Endress+Hauser) stated that these three items were 

initially submitted separately, but then blocked together. All submittals for each item have the same 

language, which is the same language from LPG-15.1 and MFM-15.1 that was approved by CWMA in 

May. Nebraska has been using a similar system for years and has positive feedback related to speed of 

testing. The same language was previously accepted by multiple regional associations. Provers for milk 

meters are getting harder to find and is affecting business owners. Move to Voting status.

The CWMA S&T Committee believes this item is fully developed and recommends Voting status. The 

Committee also believes that LPG-15.1 and MFM-15.1 should be added to Block 1.

Item Block 2 (B2) Define True Value for Use in Error Calculations

B2: A SCL-20.3 A S.5.4. Relationship of Minimum Load Cell Verification Interval to the Scale 

Division

B2: A SCL-20.4 A Table 3. Parameters of Accuracy Classes.

B2: A SCL-20.5 A Table S.6.3.a. Marking Requirements, Note 3.

B2: A SCL-20.6 A T.N.1.2. Accuracy Classes and T.N.1.3. Scale Division.

B2: A SCL-20.7 A Table 7. Maintenance Tolerances
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B2: A SCL-20.8 A Table 8. Recommended Minimum Load

NOTES: 

1. At the 2020 NCWM Interim Meeting the Committee agreed that GEN-20.1, SCL-20.1 and SCL20.2 should be removed from Block 2 and given individual consideration. The items included in 

this Block 2 are SCL-20.3, SCL-20.4, SCL-20.5, SCL-20.6, SCL-20.7, and SCL-20.8.

2. While this item was carried over from the 2020 Interim Meeting, it was not a Voting Item and 

therefore not discussed during the continuation of the 2020 Annual Meeting. Instead, it was placed 

on the 2021 Interim Meeting’s agenda and was discussed during that meeting.

Source: Mr. Ross Andersen (Retired)

Submitter’s Purpose and Justification:

This proposal has four parts:

1. Clarify the concepts in determining error in verification,

2. Correct Code references to ensure correct reference to either e or d, as appropriate,

3. Correct Code references regarding issues of scale suitability Table 8, and

4. Explain why e and d are not connected

OWM Executive Summary for Item Block 2 (B2) – Define True Value for Use in Error

Calculations

OWM Recommendation: That the Committee reconcile the entries proposed in new item SCL-23.3 

with those in this block and then withdraw this block of items from its agenda to be replaced by new 

item SCL-23.3 (additional details included in the paragraph below).

• The different proposals in this block of items were recently amended, reorganized, and resubmitted 

to the NCWM by the NCWM’s Verification Scale Division (e) Task Group (TG) to reflect changes 

agreed to by members of the TG and included in its 2nd Final report. The NCWM agreed to 

consolidate these proposals into a single new item (i.e., Item SCL-23.3) on the Committee’s 2023 

Interim Meeting agenda. The NCWM also agreed to maintain the Block 2 items on the Committee’s 

2023 Interim Meeting agenda so that the Committee could reconcile the entries during the upcoming 

2023 NCWM Interim Meeting. 

 

• The items in this block and the proposals included in new Item SCL-23.3 represent very significant 

changes to the Scales Code of NIST HB 44 in that they are an attempt to clarify which value: the 

value of the scale division (d) or verification scale division (e), are the paragraph requirements to be 

based. It is important that everyone agree with the changes proposed.

• OWM participates on the TG and looks forward to sharing its perspective with its members on the 

proposed changes. 

 
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Table 3. Summary of Recommendations

B2 – Define True Value for Use in Error

V D W A I Notes* Comments

Submitter 

OWM

WWMA 

SWMA 

NEWMA

CWMA 

NCWM

Letters of Support Letters of Opposition Notes

Industry

Manufacturers

Retailers and Consumers

*Notes Key:

1 - Submitted modified language

2 - Item not discussed

3 - No meeting held

4 - Not submitted on agenda

 5 - No recommendation or not considered

Item Under Consideration:

B2: SCL-20.3 A S.5.4. Relationship of Minimum Load Cell Verification Interval to the 

Scale Division

Amend Handbook 44, Scales Code as follows: 

S.5.4. Relationship of Minimum Load Cell Verification Interval Value to the Scale Division – The 

relationship of the value for the minimum load cell verification scale interval, vmin, to the verification

scale division, d e, for a specific scale using National Type Evaluation Program (NTEP) certified load 

cells shall comply with the following formulae where N is the number of load cells in a single 

independent1 weighing/load-receiving element (such as hopper, railroad track, or vehicle scale 

weighing/load-receiving elements): 

(a) vmin

N

≤ d e

for scales without lever systems; and

(b) vmin 

N scale multiple ( )

≤

×

d e

for scales with lever systems.

 1”Independent” means with a weighing/load-receiving element not attached to adjacent elements and 

with its own A/D conversion circuitry and displayed weight. 
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[*When the value of the scale division, d, is different from the verification scale division, e, for the 

scale, the value of e must be used in the formulae above.]

This requirement does not apply to complete weighing/load-receiving elements or scales, which satisfy 

all the following criteria:

- the complete weighing/load-receiving element or scale has been evaluated for compliance with 

T.N.8.1. Temperature under the NTEP; 

- the complete weighing/load-receiving element or scale has received an NTEP Certificate of 

Conformance; and

- the complete weighing/load-receiving element or scale is equipped with an automatic 

zero-tracking mechanism which cannot be made inoperative in the normal weighing mode. (A 

test mode which permits the disabling of the automatic zero-tracking mechanism is permissible, 

provided the scale cannot function normally while in this mode. 

[Nonretroactive as of January 1, 1994] 

(Added 1993) (Amended 1996, and 2016, and 20XX) 

B2: SCL-20.4 A Table 3. Parameters of Accuracy Classes.

Amend Handbook 44, Scales Code as follows: 

Table 3.

Parameters for Accuracy Classes

Class

Value of the Verification Scale 

Division e1 

(d or e1)

Number of Scale4 Divisions (n)

Minimum Maximum

SI Units

I equal to or greater than 1 mg 50 000 --

II 1 to 50 mg, inclusive 100 100 000

equal to or greater than 100 mg 5 000 100 000

III2,5 0.1 to 2 g, inclusive 100 10 000

equal to or greater than 5 g 500 10 000

III L3 equal to or greater than 2 kg 2 000 10 000

IIII equal to or greater than 5 g 100 1 200

U.S. Customary Units

III5 0.0002 lb to 0.005 lb, inclusive 100 10 000

0.005 oz to 0.125 oz, inclusive 100 10 000

equal to or greater than 0.01 lb 500 10 000

equal to or greater than 0.25 oz 500 10 000

III L3 equal to or greater than 5 lb 2 000 10 000

IIII greater than 0.01 lb 100 1 200

greater than 0.25 oz 100 1 200
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B2: SCL-20.5 A Table S.6.3.a. Marking Requirements, Note 3.

Amend Handbook 44, Scales Code as follows: 

3. The device shall be marked with the nominal capacity. The nominal capacity shall be shown together 

with the value of the scale division “d” (e.g., 15 × 0.005 kg, 30 × 0.01 lb, or capacity = 15 kg, 

d = 0.005 kg) in a clear and conspicuous manner and be readily apparent when viewing the reading 

face of the scale indicator unless already apparent by the design of the device. Each scale division

value or weight unit with its associated nominal capacity shall be marked on multiple range or 

multi-interval scales. In the absence of a separate marking of the verification scale division “e” (see 

Note 4), the value of the verification scale division e shall be equal to the value of the scale division 

d. 

[Nonretroactive as of January 1, 1983] 

(Amended 2005 and 20XX)

1 For Class I and II devices equipped with auxiliary reading means (i.e., a rider, a vernier, or a least 

significant decimal differentiated by size, shape, or color), the value of the verification scale division 

“e” is the value of the scale division immediately preceding the auxiliary means. The manufacturer 

may design a scale such that the verification scale division e does not be equal to the scale division d. 

To ensure the correct value for e is used, refer to marking requirements in footnotes 3 and 4 to Table 

S.6.3.a. and Table S.6.3.b. 

(Amended 20XX) 

2 A Class III scale marked “For prescription weighing only” may have a verification scale division (e) 

not less than 0.01 g. 

(Added 1986) (Amended 2003) 

3 The value of a the verification scale division (e) for crane and hopper (other than grain hopper) scales 

shall be not be less than 0.2 kg (0.5 lb). The minimum number of scale divisions shall not be less than 

1000. 

(Amended 20XX) 

4 On a multiple range or multi-interval scale, the number of divisions for each range independently shall 

not exceed the maximum specified for the accuracy class. The number of scale divisions, n, for each 

weighing range is determined by dividing the scale capacity for each range by the verification scale 

division, e, for each range. On a scale system with multiple load-receiving elements and multiple 

indications, each element considered shall not independently exceed the maximum specified for the 

accuracy class. If the system has a summing indicator, the nmax for the summed indication shall not 

exceed the maximum specified for the accuracy class.

(Added 1997) 

5

 The minimum number of scale divisions for a Class III Hopper Scale used for weighing grain shall be 

2000.)

[Nonretroactive as of January 1, 1986]

(Amended 1986, 1987, 1997, 1998, 1999, 2003, and 2004, and 20XX)
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B2: SCL-20.6 A T.N.1.2. Accuracy Classes and T.N.1.3. Scale Division.

Amend Handbook 44, Scales Code as follows: 

T.N.1.2. Accuracy Classes. – Weighing devices are divided into accuracy classes according to the number 

of scale divisions (n) and the value of the verification scale division (d) (e).

T.N.1.3. Scale Division. – This Code contains references to two types of scale divisions, the 

verification scale division (e) and the scale division (d) (see definitions in Appendix D.). The tolerance 

for a weighing device is in the order of magnitude of related to the value of the scale division (d) or 

the value of the verification scale division (e) and is generally expressed in terms of d or e. Other technical 

requirements may reference either the verification scale division (e) or scale division (d) as 

appropriate. The values of (e) and (d) are chosen by the manufacturer and are marked on the device 

pursuant to S.6.3., except that d is not used in reference to an analog device, such as an equal-arm 

balance, where the graduations do not correspond to units of weight.

B2: SCL-20.7 A Table 6. Maintenance Tolerances

Amend Handbook 44, Scales Code as follows: 

Table 6.

Maintenance Tolerances

(All values in this table are in verification scale divisions)

Tolerance in Verification Scale Divisions

1 2 3 5

Class Test Load

I 0 - 50 000 50 001 - 200 000 200 001 +

II 0 - 5 000 5 001 - 20 000 20 001 +

III 0 - 500 501 - 2 000 2 001 - 4 000 4 001 +

IIII 0 - 50 51 - 200 201 - 400 401 +

III L 0 - 500 501 - 1 000 (Add 1 d e for each additional 500 d e or fraction thereof)

B2: SCL-20.8 A Table 8. Recommended Minimum Load

Amend Handbook 44, Scales Code as follows: 

Table 8.

Recommended Minimum Load

Class Value of Scale Division

(d or e*)*

Recommended Minimum Load

(d or e*)*

I equal to or greater than 0.001 g 100

II 0.001 g to 0.05 g, inclusive 20

equal to or greater than 0.1 g 50

III All** 20

III L All 50
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Table 8.

Recommended Minimum Load

IIII All 10

*For Class I and II devices equipped with auxiliary reading means (i.e., a rider, a vernier, or a 

least significant decimal differentiated by size, shape or color), the value of the verification scale 

division “e” is the value of the scale division immediately preceding the auxiliary means. For 

Class III and IIII devices the value of “e” is specified by the manufacturer as marked on the 

device; “e” must be less than or equal to “d.” Scales manufacturers are permitted to design scales 

where the value a verification scale division e differs from the displayed scale division d. If the 

marked value of e is less than the value of d, use e in interpreting the Table. In all other cases use 

the value of d. Refer to marking requirements for d and e in footnotes 3 and 4 to Table S.6.3.a. and 

Table S.6.3.b.

(Amended 20XX)

**A minimum load of 10 d e is recommended for a weight classifier marked in accordance with a 

statement identifying its use for special applications.

(Amended 1990) (Amended 20XX)

NIST OWM Detailed Technical Analysis: 

The following was copied from OWM’s analysis of the Block 2 items for the 2022 NCWM Annual 

Conference and remains unchanged for the 2023 NCWM Interim Meeting: 

OWM looks forward to reviewing updates to the various items in this block once the NCWM Verification 

Scale Division (e) Task Group (TG) has completed its work amending the current proposals to reflect the 

agreed upon changes reported by the TG in its second report. Since there have been no updates to the 

different items in Block 2 since they were first submitted, OWM’s analysis of this group of items remains 

unchanged from the 2022 NCWM Interim Meeting as follows: 

 

It remains clear that not everyone agrees with the changes proposed by this block of items given that none 

of the four regional weights and measures associations, nor the SMA, all of which met in the fall of 2021, 

could recommend to the national S&T Committee advancement of this block of items to a Voting status. 

Two of the regional associations recommended the block be reassigned to the Verification Scale Division 

Task Group. The other two regional associations recommended the block be developing. The SMA 

supported further development and the work of the Verification Scale Division (e) Task Group. We too 

disagree with some of the changes proposed. Consequently, as a group of items considered together, OWM 

cannot support them. 

Although we are aware of the existence of a second draft report from the Verification Scale Division (e) 

Task Group that we think proposes, or at least suggests, additional changes/updates to the items in this 

block, we do not believe any of the items in Block 6 have changed since that report was first made available 

to us. We are hopeful, however, that some of the proposals in this block have been updated (but not yet 

published) or will be updated in the very near future and those updates will resolve, at least some concerns. 

We base this hope on comments made by Mr. Henry Oppermann (Weights and Measures Consulting, LLC) 

during Committee open hearings at the 2021 NEWMA Interim Meeting. Mr. Oppermann reported during 

open hearings that he had talked to the submitter of this block of items and the two had reached agreement 

on some needed changes to the proposals. Mr. Oppermann commented also, that he thought those agreed 

upon changes had perhaps already been made. Consequently, the draft of Block 2 items in NEWMA’s 

2021 S&T Interim Meeting agenda was not, in Mr. Oppermann’s opinion, the most recent draft. We are 
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somewhat encouraged by this news because we share at least some of Mr. Oppermann’s concerns with 

respect to the current items in this block. 

Further evidence that the proposals in the Committee’s 2022 Interim Meeting agenda (i.e., NCWM 

Publication 15) may have been updated, but not yet published or widely distributed, are comments made 

by the Chairman of the Verification Scale Division (e) Task Group during Committee open hearings at the 

2021 CWMA Annual meeting. That is, the CWMA’s S&T 2021 Annual Report indicates that Mr. Doug 

Musick, who was Chairman of the Verification Scale Division (e) Task Group during its existence, provided 

updates from the Task Group and would be providing changes to the item to NCWM S&T Committee 

before the July NCWM Annual meeting. Based on our review and comparison of the Block 2 items in the 

CWMA’s 2021 S&T Annual Meeting Agenda and the Committee’s 2022 Interim Meeting agenda (i.e., 

NCWM Publication 15) none of the proposals have changed. 

If there does, in fact, exist a more current draft of the proposals in Block 2 and that draft gets introduced on 

or before the 2022 NCWM Interim Meeting, we encourage the Committee to provide adequate time for 

review and discussion opposed to simply advancing any new draft for vote during the 2022 NCWM Interim 

Meeting. There are many changes proposed by this block of items (i.e., there are six individual items in 

all) and their significance should be of great enough concern to warrant, in our opinion, sufficient time for 

review and discussion, especially in light of the fact there still exists disagreement on the current proposals. 

As noted in earlier OWM comments and recommendations, the different proposals included in this block 

present several very significant changes to the Scales code of HB 44 with respect to the application of HB 

44 requirements to scales having different values of e and d. Given these two values most often differ by 

a factor of ten, it is of utmost importance that everyone agree on which value is the application of the 

different HB 44 requirements to be based. 

Summary of Discussions and Actions:

During the 2022 NCWM Interim Meeting, Mr. Rick Harshman (NIST OWM) commented that the items in 

this block represent very significant changes to the Scales Code of NIST HB 44 in that they are an attempt 

to clarify which value, the value of the scale division (d), or verification scale division (e), are the paragraph 

requirements to be based. It is important that everyone agree; however, but this has not yet been the case. 

Mr. Harshman noted that OWM disagreed with several of the changes proposed by the different items in 

this block as shown in the Committee’s current agenda. Mr. Harshman also reported that the various Block 

2 items in the Committee’s current agenda fail to reflect changes agreed to by members of the NCWM’s 

Verification Scale Division (e) Task Group (TG) as indicated in its second report to the Committee. That 

is, the proposals hadn’t been updated following the TG’s submission of its second report to the Committee.

There seemed to be a misunderstanding between the TG and Committee on who would perform this work 

and it never got done. OWM looked forward to reviewing the proposals once this updating had been 

completed. 

Mr. Doug Musick (Kansas) Chair of the Verification Scale Division (e) TG acknowledged the accuracy of 

Mr. Harshman’s reporting of the misunderstanding between the TG and Committee. He then requested the 

Committee either reassign the Block 2 items to the TG, or, if the Committee preferred, the Committee could 

perform the updating itself based on the TG’s most recent report. Mr. Musick also noted that the TG’s 

second report was included in Appendix A of the Committee’s 2022 Interim Agenda (NCWM Publication 

15). 

Mr. Russ Vires (Mettler Toledo, LLC) speaking on behalf of the SMA stated that the SMA supports the 

further development of this item and the work of the Verification Scale Division (e) Task Group. The SMA 
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would also like to encourage the use of the terminology “Verification Interval” for “e” and “Scale Division” 

for “d” in every instance that it appears in this item.

The Committee also received several comments in support of reassigning the block of items to the TG for 

further revision. 

The Committee, in consideration of the comments received, agreed to reassign the block of items to the 

Verification Scale Division (e) TG for additional updating.

During Committee open hearings at the NCWM 2022 Annual Meeting, the Committee received an update 

from the Task Group Chair Doug Musick (Kansas). Mr. Musick indicated that the Task Group created a 

report in 2021 that had been added to Publication 15 and 16 as an Appendix. This report contains an 

analysis of the items under consideration, as well as recommendations for language changes to those items. 

Mr. Musick requested a joint meeting with the Task Group and the S&T and L&R Committees for 

coordinating moving the recommended changes to the items under consideration. The Committee 

recommends this remains Assigned and is requesting the Task Group facilitate joint meeting and work on 

moving the recommended changes from the report into the items under consideration.

Regional Association Reporting:

Western Weights and Measures Association

During the 2021 Annual Meeting Open Hearing the following comments were heard:

Mr. Matt Douglas (California - DMS) remarked the language is not clear, recommend that this item be 

withdrawn (the whole block). 

Mr. Russell Vires (Scale Manufactures Association) stated this is a carryover item. SMA supports further 

development of this item, recommend that the SMA encourage the use of term: Verification Scale Interval 

for (e) and Scale Division for (d). (He can send info.) States that his comments are the same from the 

Annual Meeting.

Ms. Diane Lee (NIST OWM) remarked that the NIST OWM comments are posted on NCWM website.

The WWMA S&T Committee recommended that this item remain Informational with concern given to the 

comments given during the WWMA open hearings. During the Committee work session, clarification was 

given regarding Committee member Mr. Matt Douglas’ (California - DMS) testimony questioned whether 

or not the item provides assistance to an Inspector in the field in the performance of their job. 

Due to timing constraints during open hearings at the 2022 WWMA meeting, the Committee did not take 

comments on Assigned Items. The Committee did allow the source to provide updates on these items. No 

update was provided to the Committee. The WWMA S&T Committee recommended that this item remain 

Assigned and looks forward to a future update.

Southern Weights and Measures Association

During the 2021 Annual Meeting Open Hearing Mr. Russ Vires (SMA) supported further development of 

this item and recommended the descriptive name changes for “e” and “d” as posted on the NCWM website. 

This Committee recommended this item move forward with an Assigned status. 
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Northeastern Weights and Measures Association

During the 2021 Interim Meeting Open Hearing the following comments were heard.

Mr. Rick Harshman (NIST OWM) recommended keeping this item in Informational status due to the fact 

that the National S&T Committee has taken ownership and interpretations have been provided at NTEP 

and weighing sector meetings. Meeting notes are available on NCWM website.

Mr. Henry Opperman (Weights and Measures Consulting) objected to many of the blocked items and 

recommend to keep this item in Informational status.

Mr. Lou Staub (SMA) suggested the use of the term “verification scale interval” for “e” and “scale division” 

for “d”.

Mr. John McGuire (New Jersey) recommended keeping the item in Informational status.

The NEWMA Specifications and Tolerances Committee recommends that this item be kept in 

Informational status. 

During the 2022 Annual Meeting Open Hearings, Mr. Russ Vires (Mettler Toledo, LLC), speaking on 

behalf of the SMA, recommended the identical changes to the individual items in Block 2 as shown in the 

SMA reporting contained within this report for the SMA’s Spring 2022 meeting. Mrs. Tina Butcher (NIST 

OWM) indicated she believes the latest revisions from task group have addressed concerns.

After hearing comments from the floor, the Committee recognized the need to further develop this block 

and recommended the block retain Assigned status.

Central Weights and Measures Association

During the 2021 Interim Meeting Open Hearing the Committee heard comments from the floor. Mr. Lou 

Straub (SMA) supports item. Would like to see it written that “scale division” will have value of “d” and 

“verification scale interval” for “e”. 

CWMA S&T Committee recommended that the item be assigned back to the Verification Scale Division 

Task Group.

