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(3) For removing background PM, we 

recommend that you filter all dilution 

air, including primary full-flow dilution 

air, with high-efficiency particulate air 

(HEPA) filters that have an initial 

minimum collection efficiency 

specification of 99.97% (see § 1065.1001 

for procedures related to HEPAfiltration efficiencies). Ensure that 

HEPA filters are installed properly so 

that background PM does not leak past 

the HEPA filters. If you choose to 

correct for background PM without 

using HEPA filtration, demonstrate that 

the background PM in the dilution air 

contributes less than 50% to the net PM 

collected on the sample filter. You may 

correct net PM without restriction if you 

use HEPA filtration. 

(c) Full-flow dilution; constantvolume sampling (CVS). You may dilute 

the full flow of raw exhaust in a dilution 

tunnel that maintains a nominally 

constant volume flow rate, molar flow 

rate or mass flow rate of diluted 

exhaust, as follows: 

(1) Construction. Use a tunnel with 

inside surfaces of 300 series stainless 

steel. Electrically ground the entire 

dilution tunnel. We recommend a thinwalled and insulated dilution tunnel to 

minimize temperature differences 

between the wall and the exhaust gases. 

(2) Pressure control. Maintain static 

pressure at the location where raw 

exhaust is introduced into the tunnel 

within ± 1.2 kPa of atmospheric 

pressure. You may use a booster blower 

to control this pressure. If you test an 

engine using more careful pressure 

control and you show by engineering 

analysis or by test data that you require 

this level of control to demonstrate 

compliance at the applicable standards, 

we will maintain the same level of static 

pressure control when we test that 

engine. 

(3) Mixing. Introduce raw exhaust into 

the tunnel by directing it downstream 

along the centerline of the tunnel. You 

may introduce a fraction of dilution air 

radially from the tunnel’s inner surface 

to minimize exhaust interaction with 

the tunnel walls. You may configure the 

system with turbulence generators such 

as orifice plates or fins to achieve good 

mixing. We recommend a minimum 

Reynolds number, Re#, of 4000 for the 

diluted exhaust stream, where Re# is 

based on the inside diameter of the 

dilution tunnel. Re# is defined in 

§ 1065.640. 

(4) Flow measurement 

preconditioning. You may condition the 

diluted exhaust before measuring its 

flow rate, as long as this conditioning 

takes place downstream of any heated 

HC or PM sample probes, as follows: 

(i) You may use flow straighteners, 

pulsation dampeners, or both of these. 

(ii) You may use a filter. 

(iii) You may use a heat exchanger to 

control the temperature upstream of any 

flow meter, but you must take steps to 

prevent aqueous condensation as 

described in paragraph (c)(6) of this 

section. 

(5) Flow measurement. Section 

1065.240 describes measurement 

instruments for diluted exhaust flow. 

(6) Aqueous condensation. To ensure 

that you measure a flow that 

corresponds to a measured 

concentration, you may either prevent 

aqueous condensation between the 

sample probe location and the flow 

meter inlet in the dilution tunnel or you 

may allow aqueous condensation to 

occur and then measure humidity at the 

flow meter inlet. You may heat or 

insulate the dilution tunnel walls, as 

well as the bulk stream tubing 

downstream of the tunnel to prevent 

aqueous condensation. Calculations in 

§ 1065.645 and § 1065.650 account for 

either method of addressing humidity in 

the diluted exhaust. Note that 

preventing aqueous condensation 

involves more than keeping pure water 

in a vapor phase (see § 1065.1001). 

(7) Flow compensation. Maintain 

nominally constant molar, volumetric or 

mass flow of diluted exhaust. You may 

maintain nominally constant flow by 

either maintaining the temperature and 

pressure at the flow meter or by directly 

controlling the flow of diluted exhaust. 

You may also directly control the flow 

of proportional samplers to maintain 

proportional sampling. For an 

individual test, validate proportional 

sampling as described in § 1065.545. 

(d) Partial-flow dilution (PFD). Except 

as specified in this paragraph (d), you 

may dilute a partial flow of raw or 

previously diluted exhaust before 

measuring emissions. § 1065.240 

describes PFD-related flow 

measurement instruments. PFD may 

consist of constant or varying dilution 

ratios as described in paragraphs (d)(2) 

and (3) of this section. An example of 

a constant dilution ratio PFD is a 

‘‘secondary dilution PM’’ measurement 

system. 

(1) Applicability. (i) You may not use 

PFD if the standard-setting part 

prohibits it. 

(ii) You may use PFD to extract a 

proportional raw exhaust sample for any 

batch or continuous PM emission 

sampling over any transient duty cycle 

only if we have explicitly approved it 

according to § 1065.10 as an alternative 

procedure to the specified procedure for 

full-flow CVS. 

(iii) You may use PFD to extract a 

proportional raw exhaust sample for any 

batch or continuous gaseous emission 

sampling. 

(iv) You may use PFD to extract a 

proportional raw exhaust sample for any 

batch or continuous PM emission 

sampling over any steady-state duty 

cycle or its ramped-modal cycle (RMC) 

equivalent. 

(v) You may use PFD to extract a 

proportional raw exhaust sample for any 

batch or continuous field-testing. 

(vi) You may use PFD to extract a 

proportional diluted exhaust sample 

from a CVS for any batch or continuous 

emission sampling. 

(vii) You may use PFD to extract a 

constant raw or diluted exhaust sample 

for any continuous emission sampling. 

(2) Constant dilution-ratio PFD. Do 

one of the following for constant 

dilution-ratio PFD: 

(i) Dilute an already proportional 

flow. For example, you may do this as 

a way of performing secondary dilution 

from a CVS tunnel to achieve overall 

dilution ratio for PM sampling. 

(ii) Continuously measure constituent 

concentrations. For example, you might 

dilute to precondition a sample of raw 

exhaust to control its temperature, 

humidity, or constituent concentrations 

upstream of continuous analyzers. In 

this case, you must take into account the 

dilution ratio before multiplying the 

continuous concentration by the 

sampled exhaust flow rate. 

(iii) Extract a proportional sample 

from a separate constant dilution ratio 

PFD system. For example, you might 

use a variable-flow pump to 

proportionally fill a gaseous storage 

medium such as a bag from a PFD 

system. In this case, the proportional 

sampling must meet the same 

specifications as varying dilution ratio 

PFD in paragraph (d)(3) of this section. 

(iv) For each mode of a discrete-mode 

test (such as a locomotive notch setting 

or a specific setting for speed and 

torque), use a constant dilution ratio for 

any PM sampling. You must change the 

overall PM sampling system dilution 

ratio between modes so that the dilution 

ratio on the mode with the highest 

exhaust flow rate meets § 1065.140(e)(2) 

and the dilution ratios on all other 

modes is higher than this (minimum) 

dilution ratio by the ratio of the 

maximum exhaust flow rate to the 

exhaust flow rate of the corresponding 

other mode. This is the same dilution 

ratio requirement for RMC or field 

transient testing. You must account for 

this change in dilution ratio in your 

emission calculations. 
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37296 Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 

(3) Varying dilution-ratio PFD. All the 

following provisions apply for varying 

dilution-ratio PFD: 

(i) Use a control system with sensors 

and actuators that can maintain 

proportional sampling over intervals as 

short as 200 ms (i.e., 5 Hz control). 

(ii) For control input, you may use 

any sensor output from one or more 

measurements; for example, intake-air 

flow, fuel flow, exhaust flow, engine 

speed, and intake manifold temperature 

and pressure. 

(iii) Account for any emission transit 

time in the PFD system, as necessary. 

(iv) You may use preprogrammed data 

if they have been determined for the 

specific test site, duty cycle, and test 

engine from which you dilute 

emissions. 

(v) We recommend that you run 

practice cycles to meet the validation 

criteria in § 1065.545. Note that you 

must validate every emission test by 

meeting the validation criteria with the 

data from that specific test. Data from 

previously validated practice cycles or 

other tests may not be used to validate 

a different emission test. 

(vi) You may not use a PFD system 

that requires preparatory tuning or 

calibration with a CVS or with the 

emission results from a CVS. Rather, 

you must be able to independently 

calibrate the PFD. 

(e) Dilution air temperature, dilution 

ratio, residence time, and temperature 

control of PM samples. Dilute PM 

samples at least once upstream of 

transfer lines. You may dilute PM 

samples upstream of a transfer line 

using full-flow dilution, or partial-flow 

dilution immediately downstream of a 

PM probe. In the case of partial-flow 

dilution, you may have up to 26 cm of 

insulated length between the end of the 

probe and the dilution stage, but we 

recommend that the length be as short 

as practical. Configure dilution systems 

as follows: 

(1) Set the diluent (i.e., dilution air) 

temperature to (25 ± 5) °C. Use good 

engineering judgment to select a 

location to measure this temperature. 

We recommend that you measure this 

temperature as close as practical 

upstream of the point where diluent 

mixes with raw exhaust. 

(2) For any PM dilution system (i.e., 

CVS or PFD), dilute raw exhaust with 

diluent such that the minimum overall 

ratio of diluted exhaust to raw exhaust 

is within the range of (5:1–7:1) and is at 

least 2:1 for any primary dilution stage. 

Base this minimum value on the 

maximum engine exhaust flow rate for 

a given test interval. Either measure the 

maximum exhaust flow during a 

practice run of the test interval or 

estimate it based on good engineering 

judgment (for example, you might rely 

on manufacturer-published literature). 

(3) Configure any PM dilution system 

to have an overall residence time of 

(1 to 5) s, as measured from the location 

of initial diluent introduction to the 

location where PM is collected on the 

sample media. Also configure the 

system to have a residence time of 

at least 0.5 s, as measured from the 

location of final diluent introduction to 

the location where PM is collected on 

the sample media. When determining 

residence times within sampling system 

volumes, use an assumed flow 

temperature of 25 °C and pressure of 

101.325 kPa. 

(4) Control sample temperature to a 

(47 ± 5) °C tolerance, as measured 

anywhere within 20 cm upstream or 

downstream of the PM storage media 

(such as a filter). Measure this 

temperature with a bare-wire junction 

thermocouple with wires that are (0.500 

± 0.025) mm diameter, or with another 

suitable instrument that has equivalent 

performance. The intent of these 

specifications is to minimize heat 

transfer to or from the emissions sample 

prior to the final stage of dilution. This 

is accomplished by initially cooling the 

sample through dilution. 

■ 60. Section 1065.145 is revised to read 

as follows: 

§ 1065.145 Gaseous and PM probes, 

transfer lines, and sampling system 

components. 

(a) Continuous and batch sampling. 

Determine the total mass of each 

constituent with continuous or batch 

sampling, as described in 

§ 1065.15(c)(2). Both types of sampling 

systems have probes, transfer lines, and 

other sampling system components that 

are described in this section. 

(b) Gaseous and PM sample probes. A 

probe is the first fitting in a sampling 

system. It protrudes into a raw or 

diluted exhaust stream to extract a 

sample, such that its inside and outside 

surfaces are in contact with the exhaust. 

A sample is transported out of a probe 

into a transfer line, as described in 

paragraph (c) of this section. The 

following provisions apply to sample 

probes: 

(1) Probe design and construction. 

Use sample probes with inside surfaces 

of 300 series stainless steel or, for raw 

exhaust sampling, use any nonreactive 

material capable of withstanding raw 

exhaust temperatures. Locate sample 

probes where constituents are mixed to 

their mean sample concentration. Take 

into account the mixing of any 

crankcase emissions that may be routed 

into the raw exhaust. Locate each probe 

to minimize interference with the flow 

to other probes. We recommend that all 

probes remain free from influences of 

boundary layers, wakes, and eddies— 

especially near the outlet of a rawexhaust tailpipe where unintended 

dilution might occur. Make sure that 

purging or back-flushing of a probe does 

not influence another probe during 

testing. You may use a single probe to 

extract a sample of more than one 

constituent as long as the probe meets 

all the specifications for each 

constituent. 

(2) Probe installation on multi-stack 

engines. We recommend combining 

multiple exhaust streams from multistack engines before emission sampling 

as described in § 1065.130(c)(6). If this 

is impractical, you may install 

symmetrical probes and transfer lines in 

each stack. In this case, each stack must 

be installed such that similar exhaust 

velocities are expected at each probe 

location. Use identical probe and 

transfer line diameters, lengths, and 

bends for each stack. Minimize the 

individual transfer line lengths, and 

manifold the individual transfer lines 

into a single transfer line to route the 

combined exhaust sample to analyzers 

and/or batch samplers. For PM sampling 

the manifold design must merge the 

individual sample streams with a 

maximum angle of 12.5° relative to the 

single sample stream’s flow. Note that 

the manifold must meet the same 

specifications as the transfer line 

according to paragraph (c) of this 

section. If you use this probe 

configuration and you determine your 

exhaust flow rates with a chemical 

balance of exhaust gas concentrations 

and either intake air flow or fuel flow, 

then show by prior testing that the 

concentration of O2 in each stack 

remains within 5% of the mean O2 

concentration throughout the entire 

duty cycle. 

(3) Gaseous sample probes. Use either 

single-port or multi-port probes for 

sampling gaseous emissions. You may 

orient these probes in any direction 

relative to the raw or diluted exhaust 

flow. For some probes, you must control 

sample temperatures, as follows: 

(i) For probes that extract NOX from 

diluted exhaust, control the probe’s wall 

temperature to prevent aqueous 

condensation. 

(ii) For probes that extract 

hydrocarbons for THC or NMHC 

analysis from the diluted exhaust of 

compression-ignition engines, 2-stroke 

spark-ignition engines, or 4-stroke 

spark-ignition engines below 19 kW, we 

recommend heating the probe to 

minimize hydrocarbon contamination 

consistent with good engineering 
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judgment. If you routinely fail the 

contamination check in the 1065.520 

pretest check, we recommend heating 

the probe section to approximately 190 

°C to minimize contamination. 

(4) PM sample probes. Use PM probes 

with a single opening at the end. Orient 

PM probes to face directly upstream. If 

you shield a PM probe’s opening with 

a PM pre-classifier such as a hat, you 

may not use the preclassifier we specify 

in paragraph (e)(1) of this section. We 

recommend sizing the inside diameter 

of PM probes to approximate isokinetic 

sampling at the expected mean flow 

rate. 

(c) Transfer lines. You may use 

transfer lines to transport an extracted 

sample from a probe to an analyzer, 

storage medium, or dilution system, 

noting certain restrictions for PM 

sampling in § 1065.140(e). Minimize the 

length of all transfer lines by locating 

analyzers, storage media, and dilution 

systems as close to probes as practical. 

We recommend that you minimize the 

number of bends in transfer lines and 

that you maximize the radius of any 

unavoidable bend. Avoid using 90° 

elbows, tees, and cross-fittings in 

transfer lines. Where such connections 

and fittings are necessary, take steps, 

using good engineering judgment, to 

ensure that you meet the temperature 

tolerances in this paragraph (c). This 

may involve measuring temperature at 

various locations within transfer lines 

and fittings. You may use a single 

transfer line to transport a sample of 

more than one constituent, as long as 

the transfer line meets all the 

specifications for each constituent. The 

following construction and temperature 

tolerances apply to transfer lines: 

(1) Gaseous samples. Use transfer 

lines with inside surfaces of 300 series 

stainless steel, PTFE, VitonTM, or any 

other material that you demonstrate has 

better properties for emission sampling. 

For raw exhaust sampling, use a nonreactive material capable of 

withstanding raw exhaust temperatures. 

You may use in-line filters if they do not 

react with exhaust constituents and if 

the filter and its housing meet the same 

temperature requirements as the transfer 

lines, as follows: 

(i) For NOX transfer lines upstream of 

either an NO2-to-NO converter that 

meets the specifications of § 1065.378 or 

a chiller that meets the specifications of 

§ 1065.376, maintain a sample 

temperature that prevents aqueous 

condensation. 

(ii) For THC transfer lines for testing 

compression-ignition engines, 2-stroke 

spark-ignition engines, or 4-stroke 

spark-ignition engines below 19 kW, 

maintain a wall temperature tolerance 

throughout the entire line of (191 ±11) 

°C. If you sample from raw exhaust, you 

may connect an unheated, insulated 

transfer line directly to a probe. Design 

the length and insulation of the transfer 

line to cool the highest expected raw 

exhaust temperature to no lower than 

191 °C, as measured at the transfer line’s 

outlet. For dilute sampling, you may use 

a transition zone between the probe and 

transfer line of up to 92 cm to allow 

your wall temperature to transition to 

(191 ±11) °C. 

(2) PM samples. We recommend 

heated transfer lines or a heated 

enclosure to minimize temperature 

differences between transfer lines and 

exhaust constituents. Use transfer lines 

that are inert with respect to PM and are 

electrically conductive on the inside 

surfaces. We recommend using PM 

transfer lines made of 300 series 

stainless steel. Electrically ground the 

inside surface of PM transfer lines. 

(d) Optional sample-conditioning 

components for gaseous sampling. You 

may use the following sampleconditioning components to prepare 

gaseous samples for analysis, as long as 

you do not install or use them in a way 

that adversely affects your ability to 

show that your engines comply with all 

applicable gaseous emission standards. 

(1) NO2-to-NO converter. You may use 

an NO2-to-NO converter that meets the 

efficiency-performance check specified 

in § 1065.378 at any point upstream of 

a NOX analyzer, sample bag, or other 

storage medium. 

(2) Sample dryer. You may use either 

type of sample dryer described in this 

paragraph (d)(2) to decrease the effects 

of water on gaseous emission 

measurements. You may not use a 

chemical dryer, or use dryers upstream 

of PM sample filters. 

(i) Osmotic-membrane. You may use 

an osmotic-membrane dryer upstream of 

any gaseous analyzer or storage 

medium, as long as it meets the 

temperature specifications in paragraph 

(c)(1) of this section. Because osmoticmembrane dryers may deteriorate after 

prolonged exposure to certain exhaust 

constituents, consult with the 

membrane manufacturer regarding your 

application before incorporating an 

osmotic-membrane dryer. Monitor the 

dewpoint, Tdew, and absolute pressure, 

ptotal, downstream of an osmoticmembrane dryer. You may use 

continuously recorded values of Tdew 

and ptotal in the amount of water 

calculations specified in § 1065.645. If 

you do not continuously record these 

values, you may use their peak values 

observed during a test or their alarm 

setpoints as constant values in the 

calculations specified in § 1065.645. 

You may also use a nominal ptotal, which 

you may estimate as the dryer’s lowest 

absolute pressure expected during 

testing. 

(ii) Thermal chiller. You may use a 

thermal chiller upstream of some gas 

analyzers and storage media. You may 

not use a thermal chiller upstream of a 

THC measurement system for 

compression-ignition engines, 2-stroke 

spark-ignition engines, or 4-stroke 

spark-ignition engines below 19 kW. If 

you use a thermal chiller upstream of an 

NO2-to-NO converter or in a sampling 

system without an NO2-to-NO converter, 

the chiller must meet the NO2 lossperformance check specified in 

§ 1065.376. Monitor the dewpoint, Tdew, 

and absolute pressure, ptotal, 

downstream of a thermal chiller. You 

may use continuously recorded values 

of Tdew and ptotal in the emission 

calculations specified in § 1065.650. If 

you do not continuously record these 

values, you may use the maximum 

temperature and minimum pressure 

values observed during a test or the high 

alarm temperature setpoint and the low 

alarm pressure setpoint as constant 

values in the amount of water 

calculations specified in § 1065.645. 

You may also use a nominal ptotal, which 

you may estimate as the dryer’s lowest 

absolute pressure expected during 

testing. If it is valid to assume the 

degree of saturation in the thermal 

chiller, you may calculate Tdew based on 

the known chiller performance and 

continuous monitoring of chiller 

temperature, Tchiller. If you do not 

continuously record values of Tchiller, 

you may use its peak value observed 

during a test, or its alarm setpoint, as a 

constant value to determine a constant 

amount of water according to 

§ 1065.645. If it is valid to assume that 

Tchiller is equal to Tdew, you may use 

Tchiller in lieu of Tdew according to 

§ 1065.645. If it is valid to assume a 

constant temperature offset between 

Tchiller and Tdew, due to a known and 

fixed amount of sample reheat between 

the chiller outlet and the temperature 

measurement location, you may factor 

in this assumed temperature offset value 

into emission calculations. If we ask for 

it, you must show by engineering 

analysis or by data the validity of any 

assumptions allowed by this paragraph 

(d)(2)(ii). 

(3) Sample pumps. You may use 

sample pumps upstream of an analyzer 

or storage medium for any gas. Use 

sample pumps with inside surfaces of 

300 series stainless steel, PTFE, or any 

other material that you demonstrate has 

better properties for emission sampling. 

For some sample pumps, you must 

control temperatures, as follows: 
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37298 Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 

(i) If you use a NOX sample pump 

upstream of either an NO2-to-NO 

converter that meets § 1065.378 or a 

chiller that meets § 1065.376, it must be 

heated to prevent aqueous 

condensation. 

(ii) For testing compression-ignition 

engines, 2-stroke spark-ignition engines, 

or 4-stroke spark-ignition engines below 

19 kW, if you use a THC sample pump 

upstream of a THC analyzer or storage 

medium, its inner surfaces must be 

heated to a tolerance of (191 ±11) °C. 

(4) Ammonia Scrubber. You may use 

ammonia scrubbers for any or all 

gaseous sampling systems to prevent 

interference with NH3, poisoning of the 

NO2-to-NO converter, and deposits in 

the sampling system or analyzers. 

Follow the ammonia scrubber 

manufacturer’s recommendations or use 

good engineering judgment in applying 

ammonia scrubbers. 

(e) Optional sample-conditioning 

components for PM sampling. You may 

use the following sample-conditioning 

components to prepare PM samples for 

analysis, as long as you do not install or 

use them in a way that adversely affects 

your ability to show that your engines 

comply with the applicable PM 

emission standards. You may condition 

PM samples to minimize positive and 

negative biases to PM results, as follows: 

(1) PM preclassifier. You may use a 

PM preclassifier to remove largediameter particles. The PM preclassifier 

may be either an inertial impactor or a 

cyclonic separator. It must be 

constructed of 300 series stainless steel. 

The preclassifier must be rated to 

remove at least 50% of PM at an 

aerodynamic diameter of 10 μm and no 

more than 1% of PM at an aerodynamic 

diameter of 1 μm over the range of flow 

rates for which you use it. Follow the 

preclassifier manufacturer’s instructions 

for any periodic servicing that may be 

necessary to prevent a buildup of PM. 

Install the preclassifier in the dilution 

system downstream of the last dilution 

stage. Configure the preclassifier outlet 

with a means of bypassing any PM 

sample media so the preclassifier flow 

may be stabilized before starting a test. 

Locate PM sample media within 75 cm 

downstream of the preclassifier’s exit. 

You may not use this preclassifier if you 

use a PM probe that already has a 

preclassifier. For example, if you use a 

hat-shaped preclassifier that is located 

immediately upstream of the probe in 

such a way that it forces the sample 

flow to change direction before entering 

the probe, you may not use any other 

preclassifier in your PM sampling 

system. 

(2) Other components. You may 

request to use other PM conditioning 

components upstream of a PM 

preclassifier, such as components that 

condition humidity or remove gaseousphase hydrocarbons from the diluted 

exhaust stream. You may use such 

components only if we approve them 

under § 1065.10. 

■ 61. Section 1065.170 is amended by 

revising the introductory text and 

paragraphs (a) and (c)(1) to read as 

follows: 

§ 1065.170 Batch sampling for gaseous 

and PM constituents. 

Batch sampling involves collecting 

and storing emissions for later analysis. 

Examples of batch sampling include 

collecting and storing gaseous emissions 

in a bag or collecting and storing PM on 

a filter. You may use batch sampling to 

store emissions that have been diluted 

at least once in some way, such as with 

CVS, PFD, or BMD. You may use batchsampling to store undiluted emissions. 

(a) Sampling methods. If you extract 

from a constant-volume flow rate, 

sample at a constant-volume flow rate as 

follows: 

(1) Validate proportional sampling 

after an emission test as described in 

§ 1065.545. Use good engineering 

judgment to select storage media that 

will not significantly change measured 

emission levels (either up or down). For 

example, do not use sample bags for 

storing emissions if the bags are 

permeable with respect to emissions or 

if they offgas emissions to the extent 

that it affects your ability to demonstrate 

compliance with the applicable gaseous 

emission standards. As another 

example, do not use PM filters that 

irreversibly absorb or adsorb gases to the 

extent that it affects your ability to 

demonstrate compliance with the 

applicable PM emission standard. 

(2) You must follow the requirements 

in § 1065.140(e)(2) related to PM 

dilution ratios. For each filter, if you 

expect the net PM mass on the filter to 

exceed 400 μg, assuming a 38 mm 

diameter filter stain area, you may take 

the following actions in sequence: 

(i) First, reduce filter face velocity as 

needed to target a filter loading of 400 

μg, down to 50 cm/s or less. 