During the 2022 CWMA Annual Meeting Open Hearings the Committee received the following comments: 

Mr. Russ Vires (SMA): the SMA supports the further development of this item and the work of the 

Verification Scale Division (e) Task Group. Recommendation: the SMA would also like to encourage the 

use of the terminology “Verification Interval” for “e” and “Scale Division” for “d” in every instance that it 

appears in this item. 

Mr. Loren Minich (Kansas): items shown under consideration are not the items the Task Group has 

submitted. The SMA recommendations conflict with current task group verbiage.

Mr. Doug Musick (Kansas): this proposal got put into the National Committee Agenda Appendix for some 

reason. Hope to rebuild the task group and get cleaned up before 2022 national. “verification interval” 

should be “verification scale division” (e), and “displayed scale division” (d). Having (d) and (e) in the 

same original table was confusing to inspectors. The current Task Group changes won’t be in Pub 16 for 

the 2022 National Meeting.
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Mr. Loren Minich (Kansas): prefers the S&T Committee to evaluate the Appendix since it’s more up to 

date.

The CWMA S&T Committee recommended this item remain as Assigned.

During the 2022 CWMA Interim Meeting, the Committee received no comments on this block of items and 

recommended this block remain in an Assigned status. 

SMA 

During the 2021 Fall Meeting the SMA supports the further development of this item and the work of the 

Verification Scale Division (e) Task Group. The SMA would also like to encourage the use of the 

terminology “Verification Interval” for “e” and “Scale Division” for “d” in every instance that it appears in 

this item. The following changes are recommended to the individual items in this block:

B2: SCL-20.3 S.5.4 Relationship of Minimum Load Cell Verification Interval: No change 

B2: SCL-20.4 Table 3. Parameters of Accuracy Classes

Recommendation: The SMA recommends the following change to Table 3, Footnote 1: The 

manufacturer may design a scale such that the verification scale division verification interval e 

does not be equal to the scale division d.

B2: SCL-20.5 Table S.6.3.A. Marking Requirements, Note e: No Change 

B2: SCL-20.6 T.N.1.1. Accuracy Classes and T.N.1.3. Scale Division 

Recommendation: The SMA recommends the following change: “... except that (d) is not used 

in reference...”

B2: SCL-20.7 Table 7. Maintenance Tolerances 

Recommendation: The SMA recommends the following change: Table 6. Maintenance 

Tolerances

B2: SCL-20.8 Table 8 Recommended Minimum Load 

Recommendation: The SMA recommends the following change: Scales manufacturers are 

permitted may have to design scales where the value a verification scale interval division e differs

not equal to from the displayed scale division d.

During the 2022 Spring Meeting, the SMA reported it supported the further development of this item and 

the work of the Verification Scale Division (e) Task Group. The SMA would also like to encourage the 

use of the terminology “Verification Interval” for “e” and “Scale Division” for “d” in every instance that it 

appears in this item. 

The SMA recommended the following changes to the individual items in Block 2: 

B2: SCL-20.3 S.5.4 Relationship of Minimum Load Cell Verification Interval: No change 

B2: SCL-20.4 Table 3. Parameters of Accuracy Classes

Recommendation: The SMA recommends the following change to Table 3, Footnote 1: Class I 

and II scales may be designed such that the verification scale division verification interval e does 

not be equal to the scale division d.

B2: SCL-20.5 Table S.6.3.A. Marking Requirements, Note 3: No Change 

B2: SCL-20.6 T.N.1.2. Accuracy Classes and T.N.1.3. Scale Division 

Recommendation: The SMA recommends the following change: “... except that (d) is not used 

in reference...”

B2: SCL-20.7 Table 7. Maintenance Tolerances
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Recommendation: The SMA recommends the following change: Table 6. Maintenance 

Tolerances

B2: SCL-20.8 Table 8. Recommended Minimum Load

Recommendation: The SMA recommends striking the following language from the submitter’s 

proposal: Scales manufacturers are permitted to design scales where the value a verification scale 

division e differs from the displayed scale division d.

Rationale: When taken with the SMA’s recommendation for SCL-20.4, this will avoid duplication 

in the HB44 code. 

During the 2022 Fall Meeting, the SMA continued to support the further development of this block of items 

and the work of the Verification Scale Division (e) Task Group. The SMA would encourage the work group 

to make the final changes to this block of Assigned Items and present it to the S&T Committee and 

Membership, otherwise remove it. 

Recommendation: the SMA encourages the use of the terminology “Verification Interval” for “e” and 

“Scale Division” for “d” in every instance that it appears in the Handbook. 

The SMA recommended the following changes to the individual items in Block 2: 

B2: SCL-20.3 S.5.4 Relationship of Minimum Load Cell Verification Interval: No change 

B2: SCL-20.4 Table 3. Parameters of Accuracy Classes

Recommendation: The SMA recommends the following change to Table 3, Footnote 1: Class I 

and II scales may be designed such that the verification scale division verification interval e does 

not be equal to the scale division d.

B2: SCL-20.5 Table S.6.3.A. Marking Requirements, Note 3: No Change 

B2: SCL-20.6 T.N.1.2. Accuracy Classes and T.N.1.3. Scale Division 

Recommendation: The SMA recommends the following change: “... except that (d) is not used 

in reference...”

B2: SCL-20.8 Table 8. Recommended Minimum Load

Recommendation: The SMA recommends striking the following language from the submitter’s 

proposal: Scales manufacturers are permitted to design scales where the value a verification scale 

division e differs from the displayed scale division d.

Rationale: When taken with the SMA’s recommendation for SCL-20.4, this will avoid duplication in the 

HB44 code. 

Item Block 3 (B3) Tolerances for Distance Testing in Taximeters and Transportation 

Network Systems

B3: TXI-20.1 D T. Tolerances 

B3: TNS-20.1 D T. Tolerances

Source: New York Department of Agriculture and Markets

Submitter’s Purpose and Justification: 

Provide the same distance-measurement tolerances for the Taximeters Code and Transportation Network 

Systems Code.
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OWM Executive Summary for Item Block 3 (B3) – Tolerances for Distance Testing in Taximeters 

and Transportation Network Systems TXI-20.1 T. Tolerances and TNS-20.1 T. Tolerances

OWM Recommendation: 

• OWM concurs with the submitter's recommendation during NEWMA October 25-26, 2022 Interim 

Meeting to withdraw the proposal. OWM continues to encourage stakeholders to work with the 

USNWG to ensure that future modifications to the NIST HB 44 Taximeters and TNMS Codes fully 

consider the technology used in both applications. 

• The work to update the taximeters and TNMS codes may need to be stepped up to address issues 

identified in the areas of design and function of indicating elements, provisions for sealing, and 

location services signal loss so that these provisions are in the code for properly operating this newer 

technology in taxis. 

Table 3. Summary of Recommendations

Item B3 – TXI-20.1 T. Tolerances and TNS-20.1 T. Tolerances

V D W A I Notes* Comments

Submitter 

OWM 

WWMA 

SWMA 

NEWMA 

CWMA 

NCWM

Letters of Support Letters of Opposition Notes

Industry

Manufacturers

Retailers and Consumers

*Notes Key:

1 - Submitted modified language

2 - Item not discussed

3 - No meeting held

4 - Not submitted on agenda

 5 - No recommendation or not considered
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Item Under Consideration:

The Item Under Consideration published in the Committee’s 2023 Interim Report is shown below. 

B3: TXI-20.1 D T. Tolerances

Amend Handbook 44, Taximeters Code as follows. 

T. Tolerances

T.1. Tolerance Values.

T.1.1. On Distance Tests. – Maintenance and acceptance tolerances for taximeters shall be as 

follows: 

(a) On Overregistration: 1 % of the interval under test when the distance is 1.6 km (1 mile) 

or less. 2.5 % of the interval under test when the distance is greater than 1.6 km (1 

mile). 

B3: TNS-20.1 D T. Tolerances

Amend Handbook 44, Transportation Network Systems Code as follows: 

T. Tolerances

T.1.1. Distance Tests. – Maintenance and acceptance tolerances shall be as follows:

(a) On Overregistration: 2.5 % 1 % of the interval under test when the distance is 1.6 km 

(1 mile) or less. 2.5 % of the interval under test when the distance is greater than 1.6 

km (1 mile).

(b) On Underregistration: 2.5 % 4 % of the interval under test.

On March 23, 2022, the submitter requested the Committee replace the Item Under Consideration shown 

in the 2022 S&T Interim Report with the following. 

Modify NIST Handbook 44 Section 5.54 Taximeters Code as follows: 

T.1. Tolerance Values.

T.1.1. On Distance Tests. – Maintenance and acceptance tolerances for taximeters shall be as 

follows: 

T.1.1.1. Meters Using Distance generated from sources physically connected to the 

vehicle (e.g OBD sensor).

(a) On Overregistration: 1 % of the interval under test. 

(b) On Underregistration: 4 % of the interval under test, with an added tolerance of 30 m 

or 100 ft whenever the initial interval is included in the interval under test. 
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T.1.1.2. Meters Using Distance generated from sources not physically connected to the 

vehicle (e.g navigation satellite system such as GPS and /or other location services).

(a) On Overregistration: 2.5 % 

(b) On Underregistration: 2.5 %

Withdraw the TNMS portion of the original proposal and leave the existing TNMS Code as it currently 

appears in NIST Handbook 44. 

NIST OWM Detailed Technical Analysis:

Background: OWM appreciates the efforts of the submitter to harmonize the tolerance requirements in the 

Taximeters Code and the TNMS Code although, we did not believe it is necessary to increase the tolerance 

allowed since taximeters have been required to comply with the existing tolerances for decades. 

OWM also noted that TNMS do not typically assess fare charges based on intervals as do taximeters. 

Taximeters will accumulate fare charges by summing the number of intervals comprising the trip’s distance 

traveled and time elapsed and multiplying by the appropriate rate. In contrast, TNMS typically base the 

fare charges on the total distance (and time in some cases) for the trip. For this reason, we did not believe 

it is necessary to amend paragraphs T.1.1.(a) and (b) to refer to “interval under test” as is shown in the 

proposal. OWM recommended that this proposal be further developed with the assistance of the NIST 

USNWG on Taximeters in such a way that will better align the HB 44 Taximeters and TNMS Codes.

The NIST led U.S. National Work Group (USNWG) on Taximeters has held virtual meetings in May, June, 

and October 2020 and June 2021 to further develop standards for both taximeters and TNMS. The focus 

of these meetings was the merger of the existing HB 44 Taximeters Code and the tentative TNMS Code. 

Those members attending these meetings were in general agreement that this is the appropriate direction 

the work group should take. The USNWG also began discussions on some of the areas to be addressed in 

a unified “Transportation-for-Hire Systems” Code that could present challenges in the development of 

appropriate requirements. Those areas included the design and function of indicating elements, provisions 

for sealing, and location services signal loss. 

The submitter of the proposal (New York or NYS) agreed to work with the USNWG to further develop this 

proposal and is actively participating in those meetings. The submitter explained to the USNWG that some 

of the more recent systems submitted to the state of New York for type approval had not been able to 

comply with the existing taximeter tolerances. This failure was seen in systems that attempted to use 

location services (i.e., GPS) to measure distance. In response to that point, it was noted that other systems 

have been able to meet those tolerances and to expand the tolerances would be an approach that is not 

supported by most in the weights and measures community. 

Also included as a topic in the meetings was this proposal submitted to the NCWM S&T Committee to 

amend the HB 44 Taximeters and TNMS Codes. The USNWG agreed that the two HB 44 Codes should 

be merged and that this could be accomplished by continuing its efforts in the future. 

NIST OWM is aware that the developer of the proposal was not able to provide updates to the proposal in 

January 2022 because of technical difficulties with audio-visual equipment at the NCWM Interim Meeting. 

The NYS alternate proposal modified only the Taximeter Code tolerances and was made available on March 

23, 2022 on the NCWM website. This update was later noted in the May 2022 CWMA and NEWMA 

Annual Meeting summaries. The NYS alternate proposal established a new set of taximeter over- and 
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under-registration tolerances at 2.5 % which are equivalent to those applied to TNMS. The current 

tolerances remain in place when the taximeter source for distance measurements is connected to the vehicle. 

The proposed new tolerances apply when the taximeter’s source for distance measurement is generated 

from equipment not physically connected to the vehicle such as a GPS. This mechanism for generating 

measurement data from sources not physically connected to the vehicle is similar in the operation of a 

TNMS.

On March 23, 2022, NYS also withdrew the portion of Block 3 designated as B3: TNS-20.1 T. Tolerances, 

and no longer recommended modifying Transportation Network Measurement Systems -Tentative Code 

paragraph T.1.1. Distance Tests maintenance and acceptance tolerances for over- and under-registration 

and to reestablish the limits of permissible error of the TNMS under test as a percentage of the interval 

under test and distance traveled over the test course.

Based on the methodology used to determine distance traveled the proposal would permit a dual tolerance 

structure for vehicles within a single company or operating in the same geographic area. Work may need 

to be stepped up to address issues identified in the areas of design and function of indicating elements, 

provisions for sealing, and location services signal loss so that these provisions are in the code for properly 

operating this newer technology in taxis.

In conclusion: By December 2022 NIST OWM agreed with the submitter’s recommendation during the 

NEWMA October 25-26, 2022 Interim Meeting to withdraw the proposal. OWM continues to encourage 

stakeholders to work with the USNWG to ensure that future modifications to the NIST HB 44 Taximeters 

and TNMS Codes fully consider the technology used in both applications. 

The work to update the taximeters and TNMS codes may need to be stepped up to address issues identified 

in the areas of design and function of indicating elements, provisions for sealing, and location services 

signal loss so that these provisions are in the code for properly operating this newer technology in taxis.

Summary of Discussions and Actions:

NCWM 2022 Annual Meeting: During open hearings, the Committee received an update from submitter 

Mr. Jim Willis (New York). Based on feedback, Mr. Willis has made language changes which will be 

updated for the fall meetings. Mr. Willis requested that the item retain its Developing status.

Regional Association Reporting:

Central Weights and Measures Association

Mr. Craig VanBuren (Michigan): trying to make two measurements of the same device category equal in 

tolerance values. i.e. GPS and taxis have the same tolerance. Concerns regarding errors in the customer’s 

favor shouldn’t be a problem. But on pages 284-285, depending on physical vehicle or GPS, there are 

different tolerances? Why is the tolerance conflicting within the same block? Haven’t heard any input 

from transportation companies. Recommend withdrawal.

The CWMA S&T Committee recommended this remains as a Developing Item.

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting the following comments were received:
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Mr. Matt Douglas (California Division of Measurement Standards) wanted to hear if this update addressed 

some of the concerns raised particularly by Mr. Floren. Did see the merit in how this was developed. 

Thought this is close to being ready if not already ready for a vote. 

Mr. Kurt Floren (County of Los Angeles, California) was opposed to the original item and is against 

lowering the bar when there is technology out there that is meeting the tolerances. Didn’t think that the 

verbiage of “physically connected to the vehicle” is sufficient. Thought the item needs to be developed to 

clarify that the drive is what is connected to the vehicle. 

During open hearings, members in attendance were notified that the language in the agenda did not reflect 

the updated Item Under Consideration. Membership was not fully aware of the new language at the time 

of open hearings. Concerns were heard that terms such as “physically connected” are not specific enough 

to enforce. The WWMA S&T Committee recommended that this item should remain Developing to allow 

membership to review the updated proposal. 

Southern Weights and Measures Association

No comments were received on this item during the 2022 SWMA Annual Meeting. 

The SWMA S&T Committee recommended this item remain as a Developing Item.

Northeastern Weights and Measures Association

Mr. Jim Willis (New York), submitter, requested that this item be withdrawn. 

At the request of the submitter, the Committee recommended that this item be withdrawn.

Item Block 4 (B4) Electronically Captured Tickets or Receipts

(Note: The Item Under Consideration reflects changes that were received by the committee from the 

submitter of the item and that the Committee agreed to during its 2021 Interim Meeting work session. The 

changes are highlighted.)

B4: CLM-21.1 D S.1.4.1. Printed Ticket Recorded Representation., UR.2.6.3. Printed Ticket

Recorded Representation.

B4: MLK-XX-X D S.1.4.2 Printed Ticket Recorded Representation., UR.2.2. Printed Ticket, 

Recorded Representation. 

B4: MFM-21.2 D S.6. Printer Recorded Representations., UR.2.6. Ticket Printer, Customer 

Ticket, Recorded Representation., UR.3.4. Printed Ticket. Recorded 

Representation. 

B4: CDL-21.1 D S.1.4.1. Printed Ticket Recorded Representations., UR.2.4.2. Tickets or 

Invoices. Recorded Representation. 

B4: HGM-21.1 D S.2.6. Recorded Representations, Point of Sale Systems., S.6. Printer. Recording 

Element., UR.3.2. Vehicle-mounted Measuring Systems Ticket Printer

Recording Element., UR.3.3. Printed Ticket. Recorded Representation. 

B4: OTH-21.2 D Appendix D - Definitions.: recorded representations, recording element.

Source: Kansas Department of Agriculture, Division of Weights and Measures
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Submitter’s Purpose and Justification:

Allow recorded values to be captured electronically as an alternative to a printed ticket or receipt.

In 2014 G-S.5.6. was added to Handbook 44 to allow for the issuance of electronic receipts. At that time 

the use of the term “print”, and all variations on the word “print” was not fully addressed.

The Oxford Dictionary defines print as “a mechanical process involving the transfer of text, images, or 

designs to paper.”

The Oxford Dictionary defines record as: to “set down in writing or some other permanent form for later 

reference, especially officially.”

Values that are delivered via electronic means are recorded values and not necessarily printed vales. Printed 

indicates that a value has been transferred on to a hard document. While the intent of the 2014 amendment 

was to allow for the use of electronic receipts the terminology used is incorrect. In addition to receipts, 

there are instances where other information may be transmitted electronically.

When applying G-A.2. to weighing and measuring devices, 

G-A.2. Code Application. – This General Code shall apply to all classes of devices as covered in 

the specific codes. The specific code requirements supersede General Code requirements in all cases 

of conflict. 

(Amended 1972) 

Multiple conflicts arise in the implementation of the 2014 Amendment of G-S.5.6. This is to clarify the 

terminology in Handbook 44 and to recognize the changing technology in how transactions are recorded, 

and the information is disseminated.

OWM Executive Summary for Item Block 4 (B4) – Electronically Captured Tickets or Receipts 

OWM Recommendation: Although NIST OWM feels that all proposed changes would benefit from 

additional review, NIST OWM believes that the additional changes made to G-S.5.6 provides clarity. 

NIST OWM supported a Developing status so that changes to the B4 specific codes are carefully 

reviewed to ensure the proposed changes did not change the original intent of the specific section. 

Barring no additional specific changes to Block 4 items NIST OWM supports this item moving forward 

with a Voting status with the suggested change below. 

• Most of the changes proposed by NIST OWM are included in the proposal, except for the 

recommendation that “However” be removed from the General Code requirement in this proposal. 

We recommend that “However” be removed.

Table 3. Summary of Recommendations

Item Block 4 – Electronically captured tickets or receipts

V D W A I Notes* Comments

Submitter 

• Proposed Revisions by Submitter (09-28-

2020)

• Further Comments (01-13-2021)

OWM
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Table 3. Summary of Recommendations

Item Block 4 – Electronically captured tickets or receipts

V D W A I Notes* Comments

WWMA 

SWMA 

NEWMA 

CWMA 

NCWM

Letters of Support Letters of Opposition Notes

Industry

Manufacturers

Retailers and Consumers

*Notes Key:

1 − Submitted modified language

2 − Item not discussed

3 − No meeting held

4 − Not submitted on agenda

5 − No recommendation or not considered

Item Under Consideration:

B4: GEN-21.2 D G-S.5.6. Recorded Representations.

Amend Handbook 44, General Code as follows: 

G-S.5.6. Recorded Representations. – Insofar as they are appropriate, the requirements for 

indicating and recording elements shall also apply to recorded representations. All recorded values 

shall be printed provided presented digitally. In applications where recorded representations are

required by a specific code, the customer may be given the option of not receiving the recorded 

representation. Unless otherwise specified, recorded representations referenced in specific codes 

shall be made available to the customer as a minimum in hard copy form. However, for systems 

equipped with the capability of issuing an electronic receipt, ticket, or other recorded representation, 

the customer may be given the option to receive any required information electronically (e.g., via cell 

phone, computer, etc.) in lieu of or in addition to a hard copy. 

(Amended 1975, 2014 and 20XX) 

B4: LMD-21.2 D S.1.6.5. Money Value Computations., UR.3. Use of a Device.

Amend Handbook 44, Liquid Measuring Devices Code as follows: 

S.1.6.5. Money-Value Computations
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... 

S.1.6.5.6. Display of Quantity and Total Price, Aviation Refueling Applications. 

(a) The quantity shall be displayed throughout the transaction. 

(b) The total price shall also be displayed under one of the following conditions:

(1) The total price can appear on the face of the dispenser or through a controller adjacent 

to the device.

(2) If a device is designed to continuously compute and display the total price, then the 

total price shall be computed and displayed throughout the transaction for the quantity 

delivered. 

(c) The total price and quantity shall be displayed for at least five minutes or until the next 

transaction is initiated by using controls on the device or other customer-activated 

controls. 

(d) A printed receipt shall be available and shall include, at a minimum, the total price, 

quantity, and unit price. 