(ii) Then, for discrete-mode testing 

only, you may reduce sample time as 

needed to target a filter loading of 400 

μg, but not below the minimum sample 

time specified in the standard-setting 

part. 

(iii) Then, increase overall dilution 

ratio above the values specified in 

§ 1065.140(e)(2) to target a filter loading 

of 400 μg. 

* * * * * 

(c) * * * 

(1) If you use filter-based sampling 

media to extract and store PM for 

measurement, your procedure must 

meet the following specifications: 

(i) If you expect that a filter’s total 

surface concentration of PM will exceed 

400 μg, assuming a 38 mm diameter 

filter stain area, for a given test interval, 

you may use filter media with a 

minimum initial collection efficiency of 

98%; otherwise you must use a filter 

media with a minimum initial 

collection efficiency of 99.7%. 

Collection efficiency must be measured 

as described in ASTM D2986–95a 

(incorporated by reference in 

§ 1065.1010), though you may rely on 

the sample-media manufacturer’s 

measurements reflected in their product 

ratings to show that you meet this 

requirement. 

(ii) The filter must be circular, with an 

overall diameter of 46.50 ± 0.6 mm and 

an exposed diameter of at least 38 mm. 

See the cassette specifications in 

paragraph (c)(1)(vii) of this section. 

(iii) We highly recommend that you 

use a pure PTFE filter material that does 

not have any flow-through support 

bonded to the back and has an overall 

thickness of 40 ± 20 μm. An inert 

polymer ring may be bonded to the 

periphery of the filter material for 

support and for sealing between the 

filter cassette parts. We consider 

Polymethylpentene (PMP) and PTFE 

inert materials for a support ring, but 

other inert materials may be used. See 

the cassette specifications in paragraph 

(c)(1)(vii) of this section. We allow the 

use of PTFE-coated glass fiber filter 

material, as long as this filter media 

selection does not affect your ability to 

demonstrate compliance with the 

applicable standards, which we base on 

a pure PTFE filter material. Note that we 

will use pure PTFE filter material for 

compliance testing, and we may require 

you to use pure PTFE filter material for 

any compliance testing we require, such 

as for selective enforcement audits. 

(iv) You may request to use other 

filter materials or sizes under the 

provisions of § 1065.10. 

(v) To minimize turbulent deposition 

and to deposit PM evenly on a filter, use 

a 12.5° (from center) divergent cone 

angle to transition from the transfer-line 

inside diameter to the exposed diameter 

of the filter face. Use 300 series stainless 

steel for this transition. 

(vi) Maintain a filter face velocity near 

100 cm/s with less than 5% of the 

recorded flow values exceeding 100 

cm/s, unless you expect either the net 

PM mass on the filter to exceed 400 μg, 

assuming a 38 mm diameter filter stain 

area. Measure face velocity as the 

volumetric flow rate of the sample at the 
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Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 37299 

pressure upstream of the filter and 

temperature of the filter face as 

measured in § 1065.140(e), divided by 

the filter’s exposed area. You may use 

the exhaust stack or CVS tunnel 

pressure for the upstream pressure if the 

pressure drop through the PM sampler 

up to the filter is less than 2 kPa. 

(vii) Use a clean cassette designed to 

the specifications of Figure 1 of 

§ 1065.170 and made of any of the 

following materials: DelrinTM, 300 series 

stainless steel, polycarbonate, 

acrylonitrile-butadiene-styrene (ABS) 

resin, or conductive polypropylene. We 

recommend that you keep filter 

cassettes clean by periodically washing 

or wiping them with a compatible 

solvent applied using a lint-free cloth. 

Depending upon your cassette material, 

ethanol (C2H5OH) might be an 

acceptable solvent. Your cleaning 

frequency will depend on your engine’s 

PM and HC emissions. 

(viii) If you store filters in cassettes in 

an automatic PM sampler, cover or seal 

individual filter cassettes after sampling 

to prevent communication of semivolatile matter from one filter to 

another. 

* * * * * 

■ 62. Section 1065.190 is amended by 

revising paragraphs (c), (e), (f) and (g) to 

read as follows: 

§ 1065.190 PM-stabilization and weighing 

environments for gravimetric analysis. 

* * * * * 

(c) Verify the cleanliness of the PMstabilization environment using 

reference filters, as described in 

§ 1065.390(d). 

* * * * * 

(e) Verify the following ambient 

conditions using measurement 

instruments that meet the specifications 

in subpart C of this part: 

(1) Continuously measure dewpoint 

and ambient temperature. Use these 

values to determine if the stabilization 

and weighing environments have 

remained within the tolerances 

specified in paragraph (d) of this section 

for at least 60 min. before weighing 

sample media (e.g., filters). We 

recommend that you use an interlock 

that automatically prevents the balance 

from reporting values if either of the 

environments have not been within the 

applicable tolerances for the past 60 

min. 

(2) Continuously measure 

atmospheric pressure within the 

weighing environment. An acceptable 

alternative is to use a barometer that 

measures atmospheric pressure outside 

the weighing environment, as long as 

you can ensure that atmospheric 

pressure at the balance is always within 

±100 Pa of that outside environment 

during weighing operations. Record 

atmospheric pressure as you weigh 

filters, and use these pressure values to 

perform the buoyancy correction in 

§ 1065.690. 

(f) We recommend that you install a 

balance as follows: 

(1) Install the balance on a vibrationisolation platform to isolate it from 

external noise and vibration. 

(2) Shield the balance from convective 

airflow with a static-dissipating draft 

shield that is electrically grounded. 

(3) Follow the balance manufacturer’s 

specifications for all preventive 

maintenance. 

(4) Operate the balance manually or as 

part of an automated weighing system. 

(g) Minimize static electric charge in 

the balance environment, as follows: 

(1) Electrically ground the balance. 

(2) Use 300 series stainless steel 

tweezers if PM sample media (e.g., 

filters) must be handled manually. 

(3) Ground tweezers with a grounding 

strap, or provide a grounding strap for 

the operator such that the grounding 

strap shares a common ground with the 

balance. Make sure grounding straps 

have an appropriate resistor to protect 

operators from accidental shock. 

(4) Provide a static-electricity 

neutralizer that is electrically grounded 

in common with the balance to remove 

static charge from PM sample media 

(e.g., filters), as follows: 

(i) You may use radioactive 

neutralizers such as a Polonium (210Po) 

source. Replace radioactive sources at 

the intervals recommended by the 

neutralizer manufacturer. 

(ii) You may use other neutralizers, 

such as corona-discharge ionizers. If you 

use a corona-discharge ionizer, we 

recommend that you monitor it for 

neutral net charge according to the 

ionizer manufacturer’s 

recommendations. 

(5) We recommend that you use a 

device to monitor the static charge of 

PM sample media (e.g., filter) surface. 

(6) We recommend that you neutralize 

PM sample media (e.g., filters) to within 

±2.0 V of neutral. Measure static 

voltages as follows: 

(i) Measure static voltage of PM 

sample media (e.g., filters) according to 

the electrostatic voltmeter 

manufacturer’s instructions. 

(ii) Measure static voltage of PM 

sample media (e.g., filters) while the 

media is at least 15 cm away from any 

grounded surfaces to avoid mirror image 

charge interference. 

■ 63. Section 1065.195 is amended by 

revising paragraphs (a) and (c)(4) to read 

as follows: 

§ 1065.195 PM-stabilization environment 

for in-situ analyzers. 

(a) This section describes the 

environment required to determine PM 

in-situ. For in-situ analyzers, such as an 

inertial balance, this is the environment 

within a PM sampling system that 

surrounds the PM sample media (e.g., 

filters). This is typically a very small 

volume. 

* * * * * 

(c) * * * 

(4) Absolute pressure. Use good 

engineering judgment to maintain a 

tolerance of absolute pressure if your 

PM measurement instrument requires it. 

* * * * * 

Subpart C—[Amended] 

■ 64. Section 1065.201 is amended by 

revising paragraphs (a) and (b) and 

adding paragraph (h) to read as follows: 

§ 1065.201 Overview and general 

provisions. 

(a) Scope. This subpart specifies 

measurement instruments and 

associated system requirements related 

to emission testing in a laboratory or 

similar environment and in the field. 

This includes laboratory instruments 

and portable emission measurement 

systems (PEMS) for measuring engine 

parameters, ambient conditions, flowrelated parameters, and emission 

concentrations. 

(b) Instrument types. You may use any 

of the specified instruments as 

described in this subpart to perform 

emission tests. If you want to use one of 

these instruments in a way that is not 

specified in this subpart, or if you want 

to use a different instrument, you must 

first get us to approve your alternate 

procedure under § 1065.10. Where we 

specify more than one instrument for a 

particular measurement, we may 

identify which instrument serves as the 

reference for comparing with an 

alternate procedure. 

* * * * * 

(h) Recommended practices. This 

subpart identifies a variety of 

recommended but not required practices 

for proper measurements. We believe in 

most cases it is necessary to follow these 

recommended practices for accurate and 

repeatable measurements and we intend 

to follow them as much as possible for 

our testing. However, we do not 

specifically require you to follow these 

recommended practices to perform a 

valid test, as long as you meet the 

required calibrations and verifications 

of measurement systems specified in 

subpart D of this part. 
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37300 Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 

■ 65. Section 1065.210 is amended by 

revising paragraph (a) before the figure 

to read as follows: 

§ 1065.210 Work input and output sensors. 

(a) Application. Use instruments as 

specified in this section to measure 

work inputs and outputs during engine 

operation. We recommend that you use 

sensors, transducers, and meters that 

meet the specifications in Table 1 of 

§ 1065.205. Note that your overall 

systems for measuring work inputs and 

outputs must meet the linearity 

verifications in § 1065.307. We 

recommend that you measure work 

inputs and outputs where they cross the 

system boundary as shown in Figure 1 

of § 1065.210. The system boundary is 

different for air-cooled engines than for 

liquid-cooled engines. If you choose to 

measure work before or after a work 

conversion, relative to the system 

boundary, use good engineering 

judgment to estimate any workconversion losses in a way that avoids 

overestimation of total work. For 

example, if it is impractical to 

instrument the shaft of an exhaust 

turbine generating electrical work, you 

may decide to measure its converted 

electrical work. As another example, 

you may decide to measure the tractive 

(i.e., electrical output) power of a 

locomotive, rather than the brake power 

of the locomotive engine. In these cases, 

divide the electrical work by accurate 

values of electrical generator efficiency 

(h<1), or assume an efficiency of 1 

(h=1), which would over-estimate brakespecific emissions. For the example of 

using locomotive tractive power with a 

generator efficiency of 1 (h=1), this 

means using the tractive power as the 

brake power in emission calculations. 

Do not underestimate any work 

conversion efficiencies for any 

components outside the system 

boundary that do not return work into 

the system boundary. And do not 

overestimate any work conversion 

efficiencies for components outside the 

system boundary that do return work 

into the system boundary. In all cases, 

ensure that you are able to accurately 

demonstrate compliance with the 

applicable standards. 

* * * * * 

■ 66. Section 1065.215 is amended by 

revising paragraph (e) to read as follows: 

§ 1065.215 Pressure transducers, 

temperature sensors, and dewpoint 

sensors. 

* * * * * 

(e) Dewpoint. For PM-stabilization 

environments, we recommend chilledsurface hygrometers, which include 

chilled mirror detectors and chilled 

surface acoustic wave (SAW) detectors. 

For other applications, we recommend 

thin-film capacitance sensors. You may 

use other dewpoint sensors, such as a 

wet-bulb/dry-bulb psychrometer, where 

appropriate. 

■ 67. Section 1065.220 is amended by 

revising paragraph (d) to read as 

follows: 

§ 1065.220 Fuel flow meter. 

* * * * * 

(d) Flow conditioning. For any type of 

fuel flow meter, condition the flow as 

needed to prevent wakes, eddies, 

circulating flows, or flow pulsations 

from affecting the accuracy or 

repeatability of the meter. You may 

accomplish this by using a sufficient 

length of straight tubing (such as a 

length equal to at least 10 pipe 

diameters) or by using specially 

designed tubing bends, straightening 

fins, or pneumatic pulsation dampeners 

to establish a steady and predictable 

velocity profile upstream of the meter. 

Condition the flow as needed to prevent 

any gas bubbles in the fuel from 

affecting the fuel meter. 

■ 68. Section 1065.265 is amended by 

revising paragraph (c) to read as follows: 

§ 1065.265 Nonmethane cutter. 

* * * * * 

(c) Configuration. Configure the 

nonmethane cutter with a bypass line if 

it is needed for the verification 

described in § 1065.365. 

* * * * * 

■ 69. Section 1065.270 is amended by 

revising paragraphs (c) and (d) 

introductory text to read as follows: 

§ 1065.270 Chemiluminescent detector. 

* * * * * 

(c) NO2-to-NO converter. Place 

upstream of the CLD an internal or 

external NO2-to-NO converter that meets 

the verification in § 1065.378. Configure 

the converter with a bypass line if it is 

needed to facilitate this verification. 

(d) Humidity effects. You must 

maintain all CLD temperatures to 

prevent aqueous condensation. If you 

remove humidity from a sample 

upstream of a CLD, use one of the 

following configurations: 

* * * * * 

■ 70. Section 1065.280 is revised to read 

as follows: 

§ 1065.280 Paramagnetic and 

magnetopneumatic O2 detection analyzers. 

(a) Application. You may use a 

paramagnetic detection (PMD) or 

magnetopneumatic detection (MPD) 

analyzer to measure O2 concentration in 

raw or diluted exhaust for batch or 

continuous sampling. You may use O2 

measurements with intake air or fuel 

flow measurements to calculate exhaust 

flow rate according to § 1065.650. 

(b) Component requirements. We 

recommend that you use a PMD or MPD 

analyzer that meets the specifications in 

Table 1 of § 1065.205. Note that it must 

meet the linearity verification in 

§ 1065.307. You may use a PMD or MPD 

that has compensation algorithms that 

are functions of other gaseous 

measurements and the engine’s known 

or assumed fuel properties. The target 

value for any compensation algorithm is 

0.0% (that is, no bias high and no bias 

low), regardless of the uncompensated 

signal’s bias. 

■ 71. Section 1065.290 is amended by 

revising paragraph (c)(1) to read as 

follows: 

§ 1065.290 PM gravimetric balance. 

* * * * * 

(c) * * * 

(1) Use a pan that centers the PM 

sample media (such as a filter) on the 

weighing pan. For example, use a pan 

in the shape of a cross that has upswept 

tips that center the PM sample media on 

the pan. 

* * * * * 

Subpart D—[Amended] 

■ 72. Section 1065.303 is revised to read 

as follows: 

§ 1065.303 Summary of required 

calibration and verifications. 

The following table summarizes the 

required and recommended calibrations 

and verifications described in this 

subpart and indicates when these have 

to be performed: 

TABLE 1 OF § 1065.303.—SUMMARY OF REQUIRED CALIBRATION AND VERIFICATIONS 

Type of calibration or verification Minimum frequency a 

§ 1065.305: Accuracy, repeatability and noise ... Accuracy: Not required, but recommended for initial installation. 

Repeatability: Not required, but recommended for initial installation. 

Noise: Not required, but recommended for initial installation. 
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Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 37301 

TABLE 1 OF § 1065.303.—SUMMARY OF REQUIRED CALIBRATION AND VERIFICATIONS—Continued 

Type of calibration or verification Minimum frequency a 

§ 1065.307: Linearity ........................................... Speed: Upon initial installation, within 370 days before testing and after major maintenance. 

Torque: Upon initial installation, within 370 days before testing and after major maintenance. 

Electrical power: Upon initial installation, within 370 days before testing and after major maintenance. 

Clean gas and diluted exhaust flows: Upon initial installation, within 370 days before testing 

and after major maintenance, unless flow is verified by propane check or by carbon or oxygen balance. 

Raw exhaust flow: Upon initial installation, within 185 days before testing and after major 

maintenance, unless flow is verified by propane check or by carbon or oxygen balance. 

Gas analyzers: Upon initial installation, within 35 days before testing and after major maintenance. 

PM balance: Upon initial installation, within 370 days before testing and after major maintenance. 

Stand-alone pressure and temperature: Upon initial installation, within 370 days before testing 

and after major maintenance. 

§ 1065.308: Continuous analyzer system re- Upon initial installation, after system reconfiguration, and after major maintenance. 

sponse and recording. 

§ 1065.309: Continuous analyzer uniform re- Upon initial installation, after system reconfiguration, and after major maintenance. 

sponse. 

§ 1065.310: Torque ............................................. Upon initial installation and after major maintenance. 

§ 1065.315: Pressure, temperature, dewpoint .... Upon initial installation and after major maintenance. 

§ 1065.320: Fuel flow .......................................... Upon initial installation and after major maintenance. 

§ 1065.325: Intake flow ....................................... Upon initial installation and after major maintenance. 

§ 1065.330: Exhaust flow .................................... Upon initial installation and after major maintenance. 

§ 1065.340: Diluted exhaust flow (CVS) ............. Upon initial installation and after major maintenance. 

§ 1065.341: CVS and batch sampler Upon initial installation, within 35 days before testing, and after major maintenance. 

verification b. 

§ 1065.345: Vacuum leak ................................... Before each laboratory test according to subpart F of this part and before each field test according to subpart J of this part. 

§ 1065.350: CO2 NDIR H2O interference ........... Upon initial installation and after major maintenance. 

§ 1065.355: CO NDIR CO2 and H2O inter- Upon initial installation and after major maintenance. 

ference. 

§ 1065.360: FID calibration THC FID optimiza- Calibrate all FID analyzers: Upon initial installation and after major maintenance. 

tion, and THC FID verification. Optimize and determine CH4 response for THC FID analyzers: upon initial installation and 

after major maintenance. 

Verify CH4 response for THC FID analyzers: Upon initial installation, within 185 days before 

testing, and after major maintenance. 

§ 1065.362: Raw exhaust FID O2 interference ... For all FID analyzers: Upon initial installation, and after major maintenance. 

For THC FID analyzers: Upon initial installation, after major maintenance, and after FID optimization according to § 1065.360. 

§ 1065.365: Nonmethane cutter penetration ...... Upon initial installation, within 185 days before testing, and after major maintenance. 

§ 1065.370: CLD CO2 and H2O quench ............. Upon initial installation and after major maintenance. 

§ 1065.372: NDUV HC and H2O interference .... Upon initial installation and after major maintenance. 

§ 1065.376: Chiller NO2 penetration ................... Upon initial installation and after major maintenance. 

§ 1065.378: NO2-to-NO converter conversion .... Upon initial installation, within 35 days before testing, and after major maintenance. 

§ 1065.390: PM balance and weighing .............. Independent verification: Upon initial installation, within 370 days before testing, and after 

major maintenance. 

Zero, span, and reference sample verifications: Within 12 hours of weighing, and after major 

maintenance. 

§ 1065.395: Inertial PM balance and weighing .. Independent verification: Upon initial installation, within 370 days before testing, and after 

major maintenance. 

Other verifications: Upon initial installation and after major maintenance. 

a Perform calibrations and verifications more frequently, according to measurement system manufacturer instructions and good engineering 

judgment. b The CVS verification described in § 1065.341 is not required for systems that agree within ± 2% based on a chemical balance of carbon or 

oxygen of the intake air, fuel, and diluted exhaust. 

■ 73. Section 1065.305 is amended by 

revising paragraphs (d)(4), (d)(8), and 

(d)(9)(iii) to read as follows: 

§ 1065.305 Verifications for accuracy, 

repeatability, and noise. 

* * * * * 

(d) * * * 

(4) Use the instrument to quantify a 

NIST-traceable reference quantity, yref. 

For gas analyzers the reference gas must 

meet the specifications of § 1065.750. 

Select a reference quantity near the 

mean value expected during testing. For 

all gas analyzers, use a quantity near the 

flow-weighted mean concentration 

expected at the standard or expected 

during testing, whichever is greater. For 

noise verification, use the same zero gas 

from paragraph (e) of this section as the 

reference quantity. In all cases, allow 

time for the instrument to stabilize 

while it measures the reference 

quantity. Stabilization time may include 

time to purge an instrument and time to 

account for its response. 

* * * * * 

(8) Repeat the steps specified in 

paragraphs (d)(2) through (7) of this 

section until you have ten arithmetic 

means (y ̄ 1, y ̄ 2, y ̄ i,...y ̄ 10), ten standard 

deviations, (s1, s2, si,...s10), and ten 

errors (e1, e2, ei,...e10). 

(9) * * * 

(iii) Noise. Noise is two times the rootmean-square of the ten standard 
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37302 Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 

deviations (that is, noise = 2·rmsσ) when 

the reference signal is a zero-quantity 

signal. Refer to the example of a rootmean-square calculation in § 1065.602. 

We recommend that instrument noise be 

within the specifications in Table 1 of 

§ 1065.205. 

* * * * * 

■ 74. Section 1065.307 is amended by 

revising paragraphs (b), (c)(6), (c)(13), 

and Table 1 and adding paragraphs 

(d)(8) and (e) before the newly revised 

table to read as follows: 

§ 1065.307 Linearity verification. 

* * * * * 

(b) Performance requirements. If a 

measurement system does not meet the 

applicable linearity criteria in Table 1 of 

this section, correct the deficiency by recalibrating, servicing, or replacing 

components as needed. Repeat the 

linearity verification after correcting the 

deficiency to ensure that the 

measurement system meets the linearity 

criteria. Before you may use a 

measurement system that does not meet 

linearity criteria, you must demonstrate 

to us that the deficiency does not 

adversely affect your ability to 

demonstrate compliance with the 

applicable standards. 

(c) * * * 

(6) For all measured quantities, use 

instrument manufacturer 

recommendations and good engineering 

judgment to select reference values, yrefi, 

that cover a range of values that you 

expect would prevent extrapolation 

beyond these values during emission 

testing. We recommend selecting a zero 

reference signal as one of the reference 

values of the linearity verification. For 

stand-alone pressure and temperature 

linearity verifications, we recommend at 

least three reference values. For all other 

linearity verifications select at least ten 

reference values. 

* * * * * 

(13) Use the arithmetic means, y ̄ i, and 

reference values, y ̄ refi, to calculate leastsquares linear regression parameters and 

statistical values to compare to the 

minimum performance criteria specified 

in Table 1 of this section. Use the 

calculations described in § 1065.602. 

Using good engineering judgment, you 

may weight the results of individual 

data pairs (i.e., (yrefi, y ̄ i)), in the linear 

regression calculations. 

(d) * * * 

(8) Temperature. You may perform 

the linearity verification for temperature 

measurement systems with 

thermocouples, RTDs, and thermistors 

by removing the sensor from the system 

and using a simulator in its place. Use 

a NIST-traceable simulator that is 

independently calibrated and, as 

appropriate, cold-junction compensated. 

The simulator uncertainty scaled to 

temperature must be less than 0.5% of 

Tmax. If you use this option, you must 

use sensors that the supplier states are 

accurate to better than 0.5% of Tmax 

compared with their standard 

calibration curve. 

(e) Measurement systems that require 

linearity verification. Table 1 of this 

section indicates measurement systems 

that require linearity verifications, 

subject to the following provisions: 

(1) Perform a linearity verification 

more frequently based on the 

instrument manufacturer’s 

recommendation or good engineering 

judgment. 

(2) The expression ‘‘min’’ refers to the 

minimum reference value used during 

the linearity verification. Note that this 

value may be zero or a negative value 

depending on the signal. 

(3) The expression ‘‘max’’ generally 

refers to the maximum reference value 

used during the linearity verification. 

For example for gas dividers, xmax is the 

undivided, undiluted, span gas 

concentration. The following are special 

cases where ‘‘max’’ refers to a different 

value: 

(i) For linearity verification with a PM 

balance, mmax refers to the typical mass 

of a PM filter. 

(ii) For linearity verification of torque, 

Tmax refers to the manufacturer’s 

specified engine torque peak value of 

the lowest torque engine to be tested. 

(4) The specified ranges are inclusive. 

For example, a specified range of 0.98– 

1.02 for a1 means 0.98≤a1≤1.02. 

(5) These linearity verifications are 

optional for systems that pass the flowrate verification for diluted exhaust as 

described in § 1065.341 (the propane 

check) or for systems that agree within 

±2% based on a chemical balance of 

carbon or oxygen of the intake air, fuel, 

and exhaust. 

(6) You must meet the a1 criteria for 

these quantities only if the absolute 

value of the quantity is required, as 

opposed to a signal that is only linearly 

proportional to the actual value. 

(7) The following provisions apply for 

stand-alone temperature measurements: 

(i) The following temperature 

linearity checks are required: 

(A) Air intake. 

(B) Aftertreatment bed(s), for engines 

tested with aftertreatment devices 

subject to cold-start testing. 

(C) Dilution air for PM sampling, 

including CVS, double-dilution, and 

partial-flow systems. 