[Nonretroactive as of January 1, 2008]

(Added 2007) (Amended 20XX)

S.1.6.7. Recorded Representations. – Except for fleet sales and other price contract sales and for 

transactions where a post-delivery discount is provided, a printed receipt providing the following 

information shall be available through a built-in or separate recording element for all transactions 

conducted with point-of-sale systems or devices activated by debit cards, credit cards, and/or cash:

(a) the total volume of the delivery;*

(b) the unit price;*

(c) the total computed price;* 

(d) the product identity by name, symbol, abbreviation, or code number;* and 

(e) the dispenser designation by either an alphabetical or numerical description.** 

*[Nonretroactive as of January 1, 1986] **[Nonretroactive as of January 1, 2021] 

(Added 1985) (Amended 1997, 2012, 2014, 2018 and 20XX) 

S.1.6.8. Recorded Representations for Transactions Where a Post-Delivery Discount(s) is 

Provided. – Except for fleet sales and other price contract sales, a printed receipt providing the 

following information shall be available through a built-in or separate recording element that is part of 

the system for transactions involving a post-delivery discount:

(a) the product identity by name, symbol, abbreviation, or code number;

(b) transaction information as shown on the dispenser at the end of the delivery and prior to any 

post-delivery discount(s), including the: 
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(1) total volume of the delivery; 

(2) unit price; and 

(3) total computed price of the fuel sale. 

(c) an itemization of the post-delivery discounts to the unit price; 

(d) the final total price of the fuel sale after all post-delivery discounts are applied; and

(e) the dispenser designation by either an alphabetical or numerical description. 

[Nonretroactive as of January 1, 2021] 

(Added 2012) (Amended 2014, and 2018, and 20XX) 

... 

UR.3. Use of a Device 

... 

UR.3.3. Computing Device – Any computing device used in an application where a product or 

grade is offered for sale at one or more unit prices shall be used only for sales for which the device 

computes and displays the sales price for the selected transaction.

(Became retroactive 1999)

(Added 1989) (Amended 1992) 

The following exceptions apply: 

(a) Fleet sales and other price contract sales are exempt from this requirement.

(b) A truck stop dispenser used exclusively for refueling trucks is exempt from this requirement 

provided that:

(1) all purchases of fuel are accompanied by a printed receipt of the transaction containing 

the applicable price per gallon, the total gallons delivered, and the total price of the sale; 

and 

(Added 1993) 

(2) unless a dispenser complies with S.1.6.4.1. Display of Unit Price, the price posted on the 

dispenser and the price at which the dispenser is set to compute shall be the highest price 

for any transaction which may be conducted. 

(Added 1993) 

(c) A dispenser used in an application where a price per unit discount is offered following the 

delivery is exempt from this requirement, provided the following conditions are satisfied: 

(1) the unit price posted on the dispenser and the unit price at which the dispenser is set to 

compute prior to the application of any discount shall be the highest unit price for any 

transaction;

(Amended 2014) 
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(2) all purchases of fuel are accompanied by a receipt recorded by the system. The receipt 

shall contain:

a. the product identity by name, symbol, abbreviation, or code number; 

b. transaction information as shown on the dispenser at the end of the delivery and prior 

to any post-delivery discount including the:

1. total volume of the delivery; 

2. unit price; and 

3. total computed price of the fuel sale prior to post-delivery discounts being applied.

c. an itemization of the post-delivery discounts to the unit price; and 

d. the final total price of the fuel sale.

(Added 2012) (Amended 2014) 

(Added 1989) (Amended 1992, 1993, 2012, and 2014, and 20XX) 

UR.3.4. Printed Ticket. Recorded Representation. – The total price the total volume of the 

delivery; the price per liter or gallon; and a corresponding alpha or numeric dispenser designation*

shall be shown, either printed recorded by the device or in clear hand script, on any printed ticket

issued by a device and recorded representation containing any one of these values and shall comply 

with G-S.5.6. Establishments where no product grades are repeated are exempt from the dispenser 

designation requirement.

*[Nonretroactive as of January 1, 2021]

(Amended 2001, 2018, and 2019, and 20XX) 

B4: VTM-21.1 D S.1.1. Primary Elements., UR.2. User Requirements

Amend Handbook 44, Vehicle Tank Meter Code as follows: 

S.1.1. Primary Element

S.1.1.1. General. – A meter shall be equipped with a primary indicating element. and may also 

be equipped with a primary recording element. Except for systems used solely for the sale of 

aviation fuel into aircraft and for aircraft-related operations, a meter shall be equipped with 

a primary recording element.

(Amended 1993 and 20XX) 

Note: Except for systems used solely for the sale of aviation fuel into aircraft and for aircraftrelated operations, vehicle-tank meters shall be equipped with a primary recording element 

as required by paragraph UR.2.2. Ticket Printer; Customer Ticket. Recorded 

Representation

(Amended 1993 and 20XX) 

... 
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S.1.4.2. Printed Ticket. Recorded Representation. – If a computing-type device issues a 

printed ticket recorded representation which displays the total computed price, the ticket

recorded representation shall also have printed clearly thereon record the total quantity of the 

delivery, the appropriate fraction of the quantity, and the price per unit of quantity. 

(Amended 1989, and 20XX) 

... 

UR.2. User Requirements.

... 

UR.2.2. Ticket Printer, Customer Ticket Recording Element. – Vehicle-Mounted metering 

systems shall be equipped with a ticket printer which shall be used for means to record all sales 

where product is delivered through the meter and shall comply with G-S.5.6. A copy of the ticket 

issued by the device shall be left with provided to the customer at the time of delivery or as otherwise 

specified by the customer.

(Added 1993) (Amended 1994, and 20XX) 

B4: LPG-21.1 D S.1.1. Primary Elements., UR.2. User Requirements

Amend Handbook 44, LPG and Anhydrous Ammonia Liquid-Measuring Devices Code as follows: 

S.1.1. Primary Elements. 

S.1.1.1. General. – A meter shall be equipped with a primary indicating element and may also be 

equipped with a primary recording element. 

Note: Vehicle-mounted metering systems shall be equipped with a primary recording element as required by 

paragraph UR.2.6. Ticket Printer; Customer Ticket.Recorded Representation

(Amended 20XX)

...

S.1.1.6. Printed Ticket. Recorded Representation – Any printed ticket issued recorded 

representation created by a device of the computing type on which there is printed includes the 

total computed price, shall have printed clearly also include thereon the total volume of the 

delivery in terms of liters or gallons, and the appropriate decimal fraction of the liter or gallon, and 

the corresponding price per liter or gallon. 

(Added 1979) (Amended 1987, and 20XX) 

... 

S.1.5.5. Recorded Representations for Transactions Where a Post-Delivery Discount(s) is 

Provided. – Except for fleet sales and other price contract sales, a printed receipt recorded 

representation providing the following information shall be available through a built-in or separate 

recording element that is part of the system for transactions involving a post-delivery discount: 

(a) the product identity by name, symbol, abbreviation, or code number; 
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(b) transaction information as shown on the dispenser at the end of the delivery and prior to 

any post-delivery discount(s), including the: 

(1) total volume of the delivery;

(2) unit price; and

(3) total computed price of the fuel sale. 

(c) an itemization of the post-delivery discounts to the unit price; and 

(d) the final total price of the fuel sale after all post-delivery discounts are applied. 

(Added 2016) (Amended 20XX)

... 

UR.2. User Requirements.

... 

UR.2.6. Ticket Printer, Customer Ticket. Recorded Representation– Vehicle-Mounted metering 

systems shall be equipped with a ticket printer which shall be used for means to record all sales 

where product is delivered through the meter and shall comply with G-S.5.6. A copy of the ticket

recorded representation issued by the device shall be left with provided to the customer at the time 

of delivery or as otherwise specified by the customer. 

(Added 19932) (Amended 1994, and 20XX) 

... 

UR.2.7.2. Computing Device. – Any computing device used in an application where a product 

or grade is offered for sale at one or more unit prices shall be used only for sales for which the 

device computes and displays the sales price for the selected transaction. The following exceptions 

apply: 

(a) Fleet sales and other price contract sales are exempt from this requirement.

(b) A truck stop dispenser used exclusively for refueling trucks is exempt from this 

requirement provided that:

(1) all purchases of fuel are accompanied by a printed receipt recorded representation 

of the transaction containing the applicable price per unit of measure, the total quantity 

delivered, and the total price of the sale; and 

(2) unless a dispenser complies with S.1.5.1. Display of Unit Price, the price posted on the 

dispenser and the price at which the dispenser is set to compute shall be the highest 

price for any transaction which may be conducted. 

(c) A dispenser used in an application where a price per unit discount is offered following the 

delivery is exempt from this requirement, provided the following conditions are satisfied:
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(1) the unit price posted on the dispenser and the unit price at which the dispenser is set to 

compute shall be the highest unit price for any transaction; 

(2) all purchases of fuel are accompanied by a receipt recorded by the system for the 

transaction containing: 

a. the product identity by name, symbol, abbreviation, or code number; 

b. transaction information as shown on the dispenser at the end of the delivery and 

prior to any post-delivery discount including the:

1. total volume of the delivery;

2. unit price; and

3. total computed price of the fuel sale prior to post-delivery discounts being 

applied. 

c. an itemization of the post-delivery discounts to the unit price; and

d. the final total price of the fuel sale after all post-delivery discounts are applied. 

(Added 2016) (Amended 20XX)

B4: CLM-21.1 D S.1.4.1. Printed TicketRecorded Representation., UR.2.6.3. Printed 

TicketRecorded Representation.

Amend Handbook 44, Cryogenic Liquid-Measuring Devices Code as follows: 

S.1.4.1 Printed Ticket Recorded Representation –Any printed ticket recorded representation 

issued by a device of the computing type on which there is printed includes the total computed price

shall have printed clearly thereon also include the total quantity of the delivery, and the price per 

unit. 

(Amended 20XX) 

And

UR.2.6.2. Tickets or Invoices. Recorded representation– Any written invoice, or printed ticket,

recorded representation based on a reading of a device that is equipped with an automatic temperature 

or density compensator shall have shown thereon that the quantity delivered has been adjusted to the 

quantity at the NBP of the specific cryogenic product or the equivalent volume of gas at NTP. 

(Amended 20XX)

UR.2.6.3. Printed Ticket. Recorded Representation. – Any printed ticket issued recorded 

representation provided by a device of the computing type on which there is printed includes the 

total computed price, the total quantity of the delivery, or the price per unit, shall also show include 

the other two values. (either printed or in clear hand script).. and shall comply with G-S.5.6. 

(Amended 20XX)
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B4: MLK-21.1 D S.1.4.2. Printed Ticket Recorded Representation., UR.2.6.3. Printed 

TicketRecorded Representation.

Amend Handbook 44, Milk Meter Code as follows: 

S.1.4.2. Printed Ticket Recorded Representation – If a computing-type device issues a 

printed ticket recorded representation which displays includes the total computed price, the 

ticket recorded representation shall also have printed clearly thereon include the total quantity 

of the delivery, the appropriate fraction of the quantity, and the price per unit of quantity. 

(Amended 1989 and 20XX) 

UR.2.2. Printed Ticket. Recorded Representation. – Any printed ticket issued recorded 

representation created by a device of the computing type on which there is printed includes the total 

computed price, the total quantity, or the price per unit of quantity, shall also show include the other 

two values (either printed or in clear hand script). and shall comply with G-S.5.6. 

(Amended 1989 and 20XX) 

B4: MFM-21.2 D S.6. PrinterRecorded Representations., UR.2.6. Ticket Printer, 

Customer Ticket, Recorded Representation., UR.3.4. Printed Ticket.

Recorded Representation.

Amend Handbook 44, Mass Flow Meter Code as follows: 

S.6. Printer. Recording Element – When an assembly is equipped with means for printing recording

the measured quantity, the following conditions apply: 

(a) the scale interval shall be the same as that of the indicator; 

(b) the value of the printed recorded quantity shall be the same value as the indicated quantity;

(c) the printed recorded quantity shall also include the mass value if the mass is not the indicated 

quantity; 

[Nonretroactive as of January 1, 2021]

(d) a quantity for a delivery (other than an initial reference value) cannot be recorded until the 

measurement and delivery has been completed;

(e) the printer recording element is returned to zero when the resettable indicator is returned to 

zero; and

(f) the printed recorded values shall meet the requirements applicable to the indicated values.

(Amended 2016, and 20XX) 

S.6.1. Printed Receipt Recorded Representations. – Any When a quantity is delivered, 

printed quantity the recorded representation shall include an identification number, the time and 

date, and the name of the seller. This information may be printed by the device or pre-printed on 

the ticket.

(Amended 20XX)

And
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UR.3.3 Ticket Printer, Customer Ticket, Recorded Representation. – Vehicle-Mounted 

metering systems shall be equipped with a ticket printer which shall be used for means to record 

all sales where product is delivered through the meter and shall comply with G-S.5.6. A copy of 

the ticket recorded representation issued by the device shall be left with provided to the customer 

at the time of delivery or as otherwise specified by the customer.

(Added 19934) (Amended 20XX) 

... 

UR.3.4. Printed Ticket. Recorded Representation. – The total price, the total quantity of the 

delivery, and the price per unit shall be printed provided on any ticket recorded representation

issued by a device of the computing type and containing any one of these values. 

(Added 1993) (Amended 20XX) 

B4: CDL-21.1 D S.1.4.1. Printed TicketRecorded Representations., UR.2.4.2. Tickets or 

Invoices. Recorded Representation.

Amend Handbook 44, Carbon Dioxide Liquid-Measuring Devices Code as follows: 

S.1.4.1. Printed Ticket. Recorded Representation– Any printed ticket recorded representation

issued by a device of the computing type on which there is printed includes the total computed price 

shall have printed clearly thereon also include the total quantity of the delivery and the price per unit.

(Amended 20XX)

UR.2.4.2. Tickets or Invoices Recorded Representation. – Any written invoice or printed ticket

recorded representation based on a reading of a device that is equipped with an automatic temperature 

or density compensator shall have shown thereon include that the quantity delivered has been 

temperature or density compensated.

(Amended 20XX) 

B4: HGM-21.1 D S.2.6. Recorded Representations, Point of Sale Systems., S.6. Printer. 

Recording Element., UR.3.2. Vehicle-mounted Measuring Systems 

Ticket Printer Recording Element., UR.3.3. Printed Ticket. Recorded 

Representation.

Amend Handbook 44, Hydrogen Gas-Measuring Devices Code as follows: 

S.2.6. Recorded Representations, Point of Sale Systems. – A printed receipt shall be available 

through a built-in or separate recording element for transactions conducted with point-of-sale systems 

or devices activated by debit cards, credit cards, and/or cash. The printed receipt shall contain the 

following information for products delivered by the dispenser: 

(a) the total mass of the delivery;

(b) the unit price; 

(c) the total computed price; and
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(d) the product identity by name, symbol, abbreviation, or code number. 

(Amended 20XX)

... 

S.6. Printer. Recording Element – When an assembly is equipped with means for printing recording

the measured quantity, the printed recorded information must agree with the indications on the dispenser 

for the transaction and the printed recorded values shall be clearly defined. 

(Amended 20XX)

S.6.1. Printed Receipt. Recorded Representation – Any When a quantity is delivered, printed 

quantity the recorded representation shall include an identification number, the time and date, and 

the name of the seller. This information may be printed by the device or pre- printed on the ticket.

(Amended 20XX)

And

UR.3.2. Vehicle-mounted Measuring Systems Ticket Printer Recording Element. 

(Amended 20XX) 

UR.3.2.1. Customer Ticket Recording Element. – Vehicle-Mounted metering systems shall be 

equipped with a ticket printer which shall be used for means to record all sales where product 

is delivered through the device and shall comply with G-S.5.6. A copy of the ticket recorded 

representation issued by the device shall be left with provided to the customer at the time of 

delivery or as otherwise specified by the customer.

(Amended 20XX) 

... 

UR.3.3. Printed Ticket. Recorded Representation. – The total price, the total quantity of the 

delivery, and the price per unit shall be printed provided on any ticket recorded representation

issued by a device of the computing type and containing any one of these values. 

(Added 1993) (Amended 20XX)

B4: OTH-21.2 D Appendix D – Definitions.: recorded representations, recording 

element.

Amend Handbook 44, Appendix D – Definitions as follows: 

recorded representation. – The printed, embossed, electronic, or other representation that is recorded 

as a quantity, unit price, total price, product identity or other information required by a weighing 

or measuring device. [1.10, 2.20, 2.21, 2.22, 2.24, 2.25, 3.30, 3.31, 3.32, 3.33, 3.34, 3.35, 3.36, 3.37, 

3.38, 3.39, 3.40, 5.54, 5.55, 5.56(a), 5.56(b), 5.57, 5.58, 5.60] 

recording element. – An element incorporated in a weighing or measuring device by means of which 

itsthe device’s performance relative to quantity or money value is permanently recorded electronically 

or on a tape, ticket, card, or the like, in the form of a printed, stamped, punched, or perforated 

representation or recorded electronically in instances where that option is permitted by specific 
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code. [1.10, 2.20, 2.21, 2.22, 2.24, 2.25, 3.30, 3.31, 3.32, 3.33, 3.34, 3.35, 3.36, 3.37, 3.38, 3.39, 3.40, 

5.54, 5.55, 5.56(a), 5.56(b), 5.57, 5.58, 5.60] 

NIST OWM Detailed Technical Analysis:

Although NIST OWM feels that all proposed changes would benefit from additional review, NIST OWM 

believes that the additional changes made to G-S.5.6 provides clarity. NIST OWM believes a Developing 

status is appropriate so that changes to the B4 specific codes are carefully reviewed to ensure the proposed 

changes do not change the original intent of the specific section before moving these items forward for a 

vote. 

NIST OWM provided the previous comments. The key purpose of this block of proposals is to broaden 

the requirements by eliminating the term “print/printed” in specific NIST HB 44 codes and clarifying that 

providing an electronic recorded representation in lieu of a printed recorded representation is an acceptable 

option as was adopted in G-S.5.6. Recorded Representations in 2014. NIST OWM provides the following 

technical points for consideration.

Paragraph G-S.5.6. Recorded Representation addresses multiple points relative to recorded representations:

1. Any NIST Handbook 44 requirement applicable to indicating and recording elements also apply to 

recorded representations.

2. Recorded values must be printed in a numerical or “digital” form. The reference to the term 

“digitally” refers to the use of that term as described in the definition for “digital type,” which 

describes “digitally” as being presented in numbers. 

3. Providing the customer with an option of “not receiving a receipt” is acceptable, so long as the 

customer is making that choice to not receive a receipt.

4. For systems that are capable of issuing an electronic receipt, the customer may be given the option 

of receiving the receipt in an electronic form. However, providing the option for an electronic 

receipt does not negate any requirement for the system to provide the customer with the option of 

a hard copy receipt for those specific codes where a hard copy receipt is required. That is, the 

system may offer additional options beyond the hard copy form; however, the hard copy form must 

remain an option for the customer to choose. The first part of this also sentence recognizes that not 

all systems are capable of providing an electronic option (though this would not preclude some 

codes from requiring such an option), but when such an option is available, the customer may 

choose that option over other options provided. 

The current Item Under Consideration presents the recommended changes to G-S.5.6. Recorded 

Representations as follows:

Current Item Under Consideration in 2021 S&T Committee Interim Report:

G-S.5.6. Recorded Representations. – Insofar as they are appropriate, the requirements 

for indicating and recording elements shall also apply to recorded representations. All 

recorded values shall be printed provided presented digitally. In applications where 

recorded representations are required by a specific code, the customer may be given the 

option of not receiving the recorded representation. Unless otherwise specified, recorded 

representations referenced in specific codes shall be made available to the customer as 
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a minimum in hard copy form. However, for systems equipped with the capability of 

issuing an electronic receipt, ticket, or other recorded representation, the customer may be 

given the option to receive any required information electronically (e.g., via cell phone, 

computer, etc.) in lieu of or in addition to a hard copy. 

(Amended 1975, 2014 and 20XX)

With regard to the specific changes proposed to G-S.5.6., NIST OWM offers the following technical 

comments:

- Sentence 2: “All recorded values shall be printed provided presented digitally.”

OWM believes the proposed change to the second sentence in G-S.5.6. are appropriate. The 

original intent of the second sentence was to address the need for a numerical format. As noted 

above, the reference in that sentence to the term “digitally” refers to the use of that term as described 

in the definition for “digital type,” which describes “digitally” as being presented in numbers. The 

definition from NIST HB 44 Appendix D: 

o digital type. – A system of indication or recording of the selector type or one that advances 

intermittently in which all values are presented digitally, or in numbers. In a digital 

indicating or recording element, or in digital representation, there are no graduations. [1.10] 

The word “printed” reflects the technology that was available at the time the requirements were 

written; the use of the word “printed” was not intended to limit recorded representations to only 

hard copy form. Thus, the use of the word “presented” in place of “printed” does not change the 

original intent of that statement and helps to recognize that other forms of recorded representations 

are now available.

As an editorial comment, OWM notes that the word “provided” is not part of the current language 

in G-S.5.6. Although the intent of showing the term as struck was to distinguish it from earlier 

versions of the proposal, this term should be struck from the proposal when presenting it for 

consideration. 

- Sentence 3: “In applications where recorded representations are required by a specific code, the 

customer may be given the option of not receiving the recorded representation.”

OWM believes the proposed change to the third sentence by adding the term “by a specific code” 

is appropriate and simply emphasizes that individual codes may specify the need for a recorded 

representation. 

- Sentence 4: “Unless otherwise specified, recorded representations referenced in specific 

codes shall be made available to the customer as a minimum in hard copy form.” 

OWM believes the addition of this new fourth sentence clarifies that the customer must have the 

option of receiving the recorded representation in hard copy form but recognizes there may be some 

codes (such as the tentative code 3.40 for Electric Vehicle Fueling Systems) in which offering only 

an electronic form is acceptable.