(D) PM sample, if applicable. 

(E) Chiller sample, for gaseous 

sampling systems that use chillers to 

dry samples. 

(ii) The following temperature 

linearity checks are required only if 

specified by the engine manufacturer: 

(A) Fuel inlet. 

(B) Air outlet to the test cell’s charge 

air cooler air outlet, for engines tested 

with a laboratory heat exchanger that 

simulates an installed charge air cooler. 

(C) Coolant inlet to the test cell’s 

charge air cooler, for engines tested with 

a laboratory heat exchanger that 

simulates an installed charge air cooler. 

(D) Oil in the sump/pan. 

(E) Coolant before the thermostat, for 

liquid-cooled engines. 

(8) The following provisions apply for 

stand-alone pressure measurements: 

(i) The following pressure linearity 

checks are required: 

(A) Air intake restriction. 

(B) Exhaust back pressure. 

(C) Barometer. 

(D) CVS inlet gage pressure. 

(E) Chiller sample, for gaseous 

sampling systems that use chillers to 

dry samples. 

(ii) The following pressure linearity 

checks are required only if specified by 

the engine manufacturer: 

(A) The test cell’s charge air cooler 

and interconnecting pipe pressure drop, 

for turbo-charged engines tested with a 

laboratory heat exchanger that simulates 

an installed charge air cooler. 

(B) Fuel outlet. 

TABLE 1 OF § 1065.307.—MEASUREMENT SYSTEMS THAT REQUIRE LINEARITY VERIFICATIONS 

Measurement system Quantity Minimum verification frequency 

Linearity criteria 

xmin(a1¥1)+a0  a1 SEE r 2 

Engine speed ............................ fn ............ Within 370 days before testing ≤0.05 % fnmax .... 0.98–1.02 ≤2 % · fnmax ....... ≥0.990 

Engine torque ............................ T ............ Within 370 days before testing ≤1 % · Tmax ....... 0.98–1.02 ≤2 % · Tmax ....... ≥0.990 

Electrical work ........................... W ........... Within 370 days before testing ≤1 % · Tmax ....... 0.98–1.02 ≤2 % · Tmax ....... ≥0.990 

Fuel flow rate ............................ m ̇ ........... Within 370 days before testing d ≤1 % · m ̇ max ...... 0.98–1.02 ≤2 % · m ̇ max ...... ≥0.990 
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Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 37303 

TABLE 1 OF § 1065.307.—MEASUREMENT SYSTEMS THAT REQUIRE LINEARITY VERIFICATIONS—Continued 

Measurement system Quantity Minimum verification frequency 

Linearity criteria 

xmin(a1¥1)+a0  a1 SEE r 2 

Intake-air flow rate .................... n ̇ ............ Within 370 days before testing ≤1 % · n ̇max ....... 0.98–1.02 ≤2 % · n ̇max ....... ≥0.990 

Dilution air flow rate .................. n ̇ ............ Within 370 days before testing ≤1 % · n ̇max ....... 0.98–1.02 ≤2 % · n ̇max ....... ≥0.990 

Diluted exhaust flow rate .......... n ̇ ............ Within 370 days before testing ≤1 % · n ̇max ....... 0.98–1.02 ≤2 % · n ̇ max ....... ≥0.990 

Raw exhaust flow rate .............. n ̇ ............ Within 185 days before testing ≤1 % · n ̇max ....... 0.98–1.02 ≤2 % · n ̇max ....... ≥0.990 

Batch sampler flow rates .......... n ̇ ............ Within 370 days before testing ≤1 % · n ̇max ....... 0.98–1.02 ≤2 % · n ̇ max ....... ≥0.990 

Gas dividers .............................. x/xspan ..... Within 370 days before testing ≤0.5 % · xmax .... 0.98–1.02 ≤2 % · xmax ....... ≥0.990 

Gas analyzers for laboratory 

testing. 

x ............ Within 35 days before testing ... ≤0.5 % · xmax .... 0.99–1.01 ≤1 % · xmax ....... ≥0.998 

Gas analyzers for field testing .. x ............ Within 35 days before testing ... ≤1 % · xmax ....... 0.99–1.01 ≤1 % · xmax ....... ≥0.998 

PM balance ............................... m ........... Within 370 days before testing ≤1 % · mmax ...... 0.99–1.01 ≤1 % · mmax ...... ≥0.998 

Stand-alone pressures .............. p ............ Within 370 days before testing ≤1 % · pmax ....... 0.99–1.01 ≤1 % · pmax ....... ≥0.998 

Analog-to-digital conversion of 

stand-alone temperature signals. 

T ............ Within 370 days before testing ≤1 % · Tmax ....... 0.99–1.01 ≤1 % · Tmax ....... ≥0.998 

■ 75. Section 1065.308 is revised to read 

as follows: 

§ 1065.308 Continuous gas analyzer 

system-response and updating-recording 

verification—general. 

This section describes a general 

verification procedure for continuous 

gas analyzer system response and 

update recording. See § 1065.309 for 

verification procedures that apply for 

systems or components involving H2O 

correction. 

(a) Scope and frequency. Perform this 

verification after installing or replacing 

a gas analyzer that you use for 

continuous sampling. Also perform this 

verification if you reconfigure your 

system in a way that would change 

system response. For example, perform 

this verification if you add a significant 

volume to the transfer lines by 

increasing their length or adding a filter; 

or if you reduce the frequency at which 

you sample and record gas-analyzer 

concentrations. You do not have to 

perform this verification for gas analyzer 

systems used only for discrete-mode 

testing. 

(b) Measurement principles. This test 

verifies that the updating and recording 

frequencies match the overall system 

response to a rapid change in the value 

of concentrations at the sample probe. 

Gas analyzer systems must be optimized 

such that their overall response to a 

rapid change in concentration is 

updated and recorded at an appropriate 

frequency to prevent loss of 

information. This test also verifies that 

continuous gas analyzer systems meet a 

minimum response time. 

(c) System requirements. To 

demonstrate acceptable updating and 

recording with respect to the system’s 

overall response, use good engineering 

judgment to select one of the following 

criteria that your system must meet: 

(1) The product of the mean rise time 

and the frequency at which the system 

records an updated concentration must 

be at least 5, and the product of the 

mean fall time and the frequency at 

which the system records an updated 

concentration must be at least 5. This 

criterion makes no assumption 

regarding the frequency content of 

changes in emission concentrations 

during emission testing; therefore, it is 

valid for any testing. In any case the 

mean rise time and the mean fall time 

must be no more than 10 seconds. 

(2) The frequency at which the system 

records an updated concentration must 

be at least 5 Hz. This criterion assumes 

that the frequency content of significant 

changes in emission concentrations 

during emission testing do not exceed 1 

Hz. In any case the mean rise time and 

the mean fall time must be no more than 

10 seconds. 

(3) You may use other criteria if we 

approve the criteria in advance. 

(4) You may meet the overall PEMS 

verification in § 1065.920 instead of the 

verification in this section for field 

testing with PEMS. 

(d) Procedure. Use the following 

procedure to verify the response of a 

continuous gas analyzer system: 

(1) Instrument setup. Follow the 

analyzer system manufacturer’s start-up 

and operating instructions. Adjust the 

system as needed to optimize 

performance. 

(2) Equipment setup. We recommend 

using minimal lengths of gas transfer 

lines between all connections and fastacting three-way valves (2 inlets, 1 

outlet) to control the flow of zero and 

blended span gases to the analyzers. 

You may use a gas mixing or blending 

device to equally blend an NO-CO-CO2-

C3H8-CH4, balance N2 span gas with a 

span gas of NO2, balance purified 

synthetic air. Standard binary span 

gases may also be used, where 

applicable, in place of blended NO-COCO2-C3H8-CH4, balance N2 span gas, but 

separate response tests must then be run 

for each analyzer. In designing your 

experimental setup, avoid pressure 

pulsations due to stopping the flow 

through the gas-blending device. Note 

that you may omit any of these gas 

constituents if they are not relevant to 

your analyzers for this verification. 

(3) Data collection. (i) Start the flow 

of zero gas. 

(ii) Allow for stabilization, accounting 

for transport delays and the slowest 

instrument’s full response. 

(iii) Start recording data at the 

frequency used during emission testing. 

Each recorded value must be a unique 

updated concentration measured by the 

analyzer; you may not use interpolation 

to increase the number of recorded 

values. 

(iv) Switch the flow to allow the 

blended span gases to flow to the 

analyzer. 

(v) Allow for transport delays and the 

slowest instrument’s full response. 

(vi) Repeat the steps in paragraphs 

(d)(3)(i) through (v) of this section to 

record seven full cycles, ending with 

zero gas flowing to the analyzers. 

(vii) Stop recording. 

(e) Performance evaluation. (1) If you 

chose to demonstrate compliance with 

paragraph (c)(1) of this section, use the 

data from paragraph (d)(3) of this 

section to calculate the mean rise time, 

t10–90, and mean fall time, t10–90, for each 

of the analyzers. Multiply these times 

(in seconds) by their respective 

recording frequencies in Hertz (1/ 

second). The value for each result must 

be at least 5. If the value is less than 5, 

increase the recording frequency or 

adjust the flows or design of the 

sampling system to increase the rise 

time and fall time as needed. You may 
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also configure digital filters to increase 

rise and fall times. The mean rise time 

and mean fall time must be no greater 

than 10 seconds. 

(2) If a measurement system fails the 

criterion in paragraph (e)(1) of this 

section, ensure that signals from the 

system are updated and recorded at a 

frequency of at least 5 Hz. In any case, 

the mean rise time and mean fall time 

must be no greater than 10 seconds. 

(3) If a measurement system fails the 

criteria in paragraphs (e)(1) and (2) of 

this section, you may use the 

continuous analyzer system only if the 

deficiency does not adversely affect 

your ability to show compliance with 

the applicable standards. 

■ 76. Section 1065.309 is revised to read 

as follows: 

§ 1065.309 Continuous gas analyzer 

system-response and updating-recording 

verification—with humidified-response 

verification. 

This section describes a verification 

procedure for continuous gas analyzer 

system response and update recording 

for systems or components involving 

H2O correction. See § 1065.308 for 

verification procedures that apply for 

systems not involving humidification. 

(a) Scope and frequency. Perform this 

verification to determine a continuous 

gas analyzer’s response, where one 

analyzer’s response is compensated by 

another’s to quantify a gaseous 

emission. For this check we consider 

water vapor a gaseous constituent. You 

do not have to perform this verification 

for batch gas analyzer systems or for 

continuous analyzer systems that are 

only used for discrete-mode testing. 

Perform this verification after initial 

installation (i.e. test cell 

commissioning). The verification in this 

section is required for initial installation 

of systems or components involving 

H2O correction. For later verifications, 

you may use the procedures specified in 

§ 1065.308, as long as your system 

includes no replacement components 

involving H2O correction that have 

never been verified using the 

procedures in this section. 

(b) Measurement principles. This 

procedure verifies the time-alignment 

and uniform response of continuously 

combined gas measurements. For this 

procedure, ensure that all compensation 

algorithms and humidity corrections are 

turned on. 

(c) System requirements. Demonstrate 

that continuously combined 

concentration measurements have a 

uniform rise and fall during a system 

response to a rapid change in multiple 

gas concentrations. You must meet one 

of the following criteria: 

(1) The product of the mean rise time 

and the frequency at which the system 

records an updated concentration must 

be at least 5, and the product of the 

mean fall time and the frequency at 

which the system records an updated 

concentration must be at least 5. This 

criterion makes no assumption 

regarding the frequency content of 

changes in emission concentrations 

during emission testing; therefore, it is 

valid for any testing. In no case may the 

mean rise time or the mean fall time be 

more than 10 seconds. 

(2) The frequency at which the system 

records an updated concentration must 

be at least 5 Hz. This criterion assumes 

that the frequency content of significant 

changes in emission concentrations 

during emission testing do not exceed 1 

Hz. In no case may the mean rise time 

or the mean fall time be more than 10 

seconds. 

(3) You may use other criteria if we 

approve them in advance. 

(4) You may meet the overall PEMS 

verification in § 1065.920 instead of the 

verification in this section for field 

testing with PEMS. 

(d) Procedure. Use the following 

procedure to verify the response of a 

continuous gas analyzer system: 

(1) Instrument setup. Follow the 

analyzer system manufacturer’s start-up 

and operating instructions. Adjust the 

system as needed to optimize 

performance. 

(2) Equipment setup. We recommend 

using minimal lengths of gas transfer 

lines between all connections and fastacting three-way valves (2 inlets, 1 

outlet) to control the flow of zero and 

blended span gases to the analyzers. 

You may use a gas blending or mixing 

device to equally blend a span gas of 

NO-CO-CO2-C3H8-CH4, balance N2, with 

a span gas of NO2, balance purified 

synthetic air. Standard binary span 

gases may be used, where applicable, in 

place of blended NO-CO-CO2-C3H8-CH4, 

balance N2 span gas, but separate 

response tests must then be run for each 

analyzer. In designing your 

experimental setup, avoid pressure 

pulsations due to stopping the flow 

through the gas blending device. Span 

gases must be humidified before 

entering the analyzer; however, you may 

not humidify NO2 span gas by passing 

it through a sealed humidification 

vessel that contains water. We 

recommend humidifying your NO-COCO2-C3H8-CH4, balance N2 blended gas 

by flowing the gas mixture through a 

sealed vessel that humidifies the gas by 

bubbling it through distilled water and 

then mixing the gas with dry NO2 gas, 

balance purified synthetic air. If your 

system does not use a sample dryer to 

remove water from the sample gas, you 

must humidify your span gas by flowing 

the gas mixture through a sealed vessel 

that humidifies the gas to the highest 

sample dewpoint that you estimate 

during emission sampling by bubbling it 

through distilled water. If your system 

uses a sample dryer during testing that 

has passed the sample dryer verification 

check in § 1065.342, you may introduce 

the humidified gas mixture downstream 

of the sample dryer by bubbling it 

through distilled water in a sealed 

vessel at (25 ± 10) °C, or a temperature 

greater than the dewpoint determined in 

§ 1065.145(d)(2). In all cases, maintain 

the humidified gas temperature 

downstream of the vessel at least 5 °C 

above its local dewpoint in the line. We 

recommend that you heat all gas transfer 

lines and valves located downstream of 

the vessel as needed to avoid 

condensation. Note that you may omit 

any of these gas constituents if they are 

not relevant to your analyzers for this 

verification. If any of your gas 

constituents are not susceptible to water 

compensation, you may perform the 

response check for these analyzers 

without humidification. 

(3) Data collection. (i) Start the flow 

of zero gas. 

(ii) Allow for stabilization, accounting 

for transport delays and the slowest 

instrument’s full response. 

(iii) Start recording data at the 

frequency used during emission testing. 

Each recorded value must be a unique 

updated concentration measured by the 

analyzer; you may not use interpolation 

to increase the number of recorded 

values. 

(iv) Switch the flow to allow the 

blended span gases to flow to the 

analyzers. 

(v) Allow for transport delays and the 

slowest instrument’s full response. 

(vi) Repeat the steps in paragraphs 

(d)(3)(i) through (v) of this section to 

record seven full cycles, ending with 

zero gas flowing to the analyzers. 

(vii) Stop recording. 

(e) Performance evaluations. (1) If you 

chose to demonstrate compliance with 

paragraph (c)(1) of this section, use the 

data from paragraph (d)(3) of this 

section to calculate the mean rise time, 

t10¥90, and mean fall time, tS90¥10, for 

each of the analyzers. Multiply these 

times (in seconds) by their respective 

recording frequencies in Hz (1/second). 

The value for each result must be at 

least 5. If the value is less than 5, 

increase the recording frequency or 

adjust the flows or design of the 

sampling system to increase the rise 

time and fall time as needed. You may 

also configure digital filters to increase 

rise and fall times. In no case may the 
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mean rise time or mean fall time be 

greater than 10 seconds. 

(2) If a measurement system fails the 

criterion in paragraph (e)(1) of this 

section, ensure that signals from the 

system are updated and recorded at a 

frequency of at least 5 Hz. In no case 

may the mean rise time or mean fall 

time be greater than 10 seconds. 

(3) If a measurement system fails the 

criteria in paragraphs (e)(1) and (2) of 

this section, you may use the 

continuous analyzer system only if the 

deficiency does not adversely affect 

your ability to show compliance with 

the applicable standards. 

■ 77. Section 1065.310 is amended by 

revising paragraph (d) to read as 

follows: 

§ 1065.310 Torque calibration. 

* * * * * 

(d) Strain gage or proving ring 

calibration. This technique applies force 

either by hanging weights on a lever arm 

(these weights and their lever arm 

length are not used as part of the 

reference torque determination) or by 

operating the dynamometer at different 

torques. Apply at least six force 

combinations for each applicable 

torque-measuring range, spacing the 

force quantities about equally over the 

range. Oscillate or rotate the 

dynamometer during calibration to 

reduce frictional static hysteresis. In this 

case, the reference torque is determined 

by multiplying the force output from the 

reference meter (such as a strain gage or 

proving ring) by its effective lever-arm 

length, which you measure from the 

point where the force measurement is 

made to the dynamometer’s rotational 

axis. Make sure you measure this length 

perpendicular to the reference meter’s 

measurement axis and perpendicular to 

the dynamometer’s rotational axis. 

■ 78. Section 1065.315 is amended by 

revising paragraph (a)(2) to read as 

follows: 

§ 1065.315 Pressure, temperature, and 

dewpoint calibration. 

(a) * * * 

(2) Temperature. We recommend 

digital dry-block or stirred-liquid 

temperature calibrators, with data 

logging capabilities to minimize 

transcription errors. We recommend 

using calibration reference quantities 

that are NIST-traceable within 0.5% 

uncertainty. You may perform the 

linearity verification for temperature 

measurement systems with 

thermocouples, RTDs, and thermistors 

by removing the sensor from the system 

and using a simulator in its place. Use 

a NIST-traceable simulator that is 

independently calibrated and, as 

appropriate, cold-junction compensated. 

The simulator uncertainty scaled to 

temperature must be less than 0.5% of 

Tmax. If you use this option, you must 

use sensors that the supplier states are 

accurate to better than 0.5% of Tmax 

compared with their standard 

calibration curve. 

* * * * * 

■ 79. Section 1065.340 is amended by 

revising paragraphs (f)(5), (f)(6)(ii), (f)(7), 

(f)(9), (f)(10), (g)(6)(i), and Figure 1 to 

read as follows: 

§ 1065.340 Diluted exhaust flow (CVS) 

calibration. 

* * * * * 

(f) * * * 

(5) Set the variable restrictor to its 

wide-open position. Instead of a 

variable restrictor, you may alternately 

vary the pressure downstream of the 

CFV by varying blower speed or by 

introducing a controlled leak. Note that 

some blowers have limitations on 

nonloaded conditions. 

(6) * * * 

(ii) The mean dewpoint of the 

calibration air, Tdew. See § 1065.640 for  ̄ 

permissible assumptions during 

emission measurements. 

* * * * * 

(7) Incrementally close the restrictor 

valve or decrease the downstream 

pressure to decrease the differential 

pressure across the CFV,Dp ̄ CFV. 

* * * * * 

(9) Determine Cd and the lowest 

allowable pressure ratio, r, according to 

§ 1065.640. 

(10) Use Cd to determine CFV flow 

during an emission test. Do not use the 

CFV below the lowest allowed r, as 

determined in § 1065.640. 

* * * * * 

(g) * * * 

(6) * * * 

(i) The mean flow rate of the reference Ô flow meter,nref. This may include 

several measurements of different 

quantities, such as reference meter 

pressures and temperatures, for Ô calculating nref. 

* * * * * 

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■ 80. Section 1065.341 is amended by 

revising paragraphs (d) introductory 

text, (d)(7), and (g) introductory text to 

read as follows: 

§ 1065.341 CVS and batch sampler 

verification (propane check). 

* * * * * 

(d) If you performed the vacuum-side 

leak verification of the HC sampling 

system as described in paragraph (c)(8) 

of this section, you may use the HC 

contamination procedure in 

§ 1065.520(g) to verify HC 

contamination. Otherwise, zero, span, 

and verify contamination of the HC 

sampling system, as follows: 

* * * * * 

(7) When the overflow HC 

concentration does not exceed 2 μmol/ 

mol, record this value as xTHCinit and use 

it to correct for HC contamination as 

described in § 1065.660. 

* * * * * 

(g) You may repeat the propane check 

to verify a batch sampler, such as a PM 

secondary dilution system. 

* * * * * 

■ 81. A new § 1065.342 is added to read 

as follows: 

§ 1065.342 Sample dryer verification. 

(a) Scope and frequency. If you use a 

sample dryer as allowed in 

§ 1065.145(d)(2) to remove water from 

the sample gas, verify the performance 

upon installation, after major 

maintenance, for thermal chiller. For 

osmotic membrane dryers, verify the 

performance upon installation, after 

major maintenance, and within 35 days 

of testing. 

(b) Measurement principles. Water 

can inhibit an analyzer’s ability to 

properly measure the exhaust 

component of interest and thus is 

sometimes removed before the sample 

gas reaches the analyzer. For example 

water can negatively interfere with a 

CLD’s NOX response through collisional 

quenching and can positively interfere 

with an NDIR analyzer by causing a 

response similar to CO. 

(c) System requirements. The sample 

dryer must meet the specifications as 

determined in § 1065.145(d)(2) for 

dewpoint, Tdew, and absolute pressure, 

ptotal, downstream of the osmoticmembrane dryer or thermal chiller. 

(d) Sample dryer verification 

procedure. Use the following method to 

determine sample dryer performance, or 

use good engineering judgment to 

develop a different protocol: 

(1) Use PTFE or stainless steel tubing 

to make necessary connections. 

(2) Humidify N2 or purified air by 

bubbling it through distilled water in a 

sealed vessel that humidifies the gas to 

the highest sample dewpoint that you 

estimate during emission sampling. 

(3) Introduce the humidified gas 

upstream of the sample dryer. 

(4) Downstream of the vessel, 

maintain the humidified gas 

temperature at least 5 °C above its 

dewpoint. 

(5) Measure the humidified gas 

dewpoint, Tdew, and pressure, ptotal, as 

close as possible to the inlet of the 

sample dryer to verify the dewpoint is 

the highest that you estimated during 

emission sampling. 

(6) Measure the humidified gas 

dewpoint, Tdew, and pressure, ptotal, as 

close as possible to the outlet of the 

sample dryer. 

(7) The sample dryer meets the 

verification if the results of paragraph 

(d)(6) of this section are less than the 

dew point corresponding to the sample 

dryer specifications as determined in 

§ 1065.145(d)(2) plus 2 °C or if the mole 

fraction from (d)(6) is less than the 

corresponding sample dryer 

specifications plus 0.002 mol/mol. 

(e) Alternate sample dryer verification 

procedure. The following method may 

be used in place of the sample dryer 

verification procedure in (d) of this 

section. If you use a humidity sensor for 

continuous monitoring of dewpoint at 

the sample dryer outlet you may skip 

the performance check in § 1065.342(d), 

but you must make sure that the dryer 

outlet humidity is below the minimum 

values used for quench, interference, 

and compensation checks. 

■ 82. Section 1065.345 is revised to read 

as follows: 

§ 1065.345 Vacuum-side leak verification. 

(a) Scope and frequency. Verify that 

there are no significant vacuum-side 

leaks using one of the leak tests 

described in this section upon initial 

sampling system installation, after 

maintenance such as pre-filter changes, 

and within eight hours before each 

duty-cycle sequence. This verification 

does not apply to any full-flow portion 

of a CVS dilution system. 

(b) Measurement principles. A leak 

may be detected either by measuring a 

small amount of flow when there should 

be zero flow, or by detecting the 

dilution of a known concentration of 

span gas when it flows through the 

vacuum side of a sampling system. 

(c) Low-flow leak test. Test a sampling 

system for low-flow leaks as follows: 

(1) Seal the probe end of the system 

by taking one of the following steps: 

(i) Cap or plug the end of the sample 

probe. 

(ii) Disconnect the transfer line at the 

probe and cap or plug the transfer line. 

(iii) Close a leak-tight valve located in 

the sample transfer line within 92 cm of 

the probe. 

(2) Operate all vacuum pumps. After 

stabilizing, verify that the flow through 

the vacuum-side of the sampling system 

is less than 0.5% of the system’s normal 

in-use flow rate. You may estimate 

typical analyzer and bypass flows as an 

approximation of the system’s normal 

in-use flow rate. 

(d) Dilution-of-span-gas leak test. You 

may use any gas analyzer for this test. 

If you use a FID for this test, correct for 

any HC contamination in the sampling 

system according to § 1065.660. To 

avoid misleading results from this test, 

we recommend using only analyzers 

that have a repeatability of 0.5% or 

better at the span gas concentration used 

for this test. Perform a vacuum-side leak 

test as follows: 

(1) Prepare a gas analyzer as you 

would for emission testing. 