- Sentence 5: “However, for systems equipped with the capability of issuing an electronic receipt, 

ticket, or other recorded representation, the customer may be given the option to receive any 

required information electronically (e.g., via cell phone, computer, etc.) in lieu of or in addition to 

a hard copy.”
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OWM believes the addition of the word “However” is unnecessary and may cause confusion. The 

current form of the sentence is appropriate. Thus, OWM recommends striking the proposed 

addition of the word “However” at the start of that sentence.

Based on the assessment above OWM recommended the final proposal be modified to recommend the 

following: 

G-S.5.6. Recorded Representations. – Insofar as they are appropriate, the requirements for 

indicating and recording elements shall also apply to recorded representations. All recorded values 

shall be printed presented digitally. In applications where recorded representations are required by a 

specific code, the customer may be given the option of not receiving the recorded representation. 

Unless otherwise specified, recorded representations referenced in specific codes shall be made 

available to the customer as a minimum in hard copy form. For systems equipped with the 

capability of issuing an electronic receipt, ticket, or other recorded representation, the customer may be 

given the option to receive any required information electronically (e.g., via cell phone, computer, etc.) 

in lieu of or in addition to a hard copy. 

(Amended 1975, 2014 and 20XX) 

These changes are represented in the 2022 Interim Meeting Report, Item Under Consideration with the 

exception of striking “However” as recommended above. 

At the 2021 CWMA Annual Meeting, a suggestion was made to simplify G-S.5.6 by removing changes 

that were added to G-S.5.6 in 2014 to address systems with the capability of issuing an electronic receipt 

and, instead, specify the electronic receipt option as an acceptable form of receipt in each specific code. 

Although NIST OWM agrees that the General Code requirement may benefit from a restructuring of the 

paragraph to improve its use, NIST OWM believes there is value in providing information on options for 

recorded representation in the general code requirements. The specific intent of the decision made in 2014 

to include this language in the General Code was to avoid the need to add specific language to each code. 

By doing so, this avoids a situation in which a given code is inadvertently overlooked and the potential 

option for an electronic form of recorded representation may be in question. Thus, OWM does not believe 

the reference to electronic receipts should be removed from the General Code. 

Nevertheless, if there is a desire to streamline the paragraph, the Submitter and the Committee may wish to 

consider using an alternate format such as sub-paragraphs or bulleted points to help clarify the various 

sections of the paragraph. For example, G-S.5.6. might be restructured as follows:

G-S.5.6. Recorded Representations. – The following shall apply to recorded representations.

(a) Insofar as they are appropriate, the requirements for indicating and recording elements shall 

also apply to recorded representations.

(b) All recorded values shall be printed presented digitally.

(c) In applications where recorded representations are required by a specific code, the customer 

may be given the option of not receiving the recorded representation.
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(d) Unless otherwise specified, recorded representations referenced in specific codes shall be 

made available to the customer as a minimum in hard copy form. For systems equipped 

with the capability of issuing an electronic receipt, ticket, or other recorded representation, the 

customer may be given the option to receive any required information electronically (e.g., via 

cell phone, computer, etc.) in lieu of or in addition to a hard copy. 

(Amended 1975, 2014 and 20XX) 

In addition to its comments regarding the proposed changes to paragraph G-S.5.6. Recorded 

Representations, NIST OWM also recommends the following editorial changes to this block of items: 

B4: LMD-21.2 - UR.3.4. Printed Ticket. Strike out “Printed Ticket”

B4: VTM-21.1 - S.1.4.2. Printed Ticket Strike out “Printed Ticket”

These changes are represented in the 2022 Interim Meeting Report, Item Under Consideration. 

Summary of Discussions and Actions:

At the 2021 Interim Meeting Mr. Charles Stutesman (Kansas), submitter of the item, agreed that the item 

should be Developing and noted that updates to the Item Under Consideration were provided to the S&T 

Committee based on reviews that he had with NIST OWM. Mr. Dmitri Karimov (MMA) commented that 

the proposed changes to recognize electronically captured tickets are needed, editorial corrections are 

needed to some parts of the proposal, and he agreed with a Developing status for this item. Ms. Diane Lee 

(NIST OWM) commented that there are two proposed changes to HB 44, Mass Flow Meter Code, 

Paragraph U.R.3.3 in the 2021 Interim Agenda. One proposal is Block 4 MFM-21.2 UR.3.3. (which was 

incorrectly number as UR.2.6 in the Item Under Consideration in the 2021 Interim Meeting agenda) and 

the other is item MFM-21.1. UR.3.3. on the 2021 Interim Meeting agenda. The submitters should work 

together to provide one proposed change. 

During the Committee work session, the Committee assigned a Developing status to Item Block 4. 

At the 2021 Annual Meeting Mr. Charles Stutesman (Kansas) stated that he looks forward to maintaining 

Developing status between now and the 2022 Interim. Mr. Stutesman explained that when the electronic 

receipt provision was added to NIST HB 44 General Code requirements, a change to the specific Codes 

were needed because the specific Codes supersede the General Code. All the code sections included in this 

block have printer requirements. As such, it was not the goal to remove printers but to add the option for 

electronic receipts if customer wants it. Mr. Stutesman would appreciate comments and suggestions for 

changes to the proposal. 

During the Committee work session, the Committee assigned a Developing status to Item Block 4. 

At the 2022 Interim Meeting Mr. Stutesman noted that some editing and additional work is needed before 

forwarding as a Voting item. Mr. Stutesman recommended that the item remain Developing. California 

DMS recommended a Developing status for this item. Mr. Dmitri Karimov (MMA) commented that 

proposed changes to recognize electronically captured tickets are needed and that editorial corrections are 

needed to some parts of the proposal. Mr. Karimov agreed with a Developing status for this item. An SMA 

representative also commented on support for this item because it recognizes the importance of providing 

flexible options for recorded representations to customers. SMA sees value in the item and agreed with a 

Developing status for this item. NIST OWM agreed with the need to address current language in the 

proposal and supports development.
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During the Committee work session, the Committee assigned a Developing status to Item Block 4. The 

Committee supports the work and recommends the continued work of all stakeholders. For more 

information or to provide comment, please contact:

Mr. Charles Stutesman

Kansas Department of Agriculture

(785) 564-6683, charles.stutesman@ks.gov

At the 2022 Annual Meeting open hearings Mr. Charles Stutesman (Kansas) commented that he worked 

with NIST OWM to add changes to the item and he also requested additional feedback from interested 

parties. Mr. Stutesman requested a Developing status for this item.

During the Committee work session, the Committee agreed to a Developing status for this item to allow for 

additional comments from interested parties.

Regional Association Reporting:

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting no comments were heard on this item. During open hearings, 

no comments were heard on this item. 

The WWMA S&T Committee recommended that this item remain Developing which would allow the 

submitter to ensure the edits are applicable for the identified sections. The Committee looks forward to an 

update on this Block.

Southern Weights and Measures Association

No comments were received on this item during the 2022 SWMA Annual Meeting. The SWMA S&T 

Committee recommended this item remain as a Developing Item.

Northeastern Weights and Measures Association

Ms. Diane Lee (NIST OWM) noted that NIST is working with the State of Kansas on this item. The item 

has been on agenda and recommends that it stays on as it is addressing all codes and tickets. Mr. John 

McGuire (New Jersey) is in favor of voting but noted that the item conflicts with New Jersey law. Mr. Jim 

Willis (New York), Mr. Walt Remmert (Pennsylvania), and Ms. Cheryl Ayer (New Hampshire) recommend 

a Voting status.

After hearing comments from the floor, the Committee believes this item has merit and is fully developed. 

The Committee recommended that this item be give a Voting status. 

Central Weights and Measures Association

No comments were made from the floor. 

The CWMA S&T Committee recommended this remains as a Developing Item.
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Block 5 Items (B5) Test Drafts

B5: LMD-23.2 N.3.5. Wholesale Devices

B5: VTM-23.2 N.3. Test Drafts

Source: Murray Equipment, Inc./Total Control Systems.

Submitter’s Purpose and Justification:

Change the word “should” to “shall” to clarify the importance of using a calibrated container of adequate 

size to accept a “test draft of at least the amount delivered by the device in 1 minute at its maximum 

discharge rate” where it is referenced in Handbook 44 Vehicle-Tank Meters and the Liquid Measuring 

Devices codes.

In some locations, the largest available prover for fuel field testing is 100 gallons. In high flow situations 

over 100 gpm, the 100-gallon prover does not meet requirement of HB44. Inspectors are using what they 

have and doing the best they can. However, using a proving can smaller than what is recommended in 

HB44 can lead to errors in the field including failing an accurate metering system that would have been 

approved if the draft size was the correct size. In fact, we have experienced situations where mechanical 

registers are favored over electronic registers when smaller than recommended size test drafts are used due 

to inspectors visually estimating fractions of gallons on a mechanical register that reads out in whole gallons 

while only reading in whole gallons on electronic registers set to read in whole gallons.

In the following example, there is an aircraft refueler that normally operates at 300 GPM through a standard 

aircraft underwing fueling nozzle. The inspector is using the over-wing nozzle at 100 GPM in the available 

100-gallon proving can to test the system. The customer wants the meter to display in whole gallons due 

to the high delivery speed and large volume of delivered fuel per transaction when fueling aircraft at 300 

GPM. Because the VTM code says the test draft “should” be equal to at least the amount delivered by the 

device in 1 minute at its maximum discharge rate, the inspector felt comfortable using the 100-gallon 

proving can rather than securing a 300-gallon or larger proving can.

Besides feeling empowered to use a proving can smaller than the recommended size, the inspector also 

interpreted the text from N.4.1 Normal Tests. – “...under the conditions of the installation” to mean that the 

meter display could not be changed to indicate decimal points, but rather must be left on whole gallons. 

Most likely the meter with electronic display would have passed this “non-normal” test if the display would 

have been set to tenths or hundredths of gallons for the test draft. The 1⁄2 gallon of potential rounding error 

caused by the whole gallon display introduced an additional system error of up to 0.5% on a 100-gallon 

prover, which make is nearly impossible to pass a test with ± 0.2% of allowable error.

In the example above, the inspector set conditions that encouraged high variability in the system accuracy 

and precision. When questioned about the test draft conditions, the inspector referred to the Handbook 44 

code, interpreting it to allow the undersized proving can and not allow meter display decimal changes. 

Changing Handbook 44 text from “should” to “shall” will prevent undersize test drafts. It is also important 

to clarify what “...under the conditions of the installation” specifically refers to; that is, the fluid path 

elements such as hose length, hose type, nozzle setting, system valve settings, etc. Metering systems with 

electronic digital displays should not be handicapped due to being set for whole gallons or tenths of gallons 

especially if the proving can used is smaller than what is required or recommended by Handbook 44.

One of the technological advancements of electronic registers over mechanical registers is the option of 

quickly and easily changing the number of decimal points shown on the display. Something that literally 

takes seconds to do on an electronic register is cumbersome, time consuming, and generally not 

recommended outside of a factory on mechanical registers. With very few exceptions, customers, 
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distributers, and manufacturers favor electronic registers due to improved features, improved durability and 

accuracy. Mechanical registers, on the other hand, are becoming obsolete and should not be given 

preference due to a misunderstanding of the meaning of the phrase ”...under the conditions of the 

installation.”

The submitter acknowledges the following arguments: 

1) Some locations don’t have access to calibration containers large enough to hold the required 

test draft size. In this case, the correct size calibration container should be borrowed or rented to 

meet HB44 requirements. 

2) Everything is fine with the current code text, don’t change it. The problem is that everything is 

NOT fine now. Due to the soft “should” language rather than the un-negotiable “shall” language, 

inspectors do from time to time use smaller than recommended proving cans that can lead to failing 

an accurate metering system or approving an inaccurate system.

3) Inspectors know it is OK to change the decimal points for testing when using a calibration 

container that is smaller than is recommended. In the example above, the inspector would NOT 

allow the decimal points to be changed for testing, so not all inspectors seem to agree.

4) Inspectors may have to break the calibration seal to change the decimal point settings in some 

situations. That is why the inspectors have calibration seals.

Requested Status by Submitter: Not Specified

OWM Executive Summary for Block 5 Items (B5) – Test Drafts

OWM Recommendation: NIST OWM Supports this proposed change to remove “should” and replace 

it with “shall’ in the N.3.5. and N.3 paragraphs of the LMD Code. We also suggest that the submitters 

work together to develop one proposal for changes to LMD N.3.5. 

• To ensure that an inspector is required to use the correct size test draft, the submitter is 

recommending that “should” in LMD-23.2 N.3.5. Wholesale Devices and VTM-23.2 N.3. Test 

Drafts be changed to “shall” 

• Item LMD-23.4 on the 2022 Interim Meeting agenda is another proposal for changes to the LMD 

N.3.5 paragraph. These changes are to ensure that the paragraph is more encompassing of other test 

methods, specifically when testing SVPs. 

• We encourage the submitters of LMD-23.4 and Block 5 to work together to combine the changes 

that are being proposed to the same paragraph, N.3.5. Wholesale Devices. If the submitters are in 

agreement with combining these changes a proposed change for the combined items LMD-23.4 and 

B5: LMD N.3.5 is provided below: 

N.3.5. Wholesale Devices.– The total delivered quantity for any required accuracy test

should shall be equal to, or is recognized as being representative of, a volume equivalent to

at least the amount delivered by the device in one minute at its the meter’s maximum discharge 

rate and shall in no case be less than 200 L (50 gal). 

(Amended 1987,and 1996, and 2023)
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Table 3. Summary of Recommendations

Block 5 Items (B5) – Test Drafts

V D W A I Notes* Comments

Submitter 

OWM

WWMA 

SWMA 

NEWMA 

CWMA 

NCWM

Letters of Support Letters of Opposition Notes

Industry

Manufacturers

Retailers and 

Consumers

Regulators

*Notes Key:

1 − Submitted modified language

2 − Item not discussed

3 − No meeting held

4 − Not submitted on agenda

5 − No recommendation or not considered

B5: LMD-23.2 N.3.5. Wholesale Devices

Item Under Consideration:

Amend Handbook 44, Liquid Measuring Devices Code as follows: 

N.3.5. Wholesale Devices. - The delivered quantity shouldshall be equal to at least the amount 

delivered by the device in one minute at its maximum discharge rate and shall in no case be less than 

200L (50 gal).

B5: VTM-23.2 N.3. Test Drafts

Item Under Consideration:

Amend Handbook 44, Vehicle Tank Meters Code as follows:

N.3. Test Drafts. (VTM Code) – Test drafts shouldshall be equal to at least the amount delivered by 

the device in 1 minute at its maximum discharge rate and shall in no case be less than 180 L (50 gal) or 

225 kg (500 lb).
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NIST OWM Detailed Technical Analysis: 

To ensure that an inspector is required to use the correct size test draft, the submitter is recommending that 

“should” in LMD-23.2 N.3.5. Wholesale Devices and VTM-23.2 N.3. Test Drafts be changed to “shall”. 

Item LMD-23.4 on the 2022 Interim Meeting agenda is another proposal for changes to the LMD N.3.5 

paragraph. These changes are to ensure that the paragraph is more encompassing of other test methods, 

specifically when testing SVPs. 

We encourage the submitters of LMD-23.4 and Block 5 to work together to combine the changes that are 

being proposed to the same paragraph, N.3.5. Wholesale Devices. If the submitters are in agreement with 

combining these changes a proposed change for the combined items LMD-23.4 and B5: LMD N.3.5 is 

provided below: 

N.3.5. Wholesale Devices – The total delivered quantity for any required accuracy test should

shall be equal to, or is recognized as being representative of, a volume equivalent to at least the 

amount delivered by the device in one minute at its the meter’s maximum discharge rate and shall in 

no case be less than 200 L (50 gal). 

(Amended 1987,and 1996, and 2023) 

NIST OWM supports this proposed change to remove “should” and replace it with “shall’ in the N.3.5. and 

N.3 paragraphs of the LMD Code. We also suggest that the submitters work together to develop one 

proposal for changes to LMD N.3.5. 

Regional Association Reporting:

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting the following comments were received: Mr. Brent Price 

(Gilbarco, Inc.) - Supported the item. The word “shall” expresses more importance. 

Mr. Michael Keilty (Endress + Hauser Flow USA, Inc.) did not see why this is necessary to change from 

“should” to “shall” to fix one particular instance where there was a problem. Recommended 

withdrawal. 

Mr. Jose Arriaga (Orange County, California) stated that “Shall” is becoming a bit antiquated. The 

modern legal interpretation would be to change “shall” to “must”. 

The WWMA S&T Committee recommended that this item be assigned a Developing status. The 

Committee also recommended that the submitter of this item take into consideration the testimony heard 

during open hearings and work together with the submitter of item LMD-23.4 to develop language that will 

support both of their purposes. 

Southern Weights and Measures Association

During the 2022 Interim Meeting the following comments were received during the 2022 SWMA Annual 

Meeting Mr. Keilty (Endress+Hauser) stated that this item represented the confusion over this issue and is 

a misapplication. He recommended withdrawal. 
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Mr. Searles (API) stated that he has no issue with should to shall, and that he wasn’t sure if this correction 

would address the submitters problem. 

The SWMA S&T Committee recommended that this item be Withdrawn.

Northeastern Weights and Measures Association

During the 2022 Interim Meeting, Mr. John Hathaway (Total Control Systems/Murray Equipment) believes 

that this proposal would solve issues of inspectors using undersized provers for testing. Mr. Keilty believed

that this proposal was drafted for a single instance where a meter under test was indicating in whole gallons, 

delivering at 300 gallons per minute and tested using a 100 gallon prover. This does not warrant a change 

to the whole code due to one instance. Mr. Searles commented that the change to the code would not bother 

API but agrees with Mr. Keilty’s point. Mr. Bob Murnane (Seraphin Test Measure) commented that he 

understands the reason for the proposal, but it doesn’t make sense commonsense wise. He hopes inspectors 

would use the correct equipment. Mr. Hathaway noted that changing “should” to “shall” is making it a 

non-debatable position. Mr. Jim Willis (New York) commented that empowering inspectors in the field, 

where it is appropriate, to test with a smaller prover is an advantage if that’s all they have at their disposal. 

Mr. Willis recommended withdrawal. Mr. James Cassidy (Massachusetts) concurred with Mr. Willis. Mr. 

Jason Flint (New Jersey) commented that New Jersey relies on “should” versus “shall” due to inspectors 

trying to use a 25 gallon prover to test 800 gal/min meter and recommended a Developing status.

After hearing comments from the floor, the Committee believes the item has merit, but more discussion 

needs to be had. The Committee recommended this time be given a Developing status.

Central Weights and Measures Association

Mr. Keilty stated that this item conflicts with B1 and he does not support. Mr. Searles recommended the 

item be withdrawn. Mr. Dmitri Karimov (Liquid Controls) stated that the item stemmed from field 

inspectors trying to test 100-gal flow rate with 50 gal provers. This item conflicts with an API proposal. 

He recommended that the item be Withdraw.

The CWMA S&T Committee recommended this item be withdrawn.

Item Block 6 (B6) Commercial and Law Enforcement, Axle and Axle Group Weights

B6: SCL-22.1 S.1.14. Recorded Representation of Axle or Axle Group Weights

B6: SCL-22.3 UR.3.3. Single-Draft Vehicle Weighing., and UR.3.4. Axle and Axle Group Weight 

Values.

Source: NIST Office of Weights and Measures

Submitter’s Purpose and Justification:

This proposed change is intended to add clarification regarding the implications of using weighing and 

measuring devices for transactions that may be considered by some as commercial while there is no clear 

guidance provided.

OWM has noted a number of inquiries submitted to our office for explanation on the many and various 

issues involved with the use of weighing or measuring devices as commercial devices when there is charge 

for doing so. Law enforcement devices may be regulated in a different manner than commercial devices 
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(e.g., allows highway weight limit enforcement through multi-draft weighing) when commercial devices 

are not allowed to be used in that way. 

The submitter pointed out that there seems to be a difference in opinions regarding this practice constitutes 

a commercial transaction.

The submitter requested Voting status for these items in 2022. 

OWM Executive Summary for Item Block 6 (B6) – Commercial and Law Enforcement, Axle and 

Axle Group Weights

OWM Recommendation: That the Committee maintain the current Developing status of these items 

on its agenda. 

Reason: The SMA, during its Fall 2022 meeting, proposed additional changes to paragraph S.1.15.1. 

Axle and Axle Group Loads in item B6:22.1 and also indicated additional work is needed to the B6:SCL22.3 item. 

• When item SCL-22.1 was originally proposed there was a lag in the publication process for 2020 

and 2021; so, the numbering of the paragraph in the Item Under Consideration in this document

has been updated to S.1.15. Not so, however, in the Committee’s 2023 NCWM Interim Agenda 

(i.e., NCWM 2023 Publication 15) where it is still appears today as paragraph S.1.14. 

Consequently, OWM requests the Committee change the paragraph references S.1.14., S.1.14.1., 

and S.1.14.2. in SCL-22.1 to S.1.15., S.1.15.1., and S.1.15.2., respectively, when completing its 

Interim Meeting Report (2023 NCWM Publication 16.) 

• The first proposed sub-paragraph of SCL-22.1 (i.e., S.1.15.1) requires the ticket to clearly identify 

the particular independent scale platform associated with each printed weight value. 