(2) Supply span gas to the analyzer 

port and verify that it measures the span 

gas concentration within its expected 

measurement accuracy and 

repeatability. 

(3) Route overflow span gas to one of 

the following locations in the sampling 

system: 

(i) The end of the sample probe. 

(ii) Disconnect the transfer line at the 

probe connection, and overflow the 

span gas at the open end of the transfer 

line. 

(iii) A three-way valve installed inline between a probe and its transfer 

line, such as a system overflow zero and 

span port. 

(4) Verify that the measured overflow 

span gas concentration is within ± 0.5% 

of the span gas concentration. A 

measured value lower than expected 

indicates a leak, but a value higher than 

expected may indicate a problem with 

the span gas or the analyzer itself. A 

measured value higher than expected 

does not indicate a leak. 

(e) Vacuum-decay leak test. To 

perform this test you must apply a 

vacuum to the vacuum-side volume of 

your sampling system and then observe 

the leak rate of your system as a decay 

in the applied vacuum. To perform this 

test you must know the vacuum-side 

volume of your sampling system to 

within ± 10% of its true volume. For 

this test you must also use measurement 

instruments that meet the specifications 

of subpart C of this part and of this 

subpart D. Perform a vacuum-decay leak 

test as follows: 

(1) Seal the probe end of the system 

as close to the probe opening as possible 

by taking one of the following steps: 

(i) Cap or plug the end of the sample 

probe. 
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(ii) Disconnect the transfer line at the 

probe and cap or plug the transfer line. 

(iii) Close a leak-tight valve in-line 

between a probe and transfer line. 

(2) Operate all vacuum pumps. Draw 

a vacuum that is representative of 

normal operating conditions. In the case 

of sample bags, we recommend that you 

repeat your normal sample bag pumpdown procedure twice to minimize any 

trapped volumes. 

(3) Turn off the sample pumps and 

seal the system. Measure and record the 

absolute pressure of the trapped gas and 

optionally the system absolute 

temperature. Wait long enough for any 

transients to settle and long enough for 

a leak at 0.5% to have caused a pressure 

change of at least 10 times the 

resolution of the pressure transducer, 

then again record the pressure and 

optionally temperature. 

(4) Calculate the leak flow rate based 

on an assumed value of zero for 

pumped-down bag volumes and based 

on known values for the sample system 

volume, the initial and final pressures, 

optional temperatures, and elapsed 

time. Using the calculations specified in 

1065.644, verify that the vacuum-decay 

leak flow rate is less than 0.5% of the 

system’s normal in-use flow rate. 

■ 83. Section 1065.350 is amended by 

revising paragraphs (c) and (d) to read 

as follows: 

§ 1065.350 H2O interference verification 

for CO2 NDIR analyzers. 

* * * * * 

(c) System requirements. A CO2 NDIR 

analyzer must have an H2O interference 

that is within (0.0 ±0.4) mmol/mol, 

though we strongly recommend a lower 

interference that is within (0.0 ±0.2) 

mmol/mol. 

(d) Procedure. Perform the 

interference verification as follows: 

(1) Start, operate, zero, and span the 

CO2 NDIR analyzer as you would before 

an emission test. 

(2) Create a humidified test gas by 

bubbling zero air that meets the 

specifications in § 1065.750 through 

distilled water in a sealed vessel. If the 

sample is not passed through a dryer, 

control the vessel temperature to 

generate an H2O level at least as high as 

the maximum expected during testing. If 

the sample is passed through a dryer 

during testing, control the vessel 

temperature to generate an H2O level at 

least as high as the level determined in 

§ 1065.145(d)(2). 

(3) Introduce the humidified test gas 

into the sample system. You may 

introduce it downstream of any sample 

dryer, if one is used during testing. 

(4) Measure the humidified test gas 

dewpoint, Tdew, and pressure, ptotal, as 

close as possible to the inlet of the 

analyzer. 

(5) Downstream of the vessel, 

maintain the humidified test gas 

temperature at least 5 °C above its 

dewpoint. 

(6) Allow time for the analyzer 

response to stabilize. Stabilization time 

may include time to purge the transfer 

line and to account for analyzer 

response. 

(7) While the analyzer measures the 

sample’s concentration, record 30 

seconds of sampled data. Calculate the 

arithmetic mean of this data. The 

analyzer meets the interference 

verification if this value is within 

(0 ±0.4) mmol/mol. 

* * * * * 

■ 84. Section 1065.355 is amended by 

revising paragraph (d) to read as 

follows: 

§ 1065.355 H2O and CO2 interference 

verification for CO NDIR analyzers. 

* * * * * 

(d) Procedure. Perform the 

interference verification as follows: 

(1) Start, operate, zero, and span the 

CO NDIR analyzer as you would before 

an emission test. 

(2) Create a humidified CO2 test gas 

by bubbling a CO2 span gas through 

distilled water in a sealed vessel. If the 

sample is not passed through a dryer, 

control the vessel temperature to 

generate an H2O level at least as high as 

the maximum expected during testing. If 

the sample is passed through a dryer 

during testing, control the vessel 

temperature to generate an H2O level at 

least as high as the level determined in 

§ 1065.145(d)(2). Use a CO2 span gas 

concentration at least as high as the 

maximum expected during testing. 

(3) Introduce the humidified CO2 test 

gas into the sample system. You may 

introduce it downstream of any sample 

dryer, if one is used during testing. 

(4) Measure the humidified CO2 test 

gas dewpoint, Tdew, and pressure, ptotal, 

as close as possible to the inlet of the 

analyzer. 

(5) Downstream of the vessel, 

maintain the humidified gas 

temperature at least 5 °C above its 

dewpoint. 

(6) Allow time for the analyzer 

response to stabilize. Stabilization time 

may include time to purge the transfer 

line and to account for analyzer 

response. 

(7) While the analyzer measures the 

sample’s concentration, record its 

output for 30 seconds. Calculate the 

arithmetic mean of this data. 

(8) The analyzer meets the 

interference verification if the result of 

paragraph (d)(7) of this section meets 

the tolerance in paragraph (c) of this 

section. 

(9) You may also run interference 

procedures for CO2 and H2O separately. 

If the CO2 and H2O levels used are 

higher than the maximum levels 

expected during testing, you may scale 

down each observed interference value 

by multiplying the observed 

interference by the ratio of the 

maximum expected concentration value 

to the actual value used during this 

procedure. You may run the separate 

interference procedures concentrations 

of H2O (down to 0.025 mol/mol H2O 

content) that are lower than the 

maximum levels expected during 

testing, but you must scale up the 

observed H2O interference by 

multiplying the observed interference 

by the ratio of the maximum expected 

H2O concentration value to the actual 

value used during this procedure. The 

sum of the two scaled interference 

values must meet the tolerance in 

paragraph (c) of this section. 

* * * * * 

■ 85. Section 1065.360 is revised to read 

as follows: 

§ 1065.360 FID optimization and 

verification. 

(a) Scope and frequency. For all FID 

analyzers, calibrate the FID upon initial 

installation. Repeat the calibration as 

needed using good engineering 

judgment. For a FID that measures THC, 

perform the following steps: 

(1) Optimize the response to various 

hydrocarbons after initial analyzer 

installation and after major maintenance 

as described in paragraph (c) of this 

section. 

(2) Determine the methane (CH4) 

response factor after initial analyzer 

installation and after major maintenance 

as described in paragraph (d) of this 

section. 

(3) Verify the methane (CH4) response 

within 185 days before testing as 

described in paragraph (e) of this 

section. 

(b) Calibration. Use good engineering 

judgment to develop a calibration 

procedure, such as one based on the 

FID-analyzer manufacturer’s 

instructions and recommended 

frequency for calibrating the FID. 

Alternately, you may remove system 

components for off-site calibration. For 

a FID that measures THC, calibrate 

using C3H8 calibration gases that meet 

the specifications of § 1065.750. For a 

FID that measures CH4, calibrate using 

CH4 calibration gases that meet the 

specifications of § 1065.750. We 

recommend FID analyzer zero and span 

gases that contain approximately the 

flow-weighted mean concentration of O2 
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Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 37309 

expected during testing. If you use a FID 

to measure methane (CH4) downstream 

of a nonmethane cutter, you may 

calibrate that FID using CH4 calibration 

gases with the cutter. Regardless of the 

calibration gas composition, calibrate on 

a carbon number basis of one (C1). For 

example, if you use a C3H8 span gas of 

concentration 200 μmol/mol, span the 

FID to respond with a value of 600 

μmol/mol. As another example, if you 

use a CH4 span gas with a concentration 

of 200 μmol/mol, span the FID to 

respond with a value of 200 μmol/mol. 

(c) THC FID response optimization. 

This procedure is only for FID analyzers 

that measure THC. Use good 

engineering judgment for initial 

instrument start-up and basic operating 

adjustment using FID fuel and zero air. 

Heated FIDs must be within their 

required operating temperature ranges. 

Optimize FID response at the most 

common analyzer range expected during 

emission testing. Optimization involves 

adjusting flows and pressures of FID 

fuel, burner air, and sample to minimize 

response variations to various 

hydrocarbon species in the exhaust. Use 

good engineering judgment to trade off 

peak FID response to propane 

calibration gases to achieve minimal 

response variations to different 

hydrocarbon species. For an example of 

trading off response to propane for 

relative responses to other hydrocarbon 

species, see SAE 770141 (incorporated 

by reference in § 1065.1010). Determine 

the optimum flow rates and/or pressures 

for FID fuel, burner air, and sample and 

record them for future reference. 

(d) THC FID CH4 response factor 

determination. This procedure is only 

for FID analyzers that measure THC. 

Since FID analyzers generally have a 

different response to CH4 versus C3H8, 

determine each THC FID analyzer’s CH4 

response factor, RFCH4[THC–FID], after FID 

optimization. Use the most recent 

RFCH4[THC–FID] measured according to 

this section in the calculations for HC 

determination described in § 1065.660 

to compensate for CH4 response. 

Determine RFCH4[THC–FID] as follows, 

noting that you do not determine 

RFCH4[THC–FID] for FIDs that are 

calibrated and spanned using CH4 with 

a nonmethane cutter: 

(1) Select a C3H8 span gas 

concentration that you use to span your 

analyzers before emission testing. Use 

only span gases that meet the 

specifications of § 1065.750. Record the 

C3H8 concentration of the gas. 

(2) Select a CH4 span gas 

concentration that you use to span your 

analyzers before emission testing. Use 

only span gases that meet the 

specifications of § 1065.750. Record the 

CH4 concentration of the gas. 

(3) Start and operate the FID analyzer 

according to the manufacturer’s 

instructions. 

(4) Confirm that the FID analyzer has 

been calibrated using C3H8. Calibrate on 

a carbon number basis of one (C1). For 

example, if you use a C3H8 span gas of 

concentration 200 μmol/mol, span the 

FID to respond with a value of 600 

μmol/mol. 

(5) Zero the FID with a zero gas that 

you use for emission testing. 

(6) Span the FID with the C3H8 span 

gas that you selected under paragraph 

(d)(1) of this section. 

(7) Introduce at the sample port of the 

FID analyzer, the CH4 span gas that you 

selected under paragraph (d)(2) of this 

section. 

(8) Allow time for the analyzer 

response to stabilize. Stabilization time 

may include time to purge the analyzer 

and to account for its response. 

(9) While the analyzer measures the 

CH4 concentration, record 30 seconds of 

sampled data. Calculate the arithmetic 

mean of these values. 

(10) Divide the mean measured 

concentration by the recorded span 

concentration of the CH4 calibration gas. 

The result is the FID analyzer’s response 

factor for CH4, RFCH4[THC–FID]. 

(e) THC FID methane (CH4) response 

verification. This procedure is only for 

FID analyzers that measure THC. If the 

value of RFCH4[THC–FID] from paragraph 

(d) of this section is within ±5.0% of its 

most recent previously determined 

value, the THC FID passes the methane 

response verification. For example, if 

the most recent previous value for 

RFCH4[THC–FID] was 1.05 and it changed 

by ±0.05 to become 1.10 or it changed 

by ¥0.05 to become 1.00, either case 

would be acceptable because ±4.8% is 

less than ±5.0%. Verify RFCH4[THC–FID] as 

follows: 

(1) First verify that the flow rates and/ 

or pressures of FID fuel, burner air, and 

sample are each within ±0.5% of their 

most recent previously recorded values, 

as described in paragraph (c) of this 

section. You may adjust these flow rates 

as necessary. Then determine the 

RFCH4[THC–FID] as described in paragraph 

(d) of this section and verify that it is 

within the tolerance specified in this 

paragraph (e). 

(2) If RFCH4[THC–FID] is is not within 

the tolerance specified in this paragraph 

(e), re-optimize the FID response as 

described in paragraph (c) of this 

section. 

(3) Determine a new RFCH4[THC–FID] as 

described in paragraph (d) of this 

section. Use this new value of 

RFCH4[THC–FID] in the calculations for HC 

determination, as described in 

§ 1065.660. 

■ 86. Section 1065.362 is amended by 

revising paragraph (d) to read as 

follows: 

§ 1065.362 Non-stoichiometric raw 

exhaust FID O2 interference verification. 

* * * * * 

(d) Procedure. Determine FID O2 

interference as follows, noting that you 

may use one or more gas dividers to 

create the reference gas concentrations 

that are required to perform this 

verification: 

(1) Select three span reference gases 

that contain a C3H8 concentration that 

you use to span your analyzers before 

emission testing. Use only span gases 

that meet the specifications of 

§ 1065.750. You may use CH4 span 

reference gases for FIDs calibrated on 

CH4 with a nonmethane cutter. Select 

the three balance gas concentrations 

such that the concentrations of O2 and 

N2 represent the minimum, maximum, 

and average O2 concentrations expected 

during testing. The requirement for 

using the average O2 concentration can 

be removed if you choose to calibrate 

the FID with span gas balanced with the 

average expected oxygen concentration. 

(2) Confirm that the FID analyzer 

meets all the specifications of 

§ 1065.360. 

(3) Start and operate the FID analyzer 

as you would before an emission test. 

Regardless of the FID burner’s air source 

during testing, use zero air as the FID 

burner’s air source for this verification. 

(4) Zero the FID analyzer using the 

zero gas used during emission testing. 

(5) Span the FID analyzer using a span 

gas that you use during emission testing. 

(6) Check the zero response of the FID 

analyzer using the zero gas used during 

emission testing. If the mean zero 

response of 30 seconds of sampled data 

is within ±0.5% of the span reference 

value used in paragraph (d)(5) of this 

section, then proceed to the next step; 

otherwise restart the procedure at 

paragraph (d)(4) of this section. 

(7) Check the analyzer response using 

the span gas that has the minimum 

concentration of O2 expected during 

testing. Record the mean response of 30 

seconds of stabilized sample data as 

xO2minHC. 

(8) Check the zero response of the FID 

analyzer using the zero gas used during 

emission testing. If the mean zero 

response of 30 seconds of stabilized 

sample data is within ±0.5% of the span 

reference value used in paragraph (d)(5) 

of this section, then proceed to the next 

step; otherwise restart the procedure at 

paragraph (d)(4) of this section. 
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37310 Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 

(9) Check the analyzer response using 

the span gas that has the average 

concentration of O2 expected during 

testing. Record the mean response of 30 

seconds of stabilized sample data as 

xO2avgHC. 

(10) Check the zero response of the 

FID analyzer using the zero gas used 

during emission testing. If the mean 

zero response of 30 seconds of stabilized 

sample data is within ±0.5% of the span 

reference value used in paragraph (d)(5) 

of this section, proceed to the next step; 

otherwise restart the procedure at 

paragraph (d)(4) of this section. 

(11) Check the analyzer response 

using the span gas that has the 

maximum concentration of O2 expected 

during testing. Record the mean 

response of 30 seconds of stabilized 

sample data as xO2maxHC. 

(12) Check the zero response of the 

FID analyzer using the zero gas used 

during emission testing. If the mean 

zero response of 30 seconds of stabilized 

sample data is within ±0.5% of the span 

reference value used in paragraph (d)(5) 

of this section, then proceed to the next 

step; otherwise restart the procedure at 

paragraph (d)(4) of this section. 

(13) Calculate the percent difference 

between xO2maxHC and its reference gas 

concentration. Calculate the percent 

difference between xO2avgHC and its 

reference gas concentration. Calculate 

the percent difference between xO2minHC 

and its reference gas concentration. 

Determine the maximum percent 

difference of the three. This is the O2 

interference. 

(14) If the O2 interference is within 

±2%, the FID passes the O2 interference 

verification; otherwise perform one or 

more of the following to address the 

deficiency: 

(i) Repeat the verification to 

determine if a mistake was made during 

the procedure. 

(ii) Select zero and span gases for 

emission testing that contain higher or 

lower O2 concentrations and repeat the 

verification. 

(iii) Adjust FID burner air, fuel, and 

sample flow rates. Note that if you 

adjust these flow rates on a THC FID to 

meet the O2 interference verification, 

you have reset RFCH4 for the next RFCH4 

verification according to § 1065.360. 

Repeat the O2 interference verification 

after adjustment and determine RFCH4. 

(iv) Repair or replace the FID and 

repeat the O2 interference verification. 

(v) Demonstrate that the deficiency 

does not adversely affect your ability to 

demonstrate compliance with the 

applicable emission standards. 

■ 87. Section 1065.365 is revised to read 

as follows: 

§ 1065.365 Nonmethane cutter penetration 

fractions. 

(a) Scope and frequency. If you use a 

FID analyzer and a nonmethane cutter 

(NMC) to measure methane (CH4), 

determine the nonmethane cutter’s 

penetration fractions of methane, PFCH4, 

and ethane, PFC2H6. As detailed in this 

section, these penetration fractions may 

be determined as a combination of NMC 

penetration fractions and FID analyzer 

response factors, depending on your 

particular NMC and FID analyzer 

configuration. Perform this verification 

after installing the nonmethane cutter. 

Repeat this verification within 185 days 

of testing to verify that the catalytic 

activity of the cutter has not 

deteriorated. Note that because 

nonmethane cutters can deteriorate 

rapidly and without warning if they are 

operated outside of certain ranges of gas 

concentrations and outside of certain 

temperature ranges, good engineering 

judgment may dictate that you 

determine a nonmethane cutter’s 

penetration fractions more frequently. 

(b) Measurement principles. A 

nonmethane cutter is a heated catalyst 

that removes nonmethane hydrocarbons 

from an exhaust sample stream before 

the FID analyzer measures the 

remaining hydrocarbon concentration. 

An ideal nonmethane cutter would have 

a methane penetration fraction, PFCH4, 

of 1.000, and the penetration fraction for 

all other nonmethane hydrocarbons 

would be 0.000, as represented by 

PFC2H6. The emission calculations in 

§ 1065.660 use the measured values 

from this verification to account for less 

than ideal NMC performance. 

(c) System requirements. We do not 

limit NMC penetration fractions to a 

certain range. However, we recommend 

that you optimize a nonmethane cutter 

by adjusting its temperature to achieve 

a PFCH4 >0.85 and a PFC2H6 <0.02, as 

determined by paragraphs (d), (e), or (f) 

of this section, as applicable. If we use 

a nonmethane cutter for testing, it will 

meet this recommendation. If adjusting 

NMC temperature does not result in 

achieving both of these specifications 

simultaneously, we recommend that 

you replace the catalyst material. Use 

the most recently determined 

penetration values from this section to 

calculate HC emissions according to 

§ 1065.660 and § 1065.665 as applicable. 

(d) Procedure for a FID calibrated 

with the NMC. The method described in 

this paragraph (d) is recommended over 

the procedures specified in paragraphs 

(e) and (f) of this section. If your FID 

arrangement is such that a FID is always 

calibrated to measure CH4 with the 

NMC, then span that FID with the NMC 

using a CH4 span gas, set the product of 

that FID’s CH4 response factor and CH4 

penetration fraction, RFPFCH4[NMC–FID], 

equal to 1.0 for all emission 

calculations, and determine its 

combined ethane (C2H6) response factor 

and penetration fraction, 

RFPFC2H6[NMC–FID] as follows: 

(1) Select a CH4 gas mixture and a 

C2H6 analytical gas mixture and ensure 

that both mixtures meet the 

specifications of § 1065.750. Select a 

CH4 concentration that you would use 

for spanning the FID during emission 

testing and select a C2H6 concentration 

that is typical of the peak NMHC 

concentration expected at the 

hydrocarbon standard or equal to THC 

analyzer’s span value. 

(2) Start, operate, and optimize the 

nonmethane cutter according to the 

manufacturer’s instructions, including 

any temperature optimization. 

(3) Confirm that the FID analyzer 

meets all the specifications of 

§ 1065.360. 

(4) Start and operate the FID analyzer 

according to the manufacturer’s 

instructions. 

(5) Zero and span the FID with the 

cutter and use CH4 span gas to span the 

FID with the cutter. Note that you must 

span the FID on a C1 basis. For example, 

if your span gas has a CH4 reference 

value of 100 μmol/mol, the correct FID 

response to that span gas is 100 μmol/ 

mol because there is one carbon atom 

per CH4 molecule. 

(6) Introduce the C2H6 analytical gas 

mixture upstream of the nonmethane 

cutter. 

(7) Allow time for the analyzer 

response to stabilize. Stabilization time 

may include time to purge the 

nonmethane cutter and to account for 

the analyzer’s response. 

(8) While the analyzer measures a 

stable concentration, record 30 seconds 

of sampled data. Calculate the 

arithmetic mean of these data points. 

(9) Divide the mean by the reference 

value of C2H6, converted to a C1 basis. 

The result is the C2H6 combined 

response factor and penetration fraction, 

RFPFC2H6[NMC–FID]. Use this combined 

response factor and penetration fraction 

and the product of the CH4 response 

factor and CH4 penetration fraction, 

RFPFCH4[NMC–FID], set to 1.0 in emission 

calculations according to 

§ 1065.660(b)(2)(i) or § 1065.665, as 

applicable. 

(e) Procedure for a FID calibrated with 

propane, bypassing the NMC. If you use 

a FID with an NMC that is calibrated 

with propane, C3H8, by bypassing the 

NMC, determine its penetration 

fractions, PFC2H6[NMC–FID] and 

PFCH4[NMC–FID], as follows: 
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Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 37311 

(1) Select CH4 and C2H6 analytical gas 

mixtures that meet the specifications of 

§ 1065.750 with the CH4 concentration 

typical of its peak concentration 

expected at the hydrocarbon standard 

and the C2H6 concentration typical of 

the peak total hydrocarbon (THC) 

concentration expected at the 

hydrocarbon standard or the THC 

analyzer span value. 

(2) Start and operate the nonmethane 

cutter according to the manufacturer’s 

instructions, including any temperature 

optimization. 

(3) Confirm that the FID analyzer 

meets all the specifications of 

§ 1065.360. 

(4) Start and operate the FID analyzer 

according to the manufacturer’s 

instructions. 

(5) Zero and span the FID as you 

would during emission testing. Span the 

FID by bypassing the cutter and by 

using C3H8 span gas to span the FID. 

Note that you must span the FID on a 

C1 basis. For example, if your span gas 

has a propane reference value of 100 

μmol/mol, the correct FID response to 

that span gas is 300 μmol/mol because 

there are three carbon atoms per C3H8 

molecule. 

(6) Introduce the C2H6 analytical gas 

mixture upstream of the nonmethane 

cutter at the same point the zero gas was 

introduced. 

(7) Allow time for the analyzer 

response to stabilize. Stabilization time 

may include time to purge the 

nonmethane cutter and to account for 

the analyzer’s response. 

(8) While the analyzer measures a 

stable concentration, record 30 seconds 

of sampled data. Calculate the 

arithmetic mean of these data points. 

(9) Reroute the flow path to bypass 

the nonmethane cutter, introduce the 

C2H6 analytical gas mixture to the 

bypass, and repeat the steps in 

paragraphs (e)(7) through (8) of this 

section. 

(10) Divide the mean C2H6 

concentration measured through the 

nonmethane cutter by the mean 

concentration measured after bypassing 

the nonmethane cutter. The result is the 

C2H6 penetration fraction, 

PFC2H6[NMC–FID]. Use this penetration 

fraction according to § 1065.660(b)(2)(ii) 

or § 1065.665, as applicable. 

(11) Repeat the steps in paragraphs 

(e)(6) through (10) of this section, but 

with the CH4 analytical gas mixture 

instead of C2H6. The result will be the 

CH4 penetration fraction, PFCH4[NMC–FID]. 

Use this penetration fraction according 

to § 1065.660(b)(2)(ii) or § 1065.665, as 

applicable. 