The second proposed sub-paragraph of SCL-22.1 (i.e., S.1.15.2.) requires the summed total of all 

platforms to be identified as the vehicle’s total weight in instances where all axle and axle groups 

of the vehicle being weighed fit onto a live portion of the scale system and are weighed 

simultaneously as a single draft. In instances where the vehicle being weighed cannot be weighed 

as a single draft (e.g., oversized vehicles that do not fit onto the scale) thus necessitating weighing 

the vehicle in two drafts, the ticket must provide clear indication that the total weight is “not legalfor-trade” or similar text to make known the gross vehicle weight is not valid for use in commercial 

sales transactions. 

• SCL-22.3 proposes amending the text in the “Note” of existing HB-44 Scales Code paragraph 

UR.3.3. Single-Draft Vehicle Weighing and removing the “Note” reference. These proposed 

changes are needed because in 2022 the NCWM agreed to amend paragraph G-A.1. Commercial 

and Law-Enforcement Equipment of NIST Handbook 44 to explicitly make clear weighing and 

measuring equipment used for the purpose of providing a weight or measure for a fee constitutes 

commercial use of that equipment. Paragraph UR.3.3. currently requires a vehicle or vehicle 

combination to be weighed “commercially” on a vehicle scale only as a single draft except as noted 

in subparts (a) and (b) of the paragraph. The “Note” in UR.3.3. currently exempts highway-lawenforcement scales and scales used for the collection of statistical data from having to comply. 

Multi-independent platform vehicle scale systems typically weigh vehicles and vehicle 

combinations in multiple drafts yet comply with paragraph UR.3.3. because subpart (b) makes this 

permissible. When installed at a truck stop, the predominant commercial use of these vehicle scale 

systems is to weigh vehicles and vehicle combinations for a fee. All axles and axle groups of some 
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OWM Executive Summary for Item Block 6 (B6) – Commercial and Law Enforcement, Axle and 

Axle Group Weights

oversized vehicles, however, are not able to fit onto one of the live platforms of a vehicle scale 

system and be weighed simultaneously. This necessitates the weighing of the portion of the vehicle 

that doesn’t fit separately from the rest of the vehicle (i.e., split weighing). Weights and Measures 

officials have typically allowed this practice when the only use of those weight determinations is to 

verify compliance with highway legal load limits. Because a fee is charged, this too constitutes 

commercial use of the scale systems, but violates current paragraph UR.3.3. It is for this reason 

OWM is proposing the change to paragraph UR.3.3. 

• SCL-22.3 also adds a new HB 44 Scales Code user requirement to make clear the acceptable use of 

multi-platform vehicle scale systems to charge a fee for the commercial service of providing 

customers (usually truckers) axle weights, axle group weights, and total weight of their vehicles to 

enable them to determine compliance with state and federal legal load limits.

• OWM amended the proposal in SCL-22.3. prior to the 2022 NCWM Annual Meeting and 

recommended during S&T open hearings that the Committee update the proposal to the revised 

version. The Committee, in consideration of the comments received during open hearings, agreed 

to replace the Block 6 SCL-22.1 proposal in its Interim Meeting agenda (2022 NCWM Publication 

15) with the updated version provided by OWM. Unfortunately, the National S&T Committee 

neglected to update the proposal in its addendum sheets for the 2022 NCWM Annual Meeting and 

the version of the proposal appearing on the 2023 regional S&T Committee agendas wasn’t the 

updated version. OWM recently resubmitted the updated version to the National S&T Committee 

so the version now appearing in the Committee’s current agenda is correct. 

• OWM can support the changes recommended by the SMA during its Fall 2022 meeting to the first 

sentence of proposed new paragraph S.1.14.1. as shown in shaded text below: 

S.1.14.1. Axle and Axle Group Loads. − All recorded representations of the different axle and 

axle group loads of a vehicle when weighed in a single draft on a multi-independent platform 

vehicle scale system shall be identified by providing indication of either:

As noted earlier, however, this proposed paragraph should be referenced S.1.15.1 in the 

Committee’s current agenda.

• With respect to the SMA’s Fall 2022 position statement for item B6: SCL-22.3, OWM is very 

interested in learning more specifically the additional work SMA believes is necessary.

Table 3. Summary of Recommendations

Block 6 Items (B6) – Commercial and Law enforcement, Axle and Axle Group Weights

V D W A I Notes* Comments 

Submitter

(OWM)



WWMA  1

SWMA 

NEWMA 
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Table 3. Summary of Recommendations

Block 6 Items (B6) – Commercial and Law enforcement, Axle and Axle Group Weights

V D W A I Notes* Comments 

CWMA 

NCWM

Letters of Support Letters of Opposition Notes

Industry

Manufacturers (SMA)

The SMA supports paragraph 

S.1.15 Axle and Axle Group 

Loads with changes.

The SMA supports the intent 

of SCL-22.3 and believes 

additional development is 

needed.

Retailers and Consumers

*Notes Key:

1 − Submitted modified language

2 − Item not discussed

3 − No meeting held

4 − Not submitted on agenda

5 − No recommendation or not considered

Item Under Consideration:

B6: SCL-22.1 Recorded Representation of Axle or Axle Group Weights

Amend NIST Handbook 44, Scales Code as follows: 

S.1.15. Recorded Representations, Multi-Independent Platform1 Vehicle Scale Systems 

S.1.15.1. Axle and Axle Group Loads. - All recorded representations of the different axle 

and axle group loads of a vehicle weighed on a multi-independent platform vehicle scale 

system shall be identified by providing indication of either:

(a) the portion of the vehicle to which they represent (e.g., “axle-group 1, axle group 2, 

axle group 3,” or if using axle and axle group descriptions, “steering axle, drive axles, 

trailer axles”), or 

(b) the particular independent scale platform from which they were obtained (e.g., 

“Platform 1, Platform 2, Platform 3”). 

S.1.15.2. Total Vehicle Weight. - If a summed total of all axle and axle group loads of a 

vehicle weighed on a multi-independent platform vehicle scale system is recorded, the 

recorded value shall be clearly identified as:
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(a) “Total Vehicle Weight,” “Vehicle Weight,” (or other similar terms that clearly 

identify the value as the vehicle’s total weight) providing all axle(s) and axle groups 

of the vehicle weighed were positioned on a live portion of the weighing/load-receiving 

elements and weighed simultaneously when the summed total was determined2, or 

(b) “Not-Legal-For-Trade” unless all axle and axle groups of the vehicle weighed were 

simultaneously positioned on a live portion of the weighing/load-receiving elements 

when the summed total was determined, or the vehicle was weighed using the 

alternative method described in footnote 2 of this paragraph. 

1

Multi-independent platform means each platform of the scale is a single independent 

weighing/load-receiving element unattached to adjacent elements and with its own A/D 

conversion circuitry and displayed weight.

2

Alternatively, the individual components of the vehicle being weighed may be uncoupled, 

positioned completely on the live elements of the scale, weighed separately, and then totaled. 

B6: SCL-22.3 D UR.3.3. Single-Draft Vehicle Weighing., and UR.3.4. Axle and Axle 

Group Weight Values.

Amend Handbook 44, Scales Code as follows: 

UR.3.3. Single-Draft Vehicle Weighing – A vehicle or a coupled-vehicle combination shall be 

commercially weighed on a vehicle scale only as a single draft. That is, the total weight of such a 

vehicle or combination shall not be determined by adding together the results obtained by separately 

and not simultaneously weighing each end of such vehicle or individual elements of such coupled 

combination. However, the weight of: 

(a) a coupled combination may be determined by uncoupling the various elements (tractor, 

semitrailer, trailer), weighing each unit separately as a single draft, and adding together the 

results; or

(b) a vehicle or coupled-vehicle combination may be determined by adding together the weights 

obtained while all individual elements are resting simultaneously on more than one scale 

platform.

Note: This paragraph does not apply to highway-law-enforcement scales, and scales used for the 

collection of statistical data, or scales used to charge a fee for the service of providing weights of 

the different axle-, axle-group loads, and total weight of vehicles and coupled-vehicle 

combinations when the only use of those values is to determine compliance with highway legal 

load limits and safe distribution of the load. 

(Added 1992) (Amended 20XX)

UR.3.4. Weighing of Axle- and Axle-Group Loads – Establishing weight values for the different 

individual axle- and axle-group loads of a vehicle or coupled-vehicle combination is oftentimes 

necessary to verify compliance with state and federal highway load limits. When a fee is charged 

for the use of an axle-load scale or vehicle scale to determine such values, the transaction is 

considered “commercial” under the provisions of the General Code paragraph G-A.1. 

Commercial and Law Enforcement Equipment and the scale shall comply with all applicable 

NIST Handbook 44 requirements for commercial weighing systems. 
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When weight values for axle- and/or axle-group loads are obtained using multiple-independent 

platform vehicle scales systems where all parts of the vehicle or coupled-vehicle combination 

being weighed are simultaneously positioned on live elements of the scale, the values for the 

different axle- and axle-group loads may be summed to establish the commercial gross weight. 

In no case, however, shall a summed result of the different axle- and axle-group loads of a vehicle 

or coupled vehicle combination weighed in multiple drafts be used for commercial purposes 

except as provided in subparts (a) and (b) of paragraph UR.3.3. Single-Draft Vehicle Weighing

Renumber existing paragraphs UR.3.4 through UR.3.12. 

NIST OWM Detailed Technical Analysis:

OWM developed the two proposals in SCL-22.1 and SCL-22.3 to address perceived gaps in HB 44 Scales 

Code requirements pertaining to the design and use of multi-independent platform vehicle scale systems 

commercially used to charge a fee for the service of providing axle- and axle-group weights, as well as total 

vehicle weight to those needing them (typically commercial truck drivers). These systems are most often 

used commercially to verify compliance with federal and state vehicle load limits but at times may also be 

used to establish the net loads of products that are bought and sold by weight, establish transportation 

charges, and for other commercial purposes. 

These proposals were developed as the result of an OWM inquiry from a state questioning the permissible 

use of a multi-independent platform vehicle scale system (each platform having its own A/D conversion 

circuitry and weight indicator) that printed total vehicle weight from summing the axle- and axle-group 

loads of vehicles weighed when not all parts of those vehicles were able to fit onto a live portion of the 

scale and be weighed simultaneously. That is, the scale was being used on occasion to “split weigh” in two 

different drafts the different axle and axle groups of “over-sized” coupled-vehicle combinations because 

not all axle and axle groups would fit onto a live portion of the scale at the same time, which thus 

necessitated weighing those particular vehicles in multiple drafts. Even though the printed ticket for those 

weight determinations provided clear indication that the total vehicle weight value recorded was “non 

certifiable,” it is questionable whether or not a scale system is permitted to record this weight since HB 44 

Scales Code paragraph UR.3.3. Single-Draft Vehicle Weighing currently requires a vehicle or coupledvehicle combination to be commercially weighed on a vehicle scale only as a single draft. Note: The 

manufacturer of this particular scale system advised us that most vehicles and coupled-vehicle combinations 

that are weighed on the scale can be weighed as a single draft. That is, all axle and axle groups can be 

positioned onto a live portion of the scale to be weighed simultaneously. It is only the occasional oversized 

vehicle or coupled-vehicle combination that exceeds the length of the scale that must therefore be split 

weighed. 

We purposely chose to simplify these proposals to only address multi-independent platform vehicle scale 

systems. These systems have been installed at truck stops (and perhaps other locations) throughout the US 

for many years and are used primarily to determine axle loads, axle-group loads, and total vehicle weight 

of vehicles and coupled-vehicle combinations for a fee. Although we recognize that single-platform vehicle 

scales may also sometimes be used for this same purpose, we don’t view them as being suitable for the 

application. This is because the approach requirements for vehicle scales and axle-load scales in NIST 

HB44 are very different and few vehicle scales in commercial service have approaches that comply with 

the approach requirements for axle-load scales. Axle-load scales are required to have a straight paved 

approach in the same plane as the platform on each end of the platform. The approaches must be the same 

width as the platform and of sufficient length to ensure the level positioning of vehicles during weight 

determinations. If vehicles aren’t level when the different axle and axle groups are weighed, a portion of 
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the force of the load transfers to other axle and axle groups that aren’t positioned on the scale resulting in 

false indication. It is important to recognize that not all multi-independent platform vehicle scale systems 

may be installed with approach requirements meeting the HB 44 approach requirements for an axle-load 

scale. Many do, but we are unable to confirm that all do. We view this somewhat of an important concern 

given that these proposals, if adopted, would make it permissible to split weigh vehicles and coupledvehicle combinations for a fee providing the only use of the weighing results from doing so is to verify 

whether or not the different axle-, axle-group loads, and total vehicle weight are compliant with highway 

weight limits.

Another reason we elected to limit these proposals to only address multi-independent platform vehicle scale 

systems is that we do not believe it to be a very common practice to use single-platform vehicle scales to 

determine axle loads and axle-group loads of vehicles and coupled-vehicle combinations to verify 

compliance with federal and state vehicle load limits. Those that are using them for this purpose usually 

don’t charge a fee, i.e., the weighing is usually done as a complimentary service. 

NIST HB 44 does not currently require a multi-independent platform vehicle scale system to be equipped 

with a ticket printer and whether or not one should be required, is something to be considered. We have 

not proposed it, but perhaps others will conclude this would be an important HB 44 addition. We believe 

most (perhaps all) of the multi-independent platform vehicle scale systems currently in commercial service 

have been equipped with a ticket printer and this is likely because the few scale manufacturers of these 

systems recognize the need for the multiple indications displayed by these systems to be made available in 

printed form to the operator and customer. We also believe most of the systems currently in service comply 

with both newly proposed sub-paragraphs of S.1.14. We developed these two new sub-paragraphs 

(S.1.14.1. and S.1.14.2.) because it is important for scale operators, customers, and enforcement officials 

to be able to clearly identify from a weigh ticket the different scale platforms utilized at the time a vehicle 

was weighed and their corresponding scale indications so that the accuracy of those values (including the 

summed total) can be verified. It is also important to clearly specify on a weigh ticket generated from one 

of these scale systems that any recorded total vehicle weight value determined from summing the different 

axle- and axle-group loads of a vehicle or coupled-vehicle combination weighed in multiple drafts (i.e., 

split weighed) is “Not-Legal-For-Trade.” 

Paragraph UR.3.3. needs to be amended to address the current use of multi-independent vehicle scale 

systems to split weigh oversized vehicles for a fee. The current paragraph does not take into consideration 

both the past and present use of these scales to provide a total vehicle weight that’s most often only used to 

verify compliance with maximum legal load limits and safe distribution of the load. These systems have 

been in existence at truck stops for many years and their primary commercial use is to provide axle weights, 

axle group weights, and total vehicle weight to commercial haulers for a fee so that those haulers are able 

to determine whether or not their loads are distributed safely and within legal load limits. Years ago, (prior 

to the existence of multi-independent platform vehicle scale systems) axle-load scales served this same 

purpose at truck stops throughout the US and summing of the different axle and axle groups to determine 

total vehicle weight undoubtedly occurred to ensure total vehicle weight didn’t exceed maximum legal load 

limits when using those scales. It is also important to recognize that the weight values corresponding to the 

different axle- and axle-group loads of vehicles weighed on a multi-independent platform vehicle scale 

system are not constant; but rather fluctuate/change depending on the position of those axles and axle groups 

on the different platforms of the system when the vehicle is weighed. That is, a change of the scale 

indication of one platform is offset by a change in the opposite direction of the indication from one or both 

of the other platforms if the position of a vehicle being weighed is changed slightly forward or backwards 

from its initial position. It is only the summed total of all indications that is constant; although it too 

changes minimally since not all sections of all platforms are typically adjusted the same. For these reasons, 

OWM has provided the Committee an updated proposal to amend Scales Code paragraph UR.3.3., which 

would make it permissible to weigh in multiple drafts (i.e., split weigh) a vehicle or coupled-vehicle 
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combination and charge a fee for the service of providing weights of the different axle- and axle-group 

loads when the only use of those values is to determine compliance with highway legal load limits. 

Summary of Discussions and Actions:

Mr. Rick Harshman (NIST OWM) provided the Committee a high-level summary of its analysis of the two 

remaining items in Block 6, which included much of background information that had led OWM to submit 

the two proposals in Block 6 as well as the GEN-22.1 G.A.1. Commercial and Law-Enforcement Equipment 

item, which the Committee had previously removed from Block 6. Mr. Harshman reported that OWM had 

recently provided the Committee an updated version of the proposal in SCL-22.1 and requested the 

Committee replace the version of SCL-22.1 in its current agenda with the updated version recently received. 

Mr. Harshman also reported that OWM planned to revise the proposal in SCL-22.3 and would later 

(sometime following the 2022 NCWM Interim Meeting) submit the revised version to the Committee in 

hopes it could be reviewed by one or more of the regional weights and measures associations meeting in 

the Spring and/or Fall of 2022. Mr. Harshman recommended both items remain in a Developing status to 

allow stakeholders time to review and recommend any changes they felt necessary.

Mr. Russ Vires (Mettler Toledo LLC) speaking on behalf of the SMA reported that the SMA recommends 

Block 6 be broken apart into three individual items (i.e., GEN-22.1 Commercial and Law-Enforcement 

Equipment, SCL-22.1 Recorded Representation of Axle or Axle Group Weights, and SCL-22.3 UR.3.3. 

Single-Draft Vehicle Weighing and UR.3.4. Axle and Axle Group Weight Values). Mr. Vires then 

provided the SMA’s position and rationale for each of these items speaking verbatim from the SMA’s 

November 2, 2021 report titled “SMA Positions on the NCWM Specification and Tolerances Committee 

Report (For the NCWM Interim Meeting, January 2022, Developed November 2, 2021). NIST Technical 

Advisors note: Refer to the subheading shown below titled, “Scale Manufacturers Association (SMA-Fall 

2021 Meeting)” to view the different positions and rationales provided by Mr. Vires on behalf of the SMA 

for the items in Block 6. Mr. Vires also reported that the SMA had had the opportunity during its Fall 2021 

meeting to review the updated version of the proposal in SCL-22.1 that OWM had provided the Committee 

for replacement of the one in its current agenda and that the SMA supported the changes OWM had made.

These were several officials who spoke in support of further development of the two items in Block 6. 

Mr. Lou Straub (Fairbanks Scale) reported that Fairbanks Scale had been manufacturing the multi-platform 

“CAT” vehicle scale system for over forty years and the systems had been installed in approximately 2,000 

locations. He also reported that he fully supported the GEN-22.1 item that the Committee had earlier 

removed from Block 6. Referencing the proposal in SCL-22.1, Mr. Straub stated he agreed that the recorded 

representation of weights from individual axle or axle groups need to be clearly identified as 

“not-legal-for- trade” on the printed ticket unless the entire vehicle is positioned on live elements of the 

vehicle scale system and all axles/axle groups are weighed simultaneously. He voiced disagreement with 

the second sentence proposed in paragraph S.1.14. noting that when one considers a truck with six to eight 

axle groups that cannot fit onto the different independent platform and be weighed simultaneously, 

identifying which platform weighed each of these axle and axle groups becomes unnecessary. 

The Committee, in consideration of the comments received during open hearings, agreed to replace the 

Block 6 SCL-22.1 proposal in its Interim Meeting agenda (2022 NCWM Publication 15) with the updated 

version provided by OWM just prior to the 2022 NCWM Interim Meeting and maintain a Developing status 

on the two remaining items in Block 6. The following proposal represents the Block 6 SCL-22.1 item 

appearing in the 2022 version of NCWM Publication 15 that the Committee agreed to replace with the Item 

Under Consideration now shown in SCL-22.1:
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Item Under Consideration:

Amend Handbook 44, Scales Code as follows: 

S.1.14. Recorded Representation of Axle or Axle Group Weights. – The recorded 

representation of weights from individual axle or axle group weights shall clearly be identified as 

“not legal for trade” or “non-commercial” weight values unless the entire vehicle is positioned on 

live elements of a multiple-platform vehicle scale and where all axles/axle groups are weighed 

simultaneously. All recorded weights of axles/axle groups shall be identified as representing only 

a portion of the vehicle’s total gross weight (e.g., by axle groupings such as: “axle group 1,” “axle 

group 2,” “axle group 3,” or by individual axle description such as: “steering axle,” “drive axles,” 

“trailer axles”). 

Any total gross weight of the vehicle included in the recorded representations determined by 

summing axle weights shall be clearly identified as “not-legal-for trade” or “non-commercial” 

unless those axle weights were recorded when all parts of the vehicle rested simultaneously on 

live portions of the scale, or the individual components were uncoupled, positioned completely on 

the live elements, and weighed separately on the scale.

[subsequent requirements to be renumbered as appropriate]

On May 19, 2022, OWM provided S&T Committee Chair Mr. Bradford Bachelder an electronic file 

containing the following revised version of the B6: SCL-22.3 proposal as replacement for the current 

proposal in 2022 NCWM Publication 16. OWM requested he share it with the Committee to be considered 

as replacement for the current proposal in the Committee’s agenda.

OWM’s Revised Replacement Proposal for B6: SCL-22.3 UR.3.3. Single-Draft Vehicle Weighing, 

and UR.3.4. Axle and Axle Group Weight Values. 

Amend NIST Handbook 44, Scales Code as follows:

UR.3.3. Single-Draft Vehicle Weighing – A vehicle or a coupled-vehicle combination shall be 

commercially weighed on a vehicle scale only as a single draft. That is, the total weight of such a 

vehicle or combination shall not be determined by adding together the results obtained by separately 

and not simultaneously weighing each end of such vehicle or individual elements of such coupled 

combination. However, the weight of: 

(a) a coupled combination may be determined by uncoupling the various elements (tractor, 

semitrailer, trailer), weighing each unit separately as a single draft, and adding together the 

results; or 

(b) a vehicle or coupled-vehicle combination may be determined by adding together the weights 

obtained while all individual elements are resting simultaneously on more than one scale 

platform.