(f) Procedure for a FID calibrated with 

methane, bypassing the NMC. If you use 

a FID with an NMC that is calibrated 

with methane, CH4, by bypassing the 

NMC, determine its combined ethane 

(C2H6) response factor and penetration 

fraction, RFPFC2H6[NMC–FID], as well as 

its CH4 penetration fraction, 

PFCH4[NMC–FID], as follows: 

(1) Select CH4 and C2H6 analytical gas 

mixtures that meet the specifications of 

§ 1065.750, with the CH4 concentration 

typical of its peak concentration 

expected at the hydrocarbon standard 

and the C2H6 concentration typical of 

the peak total hydrocarbon (THC) 

concentration expected at the 

hydrocarbon standard or the THC 

analyzer span value. 

(2) Start and operate the nonmethane 

cutter according to the manufacturer’s 

instructions, including any temperature 

optimization. 

(3) Confirm that the FID analyzer 

meets all the specifications of 

§ 1065.360. 

(4) Start and operate the FID analyzer 

according to the manufacturer’s 

instructions. 

(5) Zero and span the FID as you 

would during emission testing. Span the 

FID with CH4 span gas by bypassing the 

cutter. Note that you must span the FID 

on a C1 basis. For example, if your span 

gas has a methane reference value of 100 

μmol/mol, the correct FID response to 

that span gas is 100 μmol/mol because 

there is one carbon atom per CH4 

molecule. 

(6) Introduce the C2H6 analytical gas 

mixture upstream of the nonmethane 

cutter at the same point the zero gas was 

introduced. 

(7) Allow time for the analyzer 

response to stabilize. Stabilization time 

may include time to purge the 

nonmethane cutter and to account for 

the analyzer’s response. 

(8) While the analyzer measures a 

stable concentration, record 30 seconds 

of sampled data. Calculate the 

arithmetic mean of these data points. 

(9) Reroute the flow path to bypass 

the nonmethane cutter, introduce the 

C2H6 analytical gas mixture to the 

bypass, and repeat the steps in 

paragraphs (e)(7) and (8) of this section. 

(10) Divide the mean C2H6 

concentration measured through the 

nonmethane cutter by the mean 

concentration measured after bypassing 

the nonmethane cutter. The result is the 

C2H6 combined response factor and 

penetration fraction, RFPFC2H6[NMC–FID]. 

Use this combined response factor and 

penetration fraction according to 

§ 1065.660(b)(2)(iii) or § 1065.665, as 

applicable. 

(11) Repeat the steps in paragraphs 

(e)(6) through (10) of this section, but 

with the CH4 analytical gas mixture 

instead of C2H6. The result will be the 

CH4 penetration fraction, PFCH4[NMC–FID]. 

Use this penetration fraction according 

to § 1065.660(b)(2)(iii) or § 1065.665, as 

applicable. 

■ 88. Section 1065.370 is amended by 

revising paragraphs (d), (e), and (g)(1) to 

read as follows: 

§ 1065.370 CLD CO2 and H2O quench 

verification. 

* * * * * 

(d) CO2 quench verification 

procedure. Use the following method to 

determine CO2 quench, or use good 

engineering judgment to develop a 

different protocol: 

(1) Use PTFE or stainless steel tubing 

to make necessary connections. 

(2) Connect a pressure-regulated CO2 

span gas to the port of a gas divider that 

meets the specifications in § 1065.248 at 

the appropriate time. Use a CO2 span 

gas that meets the specifications of 

§ 1065.750 and attempt to use a 

concentration that is approximately 

twice the maximum CO2 concentration 

expected to enter the CLD sample port 

during testing, if available. 

(3) Connect a pressure-regulated 

purified N2 gas to the port of a gas 

divider that meets the specifications in 

§ 1065.248 at the appropriate time. Use 

a purified N2 gas that meets the 

specifications of § 1065.750. 

(4) Connect a pressure-regulated NO 

span gas to the port of the gas divider 

that meets the specifications in 

§ 1065.248. Use an NO span gas that 

meets the specifications of § 1065.750. 

Attempt to use an NO concentration that 

is approximately twice the maximum 

NO concentration expected during 

testing, if available. 

(5) Configure the gas divider such that 

nearly equal amounts of the span gas 

and balance gas are blended with each 

other. Apply viscosity corrections as 

necessary to appropriately ensure 

correct gas division. 

(6) While flowing NO and CO2 

through the gas divider, stabilize the 

CO2 concentration downstream of the 

gas divider and measure the CO2 

concentration with an NDIR analyzer 

that has been prepared for emission 

testing. You may alternatively 

determine the CO2 concentration from 

the gas divider cut-point, applying 

viscosity correction as necessary to 

ensure accurate gas division. Record 

this concentration, xCO2meas, and use it 

in the quench verification calculations 

in § 1065.675. 

(7) Measure the NO concentration 

downstream of the gas divider. If the 

CLD has an operating mode in which it 

detects NO-only, as opposed to total 

NOX, operate the CLD in the NO-only 
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operating mode. Record this 

concentration, xNO,CO2, and use it in the 

quench verification calculations in 

§ 1065.675. 

(8) Switch the flow of CO2 off and 

start the flow of 100% purified N2 to the 

inlet port of the gas divider. Monitor the 

CO2 at the gas divider’s outlet until its 

concentration stabilizes at zero. 

(9) Measure NO concentration at the 

gas divider’s outlet. Record this value, 

xNO,N2, and use it in the quench 

verification calculations in § 1065.675. 

(10) Use the values recorded 

according to this paragraph (d) of this 

section and paragraph (e) of this section 

to calculate quench as described in 

§ 1065.675. 

(e) H2O quench verification 

procedure. Use the following method to 

determine H2O quench, or use good 

engineering judgment to develop a 

different protocol: 

(1) Use PTFE or stainless steel tubing 

to make necessary connections. 

(2) If the CLD has an operating mode 

in which it detects NO-only, as opposed 

to total NOX, operate the CLD in the NOonly operating mode. 

(3) Measure an NO calibration span 

gas that meets the specifications of 

§ 1065.750 and is near the maximum 

concentration expected during testing. 

Record this concentration, xNOdry. 

(4) Humidify the NO span gas by 

bubbling it through distilled water in a 

sealed vessel. If the sample is not passed 

through a dryer, control the vessel 

temperature to generate an H2O level at 

least as high as the maximum expected 

during testing. If the sample is passed 

through a dryer during testing, control 

the vessel temperature to generate an 

H2O level at least as high as the level 

determined in § 1065.145(d)(2). We 

recommend that you humidify the gas to 

the highest sample dewpoint that you 

estimate at the CLD inlet during 

emission sampling. Regardless of the 

humidity during this test, the quench 

verification calculations in § 1065.675 

scale the recorded quench to the highest 

dewpoint expected for flow entering the 

CLD sample port during emission 

sampling. 

(5) Introduce the humidified NO test 

gas into the sample system. You may 

introduce it downstream of any sample 

dryer, if one is used during testing. 

(6) Measure the humidified gas 

dewpoint, Tdew, and pressure, ptotal, as 

close as possible to the analyzer inlet. 

(7) Downstream of the vessel, 

maintain the humidified NO test gas 

temperature at least 5 °C above its 

dewpoint. 

(8) Allow time for the analyzer 

response to stabilize. Stabilization time 

may include time to purge the transfer 

line and to account for analyzer 

response. 

(9) While the analyzer measures the 

sample’s concentration, record the 

analyzer’s output for 30 seconds. 

Calculate the arithmetic mean of these 

data. This mean is xNOmeas. 

(10) Set xNOwet equal to xNOmeas from 

paragraph (e)(9) of this section. 

(11) Use xNOwet to calculate the 

quench according to § 1065.675. 

* * * * * 

(g) * * * 

(1) You may omit this verification if 

you can show by engineering analysis 

that for your NOX sampling system and 

your emission calculations procedures, 

the combined CO2 and H2O interference 

for your NOX CLD analyzer always 

affects your brake-specific NOX 

emission results within no more than 

±1.0% of the applicable NOX standard. 

* * * * * 

■ 89. Section 1065.372 is amended by 

revising paragraphs (d)(7) and (e)(1) to 

read as follows: 

§ 1065.372 NDUV analyzer HC and H2O 

interference verification. 

* * * * * 

(d) * * * 

(7) Multiply this difference by the 

ratio of the flow-weighted mean HC 

concentration expected at the standard 

to the HC concentration measured 

during the verification. The analyzer 

meets the interference verification of 

this section if this result is within ±2% 

of the NOX concentration expected at 

the standard. 

(e) * * * 

(1) You may omit this verification if 

you can show by engineering analysis 

that for your NOX sampling system and 

your emission calculations procedures, 

the combined HC and H2O interference 

for your NOX NDUV analyzer always 

affects your brake-specific NOX 

emission results by less than 0.5% of 

the applicable NOX standard. 

* * * * * 

■ 90. Section 1065.376 is revised to read 

as follows: 

§ 1065.376 Chiller NO2 penetration. 

(a) Scope and frequency. If you use a 

chiller to dry a sample upstream of a 

NOX measurement instrument, but you 

don’t use an NO2-to-NO converter 

upstream of the chiller, you must 

perform this verification for chiller NO2 

penetration. Perform this verification 

after initial installation and after major 

maintenance. 

(b) Measurement principles. A chiller 

removes water, which can otherwise 

interfere with a NOX measurement. 

However, liquid water remaining in an 

improperly designed chiller can remove 

NO2 from the sample. If a chiller is used 

without an NO2-to-NO converter 

upstream, it could remove NO2 from the 

sample prior NOX measurement. 

(c) System requirements. A chiller 

must allow for measuring at least 95% 

of the total NO2 at the maximum 

expected concentration of NO2. 

(d) Procedure. Use the following 

procedure to verify chiller performance: 

(1) Instrument setup. Follow the 

analyzer and chiller manufacturers’ 

start-up and operating instructions. 

Adjust the analyzer and chiller as 

needed to optimize performance. 

(2) Equipment setup and data 

collection. (i) Zero and span the total 

NOX gas analyzer(s) as you would before 

emission testing. 

(ii) Select an NO2 calibration gas, 

balance gas of dry air, that has an NO2 

concentration within ±5% of the 

maximum NO2 concentration expected 

during testing. 

(iii) Overflow this calibration gas at 

the gas sampling system’s probe or 

overflow fitting. Allow for stabilization 

of the total NOX response, accounting 

only for transport delays and instrument 

response. 

(iv) Calculate the mean of 30 seconds 

of recorded total NOX data and record 

this value as xNOXref. 

(v) Stop flowing the NO2 calibration 

gas. 

(vi) Next saturate the sampling system 

by overflowing a dewpoint generator’s 

output, set at a dewpoint of 50 °C, to the 

gas sampling system’s probe or overflow 

fitting. Sample the dewpoint generator’s 

output through the sampling system and 

chiller for at least 10 minutes until the 

chiller is expected to be removing a 

constant rate of water. 

(vii) Immediately switch back to 

overflowing the NO2 calibration gas 

used to establish xNOxref. Allow for 

stabilization of the total NOX response, 

accounting only for transport delays and 

instrument response. Calculate the 

mean of 30 seconds of recorded total 

NOX data and record this value as 

xNOxmeas. 

(viii) Correct xNOxmeas to xNOxdry based 

upon the residual water vapor that 

passed through the chiller at the 

chiller’s outlet temperature and 

pressure. 

(3) Performance evaluation. If xNOxdry 

is less than 95% of xNOxref, repair or 

replace the chiller. 

(e) Exceptions. The following 

exceptions apply: 

(1) You may omit this verification if 

you can show by engineering analysis 

that for your NOX sampling system and 

your emission calculations procedures, 

the chiller always affects your brake-

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Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 37313 

specific NOX emission results by less 

than 0.5% of the applicable NOX 

standard. 

(2) You may use a chiller that you 

determine does not meet this 

verification, as long as you try to correct 

the problem and the measurement 

deficiency does not adversely affect 

your ability to show that engines 

comply with all applicable emission 

standards. 

■ 91. Section 1065.378 is amended by 

revising paragraphs (d) and (e)(1) to read 

as follows: 

§ 1065.378 NO2-to-NO converter 

conversion verification. 

* * * * * 

(d) Procedure. Use the following 

procedure to verify the performance of 

a NO2-to-NO converter: 

(1) Instrument setup. Follow the 

analyzer and NO2-to-NO converter 

manufacturers’ start-up and operating 

instructions. Adjust the analyzer and 

converter as needed to optimize 

performance. 

(2) Equipment setup. Connect an 

ozonator’s inlet to a zero-air or oxygen 

source and connect its outlet to one port 

of a three-way tee fitting. Connect an 

NO span gas to another port, and 

(5) If the result is less than 95%, 

repair or replace the NO2-to-NO 

converter. 

(e) * * * 

(1) You may omit this verification if 

you can show by engineering analysis 

that for your NOX sampling system and 

your emission calculations procedures, 

the converter always affects your brakespecific NOX emission results by less 

than 0.5% of the applicable NOX 

standard. 

* * * * * 

■ 92. Section 1065.390 is revised to read 

as follows: 

§ 1065.390 PM balance verifications and 

weighing process verification. 

(a) Scope and frequency. This section 

describes three verifications. 

(1) Independent verification of PM 

balance performance within 370 days 

before weighing any filter. 

(2) Zero and span the balance within 

12 h before weighing any filter. 

(3) Verify that the mass determination 

of reference filters before and after a 

filter weighing session are less than a 

specified tolerance. 

Efficiency (%) = 1+ 



×100  x − x

connect the NO2-to-NO converter inlet 

to the last port. 

(3) Adjustments and data collection. 

Perform this check as follows: 

(i) Set ozonator air off, turn ozonator 

power off, and set the analyzer to NO 

mode. Allow for stabilization, 

accounting only for transport delays and 

instrument response. 

(ii) Use an NO concentration that is 

representative of the peak total NOX 

concentration expected during testing. 

The NO2 content of the gas mixture 

shall be less than 5% of the NO 

concentration. Record the concentration 

of NO by calculating the mean of 30 

seconds of sampled data from the 

analyzer and record this value as xNOref. 

(iii) Turn on the ozonator O2 supply 

and adjust the O2 flow rate so the NO 

indicated by the analyzer is about 10 

percent less than xNOref. Record the 

concentration of NO by calculating the 

mean of 30 seconds of sampled data 

from the analyzer and record this value 

as xNO∂O2mix. 

(iv) Switch the ozonator on and adjust 

the ozone generation rate so the NO 

measured by the analyzer is 20 percent 

of xNOref, while maintaining at least 10 

percent unreacted NO. Record the 

concentration of NO by calculating the 

 x x  NOxmeas − NOx+O2mix 

 NO+O2mix NOmeas  

(b) Independent verification. Have the 

balance manufacturer (or a 

representative approved by the balance 

manufacturer) verify the balance 

performance within 370 days of testing. 

(c) Zeroing and spanning. You must 

verify balance performance by zeroing 

and spanning it with at least one 

calibration weight, and any weights you 

use must that meet the specifications in 

§ 1065.790 to perform this verification. 

(1) Use a manual procedure in which 

you zero the balance and span the 

balance with at least one calibration 

weight. If you normally use mean values 

by repeating the weighing process to 

improve the accuracy and precision of 

PM measurements, use the same process 

to verify balance performance. 

(2) You may use an automated 

procedure to verify balance 

performance. For example many 

balances have internal calibration 

weights that are used automatically to 

verify balance performance. Note that if 

you use internal balance weights, the 

weights must meet the specifications in 

§ 1065.790 to perform this verification. 

(d) Reference sample weighing. Verify 

all mass readings during a weighing 

mean of 30 seconds of sampled data 

from the analyzer and record this value 

as xNOmeas. 

(v) Switch the NOX analyzer to NOX 

mode and measure total NOX. Record 

the concentration of NOX by calculating 

the mean of 30 seconds of sampled data 

from the analyzer and record this value 

as xNOxmeas. 

(vi) Switch off the ozonator but 

maintain gas flow through the system. 

The NOX analyzer will indicate the NOX 

in the NO + O2 mixture. Record the 

concentration of NOX by calculating the 

mean of 30 seconds of sampled data 

from the analyzer and record this value 

as xNOx∂O2mix. 

(vii) Turn off the ozonator O2 supply. 

The NOX analyzer will indicate the NOX 

in the original NO-in-N2 mixture. 

Record the concentration of NOX by 

calculating the mean of 30 seconds of 

sampled data from the analyzer and 

record this value as xNOxref. This value 

should be no more than 5 percent above 

the xNOref value. 

(4) Performance evaluation. Calculate 

the efficiency of the NOX converter 

efficiency by substituting the 

concentrations obtained into the 

following equation: 

session by weighing reference PM 

sample media (e.g., filters) before and 

after a weighing session. A weighing 

session may be as short as desired, but 

no longer than 80 hours, and may 

include both pre-test and post-test mass 

readings. We recommend that weighing 

sessions be eight hours or less. 

Successive mass determinations of each 

reference PM sample media (e.g., filter) 

must return the same value within ±10 

μg or ±10% of the net PM mass expected 

at the standard (if known), whichever is 

higher. If successive reference PM 

sample media (e.g., filter) weighing 

events fail this criterion, invalidate all 

individual test media (e.g., filter) mass 

readings occurring between the 

successive reference media (e.g., filter) 

mass determinations. You may reweigh 

these media (e.g., filter) in another 

weighing session. If you invalidate a 

pre-test media (e.g., filter) mass 

determination, that test interval is void. 

Perform this verification as follows: 

(1) Keep at least two samples of 

unused PM sample media (e.g., filters) 

in the PM-stabilization environment. 

Use these as references. If you collect 
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37314 Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 

PM with filters, select unused filters of 

the same material and size for use as 

references. You may periodically 

replace references, using good 

engineering judgment. 

(2) Stabilize references in the PM 

stabilization environment. Consider 

references stabilized if they have been 

in the PM-stabilization environment for 

a minimum of 30 min, and the PMstabilization environment has been 

within the specifications of 

§ 1065.190(d) for at least the preceding 

60 min. 

(3) Exercise the balance several times 

with a reference sample. We 

recommend weighing ten samples 

without recording the values. 

(4) Zero and span the balance. Using 

good engineering judgment, place a test 

mass such as a calibration weight on the 

balance, then remove it. After spanning, 

confirm that the balance returns to a 

zero reading within the normal 

stabilization time. 

(5) Weigh each of the reference media 

(e.g., filters) and record their masses. We 

recommend using substitution weighing 

as described in § 1065.590(j). If you 

normally use mean values by repeating 

the weighing process to improve the 

accuracy and precision of the reference 

media (e.g., filter) mass, you must use 

mean values of sample media (e.g., 

filter) masses. 

(6) Record the balance environment 

dewpoint, ambient temperature, and 

atmospheric pressure. 

(7) Use the recorded ambient 

conditions to correct results for 

buoyancy as described in § 1065.690. 

Record the buoyancy-corrected mass of 

each of the references. 

(8) Subtract each reference media’s 

(e.g., filter’s) buoyancy-corrected 

reference mass from its previously 

measured and recorded buoyancycorrected mass. 

(9) If any of the reference filters’ 

observed mass changes by more than 

that allowed under this paragraph, you 

must invalidate all PM mass 

determinations made since the last 

successful reference media (e.g., filter) 

mass validation. You may discard 

reference PM media (e.g., filters) if only 

one one of the filter’s mass changes by 

more than the allowable amount and 

you can positively identify a special 

cause for that filter’s mass change that 

would not have affected other inprocess filters. Thus, the validation can 

be considered a success. In this case, 

you do not have to include the 

contaminated reference media when 

determining compliance with paragraph 

(d)(10) of this section, but the affected 

reference filter must be immediately 

discarded and replaced prior to the next 

weighing session. 

(10) If any of the reference masses 

change by more than that allowed under 

this paragraph (d), invalidate all PM 

results that were determined between 

the two times that the reference masses 

were determined. If you discarded 

reference PM sample media according to 

paragraph (d)(9) of this section, you 

must still have at least one reference 

mass difference that meets the criteria in 

this paragraph (d). Otherwise, you must 

invalidate all PM results that were 

determined between the two times that 

the reference media (e.g., filters) masses 

were determined. 

Subpart E—[Amended] 

■ 93. Section 1065.405 is revised to read 

as follows: 

§ 1065.405 Test engine preparation and 

maintenance. 

This part 1065 describes how to test 

engines for a variety of purposes, 

including certification testing, 

production-line testing, and in-use 

testing. Depending on which type of 

testing is being conducted, different 

preparation and maintenance 

requirements apply for the test engine. 

(a) If you are testing an emission-data 

engine for certification, make sure it is 

built to represent production engines. 

This includes governors that you 

normally install on production engines. 

Production engines should also be 

tested with their installed governors. If 

you do not install governors on 

production engines, simulate a governor 

that is representative of a governor that 

others will install on your production 

engines. 

(b) Testing generally occurs only after 

the test engine has undergone a 

stabilization step (or in-use operation). 

If the engine has not already been 

stabilized, run the test engine, with all 

emission control systems operating, 

long enough to stabilize emission levels. 

Note that you must generally use the 

same stabilization procedures for 

emission-data engines for which you 

apply the same deterioration factors so 

low-hour emission-data engines are 

consistent with the low-hour engine 

used to develop the deterioration factor. 

(1) Unless otherwise specified in the 

standard-setting part, you may consider 

emission levels stable without 

measurement after 50 h of operation. If 

the engine needs less operation to 

stabilize emission levels, record your 

reasons and the methods for doing this, 

and give us these records if we ask for 

them. If the engine will be tested for 

certification as a low-hour engine, see 

the standard-setting part for limits on 

testing engines to establish low-hour 

emission levels. 

(2) You may stabilize emissions from 

a catalytic exhaust aftertreatment device 

by operating it on a different engine, 

consistent with good engineering 

judgment. Note that good engineering 

judgment requires that you consider 

both the purpose of the test and how 

your stabilization method will affect the 

development and application of 

deterioration factors. For example, this 

method of stabilization is generally not 

appropriate for production engines. We 

may also allow you to stabilize 

emissions from a catalytic exhaust 

aftertreatment device by operating it on 

an engine-exhaust simulator. 

(c) Record any maintenance, 

modifications, parts changes, diagnostic 

or emissions testing and document the 

need for each event. You must provide 

this information if we request it. 

(d) For accumulating operating hours 

on your test engines, select engine 

operation that represents normal in-use 

operation for the engine family. 

(e) If your engine will be used in a 

vehicle equipped with a canister for 

storing evaporative hydrocarbons for 

eventual combustion in the engine and 

the test sequence involves a cold-start or 

hot-start duty cycle, attach a canister to 

the engine before running an emission 

test. You may omit using an evaporative 

canister for any hot-stabilized duty 

cycles. You may request to omit using 

an evaporative canister during testing if 

you can show that it would not affect 

your ability to show compliance with 

the applicable emission standards. You 

may operate the engine without an 

installed canister for service 

accumulation. Prior to an emission test, 

use the following steps to attach a 

canister to your engine: 

(1) Use a canister and plumbing 

arrangement that represents the in-use 

configuration of the largest capacity 

canister in all expected applications. 

(2) Use a canister that is fully loaded 

with fuel vapors. 

(3) Connect the canister’s purge port 

to the engine. 

(4) Plug the canister port that is 

normally connected to the fuel tank. 

■ 94. Section 1065.410 is amended by 

revising paragraphs (c) and (d) to read 

as follows: 

§ 1065.410 Maintenance limits for 

stabilized test engines. 

* * * * * 

(c) Keep a record of the inspection 

and update your application to 

document any changes as a result of the 

inspection. You may use equipment, 

instruments, or engineering grade tools 
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Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 37315 

to identify bad engine components. Any 

equipment, instruments, or tools used 

for scheduled maintenance on emission 

data engines must be representative of 

what is planned to be available to 

dealerships and other service outlets. 

(d) If we determine that a part failure, 

system malfunction, or associated 

repairs have made the engine’s emission 

controls unrepresentative of production 

engines, you may no longer use it as an 

emission-data engine. Also, if your test 

engine has a major mechanical failure 

that requires you to take it apart, you 

may no longer use it as an emission-data 

engine. 

* * * * * 

■ 95. Section 1065.415 is amended by 

revising the introductory text and 

removing paragraph (a)(3) to read as 

follows: 

§ 1065.415 Durability demonstration. 

If the standard-setting part requires 

durability testing, you must accumulate 

service in a way that represents how 

you expect the engine to operate in use. 

You may accumulate service hours 

using an accelerated schedule, such as 

through continuous operation or by 

using duty cycles that are more 

aggressive than in-use operation, subject 

to any pre-approval requirements 

established in the applicable standardsetting part. 

* * * * * 

■ 96. The heading to subpart F of part 

1065 is revised to read as follows: 

Subpart F—Performing an Emission 

Test Over Specified Duty Cycles 

97. Section 1065.501 is amended by 

revising paragraphs (a) introductory 

text, (a)(1), and (b) to read as follows: 

§ 1065.501 Overview. 