Note: This paragraph does not apply to highway-law-enforcement scales, and scales used for the 

collection of statistical data, or scales used to charge a fee for the service of providing weights of 

the different axle-, axle-group loads, and total weight of vehicles and coupled-vehicle 

combinations when the only use of those values is to determine compliance with highway legal 

load limits and safe distribution of the load. 

(Added 1992) 
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UR.3.4. Weighing of Axle- and Axle-Group Loads – Establishing weight values for the different 

individual axle- and axle-group loads of a vehicle or coupled-vehicle combination is oftentimes 

necessary to verify compliance with state and federal highway load limits. When a fee is charged 

for the use of an axle-load scale or vehicle scale to determine such values, the transaction is 

considered “commercial” under the provisions of the General Code paragraph G-A.1. 

Commercial and Law Enforcement Equipment and the scale shall comply with all applicable 

NIST Handbook 44 requirements for commercial weighing systems. 

When weight values for axle- and/or axle-group loads are obtained using multiple-independent 

platform vehicle scales systems where all parts of the vehicle or coupled-vehicle combination 

being weighed are simultaneously positioned on live elements of the scale, the values for the 

different axle- and axle-group loads may be summed to establish the commercial gross weight. 

In no case, however, shall a summed result of the different axle- and axle-group loads of a vehicle 

or coupled vehicle combination weighed in multiple drafts be used for commercial purposes 

except as provided in subparts (a) and (b) of paragraph UR.3.3. Single-Draft Vehicle Weighing

Renumber existing paragraphs UR.3.4 through UR.3.12. 

Regional Association Reporting:

Western Weights and Measures Association

During the 2021 Annual Meeting Open Hearing the following comments were heard: 

Mr. Kurt Floren (Los Angeles County, California) offered up some language changes for the last part of 

subsection A and breaking into bullet points. He wants to break out equipment that is commercial, then the 

other types. It's titled “Commercial and Law Enforcement” then “other commercial” and it becomes 

confusing. Is it all commercial and subsect to our jurisdiction? Rephrase GA-1 : apply “to commercial 

equipment as follows”: ... explains that everything under is commercial. (strike “commercial” from A and 

B). Between apply and as in the first line, insert commercial equipment. Mr. Kurt Floren stated that he 

will submit a written statement to the Committee as presented during open hearings. 

Mr. Ivan Hankins (Iowa) wanted clarification as to what is being changed to make it better. It looks like 

it's already there, and he wants more definition on why this is changing. 

Ms. Cadence Matijevich (Nevada) agreeded with Mr. Floren but cautioned that we consider how the 

heading reads if we add commercial to the opening statement then there might be some interpretation that 

what is or is not commercial law enforcement equipment. (Is there a fine assessed?) Does not want to 

narrow the subsection of law enforcement devices only to commercial purposes. 

Mr. Floren offered a modification to Ms. Matijevich’s recommendation. Restructure under GA-1: insert 

subsection under 1: commercial as follows, then insert A,B,C then 2 for law enforcement.

Ms. Matijevich stated that Mr. Floren is much better at this, and his fix is good. 

Mr. Lou Straub (Fairbanks Scales) agreed with Mr. Hankins, that the original language is satisfactory. 

Language needs to say that its NTEP approved and meet handbook requirements.
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Mr. Eric Golden (Cardinal Scale) asked if a commercial transaction includes just getting a weight: he says 

yes. Change the wording that that transaction is commercial. No suggestions at this time. Mr. Floren 

missed a typo: in B2: “Basis”. 

Mrs. Tina Butcher (NIST OWM) stated that OWM submitted this Item. This was seeking to clarify 

commercial transactions. Agreed with previous testimony. They have submitted other proposals to amend 

method of sale reg. and uniform law. They have determined that HB 44 and 2 sections in HB 130 are 

slightly different. Uniform Reg. for service persons also needs to be aligned. Wants this to remain 

Developing so that they can continue to align the language and make it more uniform.

Mr. Russell Vires (Scale Manufactures Association) remarked that this a new item, the SMA has not vetted 

this yet. They will do so at November meeting. This should remain Developing so that there’s no 

unintended consequences. 

Mrs. Tina Butcher (NIST OWM) clarified that in the agenda, this is blocked with two other “companions”. 

She feels that the block should continue, however, if others think that other items in the block are ready 

(SCL-22.1 and SCL-22.3) those items can move forward. 

Mr. Don Onwiler (NCWM): SCL-22.3 is the name of the next item. 

Mr. Russell Vires (Scale Manufactures Association) stated he is looking at it as a block and is commenting 

as an entire block. Wants all three to remain Developing so that they can research. 

Mr. Lou Straub (Fairbank Scales) for SCL-22.1 he has concern about what the second sentence. Talks about 

the entire truck on the scale = not legal for trade: this is ok. Second part about axle identifications (axle 

groups) this gets difficult to identify group notifications. Wants the ticket that has already been marked as 

not legal for trade to not have to identify all axels. Wants this re-worded. They will put down axle weight 

and gross weight. Preprinted labels don't allow enough space. 

Mr. Eric Golden (Cardinal Scales) agreed with Mrs. Butcher to split the items. “Blow the block apart.” 

The second two items introduce additional items and topics. Wants to pull the second two items out. 

The WWMA S&T Committee recommended that this be assigned a Developmental status. The Committee 

recommended following the submitter’s request to remove GEN-22.1 from the Block. Based on testimony 

heard the Committee agreed to submit the following language for item GEN-22.1. The Committee noted 

that SCL-22.1 (UR.3.3.) item was reassigned as SCL-22.3. 

G-A.1. Commercial and Law-Enforcement Equipment. – These specifications, tolerances, and 

other technical requirements apply as follows: 

(1) To commercial weighing and measuring equipment

(a) To commercial weighing and measuring equipment; that is, tTo weights and measures and 

weighing and measuring devices commercially used or employed in establishing the size, 

quantity, extent, area, composition (limited to meat and poultry), constituent values (limited to 

grain), or measurement of quantities, things, produce, or articles for distribution or 

consumption, purchased, offered, or submitted for sale., hire, or award, or in computing any 

basic charge or payment for services rendered on the basis of weight or measure.

(Amended 2008 and 20XX) 
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(b) To other commercial weighing and measuring equipment:

i. when there is a fee assessed for the use of the equipment to determine a weight or 

measure;

ii. used to determine the bases of an award using count, weight, or measure; or

iii. used in computing any basic charge or payment for services rendered on the basis of 

weight or measure

(Added 20XX)

(bc)To any accessory attached to or used in connection with a commercial weighing or measuring 

device when such accessory is so designed that its operation affects the accuracy of the device. 

(cd)(2) To weighing and measuring equipment in official use for the enforcement of law or for the 

collection of statistical information by government agencies.

(These requirements should be used as a guide by the weights and measures official when, upon request, 

courtesy examinations of noncommercial equipment are made.) 

During the WWMA 2022 Annual Meeting, the following comments were received: Mr. Jan Konijnenburg 

(NIST Associate) – Stated that information is available on the website. During open hearings the Committee 

received an update from NIST OWM indicating that new language for this proposal was submitted to 

NCWM. This language was not available for review at the time of open hearings by the committee or 

membership. The WWMA S&T Committee recommended that this item should remain developing to allow 

membership to review the updated proposal. 

Southern Weights and Measures Association

During the 2021 Annual Meeting Open Hearing Mr. Russ Vires (Mettler Toledo) stated that this item needs 

work on the wording and further review by stakeholders. Its current language could have unintended 

consequences, and recommended it continue with a Developing status. 

This Committee would like clarification on the purpose and use of axle weight scale values allowed by this 

proposal beyond law enforcement use. 

This Committee recommended that this item move forward with a Developing status. 

The following comments were received during the 2022 SWMA Annual Meeting S&T open hearings: 

• Mr. Huff (Delaware) questioned whether this would allow law enforcement officials to split weigh. 

• The SWMA S&T Committee asked how legal split weighing would be initiated, how it would be 

recorded on the ticket, would scale operators be required to mark the tickets where split weighing 

had taken place, or would that be automatically done? 

The SWMA S&T Committee recommended this item remain as a Developing Item.

Northeastern Weights and Measures Association

During the 2021 Interim Meeting Open Hearing the following comments were heard. 
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GEN-22.1 

Mr. Rick Harshman (NIST OWM) commented that the language is in-need of some changes and NIST will 

be providing changes for the NCWM.

Mr. Eric Golden (Cardinal Scale) supported the intent of this item, but it may need some wordsmithing.

Mr. Lou Straub (SMA), Cheryl Ayer (New Hampshire), and John McGuire (New Jersey) all support this 

as a Developing Item.

SCL 22.1

Mr. Eric Golden (Cardinal Scale) supports this item moving forward as Developing.

Mr. Lou Straub (Fairbanks Scale) agreed with language in general. But questioned the benefit of including 

all the language on a scale ticket and the large amount of information would be difficult to fit on the ticket.

Mr. Eric Golden (Cardinal Scale) and Ms. Cheryl Ayer (New Hampshire) agreed with comments from Mr. 

Straub. 

Mr. John McGuire (New Jersey) recommended keeping this item in Developing status.

SCL 22.3

Mr. Eric Golden (Cardinal Scale) suggested to strike “non-commercial” and additional wordsmithing to 

align with paragraph UR3.4.

Mr. John McGuire (New Jersey) supported keeping this item in Developing status.

The NEWMA Specifications and Tolerances Committee recommended that this item be given a Developing 

Status.

During NEWMA’s 2022 Annual Meeting Open Hearings, the Committee heard the following comments: 

Mr. Russ Vires (SMA) recommended Block 6 be broken into two separate items. Mr. Vires indicated he

supports this item with the following language change: S.1.14.1. Axle and Axle Group Loads. - All 

recorded representations of the different axle and axle group loads of a vehicle when weighed in a single 

draft on a multi-independent platform vehicle scale system shall be identified by providing indication of 

either. Mrs. Tina Butcher (NIST OWM) commented that this item needs development. 

After hearing comments from the floor, the Committee recognized the need to further develop this block 

and recommended the block retain Developing status. 

During NEWMA’s 2023 Interim Meeting, Mr. Rick Harshman (NIST OWM) gave updates on a NIST 

analysis for SCL-22.1. He noted that SCL-22.3 has changed from what is in the agenda, which was shared 

with the body. Mr. Lou Sakin (Holliston, Massachusetts), Mr. Walt Remert (Pennsylvania), Mr. John 

McGuire (New Jersey), Mr. Jim Willis (New York), Mr. James Cassidy (Massachusetts), and Ms. Cheryl 

Ayer (New Hampshire) recommended that this item be assigned a Voting status. After hearing comments 

from the floor, the Committee believes this item has merit and is fully developed. The Committee 

recommended that this item be give a Voting status.
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Central Weights and Measures Association

During the 2021 Interim Meeting Open Hearing the Committee heard comments from the floor. Mr. Loren 

Minnich (Kansas) suggested change he sent to the Committee (in green).

B6: GEN-22.1 

G-A.1. Commercial and Law-Enforcement Equipment. – These specifications, tolerances, and 

other technical requirements apply as follows: 

(a) To commercial weighing and measuring equipment; that is, to weights and measures and 

weighing and measuring devices commercially used or employed in establishing the size, 

quantity, extent, area, composition (limited to meat and poultry), constituent values (limited to 

grain), or measurement of quantities, things, produce, or articles for distribution or 

consumption, purchased, offered, or submitted for sale., hire, or award, or in computing any 

basic charge or payment for services rendered on the basis of weight or measure. 

(Amended 2008 and 20XX) 

(c) To other commercial weighing and measuring equipment:

i. when there is a fee assessed for the use of the equipment to determine a weight or 

measure;

ii. used to determine the bases of an award using count, weight, or measure when using 

weight, measure, or count as the basis to determine an award; or

iii. used in computing any basic charge or payment for services rendered on the basis of 

weight or measure

(Added 20XX)

Mr. Loren Minnich (Kansas) also asked NIST for clarification on G-A.1. because different states already 

interrupt rule different ways. Ms. Diane Lee (NIST OWM) agreed with Mr. Minnich and suggested it be 

Developing. Mr. Eric Golden (Cardinal Scales) agreed with the spirit of the proposal; it is indeed a 

“commercial transaction” to charge a person a fee solely for the purpose of obtaining a weight of a vehicle 

– it is not required to have to undergo a sales transaction of weighed product in order for it to be considered 

a commercial transaction. Mr. Golden also recommended striking out the following (in red) stating the 

reasoning behind this is by leaving the “non-commercial” language in the proposal, it defeats the purpose 

of the proposal, which is to officially clarify what a non-commercial transaction is.

B6: SCL-22.1 S.1.14. Recorded Representation of Axle or Axle Group Weights

S.1.14. Recorded Representation of Axle or Axle Group Weights. – The recorded representation 

of weights from individual axle or axle group weights shall clearly be identified as “not legal for 

trade” or “non-commercial” weight values unless the entire vehicle is positioned on live elements 

of a multiple-platform vehicle scale and where all axles/axle groups are weighed 

simultaneously. All recorded weights of axles/axle groups shall be identified as representing only 

a portion of the vehicle’s total gross weight (e.g., by axle groupings such as: “axle group 1,” “axle 

group 2,” “axle group 3,” or by individual axle description such as: “steering axle,” “drive axles,” 

“trailer axles”). 
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Any total gross weight of the vehicle included in the recorded representations determined by 

summing axle weights shall be clearly identified as “not-legal-for trade” or “non-commercial”

unless those axle weights were recorded when all parts of the vehicle rested simultaneously on 

live portions of the scale, or the individual components were uncoupled, positioned completely on 

the live elements, and weighed separately on the scale.

Mrs. Tina Butcher (NIST OWM) agreed G-A.1. needed more work and had no objection to Mr. Golden’s 

suggestion of splitting SCL-22.1 and SCL-22.3. Mr. Lou Straub (Fairbanks) says current G-A.1. is already 

correct. He also agreed with Mr. Golden from Cardinal Scales on SCL 22.1. Mr. Doug Musick (Kansas) 

agreed with Mr. Straub. Says that item is not practical for all vehicles out there. Keep as Developing. Mr. 

Ivan Hankins (Iowa) feels G-A.1. is already correct. Mr. Charles Stutesman (Kansas) stated original 

language is good as written. 

CWMA S&T Committee recommended that GEN 22.1 be withdrawn and SCL-22.1 and SCL 22.3 remain 

Developing. 

During the 2022 CWMA Annual Meeting Open Hearing the Committee heard the following comments: 

Mr. Russ Vires (SMA): the SMA recommended that Block 6 be broken apart into two (2) individual items. 

Each of these items deals with a separate topic that needs to be discussed individually. Regarding SCL22.1: The SMA supports this item with the following changes: “S.1.14.1. Axle and Axle Group Loads. - 

All recorded representations of the different axle and axle group loads of a vehicle when weighed in a 

single draft on a multi-independent platform vehicle scale system shall be identified by providing 

indication of either:” 

Identifying the recorded weight values for the axle/axle groups as required in S.1.14.1.(a) is only necessary 

when the vehicle can be weighed in a single draft. 

The CWMA agreed to recommend further development of this block of items.

During CWMA’s 2023 Interim Meeting, no comments were received on the block of items and the CWMA 

recommended a Developing status. 

Scale Manufacturers Association (SMA-Fall 2021 Meeting)

The SMA recommended that Block 6 be broken apart into three (3) individual items. 

Rationale: Each of these items deals with a separate topic that needs to be discussed individually.

B6: GEN-22.1 G.A.1. COMMERCIAL AND LAW-ENFORCEMENT EQUIPMENT

Position: The SMA supports this item. 

Rationale: The proposed item provides clarity to define what constitutes a “commercial transaction”.

B6: SCL-22.1 S.1.14. RECORDED REPRESENTATION OF AXLE OR AXLE GROUP WEIGHTS

Position: The SMA supports this item with the following changes:

S.1.14. Recorded Representation of Axle or Axle Group Weights. – The recorded representation of 

weights from individual axle or axle group weights shall clearly be identified as “not legal for trade” 
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or “non-commercial” weight values unless the entire vehicle is positioned on live elements of a 

multiple-platform vehicle scale and where all axles/axle groups are weighed simultaneously. All 

recorded weights of axles/axle groups shall be identified as representing only a portion of the vehicle’s 

total gross weight (e.g., by axle groupings such as: “axle group 1,” “axle group 2,” “axle group 3,” or 

by individual axle description such as: “steering axle,” “drive axles,” “trailer axles”). 

Any total gross weight of the vehicle included in the recorded representations determined by 

summing axle weights shall be clearly identified as “not-legal-for trade” or “non-commercial” unless

those axle weights were recorded when all parts of the vehicle rested simultaneously on live portions

of the scale, or the individual components were uncoupled, positioned completely on the live 

elements, and weighed separately on the scale.

Rationale: the item attempts to define what constitutes a “commercial transaction”, but the words “noncommercial” reduces its clarity. Secondly, it is not necessary to label each weight value of axle/axle group 

weights as “not legal for trade”; putting the words “not legal for trade” on the recorded representation once 

is adequate.

B6: SCL-22.3 UR.3.3. SINGLE-DRAFT VEHICLE WEIGHING., AND UR.3.4. AXLE AND AXLE 

GROUP WEIGHT VALUES

Position: the SMA supports this item.

SMA-Spring 2022 Meeting 

The SMA recommended that Block 6 be broken apart into three (3) individual items. 

Rationale: each of these items deals with a separate topic that needs to be discussed individually. 

B6: SCL-22.1 D S.1.14. RECORDED REPRESENTATION OF AXLE OR AXLE GROUP WEIGHTS

Position: the SMA supports this item with the following changes: 

S.1.14.1. Axle and Axle Group Loads. All recorded representations of the different axle and

axle group loads of a vehicle when weighed in a single draft on a multi-independent platform vehicle 

scale system shall be identified by providing indication of either:

Rationale: identifying the recorded weight values for the axle/axle groups as required in S.1.14.1.(a) is

only necessary when the vehicle can be weighed in a single draft. 

B6: SCL-22.3 D UR.3.3. SINGLE-DRAFT VEHICLE WEIGHING., AND UR.3.4.

AXLE AND AXLE GROUP WEIGHT VALUES

Position: the SMA supports the intent of this item and believes that additional work is necessary.

SMA-Fall 2022 Meeting 

NIST Technical Advisors Note: There were originally three items in this block, however, currently there 

are only two as the third item (GEN-22.1 Commercial and Law-Enforcement Equipment) was previously 

removed from the block, voted on at the 2022 NCWM Annual Meeting, and adopted. 
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The SMA recommended that Block 6 be broken apart into three (3) individual items. 

Rationale: each of these items deals with a separate topic that needs to be discussed individually. 

B6:SCL-22.1 D S.1.14. RECORDED REPRESENTATION OF AXLE OR AXLE GROUP WEIGHTS

The SMA supports this item with the following changes (shown shaded): 

S.1.14.1. Axle and Axle Group Loads. − All recorded representations of the different axle and axle 

group loads of a vehicle when weighed in a single draft on a multi-independent platform vehicle scale 

system shall be identified by providing indication of either:

Rationale: identifying the recorded weight values for the axle/axle groups as required in S.1.14.1.(a) is 

only necessary when the vehicle can be weighed in a single draft. 

B6:SCL-22.3 D UR.3.3. SINGLE-DRAFT VEHICLE WEIGHING., AND UR.3.4. AXLE AND AXLE 

GROUP WEIGHT VALUES

The SMA supports the intent of this item and believes that additional work is necessary. 

Item Block 7 (B7) Tolerances on Tests Using Transfer Standards

B7: CLM-22.1 D T.3. On Tests Using Type 2 Transfer Standards 

B7: CDL-22.1 D T.3. On Tests Using Type 2 Transfer Standards 

B7: HGM-22.1 D T.4. Tolerance Application on Tests Using Type 2 Transfer Standard Test Method

(Note: The Item Under Consideration was revised by the submitter based on comments from the 2022 

Interim Meeting.) 

Source: Seraphin Test Measure Company, A Division of Pemberton Fabricators, Inc.

Submitter’s Purpose and Justification:

The purpose of these proposals is to change the language in the tolerance paragraphs to provide consistency 

with the changes in the combined amended proposals of 2022 S&T Agenda Item Block 8 (GEN-19.1. and 

OTH-22.1). In the codes mentioned below, the current language of Handbook 44 states that when transfer 

standards are used, the basic tolerances to be applied to the devices under test are to be increased by the 

uncertainty of the transfer standard (i.e., two times the standard deviation of the transfer standard). The 

proposed language simply states that the formula given in the General Code (the proposed G-T.5.) be used, 

rather than repeat the formula in each of the specific codes listed below.

In the codes mentioned above, when transfer standards are used, the basic tolerances to be applied to the 

devices under test are to be increased by the uncertainty of the transfer standard (i.e., two times the standard 

deviation of the transfer standard). The proposed changes incorporate the OIML R117 formula to state 

how the tolerance is to be increased when transfer standards are used. The formula effectively places an 

upper limit on how large the uncertainty associated with the transfer standard can be.

This item has been assigned to the submitter for further development. For more information or to provide 

comment, please contact: 

Mr. Bob Murnane
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Seraphin Test Measure Co.

(609) 267-922, rmurnane@pemfab.com 

The current paragraphs already state that, when transfer standards are used, the tolerances are to be 

increased by two standard deviations for the repeatability of the transfer standard. One can argue that effect 

of the proposed changes is small and not necessary. The proposed changes are intended to provide 

consistency with the changes proposed in the amended proposals of 2021 S&T Agenda Block 1 Item GEN19.1. 

The submitter requested that this be a Voting Item in 2022. 

OWM Executive Summary for Item Block 7 (B7) – Tolerances on Tests Using Transfer Standards

OWM Recommendation: When the S&T Committee presents Block 8 for a vote, OWM agrees that 

Block 7 should also go forward for a vote. 

• Block 7 Items are proposed changes to NIST HB 44 Codes that have transfer standard tolerance 

requirements.

• Because of the larger uncertainties associate with the use of transfer standards, the current Code 

requirement increases the tolerance to account for the uncertainties in the tolerance.

• The proposal is to revise the transfer standard tolerance requirements with an equation to calculate 

the tolerances for Type 2 Transfer standards and to clarify that these standards are considered Type 

2 standards. 

• The equation places an upper limit on how large the uncertainty associated with the transfer standard 

can be.

Table 3. Summary of Recommendations

Block 7 Items (B7) – Tolerances on Tests Using Transfer Standards

V D W A I Notes* Comments

Submitter 

• Updated Proposal from Seraphin Test 

Measure Co requesting Block 7 be 

designated as a Voting item when Block 

8 is designated as Voting.

• (01-06-2022)

OWM • When Block 8 is voting

WWMA 

SWMA 

NEWMA 

CWMA 

NCWM

Letters of Support Letters of Opposition Notes
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Table 3. Summary of Recommendations

Block 7 Items (B7) – Tolerances on Tests Using Transfer Standards

V D W A I Notes* Comments

Industry

Comments from 

Emerson-Micro Motion 

(09-27-21)

Manufacturers

Retailers and Consumers

*Notes Key:

1 − Submitted modified language

2 − Item not discussed

3 − No meeting held

4 − Not submitted on agenda

5 − No recommendation or not considered

B7: CLM-22.1 D T.3. On Tests Using Type 2 Transfer Standards.

Amend Handbook 44, Cryogenic Liquid-Measuring Devices Code as follows:

T.3. On Tests Using Type 2 Transfer Standards. – To the basic tolerance values that would 

otherwise be applied, there shall be added an amount equal to two times the standard deviation of the 

applicable transfer standard when compared to a basic reference standard. When commercial meters 

are tested using a Type 2 transfer standard, the tolerance applied to the meter under test shall be 

calculated using the formula specified in the General Code Tolerance section. 

(Amended 202X)

B7: CDL-22.1 D T.3. On Tests Using Type 2 Transfer Standards.

Amend Handbook 44, Carbon Dioxide Liquid-Measuring Devices Code as follows:

T.3. On Tests Using Type 2 Transfer Standards. – To the basic tolerance values that would 

otherwise be applied, there shall be added an amount equal to two times the standard deviation of the 

applicable transfer standard when compared to a basic reference standard. When commercial meters 

are tested using a Type 2 transfer standard, the tolerance applied to the meter under test shall be 

calculated using the formula specified in the General Code Tolerance section.

(Amended 202X) 

B7: HGM-22.1 D T.4. Tolerance Application on Tests Using Type 2 Transfer Standard 

Test Method.

Amend Handbook 44, Hydrogen Gas-Measuring Devices Code as follows:

T.4. Tolerance Application on Tests Using Type 2 Transfer Standard Test Method. – To the basic 

tolerance values that would otherwise be applied, there shall be added an amount equal to two times 

the standard deviation of the applicable transfer standard when compared to a basic reference standard. 

When commercial meters are tested using a Type 2 transfer standard, the tolerance applied to 
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the meter under test shall be calculated using the formula specified in the General Code 

Tolerance section.

(Amended 202X)

NIST OWM Detailed Technical Analysis:

Seraphin proposed Block 7 Items to address the changes that are proposed in Block 8 concerning transfer 

standards. Block 7 items in the Interim Meeting Report were revised based on comments heard during the 

2022 Interim Meeting. 

Transfer standards are address in the Cryogenic Liquid-Measuring Devices Code, the Carbon Dioxide 

Liquid-Measuring Devices Code and the Hydrogen Gas-Measuring Devices Code. These codes already 

specify that a larger tolerance be used when transfer standards are used to account for the higher uncertainty 

associated with these types of standards and the fact that they will not likely meet the fundamental 

considerations paragraph 3.2 tolerances for Standards. 

The proposed changes in Block 8 define the different types of standards (Field Standard, Type 1 Transfer 

Standard and Type 2 Transfer Standard). Block 8 also proposes to add a General code requirement with an 

equation that should be used to determine the tolerance for type 2 transfer standards because Type 2 transfer 

standards will not likely meet the fundamental considerations concerning the error and uncertainty. The 

equation places an upper limit on how large the uncertainty associated with the transfer standard can be.

Block 7 makes changes to the aforementioned codes to reference the General Code requirement with the 

equation that will be used to calculate the tolerance when using type 2 transfer standards in these codes. 

When the S&T Committee presents the combined item GEN-19.1 and OTH-22.1, Block 8 item for a vote, 

then this item, Block 7 may also go forward for a vote. 

Summary of Discussions and Actions:

At the 2022 Interim Meeting the Committee recommended that this item be given a Developing status for 

further development by the submitter based on comments heard during the 2022 Interim Meeting. Since 

the 2022 Interim Meeting, the submitter made additional changes to the items under consideration which 

are currently reflected in Block 7 above. These changes add “Type 2” to clarify the type of transfer standard 

and references the revised equation in the proposed Block 8 item of this report. 

At the 2022 Annual Meeting the submitter provided no comments and as a Developing Item no additional 

comments were heard on this this item. 

During the Committee work session the committee agreed to maintain a Developing status for this item. 

Regional Association Reporting:

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting the following comments were received: Mr. Robert Murnane 

(Seraphin Test Measure Company) - wanted everyone to look at the version that was posted to the WWMA 

website, the most current version. Addressed multiple changes present in the updated language. Asked 

that this item be a voting item, only if Block 8 passes. 
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Mr. Michael Keilty (Endress + Hauser Flow USA, Inc.) didn’t see where there is a formula to be calculated, 

in the HB44 general code. Also affirmed that Block 7 is dependent on Block 8. 

Mr. Robert Murnane (Seraphin Test Measure Company) clarified that the formula is in Block 8, that is why 

Block 7 should only move forward if Block 8 is passed. 

During open hearings, members in attendance were notified that the language in the agenda did not reflect 

the updated Item Under Consideration. Membership was not fully aware of the new language at the time 

of open hearings. The WWMA S&T Committee recommended that this item should remain Developing to 

allow membership to review the updated proposal. The Committee further recommended that this item be 

blocked with Block 8 as the items in Block 7 are contingent on Block 8 items.

 

Southern Weights and Measures Association

The following comments were received during the 2022 SWMA Annual Meeting: Mr. Keilty 

(Endress+Hauser) stated that Block 7 is dependent on Block 8, and both blocks should receive the same 

status. He had no recommendation on it. This is an example where meters are being added into three codes.

The SWMA S&T Committee recommended this item remain as a Developing Item.

Northeastern Weights and Measures Association

During the 2022 Interim Meeting Mr. Murnane commented that the item that appears in the agenda is not 

what has been proposed as there are many typos. A true version of the item was submitted to the NEWMA 

S&T Chair and shared with the body. Mr. Murnane asks that the same status be given to Block 7 and Block 

8 as they are directly linked. 

Mr. Keilty indicated that he drafted LPG-15.1 and MFM-15.1 based on these codes. The standards are 

meters, but they have 2x the deviation, which do not meet 1/3 requirement recommended in the 

Fundamental Considerations. Mr. Keilty recommended a developing status. (Mr. Keilty was experiencing 

internet connection problems during his comments and the Committee may not have been able to hear his 

entire testimony).

After hearing comments from the floor, the Committee believes this item has merit and is full developed. 

The Committee recommended that this item be assigned a Voting status.

Central Weights and Measures Association 

During the 2022 Interim Meeting, Bob Murnane (Seraphin) stated that Block 7 cannot stand alone without 

Block 8 moving forward. 

The CWMA S&T Committee believes this item is fully developed and recommends Voting status. 
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Item Block 8 (B8) G-T.5. Tolerances on Tests When Transfer Standards are Used., 

Appendix A, Section 3.2. Tolerances for Standards., and Appendix D – Definitions: 

standards, field., transfer standard. and standard, transfer. Appendix A: Fundamental 

Considerations, 3. Testing Apparatus 

B8: GEN-19.1 D G-T.5. Tolerances on Tests When Transfer Standards are Used., Appendix A, Section 

3.2. Tolerances for Standards., and Appendix D – Definitions: standards, field., 

transfer standard. and standard, transfer.

B8: OTH-22.1 D Appendix A: Fundamental Considerations, 3. Testing Apparatus 

(Note: These proposals are a combined modification of the 2021 S&T Agenda Block 1 Items GEN-19.1 

and OTH-22.1. Since the S&T Committee has changed item GEN-19.1 from “assigned” to “developing,” 

the submitter has worked with NIST OWM to revise and combine the original proposals of GEN-19.1 and 

OTH-22.1 to address discussions within the NCWM Field Standards Task Group and other comments 

received at the regional weights and measures meetings on the proposals. These items are related, so they 

are presented together. These OWM and Seraphin proposals were submitted to the S&T Committee just 

before the 2022 Interim Meeting.

Note: The joint OWM and Seraphin proposals submitted to the S&T Committee just before the 2022 

Interim Meeting were updated with two changes at the request of the Submitters following the 2022 Interim 

Meeting. The first change is in the definition of “Standard, Field.” The words “(typically one year)” were 

replaced with “(as determined by the Director)”. The second change was to add the words “to the 

International System of Units (SI)” in the section 3.1.3. of the Fundamental Considerations. These two 

changes are reflected in the items below.) 

Note: The current Item Under Consideration represents additional changes made by the submitters in 

November 2022 based on comments received from the regional meetings in 2022. 

Source: The NIST Office of Weights and Measures and Seraphin Test Measure Company have combined 

their previously separate proposals into a single proposal. 

Submitter’s Purpose and Justification:

(a) Add a tolerance statement to the General Code that applies whenever a Type 2 transfer standard is 

used; 

(b) Clarify in the Fundamental Considerations (Appendix A of Handbook 44) that the authority to 

approve field test standards rests with the regulatory official and that specific types of field test 

standards need not be identified in the body of a Handbook 44 Code in order to be approved by the 

weights and measures director;

(c) Add text to Section 3.2. Tolerances for Standards of the Fundamental Considerations (Appendix A 

of Handbook 44) to recognize the wide range of transfer standards already recognized in Handbook 

44, explain the critical differences between field standards and transfer standards, and to specify 

the formula to be used to calculate the device tolerance when the uncertainty of the transfer standard 

exceeds the one-third requirement; and

(d) Add definitions to Appendix D of Handbook 44 for field standard and Type 1 and Type 2 transfer 

standards that identify the critical characteristics for field and transfer standards.
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Footnote 2 in the Fundamental Consideration of NIST Handbook 44 already provides a statement regarding 

the authority of the Director to approve field test standards or equipment, OWM believes including 

additional information regarding the essential elements of traceability and a reference to specific 

measurement practices would be helpful to both emphasize that authority and provide guidance to Directors 

and industry regarding the selection of appropriate field test standards. 

NIST OWM recommends the guidance originally included in Footnote 2 along with the additional 

references to the “Essential Elements” described above are best included in the body of Section 3 for clarity 

and ease of use. Consequently, OWM recommends deleting the existing Footnote 2 and incorporating its 

contents into the body of Section 3.

OWM also believes that some may erroneously believe that field test standards must be specifically listed 

within a NIST Handbook 44 code in order to be used in the inspection and testing of devices covered by 

that code. Providing a clear statement that this is not the case along with a reference to the required criteria 

may help alleviate this misunderstanding.

A tolerance statement is added to the general code that addresses uncertainties of Type 2 Transfer standards

since they do not meet the NIST Handbook 44 Fundamental Consideration that state “When the standard 

is used without correction, its combined error and uncertainty must be less than one-third of the applicable 

device tolerance”. Several equations were considered to included an OIML equation. After discussion an 

alternative equation was agreed upon. An assessment of the two equations, the 2/3 Formula: Increased 

MPE = (2/3 x MPE + U) with an upper limit of UMAX = 2/3 MPE and the OIML Formula: Reduced MPE 

= (4/3 × MPE – U) are provided below:

The OIML formula and the 2/3 formula are similar, but they take different approaches to establish the 

tolerances for the device under test. The 2/3 formula is more logical, more technically consistent with the 

Handbook 44 concept of Type 2 transfer standards, and it is easier to understand. The 2/3 formula combines 

the tolerance that remains to be used by the commercial device with the growing uncertainty of the T2TS 

into one total tolerance value, whereas the OIML Reduced MPE calculates only the tolerance applied to 

test of the commercial meter under test. When Type 2 transfer standards are used in the field, the 

uncertainties associated with the T2TS should be recorded on the report form or a copy of the calibration 

certificate should be left with the test report, so the uncertainty values are available on site and can be used 

in an analysis should the tests with another T2TS generate different results.

The most accurate reference standard that is available should always be used for any field test. However, 

when the only practical option for a field test that is available is a Type 2 transfer standard, the 2/3 formula 

will err in favor of the commercial device to avoid failing a device that should have passed. Conversely, 

the OIML Reduced MPE might result in failing a commercial device that would have passed had a more 

accurate (e.g., Type 1 transfer or field) reference standard been available to use for the test.

Field standards are intended to have an error and uncertainty less than or equal to 1/3 of the tolerance 

applied to the commercial device under test. When a Type 2 transfer standard has an uncertainty slightly 

greater than 1/3 of the tolerance, then, using the 2/3 formula, the total tolerance applied to the device under 

test increases above the H44 tolerance by the amount that the uncertainty associated with the Type 2 transfer 

standard exceeds the 1/3 limit, thereby establishing a total tolerance slightly greater than the NIST 

Handbook 44 tolerances specified in the applicable codes and keeping the portion of the tolerance that 

remains allocated to the device under test at a constant level equal to 2/3 of the NIST Handbook 44

tolerance.
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Type 2 Transfer Standards: Uncertainty is Added to the Tolerance

When the uncertainty associated with a T2TS exceeds 1/3 of the tolerance applied to the device under test, 

the uncertainty of the T2TS is recognized in the field test result by increasing the tolerance that is applied 

to the device under test. The OIML formula and the 2/3 formula take different approaches to increasing 

the tolerance for the device under test. 

OWM Executive Summary for Item Block 8 (B8) – G-T.5. Tolerances on Tests When Transfer 

Standards Are Used, Appendix A, Section 3.2. Tolerances for Standards., and Appendix D –

Definitions: Standards, Field., and Standard, Transfer. Appendix A: Fundamental 

Considerations, 3. Testing Apparatus

OWM Recommendation: The submitters agree that these items, GEN-19.1 and OTH-22.1 are fully 

developed and requested that this S&T committee consider that Block 8 item be a Voting Item in 2023.

• State and industry have a need to use various types of test standards to evaluate commercial devices 

installed in the marketplace. NIST OWM recognizes the need to use various standards to test

commercial devices and support the use of these standards when test data supports its use.

• Block 8 clarifies the use and definition of three types of standards to be included in NIST HB 44: 

(1) Fields Standards, (2) Type 1 Transfer Standards and (3) Type 2 Transfer Standards; it provides 

an equation that should be used to calculate the tolerances when Type 2 transfer standards are used; 

provides definitions for Field Standards, Type 1 Transfer Standards and Type 2 Transfer Standards, 
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and provides clarification that the State Director has the authority to approve the use of standard 

and that specific requirements in NIST HB 44 code are not necessary to approve a standard for use. 

• Two items, LPG-15.1 and MFM-15.1 in the Interim Meeting Report (Publication 16), include a 

purpose statement that the proposals are added to allow field standard meters to be used to test and 

place into service dispensers and delivery system flow meters. Block 8 items clarify what has 

always been recognized in NIST HB 44 concerning the responsibility for acceptance of a standard 

and notes that specific code changes are not necessary for a field standard to be adequate for use. If 

Block 8 is adopted it accomplishes the same goal as LPG-15.1 and MFM-15.1. and the objectives 

of Micheal Keilty are met with Block 8. The adoption of Block 8 would not only accomplish the 

same goal it also provides for a broad criteria and provide for the acceptance of other standards.

• In addition to the changes in Block 8, GEN-23.1 adds a General Code requirement so that rather 

than revising a specific code in Handbook 44 every time a new field or transfer standard is proposed 

or developed, an overall statement in the General Code recognizes the use of other field and transfer 

standards that meet the requirements for use as field or transfer standards. 

• NIST OWM also observed that the definitions in Block 8 should include appropriate references to 

the NIST HB 44 codes.

• It was noted that the term “Standard, Field” has a different definition in NIST HB 130. It appears 

that the definition in NIST HB 130 describes the standard from a laboratory perspective and 

hierarchy of testing. As such, some future effort may be needed to harmonize the terms across all 

NIST handbooks. 

Table 3. Summary of Recommendations

BLOCK 8 ITEM (B8) – G-T.5. Tolerances on Tests When Transfer Standards are Used., Appendix 

A, Section 3.2. Tolerances for Standards., and Appendix D – Definitions: standards, field., transfer 

standard. and standard, transfer. Appendix A: Fundamental Considerations, 3. Testing

Apparatus

V D W A I Notes* Comments

Submitter 

OWM

WWMA 

SWMA 

NEWMA 

CWMA 

NCWM

Letters of Support Letters of Opposition Notes

Industry

Updated Proposal from 

Seraphine Test 

Measure Co. (01-06-

2022)
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Table 3. Summary of Recommendations

BLOCK 8 ITEM (B8) – G-T.5. Tolerances on Tests When Transfer Standards are Used., Appendix 

A, Section 3.2. Tolerances for Standards., and Appendix D – Definitions: standards, field., transfer 

standard. and standard, transfer. Appendix A: Fundamental Considerations, 3. Testing

Apparatus

V D W A I Notes* Comments

Manufacturers

Retailers and Consumers

*Notes Key:

1 − Submitted modified language

2 − Item not discussed

3 − No meeting held

4 − Not submitted on agenda

5 − No recommendation or not considered

Item Under Consideration:

B8: GEN-19.1 D G-T.5. Tolerances on Tests When Transfer Standards are Used., 

Appendix A, Section 3.2. Tolerances for Standards., and Appendix D – Definitions:

standards, field., transfer standard. and standard, transfer.

Amend Handbook 44, General Code as follows: 

G-T.5. Tolerances on Tests When Type 2 Transfer Standards Are Used. – When Type 2 transfer 

standards are used, the following formula shall be used to compute the tolerance applicable to 

the device under test:

Increased MPE = (2/3 x MPE + U)

with an upper limit of UMAX = 2/3 MPE

Where MPE is the basic tolerance that applies when using a basic reference standard; and

U = uncertainty associated with the Type 2 transfer standard.

The increase in the applied tolerance when using a Type 2 transfer standard applies only to the 

basic tolerances for devices as defined in Handbook 44; that is acceptance, maintenance and 

minimum tolerances. Note that the repeatability tolerance and the special test tolerances are NOT 

increased.

Codes 5.56.(a) Grain Moisture Meters, 5.56.(b) Grain Moisture Meters, and 5.57. Near-Infrared 

Grain Analyzers are exempt from this requirement because NIST Handbook 159 has 

requirements for monitoring and retesting grain samples to ensure adequate stability and the 

tolerances for the devices under test already incorporate the uncertainty associated with the use 

of grain samples as transfer standards. The code 2.21. Belt-Conveyor Scale Systems Code is also 

exempt because relative and absolute tolerances are included in the code.

Amend Handbook 44 Appendix D – Definitions as follows.
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Standard, Field. – A physical artifact, static or dynamic measurement devices, such as scales, 

meters, etc., or a reference material that (a) meets the requirements of the Fundamental 

Considerations, Section 3.2., (b) is stable (accurate and repeatable) over an extended period of 

time (as determined by the Director), (c) is valid (corrections that may be used) over the range of 

environmental and operational parameters in which the commercial measuring devices are used, 

and (d) is traceable to the reference or working standards through comparisons, using acceptable

laboratory procedures. [1.10] 

(Added 202X) 

transfer standard. – A measurement system designed for use in proving and testing cryogenic

liquid-measuring devices. [3.38]

Standard, Transfer, Type 1 and Type 2. − A physical artifact, static or dynamic measurement 

devices, such as scales, meters, etc., or a reference material that is proven to be stable (accurate 

and repeatable) for a short time under the limited environmental and operational conditions 

during which the transfer standard is used. A Type 1 transfer standard is a transfer standard 

that meets the one-third accuracy requirement for a short time over a limited range of 

environmental conditions and/or a limited range of operating conditions in which it is used. A 

Type 2 transfer standard is one that does not meet the one-third requirement and may not be 

stable or valid over an extended time period or over wide ranges of environmental or operating 

conditions. [1.10]

(Added 202X)

B8: OTH-22.1 D Appendix A: Fundamental Considerations, 3. Testing Apparatus

Amend Handbook 44, Appendix A: Fundamental Considerations as shown below. Delete Footnote 2 

referenced in Section 3. Testing Apparatus of NIST Handbook 44 Appendix A, Fundamental 

Considerations, moving portions of the footnote into Section 3.1 as part of the proposed changes to Section 

3.1 shown above. Note that no changes are proposed to Footnote 1. 