(a) Use the procedures detailed in this 

subpart to measure engine emissions 

over a specified duty cycle. Refer to 

subpart J of this part for field test 

procedures that describe how to 

measure emissions during in-use engine 

operation. This section describes how 

to: 

(1) Map your engine, if applicable, by 

recording specified speed and torque 

data, as measured from the engine’s 

primary output shaft. 

* * * * * 

(b) An emission test generally consists 

of measuring emissions and other 

parameters while an engine follows one 

or more duty cycles that are specified in 

the standard-setting part. There are two 

general types of duty cycles: 

(1) Transient cycles. Transient duty 

cycles are typically specified in the 

standard-setting part as a second-bysecond sequence of speed commands 

and normalized torque (or power) 

commands. Operate an engine over a 

transient cycle such that the speed and 

torque of the engine’s primary output 

shaft follows the target values. 

Proportionally sample emissions and 

other parameters and use the 

calculations in subpart G of this part to 

calculate emissions. Start a transient test 

according to the standard-setting part, as 

follows: 

(i) A cold-start transient cycle where 

you start to measure emissions just 

before starting an engine that has not 

been warmed up. 

(ii) A hot-start transient cycle where 

you start to measure emissions just 

before starting a warmed-up engine. 

(iii) A hot running transient cycle 

where you start to measure emissions 

after an engine is started, warmed up, 

and running. 

(2) Steady-state cycles. Steady-state 

duty cycles are typically specified in the 

standard-setting part as a list of discrete 

operating points (modes or notches), 

where each operating point has one 

value of a normalized speed command 

and one value of a normalized torque (or 

power) command. Ramped-modal 

cycles for steady-state testing also list 

test times for each mode and transition 

times between modes where speed and 

torque are linearly ramped between 

modes, even for cycles with % power. 

Start a steady-state cycle as a hot 

running test, where you start to measure 

emissions after an engine is started, 

warmed up and running. You may run 

a steady-state duty cycle as a discretemode cycle or a ramped-modal cycle, as 

follows: 

(i) Discrete-mode cycles. Before 

emission sampling, stabilize an engine 

at the first discrete mode. Sample 

emissions and other parameters for that 

mode and then stop emission sampling. 

Record mean values for that mode, and 

then stabilize the engine at the next 

mode. Continue to sample each mode 

discretely and calculate weighted 

emission results according to the 

standard-setting part. 

(ii) Ramped-modal cycles. Perform 

ramped-modal cycles similar to the way 

you would perform transient cycles, 

except that ramped-modal cycles 

involve mostly steady-state engine 

operation. Generate a ramped-modal 

duty cycle as a sequence of second-bysecond (1 Hz) reference speed and 

torque points. Run the ramped-modal 

duty cycle in the same manner as a 

transient cycle and use the 1 Hz 

reference speed and torque values to 

validate the cycle, even for cycles with 

% power. Proportionally sample 

emissions and other parameters during 

the cycle and use the calculations in 

subpart G of this part to calculate 

emissions. 

* * * * * 

■ 98. Section 1065.510 is revised to read 

as follows: 

§ 1065.510 Engine mapping. 

(a) Applicability, scope, and 

frequency. An engine map is a data set 

that consists of a series of paired data 

points that represent the maximum 

brake torque versus engine speed, 

measured at the engine’s primary output 

shaft. Map your engine if the standardsetting part requires engine mapping to 

generate a duty cycle for your engine 

configuration. Map your engine while it 

is connected to a dynamometer or other 

device that can absorb work output from 

the engine’s primary output shaft 

according to § 1065.110. Configure any 

auxiliary work inputs and outputs such 

as hybrid, turbo-compounding, or 

thermoelectric systems to represent 

their in-use configurations, and use the 

same configuration for emission testing. 

See Figure 1 of § 1065.210. This may 

involve configuring initial states of 

charge and rates and times of auxiliarywork inputs and outputs. We 

recommend that you contact the 

Designated Compliance Officer before 

testing to determine how you should 

configure any auxiliary-work inputs and 

outputs. Use the most recent engine 

map to transform a normalized duty 

cycle from the standard-setting part to a 

reference duty cycle specific to your 

engine. Normalized duty cycles are 

specified in the standard-setting part. 

You may update an engine map at any 

time by repeating the engine-mapping 

procedure. You must map or re-map an 

engine before a test if any of the 

following apply: 

(1) If you have not performed an 

initial engine map. 

(2) If the atmospheric pressure near 

the engine’s air inlet is not within ± 5 

kPa of the atmospheric pressure 

recorded at the time of the last engine 

map. 

(3) If the engine or emission-control 

system has undergone changes that 

might affect maximum torque 

performance. This includes changing 

the configuration of auxiliary work 

inputs and outputs. 

(4) If you capture an incomplete map 

on your first attempt or you do not 

complete a map within the specified 

time tolerance. You may repeat mapping 

as often as necessary to capture a 

complete map within the specified time. 

(b) Mapping variable-speed engines. 

Map variable-speed engines as follows: 

(1) Record the atmospheric pressure. 
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37316 Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 

(2) Warm up the engine by operating 

it. We recommend operating the engine 

at any speed and at approximately 75% 

of its expected maximum power. 

Continue the warm-up until the engine 

coolant, block, or head absolute 

temperature is within ± 2% of its mean 

value for at least 2 min or until the 

engine thermostat controls engine 

temperature. 

(3) Operate the engine at its warm idle 

speed. 

(i) For engines with a low-speed 

governor, set the operator demand to 

minimum, use the dynamometer or 

other loading device to target a torque 

of zero on the engine’s primary output 

shaft, and allow the engine to govern the 

speed. Measure this warm idle speed; 

we recommend recording at least 30 

values of speed and using the mean of 

those values. 

(ii) For engines without a low-speed 

governor, set the dynamometer to target 

a torque of zero on the engine’s primary 

output shaft, and manipulate the 

operator demand to control the speed to 

target the manufacturer-declared value 

for the lowest engine speed possible 

with minimum load (also known as 

manufacturer-declared warm idle 

speed). 

(iii) For all variable-speed engines 

(with or without a low-speed governor), 

if a nonzero idle torque is representative 

of in-use operation, you may target the 

manufacturer-declared idle torque. If 

you measure the warm idle speed with 

the manufacturer-declared torque at this 

step, you may omit the speed 

measurement in paragraph (b)(6) of this 

section. 

(4) Set operator demand to maximum 

and control engine speed at (95 ± 1) % 

of its warm idle speed determined above 

for at least 15 seconds. For engines with 

reference duty cycles whose lowest 

speed is greater than warm idle speed, 

you may start the map at (95 ± 1) % of 

the lowest reference speed. 

(5) Perform one of the following: 

(i) For any engine subject only to 

steady-state duty cycles (i.e., discretemode or ramped-modal), you may 

perform an engine map by using 

discrete speeds. Select at least 20 evenly 

spaced setpoints between warm idle and 

the highest speed above maximum 

mapped power at which (50 to 75)% of 

maximum power occurs. If this highest 

speed is unsafe or unrepresentative (e.g., 

for ungoverned engines), use good 

engineering judgment to map up to the 

maximum safe speed or the maximum 

representative speed. At each setpoint, 

stabilize speed and allow torque to 

stabilize. Record the mean speed and 

torque at each setpoint. We recommend 

that you stabilize an engine for at least 

15 seconds at each setpoint and record 

the mean feedback speed and torque of 

the last (4 to 6) seconds. Use linear 

interpolation to determine intermediate 

speeds and torques. Use this series of 

speeds and torques to generate the 

power map as described in paragraph (e) 

of this section. 

(ii) For any variable-speed engine, you 

may perform an engine map by using a 

continuous sweep of speed by 

continuing to record the mean feedback 

speed and torque at 1 Hz or more 

frequently and increasing speed at a 

constant rate such that it takes (4 to 6) 

min to sweep from 95% of warm idle to 

the highest speed above maximum 

power at which (50 to 75)% of 

maximum power occurs. If this highest 

speed is unsafe or unrepresentative (e.g., 

for ungoverned engines), use good 

engineering judgment to map up to the 

maximum safe speed or the maximum 

representative speed. Stop recording 

after you complete the sweep. From the 

series of mean speed and maximum 

torque values, use linear interpolation to 

determine intermediate values. Use this 

series of speeds and torques to generate 

the power map as described in 

paragraph (e) of this section. 

(6) For engines with a low-speed 

governor, if a nonzero idle torque is 

representative of in-use operation, 

operate the engine at warm idle with the 

manufacturer-declared idle torque. Set 

the operator demand to minimum, use 

the dynamometer to target the declared 

idle torque, and allow the engine to 

govern the speed. Measure this speed 

and use it as the warm idle speed for 

cycle generation in § 1065.512. We 

recommend recording at least 30 values 

of speed and using the mean of those 

values. You may map the idle governor 

at multiple load levels and use this map 

to determine the measured warm idle 

speed at the declared idle torque. 

(c) Negative torque mapping. If your 

engine is subject to a reference duty 

cycle that specifies negative torque 

values (i.e., engine motoring), generate a 

motoring map by any of the following 

procedures: 

(1) Multiply the positive torques from 

your map by ¥40%. Use linear 

interpolation to determine intermediate 

values. 

(2) Map the amount of negative torque 

required to motor the engine by 

repeating paragraph (b) of this section 

with minimum operator demand. 

(3) Determine the amount of negative 

torque required to motor the engine at 

the following two points near the ends 

of the engine’s speed range. Operate the 

engine at these two points at minimum 

operator demand. Use linear 

interpolation to determine intermediate 

values. 

(i) Low-speed point. For engines 

without a low-speed governor, 

determine the amount of negative torque 

at warm idle speed. For engines with a 

low-speed governor, motor the engine 

above warm idle speed so the governor 

is inactive and determine the amount of 

negative torque at that speed. 

(ii) High-speed point. For engines 

without a high-speed governor, 

determine the amount of negative torque 

at the maximum safe speed or the 

maximum representative speed. For 

engines with a high-speed governor, 

determine the amount of negative torque 

at a speed at or above nhi per 

§ 1065.610(c)(2). 

(d) Mapping constant-speed engines. 

For constant-speed engines, generate a 

map as follows: 

(1) Record the atmospheric pressure. 

(2) Warm up the engine by operating 

it. We recommend operating the engine 

at approximately 75% of the engine’s 

expected maximum power. Continue 

the warm-up until the engine coolant, 

block, or head absolute temperature is 

within ±2% of its mean value for at least 

2 min or until the engine thermostat 

controls engine temperature. 

(3) You may operate the engine with 

a production constant-speed governor or 

simulate a constant-speed governor by 

controlling engine speed with an 

operator demand control system 

described in § 1065.110. Use either 

isochronous or speed-droop governor 

operation, as appropriate. 

(4) With the governor or simulated 

governor controlling speed using 

operator demand, operate the engine at 

no-load governed speed (at high speed, 

not low idle) for at least 15 seconds. 

(5) Record at 1 Hz the mean of 

feedback speed and torque. Use the 

dynamometer to increase torque at a 

constant rate. Unless the standardsetting part specifies otherwise, 

complete the map such that it takes (2 

to 4) min to sweep from no-load 

governed speed to the lowest speed 

below maximum mapped power at 

which the engine develops (85–95)% of 

maximum mapped power. You may 

map your engine to lower speeds. Stop 

recording after you complete the sweep. 

Use this series of speeds and torques to 

generate the power map as described in 

paragraph (e) of this section. 

(e) Power mapping. For all engines, 

create a power-versus-speed map by 

transforming torque and speed values to 

corresponding power values. Use the 

mean values from the recorded map 

data. Do not use any interpolated 

values. Multiply each torque by its 

corresponding speed and apply the 
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Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 37317 

appropriate conversion factors to arrive 

at units of power (kW). Interpolate 

intermediate power values between 

these power values, which were 

calculated from the recorded map data. 

(f) Measured and declared test speeds 

and torques. You must select test speeds 

and torques for cycle generation as 

required in this paragraph (f). 

‘‘Measured’’ values are either directly 

measured during the engine mapping 

process or they are determined from the 

engine map. ‘‘Declared’’ values are 

specified by the manufacturer. When 

both measured and declared values are 

available, you may use declared test 

speeds and torques instead of measured 

speeds and torques if they meet the 

criteria in this paragraph (f). Otherwise, 

you must use measured speeds and 

torques derived from the engine map. 

(1) Measured speeds and torques. 

Determine the applicable speeds and 

torques for the duty cycles you will run: 

(i) Measured maximum test speed for 

variable-speed engines according to 

§ 1065.610. 

(ii) Measured maximum test torque 

for constant-speed engines according to 

§ 1065.610. 

(iii) Measured ‘‘A’’, ‘‘B’’, and ‘‘C’’ 

speeds for variable-speed engines 

according to § 1065.610. 

(iv) Measured intermediate speed for 

variable-speed engines according to 

§ 1065.610. 

(v) For variable-speed engines with a 

low-speed governor, measure warm idle 

speed according to § 1065.510(b) and 

use this speed for cycle generation in 

§ 1065.512. For engines with no lowspeed governor, instead use the 

manufacturer-declared warm idle speed. 

(2) Required declared speeds. You 

must declare the lowest engine speed 

possible with minimum load (i.e., 

manufacturer-declared warm idle 

speed). This is applicable only to 

variable-speed engines with no lowspeed governor. For engines with no 

low-speed governor, the declared warm 

idle speed is used for cycle generation 

in § 1065.512. Declare this speed in a 

way that is representative of in-use 

operation. For example, if your engine 

is typically connected to an automatic 

transmission or a hydrostatic 

transmission, declare this speed at the 

idle speed at which your engine 

operates when the transmission is 

engaged. 

(3) Optional declared speeds. You 

may use declared speeds instead of 

measured speeds as follows: 

(i) You may use a declared value for 

maximum test speed for variable-speed 

engines if it is within (97.5 to 102.5)% 

of the corresponding measured value. 

You may use a higher declared speed if 

the length of the ‘‘vector’’ at the 

declared speed is within 2.0% of the 

length of the ‘‘vector’’ at the measured 

value. The term vector refers to the 

square root of the sum of normalized 

engine speed squared and the 

normalized full-load power (at that 

speed) squared, consistent with the 

calculations in § 1065.610. 

(ii) You may use a declared value for 

intermediate, ‘‘A’’, ‘‘B’’, or ‘‘C’’ speeds 

for steady-state tests if the declared 

value is within (97.5 to 102.5)% of the 

corresponding measured value. 

(4) Required declared torques. If a 

nonzero idle or minimum torque is 

representative of in-use operation, you 

must declare the appropriate torque as 

follows: 

(i) For variable-speed engines, declare 

a warm idle torque that is representative 

of in-use operation. For example, if your 

engine is typically connected to an 

automatic transmission or a hydrostatic 

transmission, declare the torque that 

occurs at the idle speed at which your 

engine operates when the transmission 

is engaged. Use this value for cycle 

generation. You may use multiple warm 

idle torques and associated idle speeds 

in cycle generation for representative 

testing. For example, for cycles that start 

the engine and begin with idle, you may 

start a cycle in idle with the 

transmission in neutral with zero torque 

and later switch to a different idle with 

the transmission in drive with the CurbIdle Transmission Torque (CITT). For 

variable-speed engines intended 

primarily for propulsion of a vehicle 

with an automatic transmission where 

that engine is subject to a transient duty 

cycle with idle operation, you must 

declare a CITT. You must specify a CITT 

based on typical applications at the 

mean of the range of idle speeds you 

specify at stabilized temperature 

conditions. 

(ii) For constant-speed engines, 

declare a warm minimum torque that is 

representative of in-use operation. For 

example, if your engine is typically 

connected to a machine that does not 

operate below a certain minimum 

torque, declare this torque and use it for 

cycle generation. 

(5) Optional declared torques. For 

constant-speed engines you may declare 

a maximum test torque. You may use 

the declared value for cycle generation 

if it is within (95 to 100)% of the 

measured value. 

(g) Other mapping procedures. You 

may use other mapping procedures if 

you believe the procedures specified in 

this section are unsafe or 

unrepresentative for your engine. Any 

alternate techniques you use must 

satisfy the intent of the specified 

mapping procedures, which is to 

determine the maximum available 

torque at all engine speeds that occur 

during a duty cycle. Identify any 

deviations from this section’s mapping 

procedures when you submit data to us. 

■ 99. Section 1065.512 is revised to read 

as follows: 

§ 1065.512 Duty cycle generation. 

(a) Generate duty cycles according to 

this section if the standard-setting part 

requires engine mapping to generate a 

duty cycle for your engine 

configuration. The standard-setting part 

generally defines applicable duty cycles 

in a normalized format. A normalized 

duty cycle consists of a sequence of 

paired values for speed and torque or for 

speed and power. 

(b) Transform normalized values of 

speed, torque, and power using the 

following conventions: 

(1) Engine speed for variable-speed 

engines. For variable-speed engines, 

normalized speed may be expressed as 

a percentage between warm idle speed, 

fnidle, and maximum test speed, fntest, or 

speed may be expressed by referring to 

a defined speed by name, such as 

‘‘warm idle,’’ ‘‘intermediate speed,’’ or 

‘‘A,’’ ‘‘B,’’ or ‘‘C’’ speed. Section 

1065.610 describes how to transform 

these normalized values into a sequence 

of reference speeds, fnref. Running duty 

cycles with negative or small 

normalized speed values near warm idle 

speed may cause low-speed idle 

governors to activate and the engine 

torque to exceed the reference torque 

even though the operator demand is at 

a minimum. In such cases, we 

recommend controlling the 

dynamometer so it gives priority to 

follow the reference torque instead of 

the reference speed and let the engine 

govern the speed. Note that the cyclevalidation criteria in § 1065.514 allow 

an engine to govern itself. This 

allowance permits you to test engines 

with enhanced-idle devices and to 

simulate the effects of transmissions 

such as automatic transmissions. For 

example, an enhanced-idle device might 

be an idle speed value that is normally 

commanded only under cold-start 

conditions to quickly warm up the 

engine and aftertreatment devices. In 

this case, negative and very low 

normalized speeds will generate 

reference speeds below this higher 

enhanced idle speed and we 

recommend controlling the 

dynamometer so it gives priority to 

follow the reference torque, controlling 

the operator demand so it gives priority 

to follow reference speed and let the 

engine govern the speed when the 

operator demand is at minimum. 
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37318 Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 

(2) Engine torque for variable-speed 

engines. For variable-speed engines, 

normalized torque is expressed as a 

percentage of the mapped torque at the 

corresponding reference speed. Section 

1065.610 describes how to transform 

normalized torques into a sequence of 

reference torques, Tref. Section 1065.610 

also describes special requirements for 

modifying transient duty cycles for 

variable-speed engines intended 

primarily for propulsion of a vehicle 

with an automatic transmission. Section 

1065.610 also describes under what 

conditions you may command Tref 

greater than the reference torque you 

calculated from a normalized duty 

cycle. This provision permits you to 

command Tref values that are limited by 

a declared minimum torque. For any 

negative torque commands, command 

minimum operator demand and use the 

dynamometer to control engine speed to 

the reference speed, but if reference 

speed is so low that the idle governor 

activates, we recommend using the 

dynamometer to control torque to zero, 

CITT, or a declared minimum torque as 

appropriate. Note that you may omit 

power and torque points during 

motoring from the cycle-validation 

criteria in § 1065.514. Also, use the 

maximum mapped torque at the 

minimum mapped speed as the 

maximum torque for any reference 

speed at or below the minimum mapped 

speed. 

(3) Engine torque for constant-speed 

engines. For constant-speed engines, 

normalized torque is expressed as a 

percentage of maximum test torque, 

Ttest. Section 1065.610 describes how to 

transform normalized torques into a 

sequence of reference torques, Tref. 

Section 1065.610 also describes under 

what conditions you may command Tref 

greater than the reference torque you 

calculated from the normalized duty 

cycle. This provision permits you to 

command Tref values that are limited by 

a declared minimum torque. 

(4) Engine power. For all engines, 

normalized power is expressed as a 

percentage of mapped power at 

maximum test speed, fntest, unless 

otherwise specified by the standardsetting part. Section 1065.610 describes 

how to transform these normalized 

values into a sequence of reference 

powers, Pref. Convert these reference 

powers to corresponding torques for 

operator demand and dynamometer 

control. Use the reference speed 

associated with each reference power 

point for this conversion. As with cycles 

specified with % torque, issue torque 

commands more frequently and linearly 

interpolate between these reference 

torque values generated from cycles 

with % power. 

(5) Ramped-modal cycles. For ramped 

modal cycles, generate reference speed 

and torque values at 1 Hz and use this 

sequence of points to run the cycle and 

validate it in the same manner as with 

a transient cycle. During the transition 

between modes, linearly ramp the 

denormalized reference speed and 

torque values between modes to 

generate reference points at 1 Hz. Do not 

linearly ramp the normalized reference 

torque values between modes and then 

denormalize them. Do not linearly ramp 

normalized or denormalized reference 

power points. These cases will produce 

nonlinear torque ramps in the 

denormalized reference torques. If the 

speed and torque ramp runs through a 

point above the engine’s torque curve, 

continue to command the reference 

torques and allow the operator demand 

to go to maximum. Note that you may 

omit power and either torque or speed 

points from the cycle-validation criteria 

under these conditions as specified in 

§ 1065.514. 

(c) For variable-speed engines, 

command reference speeds and torques 

sequentially to perform a duty cycle. 

Issue speed and torque commands at a 

frequency of at least 5 Hz for transient 

cycles and at least 1 Hz for steady-state 

cycles (i.e., discrete-mode and rampedmodal). Linearly interpolate between 

the 1 Hz reference values specified in 

the standard-setting part to determine 

more frequently issued reference speeds 

and torques. During an emission test, 

record the feedback speeds and torques 

at a frequency of at least 5 Hz for 

transient cycles and at least 1 Hz for 

steady-state cycles. For transient cycles, 

you may record the feedback speeds and 

torques at lower frequencies (as low as 

1 Hz) if you record the average value 

over the time interval between recorded 

values. Calculate the average values 

based on feedback values updated at a 

frequency of at least 5 Hz. Use these 

recorded values to calculate cyclevalidation statistics and total work. 

(d) For constant-speed engines, 

operate the engine with the same 

production governor you used to map 

the engine in § 1065.510 or simulate the 

in-use operation of a governor the same 

way you simulated it to map the engine 

in § 1065.510. Command reference 

torque values sequentially to perform a 

duty cycle. Issue torque commands at a 

frequency of at least 5 Hz for transient 

cycles and at least 1 Hz for steady-state 

cycles (i.e., discrete-mode, rampedmodal). Linearly interpolate between 

the 1 Hz reference values specified in 

the standard-setting part to determine 

more frequently issued reference torque 

values. During an emission test, record 

the feedback speeds and torques at a 

frequency of at least 5 Hz for transient 

cycles and at least 1 Hz for steady-state 

cycles. For transient cycles, you may 

record the feedback speeds and torques 

at lower frequencies (as low as 1 Hz) if 

you record the average value over the 

time interval between recorded values. 

Calculate the average values based on 

feedback values updated at a frequency 

of at least 5 Hz. Use these recorded 

values to calculate cycle-validation 

statistics and total work. 

(e) You may perform practice duty 

cycles with the test engine to optimize 

operator demand and dynamometer 

controls to meet the cycle-validation 

criteria specified in § 1065.514. 

■ 100. Section 1065.514 is revised to 

read as follows: 

§ 1065.514 Cycle-validation criteria for 

operation over specified duty cycles. 

Validate the execution of your duty 

cycle according to this section unless 

the standard-setting part specifies 

otherwise. This section describes how to 

determine if the engine’s operation 

during the test adequately matched the 

reference duty cycle. This section 

applies only to speed, torque, and 

power from the engine’s primary output 

shaft. Other work inputs and outputs are 

not subject to cycle-validation criteria. 

You must compare the original 

reference duty cycle points generated as 

described in § 1065.512 to the 

corresponding feedback values recorded 

during the test. You may compare 

reference duty cycle points recorded 

during the test to the corresponding 

feedback values recorded during the test 

as long as the recorded reference values 

match the original points generated in 

§ 1065.512. The number of points in the 

validation regression are based on the 

number of points in the original 

reference duty cycle generated in 

§ 1065.512. For example if the original 

cycle has 1199 reference points at 1 Hz, 

then the regression will have up to 1199 

pairs of reference and feedback values at 

the corresponding moments in the test. 

The feedback speed and torque signals 

may be filtered—either in real-time 

while the test is run or afterward in the 

analysis program. Any filtering that is 

used on the feedback signals used for 

cycle validation must also be used for 

calculating work. Feedback signals for 

control loops may use different filtering. 

(a) Testing performed by EPA. Our 

tests must meet the specifications of 

paragraph (f) of this section, unless we 

determine that failing to meet the 

specifications is related to engine 

performance rather than to 
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Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 37319 

shortcomings of the dynamometer or affect your ability to show compliance calculating work. You may use linear 

other laboratory equipment. with the applicable emission standards. interpolation between successive (b) Testing performed by (c) Time-alignment. Because time lag recorded feedback signals to time shift manufacturers. Emission tests that meet between feedback values and the an amount that is a fraction of the 

the specifications of paragraph (f) of this reference values may bias cycle- recording period. section satisfy the standard-setting validation results, you may advance or (d) Omitting additional points. part’s requirements for duty cycles. You delay the entire sequence of feedback 

may ask to use a dynamometer or other engine speed and torque pairs to Besides engine cranking, you may omit

additional points from cycle-validation laboratory equipment that cannot meet synchronize them with the reference statistics as described in the following those specifications. We will approve sequence. If you advance or delay table: your request as long as using the feedback signals for cycle validation, 

alternate equipment does not adversely you must make the same adjustment for 

TABLE 1 OF § 1065.514.—PERMISSIBLE CRITERIA FOR OMITTING POINTS FROM DUTY-CYCLE REGRESSION STATISTICS 

When operator demand 

is at its . . . you may omit . . . if . . . 

For reference duty cycles that are specified in terms of speed and torque (fnref, Tref): 

minimum ....................... power and torque ................. Tref < 0% (motoring). 

minimum ....................... power and speed ................. fnref = 0% (idle speed) and Tref = 0% (idle torque) and Tref¥(2% · Tmax mapped) < T < 

Tref + (2% · Tmax mapped). 

minimum ....................... power and either torque or fn > fnref or T > Tref but not if fn > (fnref · 102%) and T > Tref + (2% · Tmax, mapped). 

speed. 

maximum ...................... power and either torque or fn < fnref or T < Tref but not if fn < (fnref · 98%) and T < Tref¥(2% · Tmax, mapped). 

speed. 

For reference duty cycles that are specified in terms of speed and power (fnref, Pref): 

minimum ....................... power and torque ................. < Pref < 0% (motoring). 

minimum ....................... power and speed ................. fnref = 0% (idle speed) and Pref = 0% (idle power) and Pref¥(2% · Pmax mapped) <P < 

Pref + (2% · Pmax mapped). 

minimum ....................... power and either torque or fn >fnref or P > Pref but not if fn > (fnref · 102%) and P > Pref + (2% · Pmax mapped). 

speed. 

maximum ...................... power and either torque or fn < fnref or P < Pref but not if fn < (fnref · 98%) and P < Pref¥(2% · Pmax mapped). 

speed. 

(e) Statistical parameters. Use the 

remaining points to calculate regression 

statistics described in § 1065.602. 

Round calculated regression statistics to 

the same number of significant digits as 

the criteria to which they are compared. 

Refer to Table 2 of § 1065.514 for the 

default criteria and refer to the standardsetting part to determine if there are 

other criteria for your engine. Calculate 

the following regression statistics: 

(1) Slopes for feedback speed, a1fn, 

feedback torque, a1T, and feedback 

power a1P. 

(2) Intercepts for feedback speed, a0fn, 

feedback torque, a0T, and feedback 

power a0P. 

(3) Standard estimates of error for 

feedback speed, SEEfn, feedback torque, 

SEET, and feedback power SEEP. 

(4) Coefficients of determination for 

feedback speed, r2

fn, feedback torque, 

r2

T, and feedback power r2P. 

(f) Cycle-validation criteria. Unless 

the standard-setting part specifies 

otherwise, use the following criteria to 

validate a duty cycle: 

(1) For variable-speed engines, apply 

all the statistical criteria in Table 2 of 

this section. 

(2) For constant-speed engines, apply 

only the statistical criteria for torque in 

Table 2 of this section. 

(3) For discrete-mode steady-state 

testing, apply cycle-validation criteria 

using one of the following approaches: 

(i) Treat the sampling periods from 

the series of test modes as a continuous 

sampling period, analogous to rampedmodal testing and apply statistical 

criteria as described in paragraph (f)(1) 

or (2) of this section. 

(ii) Evaluate each mode separately to 

validate the duty cycle. For variablespeed engines, all speed values 

measured during the sampling period 

for each mode would need to stay 

within a tolerance of 2 percent of the 

reference value, and all load values 

would need to stay within a tolerance of 

2 percent or ± 0.27 N·m of the reference 

value, whichever is greater. Also, the 

mean speed value during the sampling 

period for each mode would need to be 

within 1 percent of the reference value, 

and the mean load value would need to 

stay within 1 percent or ± 0.12 N·m of 

the reference value, whichever is 

greater. The same torque criteria apply 

for constant-speed engines but the speed 

criteria do not apply. 

TABLE 2 OF § 1065.514.—DEFAULT STATISTICAL CRITERIA FOR VALIDATING DUTY CYCLES 

Parameter Speed Torque Power 

Slope, a1 ........................................ 

Absolute value of intercept, a0 .... 

Standard error of estimate, SEE ... 

Coefficient of determination, r 2 ..... 

0.950 ≤ a1 ≤ 1.030 ........................ 

≤ 10% of warm idle ...................... 

≤ 5.0% of maximum test speed ... 

≥ 0.970 .......................................... 

0.830 ≤ a1 ≤ 1.030 ........................ 

≤ 2.0% of maximum mapped 

torque. 

≤ 10% of maximum mapped 

torque. 

≥ 0.850 .......................................... 

0.830 ≤ a1 ≤ 1.030. 

≤ 2.0% of maximum 

power. 

≤ 10% of maximum 

power. 

≥ 0.910. 

mapped 

mapped 
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37320 Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 

■ 101. Section 1065.520 is revised to 

read as follows: 

§ 1065.520 Pre-test verification procedures 

and pre-test data collection. 

(a) If your engine must comply with 

a PM standard, follow the procedures 

for PM sample preconditioning and tare 

weighing according to § 1065.590. 

(b) Unless the standard-setting part 

specifies different tolerances, verify that 

ambient conditions are within the 

following tolerances before the test: 

(1) Ambient temperature of 

(20 to 30) °C. 

(2) Atmospheric pressure of (80.000 to 

103.325) kPa and within ± 5 kPa of the 

value recorded at the time of the last 

engine map. 

(3) Dilution air conditions as specified 

in § 1065.140, except in cases where you 

preheat your CVS before a cold start 

test. 

(c) You may test engines at any 

intake-air humidity, and we may test 

engines at any intake-air humidity. 

(d) Verify that auxiliary-work inputs 

and outputs are configured as they were 

during engine mapping, as described 

in§ 1065.510(a). 

(e) You may perform a final 

calibration of the speed, torque, and 

proportional-flow control systems, 

which may include performing practice 

duty cycles. 

(f) You may perform the following 

recommended procedure to 

precondition sampling systems: 

(1) Start the engine and use good 

engineering judgment to bring it to one 

of the following: 

(i) 100% torque at any speed above its 

peak-torque speed. 

(ii) 100% operator demand. 

(2) Operate any dilution systems at 

their expected flow rates. Prevent 

aqueous condensation in the dilution 

systems. 

(3) Operate any PM sampling systems 

at their expected flow rates. 

(4) Sample PM for at least 10 min 

using any sample media. You may 

change sample media during 

preconditioning. You may discard 

preconditioning samples without 

weighing them. 

(5) You may purge any gaseous 

sampling systems during 

preconditioning. 

(6) You may conduct calibrations or 

verifications on any idle equipment or 

analyzers during preconditioning. 

(7) Proceed with the test sequence 

described in § 1065.530(a)(1). 

(g) Verify the amount of nonmethane 

contamination in the exhaust and 

background HC sampling systems 

within eight hours of starting each dutycycle sequence for laboratory tests. You 

may verify the contamination of a 

background HC sampling system by 

reading the last bag fill and purge using 

zero gas. For any NMHC measurement 

system that involves separately 

measuring methane and subtracting it 

from a THC measurement, verify the 

amount of THC contamination using 

only the THC analyzer response. There 

is no need to operate any separate 

methane analyzer for this verification, 

however you may measure and correct 

for THC contamination in the CH4 

sample train for the cases where NMHC 

is determined by subtracting CH4 from 

THC, using an NMC as configured in 

§ 1065.365(d), (e), and (f); and the 

calculations in § 1065.660(b)(2). Perform 

this verification as follows: 

(1) Select the HC analyzer range for 

measuring the flow-weighted mean 

concentration expected at the HC 

standard. 

(2) Zero the HC analyzer at the 

analyzer zero or sample port. Note that 

FID zero and span balance gases may be 

any combination of purified air or 

purified nitrogen that meets the 

specifications of § 1065.750. We 

recommend FID analyzer zero and span 

gases that contain approximately the 

flow-weighted mean concentration of O2 

expected during testing. 

(3) Span the HC analyzer using span 

gas introduced at the analyzer span or 

sample port. Span on a carbon number 

basis of one (C1). For example, if you 

use a C3H8 span gas of concentration 

200 μmol/mol, span the FID to respond 

with a value of 600 μmol/mol. 

(4) Overflow zero gas at the HC probe 

or into a fitting between the HC probe 

and its transfer line. 

(5) Measure the THC concentration in 

the sampling and background systems 

as follows: 

(i) For continuous sampling, record 

the mean THC concentration as 

overflow zero air flows. 

(ii) For batch sampling, fill the sample 

medium (e.g., filter) and record its mean 

THC concentration. 

(iii) For the background system, 

record the mean THC concentration of 

the last fill and purge. 

(6) Record this value as the initial 

THC concentration, xTHC[THC–FID]init, and 

use it to correct measured values as 

described in § 1065.660. 

(7) If any of the xTHC[THC–FID]init values 

exceed the greatest of the following 

values, determine the source of the 

contamination and take corrective 

action, such as purging the system 

during an additional preconditioning 

cycle or replacing contaminated 

portions: 

(i) 2% of the flow-weighted mean wet, 

net concentration expected at the HC 

(THC or NMHC) standard. 

(ii) 2% of the flow-weighted mean 

wet, net concentration of HC (THC or 

NMHC) measured during testing. 

(iii) 2 μmol/mol. 

(8) If corrective action does not 

resolve the deficiency, you may request 

to use the contaminated system as an 

alternate procedure under § 1065.10. 

■ 102. Section 1065.525 is revised to 

read as follows: 

§ 1065.525 Engine starting, restarting, 

shutdown, and optional repeating of void 

discrete modes. 

(a) Start the engine using one of the 

following methods: 

(1) Start the engine as recommended 

in the owners manual using a 

production starter motor or air-start 

system and either an adequately charged 

battery, a suitable power supply, or a 

suitable compressed air source. 

(2) Use the dynamometer to start the 

engine. To do this, motor the engine 

within ±25% of its typical in-use 

cranking speed. Stop cranking within 1 

second of starting the engine. 

(b) If the engine does not start after 15 

seconds of cranking, stop cranking and 

determine why the engine failed to start, 

unless the owners manual or the 

service-repair manual describes the 

longer cranking time as normal. 

(c) Respond to engine stalling with 

the following steps: 

(1) If the engine stalls during warmup before emission sampling begins, 

restart the engine and continue warmup. 

(2) If the engine stalls during 

preconditioning before emission 

sampling begins, restart the engine and 

restart the preconditioning sequence. 

(3) If the engine stalls at any time after 

emission sampling begins for a transient 

test or ramped-modal cycle test, the test 

is void. 

(4) Except as described in paragraph 

(d) of this section, void the test if the 

engine stalls at any time after emission 

sampling begins. 

(d) If emission sampling is interrupted 

during one of the modes of a discretemode test, you may void the results only 

for that individual mode and perform 

the following steps to continue the test: 

(1) If the engine has stalled, restart the 

engine. 

(2) Use good engineering judgment to 

restart the test sequence using the 

appropriate steps in § 1065.530(b). 

(3) Precondition the engine by 

operating at the previous mode for 

approximately the same amount of time 

it operated at that mode for the last 

emission measurement. 
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Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 37321 

(4) Advance to the mode at which the 

engine stalled and continue with the 

duty cycle as specified in the standardsetting part. 

(5) Complete the remainder of the test 

according to the requirements in this 

subpart. 

(e) Shut down the engine according to 

the manufacturer’s specifications. 

■ 103. Section 1065.530 is revised to 

read as follows: 

§ 1065.530 Emission test sequence. 

(a) Time the start of testing as follows: 

(1) Perform one of the following if you 

precondition sampling systems as 

described in § 1065.520(f): 

(i) For cold-start duty cycles, shut 

down the engine. Unless the standardsetting part specifies that you may only 

perform a natural engine cooldown, you 

may perform a forced engine cooldown. 

Use good engineering judgment to set 

up systems to send cooling air across 

the engine, to send cool oil through the 

engine lubrication system, to remove 

heat from coolant through the engine 

cooling system, and to remove heat from 

any exhaust aftertreatment systems. In 

the case of a forced aftertreatment 

cooldown, good engineering judgment 

would indicate that you not start 

flowing cooling air until the 

aftertreatment system has cooled below 

its catalytic activation temperature. For 

platinum-group metal catalysts, this 

temperature is about 200 °C. Once the 

aftertreatment system has naturally 

cooled below its catalytic activation 

temperature, good engineering judgment 

would indicate that you use clean air 

with a temperature of at least 15 °C, and 

direct the air through the aftertreatment 

system in the normal direction of 

exhaust flow. Do not use any cooling 

procedure that results in 

unrepresentative emissions (see 

§ 1065.10(c)(1)). You may start a coldstart duty cycle when the temperatures 

of an engine’s lubricant, coolant, and 

aftertreatment systems are all between 

(20 and 30) °C. 

(ii) For hot-start emission 

measurements, shut down the engine. 

Start the hot-start duty cycle as 

specified in the standard-setting part. 

(iii) For testing that involves hotstabilized emission measurements, such 

as any steady-state testing, you may 

continue to operate the engine at 

maximum test speed and 100% torque 

if that is the first operating point. 

Otherwise, operate the engine at warm 

idle or the first operating point of the 

duty cycle. In any case, start the 

emission test within 10 min after you 

complete the preconditioning 

procedure. 

(2) If you do not precondition 

sampling systems, perform one of the 

following: 

(i) For cold-start duty cycles, prepare 

the engine according to paragraph 

(a)(1)(i) of this section. 

(ii) For hot-start emission 

measurements, first operate the engine 

at any speed above peak-torque speed 

and at (65 to 85)% of maximum mapped 

power until either the engine coolant, 

block, or head absolute temperature is 

within ±2% of its mean value for at least 

2 min or until the engine thermostat 

controls engine temperature. Shut down 

the engine. Start the duty cycle within 

20 min of engine shutdown. 

(iii) For testing that involves hotstabilized emission measurements, bring 

the engine either to warm idle or the 

first operating point of the duty cycle. 

Start the test within 10 min of achieving 

temperature stability. Determine 

temperature stability either as the point 

at which the engine coolant, block, or 

head absolute temperature is within 

±2% of its mean value for at least 2 min, 

or as the point at which the engine 

thermostat controls engine temperature. 

(b) Take the following steps before 

emission sampling begins: 

(1) For batch sampling, connect clean 

storage media, such as evacuated bags or 

tare-weighed filters. 

(2) Start all measurement instruments 

according to the instrument 

manufacturer’s instructions and using 

good engineering judgment. 

(3) Start dilution systems, sample 

pumps, cooling fans, and the datacollection system. 

(4) Pre-heat or pre-cool heat 

exchangers in the sampling system to 

within their operating temperature 

tolerances for a test. 

(5) Allow heated or cooled 

components such as sample lines, 

filters, chillers, and pumps to stabilize 

at their operating temperatures. 

(6) Verify that there are no significant 

vacuum-side leaks according to 

§ 1065.345. 

(7) Adjust the sample flow rates to 

desired levels, using bypass flow, if 

desired. 

(8) Zero or re-zero any electronic 

integrating devices, before the start of 

any test interval. 

(9) Select gas analyzer ranges. You 

may automatically or manually switch 

gas analyzer ranges during a test only if 

switching is performed by changing the 

span over which the digital resolution of 

the instrument is applied. During a test 

you may not switch the gains of an 

analyzer’s analog operational 

amplifier(s). 

(10) Zero and span all continuous 

analyzers using NIST-traceable gases 

that meet the specifications of 

§ 1065.750. Span FID analyzers on a 

carbon number basis of one (1), C1. For 

example, if you use a C3H8 span gas of 

concentration 200 μmol/mol, span the 

FID to respond with a value of 600 

μmol/mol. Span FID analyzers 

consistent with the determination of 

their respective response factors, RF, 

and penetration fractions, PF, according 

to § 1065.365. 

(11) We recommend that you verify 

gas analyzer responses after zeroing and 

spanning by sampling a calibration gas 

that has a concentration near one-half of 

the span gas concentration. Based on the 

results and good engineering judgment, 

you may decide whether or not to rezero, re-span, or re-calibrate a gas 

analyzer before starting a test. 

(12) If you correct for dilution air 

background concentrations of engine 

exhaust constituents, start measuring 

and recording background 

concentrations. 

(13) Drain any condensate from the 

intake air system and close any intake 

air condensate drains that are not 

normally open during in-use operation. 

(c) Start testing as follows: 

(1) If an engine is already running and 

warmed up, and starting is not part of 

the duty cycle, perform the following for 

the various duty cycles: 

(i) Transient and steady-state rampedmodal cycles. Simultaneously start 

running the duty cycle, sampling 

exhaust gases, recording data, and 

integrating measured values. 

(ii) Steady-state discrete-mode cycles. 

Control the engine operation to match 

the first mode in the test cycle. This will 

require controlling engine speed and 

load, engine load, or other operator 

demand settings, as specified in the 

standard-setting part. Follow the 

instructions in the standard-setting part 

to determine how long to stabilize 

engine operation at each mode, how 

long to sample emissions at each mode, 

and how to transition between modes. 

(2) If engine starting is part of the duty 

cycle, initiate data logging, sampling of 

exhaust gases, and integrating measured 

values before attempting to start the 

engine. Initiate the duty cycle when the 

engine starts. 

(d) At the end of each test interval, 

continue to operate all sampling and 

dilution systems to allow the sampling 

system’s response time to elapse. Then 

stop all sampling and recording, 

including the recording of background 

samples. Finally, stop any integrating 

devices and indicate the end of the duty 

cycle in the recorded data. 

(e) Shut down the engine if you have 

completed testing or if it is part of the 

duty cycle. 
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(f) If testing involves another duty 

cycle after a soak period with the engine 

off, start a timer when the engine shuts 

down, and repeat the steps in 

paragraphs (b) through (e) of this section 

as needed. 

(g) Take the following steps after 

emission sampling is complete: 

(1) For any proportional batch sample, 

such as a bag sample or PM sample, 

verify that proportional sampling was 

maintained according to § 1065.545. 

Void any samples that did not maintain 

proportional sampling according to 

§ 1065.545. 

(2) Place any used PM samples into 

covered or sealed containers and return 

them to the PM-stabilization 

environment. Follow the PM sample 

post-conditioning and total weighing 

procedures in § 1065.595. 

(3) As soon as practical after the duty 

cycle is complete, or during the soak 

period if practical, perform the 

following: 

(i) Zero and span all batch gas 

analyzers no later than 30 minutes after 

the duty cycle is complete, or during the 

soak period if practical. 

(ii) Analyze any conventional gaseous 

batch samples no later than 30 minutes 

after the duty cycle is complete, or 

during the soak period if practical. 

(iii) Analyze background samples no 

later than 60 minutes after the duty 

cycle is complete. 

(iv) Analyze non-conventional 

gaseous batch samples, such as ethanol 

(NMCHE) as soon as practical using 

good engineering judgment. 

(4) After quantifying exhaust gases, 

verify drift as follows: 

(i) For batch and continuous gas 

anlyzers, record the mean analyzer 

value after stabilizing a zero gas to the 

analyzer. Stabilization may include time 

to purge the analyzer of any sample gas, 

plus any additional time to account for 

analyzer response. 

(ii) Record the mean analyzer value 

after stabilizing the span gas to the 

analyzer. Stabilization may include time 

to purge the analyzer of any sample gas, 

plus any additional time to account for 

analyzer response. 

(iii) Use these data to validate and 

correct for drift as described in 

§ 1065.550. 

(h) Unless the standard-setting part 

specifies otherwise, determine whether 

or not the test meets the cycle-validation 

criteria in § 1065.514. 

(1) If the criteria void the test, you 

may retest using the same denormalized 

duty cycle, or you may re-map the 

engine, denormalize the reference duty 

cycle based on the new map and retest 

the engine using the new denormalized 

duty cycle. 

(2) If the criteria void the test for a 

constant-speed engine only during 

commands of maximum test torque, you 

may do the following: 

(i) Determine the first and last 

feedback speeds at which maximum test 

torque was commanded. 

(ii) If the last speed is greater than or 

equal to 90% of the first speed, the test 

is void. You may retest using the same 

denormalized duty cycle, or you may remap the engine, denormalize the 

reference duty cycle based on the new 

map and retest the engine using the new 

denormalized duty cycle. 

(iii) If the last speed is less than 90% 

of the first speed, reduce maximum test 

torque by 5%, and proceed as follows: 

(A) Denormalize the entire duty cycle 

based on the reduced maximum test 

torque according to § 1065.512. 

(B) Retest the engine using the 

denormalized test cycle that is based on 

the reduced maximum test torque. 

(C) If your engine still fails the cycle 

criteria, reduce the maximum test 

torque by another 5% of the original 

maximum test torque. 

(D) If your engine fails after repeating 

this procedure four times, such that 

your engine still fails after you have 

reduced the maximum test torque by 

20% of the original maximum test 

torque, notify us and we will consider 

specifying a more appropriate duty 

cycle for your engine under the 

provisions of § 1065.10(c). 

(i) [Reserved] 

(j) Measure and record ambient 

temperature, pressure, and humidity, as 

appropriate. 

■ 104. Section 1065.545 is revised to 

read as follows: 

§ 1065.545 Validation of proportional flow 

control for batch sampling and minimum 

dilution ratio for PM batch sampling. 

For any proportional batch sample 

such as a bag or PM filter, demonstrate 

that proportional sampling was 

maintained using one of the following, 

noting that you may omit up to 5% of 

the total number of data points as 

outliers: 

(a) For any pair of flow meters, use 

recorded sample and total flow rates, 

where total flow rate means the raw 

exhaust flow rate for raw exhaust 

sampling and the dilute exhaust flow 

rate for CVS sampling, or their 1 Hz 

means with the statistical calculations 

in § 1065.602. Determine the standard 

error of the estimate, SEE, of the sample 

flow rate versus the total flow rate. For 

each test interval, demonstrate that SEE 

was less than or equal to 3.5% of the 

mean sample flow rate. 

(b) For any pair of flow meters, use 

recorded sample and total flow rates, 

where total flow rate means the raw 

exhaust flow rate for raw exhaust 

sampling and the dilute exhaust flow 

rate for CVS sampling, or their 1 Hz 

means to demonstrate that each flow 

rate was constant within ±2.5% of its 

respective mean or target flow rate. You 

may use the following options instead of 

recording the respective flow rate of 

each type of meter: 

(1) Critical-flow venturi option. For 

critical-flow venturis, you may use 

recorded venturi-inlet conditions or 

their 1 Hz means. Demonstrate that the 

flow density at the venturi inlet was 

constant within ±2.5% of the mean or 

target density over each test interval. 

For a CVS critical-flow venturi, you may 

demonstrate this by showing that the 

absolute temperature at the venturi inlet 

was constant within ±4% of the mean or 

target absolute temperature over each 

test interval. 

(2) Positive-displacement pump 

option. You may use recorded pumpinlet conditions or their 1 Hz means. 

Demonstrate that the flow density at the 

pump inlet was constant within ±2.5% 

of the mean or target density over each 

test interval. For a CVS pump, you may 

demonstrate this by showing that the 

absolute temperature at the pump inlet 

was constant within ±2% of the mean or 

target absolute temperature over each 

test interval. 

(c) Using good engineering judgment, 

demonstrate with an engineering 

analysis that the proportional-flow 

control system inherently ensures 

proportional sampling under all 

circumstances expected during testing. 

For example, you might use CFVs for 

both sample flow and total flow and 

demonstrate that they always have the 

same inlet pressures and temperatures 

and that they always operate under 

critical-flow conditions. 

(d) Use measured or calculated flows 

and/or tracer gas concentrations (e.g., 

CO2) to determine the minimum 

dilution ratio for PM batch sampling 

over the test interval. 

■ 105. Section 1065.550 is revised to 

read as follows: 

§ 1065.550 Gas analyzer range validation, 

drift validation, and drift correction. 

(a) Range validation. If an analyzer 

operated above 100% of its range at any 

time during the test, perform the 

following steps: 

(1) For batch sampling, re-analyze the 

sample using the lowest analyzer range 

that results in a maximum instrument 

response below 100%. Report the result 

from the lowest range from which the 

analyzer operates below 100% of its 

range. 
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(2) For continuous sampling, repeat 

the entire test using the next higher 

analyzer range. If the analyzer again 

operates above 100% of its range, repeat 

the test using the next higher range. 