2 Recommendations regarding the specifications and tolerances for suitable field standards may 

be obtained from the Office of Weights and Measures of the National Institute of Standards and 

Technology. Standards will meet the specifications of the National Institute of Standards and 

Technology Handbook 105-Series standards (or other suitable and designated standards). This 

section shall not preclude the use of additional field standards and/or equipment, as approved by 

the Director, for uniform evaluation of device performance.

3.1. Adequacy.2 – Tests can be made properly only if, among other things, adequate testing apparatus 

is available. Testing apparatus may be considered adequate only when it is properly designed for its 

intended use, when it is so constructed that it will retain its characteristics for a reasonable period under 

conditions of normal use, when it is available in denominations appropriate for a proper determination 

of the value or performance of the commercial equipment under test, and when it is accurately 

calibrated.

3.1.1. Essential Elements of Traceability. To ensure that field test standards and test 

methods provide for measurements that are traceable to the International System of Units 

(SI), through NIST or other National Metrology Institutes, they must satisfy the “Essential 

Elements of Traceability.” As explained in NIST IR6969 GMP-13 Good Measurement 

Practice for Ensuring Metrological Traceability, these elements include the following.
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• Realization of SI Units 

• Unbroken Chain of Comparisons

• Documented Calibration Program

• Documented Measurement Uncertainty

• Documented Measurement Procedure

• Accredited Technical Competence

• Measurement Assurance

3.1.2. Specifications for Standards. Standards will meet the specifications of the National 

Institute of Standards and Technology Handbook 105-Series standards or other appropriate 

designated documentary standards (e.g., ASTM, ASME, etc.). Recommendations regarding 

the specifications and tolerances for suitable field standards may be obtained from the Office 

of Weights and Measures of the National Institute of Standards and Technology.

3.1.3. Authority for Approving Field Test Standards and/or Equipment. This section shall 

not preclude the use of additional field standards and/or equipment, as approved by the 

Director, for uniform evaluation of device performance. Specific types of field test standards 

are not required to be identified in a NIST Handbook 44 code in order to be considered 

suitable. Provided the standards meet the “Essential Elements of Traceability” (described in 

Section 3.1.1. above) that help ensure the standards are suitable and capable of supporting 

measurements traceable to the International System of Units (SI) through NIST or other 

National Metrology Institutes, they need only be approved by the Director.

3.2. Tolerances for Standards. – Except for work of relatively high precision, it is recommended 

that the accuracy of standards used in testing commercial weighing and measuring equipment be 

established and maintained so that the use of corrections is not necessary. When the standard is used 

without correction, its combined error and uncertainty must be less than one-third of the applicable 

device tolerance.

Device testing is complicated to some degree when corrections to standards are applied. When using 

a correction for a field standard or a transfer standard, the uncertainty associated with the corrected 

value must be less than one-third of the applicable device tolerance. The reason for this requirement is 

to give the device being tested as nearly as practicable the full benefit of its own tolerance.

Whenever possible and practical, field standards should be used to test commercial weighing and 

measuring devices. However, where it is impractical or unduly cumbersome to use field 

standards, transfer standards may be used. There are two categories of transfer standards. The 

critical criteria that distinguish between these standards are: (1) the accuracy and uncertainty 

of the standard; (2) the stability as a standard over an extended period; and (3) proven validity 

or performance of the standard over the range of environmental and operational conditions in 

which the standard may be used.

A “field standard” is one that meets the one-third requirement mentioned earlier in this section. 

Additionally, the field standard maintains its validity or stability as a standard over an extended 

period (defined based on data of the standard’s stability by an authorized metrology lab or as 
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specified by the Director) and is known to maintain its value as a standard over the full range of 

environmental conditions and the range of operating conditions in which the standard may be 

used to test commercial weighing and measuring devices. 

Transfer standards do not meet one or more of these critical criteria. One category of transfer 

standards, which is referred to here as a “Type 1 transfer standard,” is a transfer standard that 

meets the one-third accuracy requirement for a short time, under a limited range of 

environmental conditions and/or a limited range of operating conditions. The accuracy of a Type 

1 transfer standard may have to be verified through testing each time it is used to verify that the 

desired accuracy and performance can be achieved when the Type 1 transfer standard is used 

under the limited environmental and operating conditions. When a Type 1 transfer standard is 

used, the basic tolerances specified for the commercial weighing and measuring devices are 

applied as specified in the applicable codes.

The second category of transfer standard, which is referred to here as a “Type 2 transfer 

standard,” is one that does not meet the one-third requirement. The Type 2 transfer standard 

must be stable and valid under the environmental or operating conditions in which it is used. The 

performance characteristics must be confirmed with sufficient data to properly characterize the 

uncertainty associated with the Type 2 transfer standard. When a Type 2 transfer standard is 

used, the tolerances applicable to the commercial weighing and measuring device must be 

increased to recognize the large uncertainty associated with the Type 2 transfer standard. When 

commercial weighing and measuring devices are tested using a Type 2 transfer standard, the 

tolerance applied to the commercial weighing and measuring devices meter under test shall be 

determined as specified in the General Code.

(Added 202X)

3.3. Accuracy of Field Standards. – Prior to the official use of testing apparatus, its accuracy 

should invariably be verified. Field standards should be calibrated as often as circumstances 

require. By their nature, metal volumetric field standards are more susceptible to damage in 

handling than are standards of some other types. A field standard should be calibrated whenever 

damage is known or suspected to have occurred or significant repairs have been made. In addition, 

field standards, particularly volumetric standards, should be calibrated with sufficient frequency to 

affirm their continued accuracy, so that the official may always be in an unassailable position with 

respect to the accuracy of his testing apparatus. Secondary field standards, such as special fabric 

testing tapes, should be verified much more frequently than such basic standards as steel tapes 

or volumetric provers to demonstrate their constancy of value or performance.

Accurate and dependable results cannot be obtained with faulty or inadequate field standards. If either 

the service person or official is poorly equipped, their results cannot be expected to check consistently. 

Disagreements can be avoided and the servicing of commercial equipment can be expedited and 

improved if service persons and officials give equal attention to the adequacy and maintenance of their 

testing apparatus.

NIST OWM Detailed Technical Analysis:

State and industry have a need to use various types of test standards to evaluate commercial devices installed 

in the marketplace. NIST OWM recognizes the need to use various standards to test commercial devices 

and support the use of these standards when test data supports its use. Several proposals for changes to 

NIST HB 44 have been considered to address the use of these standards. Some were to address terminology 

for various types of standards in NIST HB 44. Other proposals were to provide specific requirements for 
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some codes in NIST HB 44 for the purpose of recognizing these standards in the handbook, but the 

responsibility for recognition of standards is already address in the fundamental consideration section in 

NIST HB 44. These proposals also included varying terms used to describe these standards and were 

subsequently all combined as a Block item and assigned to a task group. With limited success as a block 

item, it was decided to separate these items into their original block and individual items for consideration, 

some of the items were withdrawn. Block 8 items are a combined modification of the 2021 S&T Agenda 

Block 1 Item GEN-19.1 and OTH-22.1. With the S&T Committee changes to the status of item GEN-19.1 

from “assigned” to “developing,” the submitter, Seraphin and NIST OWM seeing the need to add 

clarification to NIST HB 44 for the different terms used to address standards that are used to test commercial 

devices and the need to provide clarification as to what is needed for States to accept various types of 

standards, worked together to develop Item Block 8. These proposals were revised to address discussions 

within the NCWM Field Standards Task Group and other comments received at the regional weights and 

measures associations meetings and the 2022 Interim Meeting. There is also a companion item Block 7 

that helps to clarify the use of the term transfer standards in NIST HB 44.

Block 8 clarifies the use and definition of three types of standards to be included in NIST HB 44: (1) Fields 

Standards, (2) Type 1 Transfer Standards and (3) Type 2 Transfer Standards; it provides an equation that 

should be used to calculate the tolerances when Type 2 transfer standards are used; provides definitions 

for Field Standards, Type 1 Transfer Standards and Type 2 Transfer Standards, and provides clarification 

that the State Director has the authority to approve the use of standard and that specific requirements in 

NIST HB 44 code are not necessary to approve a standard for use. 

Although 3 types of standards are to be specified in NIST HB 44, language has been added in Block 8 such 

that whenever possible and practical, field standards should be used to test commercial devices. Definitions 

are provided for the three different types of standards. Separating the standards into 3 types helps to 

determine what specifications should be used for the standards combined error and uncertainty or whether 

the tolerances should be increased to account for the error in the standard. Both Field Standards and Type 

1 Transfer standards must comply with the current Fundamental Considerations in NIST HB 44 that state 

“When a Standard is used without correction, its combined error and uncertainty must be less than onethird of the applicable device tolerance”. This allows the device under test to have more than 2/3 of the 

tolerance associated with the test. Type 2 Transfer Standards do not meet the one-third requirement and 

may not be stable or valid over an extended time-period or over wide ranges of environmental or operating 

conditions. With the inability to meet the one-third requirements for the uncertainty in the standard that 

Field Standards and Type 1 Transfer Standard are required to meet, an equation was added to the general 

code for all Type 2 Transfer Standards in NIST HB 44 to multiply the basic tolerance (the applicable 

tolerance, maintenance, acceptance, or special test tolerances by 2/3 and adding the uncertainty of the 

standard. This increases the total tolerance when using a Type 2 transfer standard to account for the 

uncertainty of the standard. 

Although a larger tolerance is used to account for the uncertainty in Type 2 standards, allowing an unlimited 

amount of uncertainty to be added to the tolerance adds an open-ended amount of uncertainty to the 

tolerance and the larger the tolerance that is allowed the more lead way is given to the device under test and 

the more disadvantage to the customer. As such a stipulation was added that the maximum limit for the 

uncertainty of type 2 standards must be 2/3 of the MPE. The proposed equation provides a uniform method 

for considering the uncertainties associated with Type 2 Standards. An example of calculating the equation 

is provided below. 

Increased MPE = (2/3 x MPE + U)

with an upper limit of UMAX = 2/3 MPE
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Example Calculation

Increased MPE = (2/3 x 0.01 + 0.005) 

= 0.01166 

In this example the UMAX does not exceed 2/3 MPE which = 0.007 

Mr. Henry Oppermann (Seraphin) provided an analysis of the equation which is provided in the Justification 

of this Technical Analysis. 

This Block also helps to clarify that the Director has the authority to approve Standards for use within a 

jurisdiction. This information is already included in a footnote in the Fundamental Considerations but has 

been moved to Section 3 in the Fundamental Considerations. Language was also added to clarify that 

specific language is not needed in various NIST HB Codes in order that these standards be accepted. Two 

items, LPG-15.1 and MFM-15.1 in the Interim Meeting Report (Publication 16), include a purpose 

statement that the proposals are added to allow field standard meters to be used to test and place into service 

dispensers and delivery system flow meters. Block 8 items clarify what has always been recognized in 

NIST HB 44 concerning the responsibility for acceptance of a standard and notes that specific code changes 

are not necessary for a standard to be adequate for use. Please see additional NIST OWM concerns with 

items LPG-15.1 and MFM-15.1 in the NIST OWM Technical Analysis for these items. 

In addition to the changes in Block 8, a new Form 15 for the 2023 cycle which is not included in the 2022 

Publication 16 and has not been addressed separately in the 2022 NIST OWM Technical Analysis, has been 

circulated to the Spring 2022 Regional Associations (NEWMA and CWMA) that will also impact LPG15.1 and MFM-15.1 and Block 7 items. This proposal adds a General Code requirement so that rather than 

revising a specific code in Handbook 44 every time a new field or transfer standard is proposed or 

developed, an overall statement in the General Code recognizes the use of other field and transfer standards 

that meet the requirements for use as field or transfer standards is proposed as follows:

G-N.3. Test Methods. – Permissible test methods for verifying compliance of weighing and 

measuring systems with the provisions of the General Code and Specific Codes include, but are 

not limited to, test methods and apparatus that have been approved by the State Director of 

weights and measures as outlined in Appendix A - Fundamental Considerations, Section 3. 

Testing Apparatus.

For those who believe a specific statement in Handbook 44 is needed to recognize additional field and 

transfer standards, the proposed addition of G-N.3. will provide the reference they want without the need 

to change individual codes on a regular basis to recognize each particular field or transfer standard. 

The submitters agree that these items, GEN-19.1 and OTH-22.1 are fully developed and requested that this 

S&T Committee consider that this combined item be a Voting Item in 2023.

Summary of Discussions and Actions:

At the 2022 Interim Meeting there was discussion concerning specifying a 1-year length of time for the 

stability of a field standard. The concern was whether or not this was an appropriate length of time and 

how a specific length of time for a standards stability could change due to many factors. Some expressed 

concerns with more time needed to review the latest edition of the proposal. NIST and Seraphin agreed to 

further develop the item and NIST OWM requested that both GEN-19.1 and the OTH-22.1 be combined. 
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During their work session, the Committee agreed to combine both GEN-19.1 and OTH-22.1 and agreed to 

a Developing status for this item. For more information or to provide comment, please contact:

Mr. Robert Murnane

Seraphin Test Measure Company 

A Division of Pemberton Fabricators, Inc. 

(609) 267-0922, rmurnane@pemfb.com 

or 

Ms. G. Diane Lee

NIST Office of Weights and Measures

diane.lee@nist.gov

At the 2022 Annual Meeting Open hearings the Committee heard comments for Mrs. Tina Butcher, the 

submitter of this item. Mrs. Butcher provided the NIST OWM technical analysis for this item as provided 

in the executive summary of the report. Mrs. Butcher noted that this item is ready to move forward as 

voting for the 2023 NCWM cycle. 

During the Committee work session since the item status was Developing it remained Developing.

Regional Association Reporting:

Western Weights and Measures Association

During the WWMA 2022 Annual Meeting the following comments were received. Mr. Robert Murnane 

(Seraphin Test Measure Company) asked if they had the updated proposal online? The September 1st

version was so that we didn’t have to hunt and peck to find words to change. 3.2: Tolerance for Standards: 

in the first paragraph, where it says accuracy of standards it should say “field standards”. On S&T agenda 

page 309, line 42, it should say “field standard or transfer standard”. It is up to the discretion of the State 

Director.

 

Mr. Matt Douglas (S&T Committee) commented that the equation, it looks like when the error of the 

transfer standard is less than 1/3 the applicable tolerance, you would end up with a lower tolerance for the 

device - even though it looks like the intention would be to give an extended tolerance. 

Mr. Murnane stated that the equation gives the benefit to the meter, I'll ask you to look at that paper. 

Mr. Michael Keilty (Endress+Hauser) remarked that adding “Weighing and Measuring” is a good idea. If 

you were testing a type 1 then you don't use the formula. When you have a type 2 device then you would 

use the formula to calculate the corrections allowed. I recommend Developing. 

Mr. Kurt Floren (County of Los Angeles) stated he did not want to be a hurdle to this. I’m still struggling. 

I’m picturing myself in a courtroom because we’ve taken formal enforcement action. We aren’t equipped 

to test all “field conditions” in a Metrology lab. Is there any way for us to clarify certain things? What is 

an extended time and what is a short time with regard to how long a device remains accurate? I cannot 

define that, and I have continued questions. 

Mr. Brent Price (Gilbarco) commented that S&T Page 310, line 8: I’m questioning if we need that last 

sentence. 
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Mr. Keilty wondered what does long-term vs short-term mean? I recommend that the item continue to be 

developing and answer Mr. Floren’s questions. 

Mr. Murnane stated this is our current attempt at this. There needs to be definitions, there is no real 

definition. What are you guys doing now to defend yourselves with no definition (referencing transfer 

standard vs field standard). I look for input but haven’t had much. I think this could be a Voting Item. 

Mr. Floren stated that field standard encompasses everything imaginable. It suggests that we have to 

evidence that every block weight that we have has been tested and proven to be stable under every possible 

scenario. We need to be very specific about what is a transfer standard. 

During open hearings, Mr. Murnaneprovided testimony with changes to the proposed language which is 

now posted on the WWMA website. The WWMA S&T Committee recommended that this item should 

remain Developing, and that the submitter provides the updated language to NCWM to allow membership 

to review the updated proposal. The Committee further recommended that this item be blocked with Block 

7 as the items in Block 7 are contingent on Block 8 items. 

Southern Weights and Measures Association

The following comments were received during the 2022 SWMA Annual Meeting: Mr. Murnane stated that 

you can’t always define every environmental issue, and we must be able to use judgment. 

Mr. Keilty stated that Block 8 adds a definition for Type 1 and 2 Transfer Standards into the code, and he 

recommends this item move forward as Developing. 

The SWMA S&T Committee questioned why the submitter wants to move some of these items into code 

when they have been traditionally covered by the Fundamental Considerations. Additionally, the 

Committee questioned the open-ended nature of the timeframe component in defining the type of standard, 

and section 3.1.1. Essential Elements of Traceability potentially restricting the Directors authority in 

allowing certain standards to be used. The Committee also requests documentation of specific standards in 

use and which type of standard they would be based on these definitions.

The SWMA S&T Committee recommended this item move forward as a Developing Item. 

Northeastern Weights and Measures Association

During the 2022 Interim Meeting, Mr. Murnane . commented that the item that appears in the agenda is not 

what has been proposed as there are many typos. A true version of the item was submitted to the NEWMA 

S&T Chair and shared with the body. Mr. Murnane asks that the same status be given to Block 7 and Block 

8 as they are directly linked. Mr. Murnane indicated that this proposal draws from the Fundamental 

Considerations and clarifies that State Directors have the authority to use any standards. Mr. Michael Keilty 

(Endress Hauser) questioned Section 3.2 that was shaded, regarding corrections by a metrology lab and 

clarification was given by Mr. Murnane. Mr Keilty stated that he understands what is being done to 

introduce type 1 and type 2 transfer standards, but transfer standards are not always stable and type 2 

standards do not meet 1/3 requirement in the Fundamental Consideration and has questions about “time” 

and “environmental conditions”. 

After hearing comments from the floor, the Committee believes this item has merit and is full developed. 

The Committee recommended that this item be assigned a Voting status.
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Central Weights and Measures Association 

During the 2022 Interim Meeting, Mr. Murnane stated that the nomenclature has been cleaned up since 

previous version. The intent has not changed, simply clarifications. Former contended point was referring 

to only measuring devices instead of weighing and measuring devices. Wants this change, which was 

provided to the Committee in writing, to be included and moved forward with this item. 

The CWMA S&T Committee believes this item is fully developed and recommend Voting status with the 

following changes which were provided by the submitter: 

Whenever possible and practical, field standards should be used to test commercial weighing and 

measuring devices. However, where it is impractical or unduly cumbersome to use field standards, 

transfer standards may be used. There are two categories of transfer standards. The critical criteria 

that distinguish between these standards are: (1) the accuracy and uncertainty of the standard; (2) 

the stability as a standard over an extended period; and (3) proven validity or performance of the 

standard over the range of environmental and operational conditions in which the standard may be 

used. 

A “field standard” is one that meets the one-third requirement mentioned earlier in this section. 

Additionally, the field standard maintains its validity or stability as a standard over an extended 

period (defined based on data of the standard’s stability by an authorized metrology lab or as 

specified by the Director) and is known to maintain its value as a standard over the full range of 

environmental conditions and the range of operating conditions in which the standard may be used 

to test commercial weighing and measuring devices. Corrections, as documented by an authorized 

metrology laboratory, may be used. 

Transfer standards do not meet one or more of these critical criteria. One category of transfer 

standards, which is referred to here as a “Type 1 transfer standard,” is a transfer standard that meets 

the one-third accuracy requirement for a short time, under a limited range of environmental 

conditions and/or a limited range of operating conditions. The accuracy of a Type 1 transfer standard 

may have to be verified through testing each time it is used to verify that the desired accuracy and 

performance can be achieved when the Type 1 transfer standard is used under the limited 

environmental and operating conditions. When a Type 1 transfer standard is used, the basic 

tolerances specified for the commercial weighing and measuring devices are applied as specified in 

the applicable codes. 

The second category of transfer standard, which is referred to here as a “Type 2 transfer standard,” 

is one that does not meet the one-third requirement. The Type 2 transfer standard must be stable 

and valid under the environmental or operating conditions in which it is used. The performance 

characteristics must be confirmed with sufficient data to properly characterize the uncertainty 

associated with the Type 2 transfer standard. When a Type 2 transfer standard is used, the tolerances 

applicable to the commercial weighing and measuring devices must be increased to recognize the 

large uncertainty or corrections associated with the Type 2 transfer standard. When commercial 

meters weighing and measuring devices are tested using a Type 2 transfer standard, the tolerance 

applied to the commercial weighing and measuring devices meter under test shall be determined as 

specified in the General Code.

(Added 202X)

3.2. Tolerances for Standards. – Except for work of relatively high precision, it is recommended that 

the accuracy of field standards used in testing commercial weighing and measuring equipment be 
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established and maintained so that the use of corrections is not necessary. When the field standard is used 

without correction, its combined error and uncertainty must be less than one-third of the applicable device 

tolerance. 

Device testing is complicated to some degree when corrections to standards are applied. When using a 

correction for a field standard or a transfer standard, the uncertainty associated with the corrected value 

must be less than one-third of the applicable device tolerance. The reason for this requirement is to give the 

device being tested as nearly as practicable the full benefit of its own tolerance. 

References: 

[1] NIST OWM Analysis and Executive Summary reports https://www.nist.gov/pml/weights-andmeasures/publications/owm-technical-analysis

[2] National Conference on Weights and Measures Publication 15 (2023) and 16 (2022) 

https://www.ncwm.com

[3] 1905-2022 NCWM Annual Conference reports https://www.nist.gov/pml/owm/publications/ncwmannual-reports