Continue to repeat the test until the 

analyzer always operates at less than 

100% of its range. 

(b) Drift validation and drift 

correction. Calculate two sets of brakespecific emission results. Calculate one 

set using the data before drift correction 

and calculate the other set after 

correcting all the data for drift according 

to § 1065.672. Use the two sets of brakespecific emission results as follows: 

(1) This test is validated for drift if, for 

each regulated pollutant, the difference 

between the uncorrected and the 

corrected brake-specific emission values 

is within ±4% of the uncorrected results 

or applicable standard, whichever is 

greater. If not, the entire test is void. 

(2) If the test is validated for drift, you 

must use only the drift-corrected 

emission results when reporting 

emissions, unless you demonstrate to us 

that using the drift-corrected results 

adversely affects your ability to 

demonstrate that your engine complies 

with the applicable standards. 

■ 106. Section 1065.590 is revised to 

read as follows: 

§ 1065.590 PM sampling media (e.g., 

filters) preconditioning and tare weighing. 

Before an emission test, take the 

following steps to prepare PM sampling 

media (e.g., filters) and equipment for 

PM measurements: 

(a) Make sure the balance and PMstabilization environments meet the 

periodic verifications in § 1065.390. 

(b) Visually inspect unused sample 

media (e.g., filters) for defects and 

discard defective media. 

(c) To handle PM sampling media 

(e.g., filters), use electrically grounded 

tweezers or a grounding strap, as 

described in § 1065.190. 

(d) Place unused sample media (e.g., 

filters) in one or more containers that 

are open to the PM-stabilization 

environment. If you are using filters, 

you may place them in the bottom half 

of a filter cassette. 

(e) Stabilize sample media (e.g., 

filters) in the PM-stabilization 

environment. Consider an unused 

sample medium stabilized as long as it 

has been in the PM-stabilization 

environment for a minimum of 30 min, 

during which the PM-stabilization 

environment has been within the 

specifications of § 1065.190. 

(f) Weigh the sample media (e.g., 

filters) automatically or manually, as 

follows: 

(1) For automatic weighing, follow the 

automation system manufacturer’s 

instructions to prepare samples for 

weighing. This may include placing the 

samples in a special container. 

(2) For manual weighing, use good 

engineering judgment to determine if 

substitution weighing is necessary to 

show that an engine meets the 

applicable standard. You may follow the 

substitution weighing procedure in 

paragraph (j) of this section, or you may 

develop your own procedure. 

(g) Correct the measured mass of each 

sample medium (e.g., filter) for 

buoyancy as described in § 1065.690. 

These buoyancy-corrected values are 

subsequently subtracted from the posttest mass of the corresponding sample 

media (e.g., filters) and collected PM to 

determine the mass of PM emitted 

during the test. 

(h) You may repeat measurements to 

determine the mean mass of each 

sample medium (e.g., filter). Use good 

engineering judgment to exclude 

outliers from the calculation of mean 

mass values. 

(i) If you use filters as sample media, 

load unused filters that have been tareweighed into clean filter cassettes and 

place the loaded cassettes in a clean, 

covered or sealed container before 

removing them from the stabilization 

environment for transport to the test site 

for sampling. We recommend that you 

keep filter cassettes clean by 

periodically washing or wiping them 

with a compatible solvent applied using 

a lint-free cloth. Depending upon your 

cassette material, ethanol (C2H5OH) 

might be an acceptable solvent. Your 

cleaning frequency will depend on your 

engine’s level of PM and HC emissions. 

(j) Substitution weighing involves 

measurement of a reference weight 

before and after each weighing of PM 

sampling media (e.g., filters). While 

substitution weighing requires more 

measurements, it corrects for a balance’s 

zero-drift and it relies on balance 

linearity only over a small range. This 

is most advantageous when quantifying 

net PM masses that are less than 0.1% 

of the sample medium’s mass. However, 

it may not be advantageous when net 

PM masses exceed 1% of the sample 

medium’s mass. If you utilize 

substitution weighing, it must be used 

for both pre-test and post-test weighing. 

The same substitution weight must be 

used for both pre-test and post-test 

weighing. Correct the mass of the 

substitution weight for buoyancy if the 

density of the substitution weight is less 

than 2.0 g/cm3. The following steps are 

an example of substitution weighing: 

(1) Use electrically grounded tweezers 

or a grounding strap, as described in 

§ 1065.190. 

(2) Use a static neutralizer as 

described in § 1065.190 to minimize 

static electric charge on any object 

before it is placed on the balance pan. 

(3) Select a substitution weight that 

meets the requirements for calibration 

weights found in § 1065.790. The 

substitution weight must also have the 

same density as the weight you use to 

span the microbalance, and be similar in 

mass to an unused sample medium (e.g., 

filter). A 47 mm PTFE membrane filter 

will typically have a mass in the range 

of 80 to 100 mg. 

(4) Record the stable balance reading, 

then remove the calibration weight. 

(5) Weigh an unused sample medium 

(e.g., a new filter), record the stable 

balance reading and record the balance 

environment’s dewpoint, ambient 

temperature, and atmospheric pressure. 

(6) Reweigh the calibration weight 

and record the stable balance reading. 

(7) Calculate the arithmetic mean of 

the two calibration-weight readings that 

you recorded immediately before and 

after weighing the unused sample. 

Subtract that mean value from the 

unused sample reading, then add the 

true mass of the calibration weight as 

stated on the calibration-weight 

certificate. Record this result. This is the 

unused sample’s tare weight without 

correcting for buoyancy. 

(8) Repeat these substitution-weighing 

steps for the remainder of your unused 

sample media. 

(9) Once weighing is completed, 

follow the instructions given in 

paragraphs (g) through (i) of this section. 

■ 107. Section 1065.595 is revised to 

read as follows: 

§ 1065.595 PM sample post-conditioning 

and total weighing. 

After testing is complete, return the 

sample media (e.g., filters) to the 

weighing and PM-stabilization 

environments. 

(a) Make sure the weighing and PMstabilization environments meet the 

ambient condition specifications in 

§ 1065.190(e)(1). If those specifications 

are not met, leave the test sample media 

(e.g., filters) covered until proper 

conditions have been met. 

(b) In the PM-stabilization 

environment, remove PM samples from 

sealed containers. If you use filters, you 

may remove them from their cassettes 

before or after stabilization. We 

recommend always removing the top 

portion of the cassette before 

stabilization. When you remove a filter 

from a cassette, separate the top half of 
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37324 Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 

the cassette from the bottom half using 

a cassette separator designed for this 

purpose. 

(c) To handle PM samples, use 

electrically grounded tweezers or a 

grounding strap, as described in 

§ 1065.190. 

(d) Visually inspect the sampling 

media (e.g., filters) and collected 

particulate. If either the sample media 

(e.g., filters) or particulate sample 

appear to have been compromised, or 

the particulate matter contacts any 

surface other than the filter, the sample 

may not be used to determine 

particulate emissions. In the case of 

contact with another surface, clean the 

affected surface before continuing. 

(e) To stabilize PM samples, place 

them in one or more containers that are 

open to the PM-stabilization 

environment, as described in 

§ 1065.190. If you expect that a sample 

medium’s (e.g., filter’s) total surface 

concentration of PM will be less than 

400 μg, assuming a 38 mm diameter 

filter stain area, expose the filter to a 

PM-stabilization environment meeting 

the specifications of § 1065.190 for at 

least 30 minutes before weighing. If you 

expect a higher PM concentration or do 

not know what PM concentration to 

expect, expose the filter to the 

stabilization environment for at least 60 

minutes before weighing. Note that 400 

μg on sample media (e.g., filters) is an 

approximate net mass of 0.07 g/kW·hr 

for a hot-start test with compressionignition engines tested according to 40 

CFR part 86, subpart N, or 50 mg/mile 

for light-duty vehicles tested according 

to 40 CFR part 86, subpart B. 

(f) Repeat the procedures in 

§ 1065.590(f) through (i) to determine 

post-test mass of the sample media (e.g., 

filters). 

(g) Subtract each buoyancy-corrected 

tare mass of the sample medium (e.g., 

filter) from its respective buoyancycorrected mass. The result is the net PM 

mass, mPM. Use mPM in emission 

calculations in § 1065.650. 

Subpart G—[Amended] 

■ 108. Section 1065.601 is amended by 

revising paragraph (c)(1) to read as 

follows: 

§ 1065.601 Overview. 

* * * * * 

(c) * * * 

(1) Mass-based emission calculations 

prescribed by the International 

Organization for Standardization (ISO), 

according to ISO 8178, except the 

following: 

(i) ISO 8178–1 Section 14.4, NOX 

Correction for Humidity and 

Temperature. See § 1065.670 for 

approved methods for humidity 

corrections. 

(ii) ISO 8178–1 Section 15.1, 

Particulate Correction Factor for 

Humidity. 

* * * * * 

■ 109. Section 1065.602 is amended by 

revising paragraphs (f)(3) before the 

table and (l) introductory text to read as 

follows: 

§ 1065.602 Statistics. 

* * * * * 

(f) * * * 

(3) Use Table 1 of this section to 

compare t to the tcrit values tabulated 

versus the number of degrees of 

freedom. If t is less than tcrit, then t 

passes the t-test. The Microsoft Excel 

software package contains a TINV 

function that returns results equivalent 

to § 1065.602 Table 1 and may be used 

in place of Table 1. 

* * * * * 

(l) Flow-weighted mean 

concentration. In some sections of this 

part, you may need to calculate a flowweighted mean concentration to 

determine the applicability of certain 

provisions. A flow-weighted mean is the 

mean of a quantity after it is weighted 

proportional to a corresponding flow 

rate. For example, if a gas concentration 

is measured continuously from the raw 

exhaust of an engine, its flow-weighted 

mean concentration is the sum of the 

products of each recorded concentration 

times its respective exhaust molar flow 

rate, divided by the sum of the recorded 

flow rate values. As another example, 

the bag concentration from a CVS 

system is the same as the flow-weighted 

mean concentration because the CVS 

system itself flow-weights the bag 

concentration. You might already expect 

a certain flow-weighted mean 

concentration of an emission at its 

standard based on previous testing with 

similar engines or testing with similar 

equipment and instruments. If you need 

to estimate your expected flow-weighted 

mean concentration of an emission at its 

standard, we recommend using the 

following examples as a guide for how 

to estimate the flow-weighted mean 

concentration expected at the standard. 

Note that these examples are not exact 

and that they contain assumptions that 

are not always valid. Use good 

engineering judgment to determine if 

you can use similar assumptions. 

* * * * * 

■ 110. Section 1065.610 is revised to 

read as follows: 

§ 1065.610 Duty cycle generation. 

This section describes how to 

generate duty cycles that are specific to 

your engine, based on the normalized 

duty cycles in the standard-setting part. 

During an emission test, use a duty 

cycle that is specific to your engine to 

command engine speed, torque, and 

power, as applicable, using an engine 

dynamometer and an engine operator 

demand. Paragraph (a) of this section 

describes how to ‘‘normalize’’ your 

engine’s map to determine the 

maximum test speed and torque for your 

engine. The rest of this section describes 

how to use these values to 

‘‘denormalize’’ the duty cycles in the 

standard-setting parts, which are all 

published on a normalized basis. Thus, 

the term ‘‘normalized’’ in paragraph (a) 

of this section refers to different values 

than it does in the rest of the section. 

(a) Maximum test speed, fntest. This 

section generally applies to duty cycles 

for variable-speed engines. For constantspeed engines subject to duty cycles that 

specify normalized speed commands, 

use the no-load governed speed as the 

measured fntest. This is the highest 

engine speed where an engine outputs 

zero torque. For variable-speed engines, 

determine the measured fntest from the 

power-versus-speed map, generated 

according to § 1065.510, as follows: 

(1) Based on the map, determine 

maximum power, Pmax, and the speed at 

which maximum power occurred, fnPmax. 

Divide every recorded power by Pmax 

and divide every recorded speed by 

fnPmax. The result is a normalized powerversus-speed map. Your measured fntest 

is the speed at which the sum of the 

squares of normalized speed and power 

is maximum, as follows: 

fntest = fni at the maximum of (fnnormi2 + 

Pnormi2) 

Eq. 1065.610–1 

Where: 


fntest = maximum test speed. 


i = an indexing variable that represents one 


recorded value of an engine map. 

fnnormi = an engine speed normalized by 

dividing it by fnPmax. 

Pnormi = an engine power normalized by 

dividing it by Pmax. 

Example: 

(fnnorm1 = 1.002, Pnorm1 = 0.978, fn1 = 2359.71) 

(fnnorm2 = 1.004, Pnorm2 = 0.977, fn2 = 2364.42) 

(fnnorm3 = 1.006, Pnorm3 = 0.974, fn3 = 2369.13) 

(fnnorm12 + Pnorm12) = (1.0022 + 0.9782) = 1.960 

(fnnorm22 + Pnorm22) = (1.0042 + 0.9772) = 1.963 

(fnnorm32 + Pnorm32) = (1.0062 + 0.9742) = 1.961 

maximum = 1.963 at i = 2 

fntest = 2364.42 rev/min 

(2) For variable-speed engines, 

transform normalized speeds to 

reference speeds according to paragraph 

(c) of this section by using the measured 

maximum test speed determined 

according to paragraph (a)(1) of this 

section—or use your declared maximum 

test speed, as allowed in § 1065.510. 
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(3) For constant-speed engines, 

transform normalized speeds to 

reference speeds according to paragraph 

(c) of this section by using the measured 

no-load governed speed—or use your 

declared maximum test speed, as 

allowed in § 1065.510. 

(b) Maximum test torque, Ttest. For 

constant-speed engines, determine the 

measured Ttest from the power-versusspeed map, generated according to 

§ 1065.510, as follows: 

(1) Based on the map, determine 

maximum power, Pmax, and the speed at 

which maximum power occurs, fnPmax. 

Divide every recorded power by Pmax 

and divide every recorded speed by 

fnPmax. The result is a normalized powerversus-speed map. Your measured Ttest 

is the torque at which the sum of the 

squares of normalized speed and power 

is maximum, as follows: 

Ttest = Ti at the maximum of (fnnormi2 + 

Pnormi2) 

Eq. 1065.610–2 

Where: 


Ttest = maximum test torque. 


Example: 


(fnnorm1 = 1.002, Pnorm1 = 0.978, T1 = 722.62 

N·m) 

(fnnorm2 = 1.004, Pnorm2 = 0.977, T2 = 720.44 

N·m) 

(fnnorm3 = 1.006, Pnorm3 = 0.974, T3 = 716.80 

N·m) 

(fnnorm12 + Pnorm12) = (1.0022 + 0.9782) = 1.960 

(fnnorm12 + Pnorm12) = (1.0042 + 0.9772) = 1.963 

(fnnorm12 + Pnorm12) = (1.0062 + 0.9742) = 1.961 

maximum = 1.963 at i = 2 

Ttest = 720.44 N·m 

(2) Transform normalized torques to 

reference torques according to 

paragraph (d) of this section by using 

the measured maximum test torque 

determined according to paragraph 

(b)(1) of this section—or use your 

declared maximum test torque, as 

allowed in § 1065.510. 

(c) Generating reference speed values 

from normalized duty cycle speeds. 

Transform normalized speed values to 

reference values as follows: 

(1) % speed. If your normalized duty 

cycle specifies % speed values, use your 

warm idle speed and your maximum 

test speed to transform the duty cycle, 

as follows: 

fnref = % speed · (fntest ¥ fnidle) + fnidle 

Eq. 1065.610–3 

Example: 

% speed = 85% 

fntest = 2364 rev/min 

fnidle = 650 rev/min 

fnref = 85% · (2364¥650 ) + 650 

fnref = 2107 rev/min 

(2) A, B, and C speeds. If your 

normalized duty cycle specifies speeds 

as A, B, or C values, use your powerversus-speed curve to determine the 

lowest speed below maximum power at 

which 50% of maximum power occurs. 

Denote this value as nlo. Take nlo to be 

warm idle speed if all power points at 

speeds below the maximum power 

speed are higher than 50% of maximum 

power. Also determine the highest 

speed above maximum power at which 

70% of maximum power occurs. Denote 

this value as nhi. If all power points at 

speeds above the maximum power 

speed are higher than 70% of maximum 

power, take nhi to be the declared 

maximum safe engine speed or the 

declared maximum representative 

engine speed, whichever is lower. Use 

nhi and nlo to calculate reference values 

for A, B, or C speeds as follows: 

fnrefA = 0.25 · (nhi ¥ nlo) + nlo 

Eq. 1065.610–4 

fnrefB = 0.50 · (nhi ¥ nnlo) + nlo 

Eq. 1065.610–5 

fnrefC = 0.75 · (nhi ¥ nlo) + nlo 

Eq. 1065.610–6 

Example: 

nlo = 1005 rev/min 

nhi = 2385 rev/min 

fnrefA = 0.25 · (2385¥1005) + 1005 

fnrefB = 0.50 · (2385¥1005) + 1005 

fnrefC = 0.75 · (2385¥1005) + 1005 

fnrefA = 1350 rev/min 

fnrefB = 1695 rev/min 

fnrefC = 2040 rev/min 

(3) Intermediate speed. If your 

normalized duty cycle specifies a speed 

as ‘‘intermediate speed,’’ use your 

torque-versus-speed curve to determine 

the speed at which maximum torque 

occurs. This is peak torque speed. 

Identify your reference intermediate 

speed as one of the following values: 

(i) Peak torque speed if it is between 

(60 and 75)% of maximum test speed. 

(ii) 60% of maximum test speed if 

peak torque speed is less than 60% of 

maximum test speed. 

(iii) 75% of maximum test speed if 

peak torque speed is greater than 75% 

of maximum test speed. 

(d) Generating reference torques from 

normalized duty-cycle torques. 

Transform normalized torques to 

reference torques using your map of 

maximum torque versus speed. 

(1) Reference torque for variablespeed engines. For a given speed point, 

multiply the corresponding % torque by 

the maximum torque at that speed, 

according to your map. If your engine is 

subject to a reference duty cycle that 

specifies negative torque values (i.e., 

engine motoring), use negative torque 

for those motoring points (i.e., the 

motoring torque). If you map negative 

torque as allowed under § 1065.510 

(c)(2) and the low-speed governor 

activates, resulting in positive torques, 

you may replace those positive motoring 

mapped torques with negative values 

between zero and the largest negative 

motoring torque. For both maximum 

and motoring torque maps, linearly 

interpolate mapped torque values to 

determine torque between mapped 

speeds. If the reference speed is below 

the minimum mapped speed (i.e., 95% 

of idle speed or 95% of lowest required 

speed, whichever is higher), use the 

mapped torque at the minimum mapped 

speed as the reference torque. The result 

is the reference torque for each speed 

point. 

(2) Reference torque for constantspeed engines. Multiply a % torque 

value by your maximum test torque. The 

result is the reference torque for each 

point. 

(3) Required deviations. We require 

the following deviations for variablespeed engines intended primarily for 

propulsion of a vehicle with an 

automatic transmission where that 

engine is subject to a transient duty 

cycle with idle operation. These 

deviations are intended to produce a 

more representative transient duty cycle 

for these applications. For steady-state 

duty cycles or transient duty cycles with 

no idle operation, these requirements do 

not apply. Idle points for steady state 

duty cycles of such engines are to be run 

at conditions simulating neutral or park 

on the transmission. 

(i) Zero-percent speed is the warm 

idle speed measured according to 

§ 1065.510(b)(6) with CITT applied, i.e., 

measured warm idle speed in drive. 

(ii) If the cycle begins with a set of 

contiguous idle points (zero-percent 

speed, and zero-percent torque), leave 

the reference torques set to zero for this 

initial contiguous idle segment. This is 

to represent free idle operation with the 

transmission in neutral or park at the 

start of the transient duty cycle, after the 

engine is started. If the initial idle 

segment is longer than 24 s, change the 

reference torques for the remaining idle 

points in the initial contiguous idle 

segment to CITT (i.e., change idle points 

corresponding to 25 s to the end of the 

initial idle segment to CITT). This is to 

represent shifting the transmission to 

drive. 

(iii) For all other idle points, change 

the reference torque to CITT. This is to 

represent the transmission operating in 

drive. 

(iv) If the engine is intended primarily 

for automatic transmissions with a 

Neutral-When-Stationary feature that 

automatically shifts the transmission to 

neutral after the vehicle is stopped for 

a designated time and automatically 

shifts back to drive when the operator 

increases demand (i.e., pushes the 

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� = 

� = 

37326 Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 

accelerator pedal), change the reference 

torque back to zero for idle points in 

drive after the designated time. 

(v) For all points with normalized 

speed at or below zero percent and 

reference torque from zero to CITT, set 

the reference torque to CITT. This is to 

provide smoother torque references 

below idle speed. 

(vi) For motoring points, make no 

changes. 

(vii) For consecutive points with 

reference torques from zero to CITT that 

immediately follow idle points, change 

their reference torques to CITT. This is 

to provide smooth torque transition out 

of idle operation. This does not apply if 

the Neutral-When-Stationary feature is 

used and the transmission has shifted to 

neutral. 

(viii) For consecutive points with 

reference torque from zero to CITT that 

immediately precede idle points, change 

their reference torques to CITT. This is 

to provide smooth torque transition into 

idle operation. 

(4) Permissible deviations for any 

engine. If your engine does not operate 

below a certain minimum torque under 

normal in-use conditions, you may use 

a declared minimum torque as the 

reference value instead of any value 

denormalized to be less than the 

declared value. For example, if your 

engine is connected to a hydrostatic 

transmission and it has a minimum 

torque even when all the driven 

n�ref = 

Where: 


Nref = reference molar flow rate.
  ̇
 

Vstdref = reference volume flow rate, corrected
  ̇ 

to a standard pressure and a standard 

temperature. 

Vactref = reference volume flow rate at the  ̇ 

actual pressure and temperature of the 

flow rate. 

Nref = reference mass flow.  ̇
 

pstd = standard pressure. 


pact = actual pressure of the flow rate. 


Tstd = standard temperature. 


Tact = actual temperature of the flow rate. 


R = molar gas constant. 


Mmix = molar mass of the flow rate. 


Example 1: 


Vstdref = 1000.00 ft3/min = 0.471948 m3/s
  ̇
 

p = 29.9213 in Hg @ 32 °F = 101325 Pa 


T = 68.0 °F = 293.15 K 


R = 8.314472 J/(mol · K) 


0 471948 101325 . ⋅ nref 293 15 8 314472 . ⋅ .

N ̇ ref = 19.169 mol/s 

Example 2: 


Mref = 17.2683 kg/min = 287.805 g/s
  ̇ 

hydraulic actuators and motors are 

stationary and the engine is at idle, then 

you may use this declared minimum 

torque as a reference torque value 

instead of any reference torque value 

generated under paragraph (d)(1) or (2) 

of this section that is between zero and 

this declared minimum torque. 

(e) Generating reference power values 

from normalized duty cycle powers. 

Transform normalized power values to 

reference speed and power values using 

your map of maximum power versus 

speed. 

(1) First transform normalized speed 

values into reference speed values. For 

a given speed point, multiply the 

corresponding % power by the mapped 

power at maximum test speed, fntest, 

unless specified otherwise by the 

standard-setting part. The result is the 

reference power for each speed point, 

Pref. Convert these reference powers to 

corresponding torques for operator 

demand and dynamometer control and 

for duty cycle validation per 1065.514. 

Use the reference speed associated with 

each reference power point for this 

conversion. As with cycles specified 

with % torque, linearly interpolate 

between these reference torque values 

generated from cycles with % power. 

(2) Permissible deviations for any 

engine. If your engine does not operate 

below a certain power under normal inuse conditions, you may use a declared 

V ⋅ p V ⋅ p m� stdref std = actref act ref = Eq. 1065.640-1 T std ⋅ R T act ⋅ R Mmix 

Mmix = 28.7805 g/mol 

287 05 . nref 28 7805 . 

n ̇ ref = 10.0000 mol/s 

(e) CFV calibration. Some CFV flow 

meters consist of a single venturi and 

some consist of multiple venturis, 

where different combinations of 

venturis are used to meter different flow 

rates. For CFV flow meters that consist 

of multiple venturis, either calibrate 

each venturi independently to 

determine a separate discharge 

coefficient, Cd, for each venturi, or 

calibrate each combination of venturis 

as one venturi. In the case where you 

calibrate a combination of venturis, use 

the sum of the active venturi throat 

areas as At, the square root of the sum 

of the squares of the active venturi 

throat diameters as dt, and the ratio of 

the venturi throat to inlet diameters as 

the ratio of the square root of the sum 

minimum power as the reference value 

instead of any value denormalized to be 

less than the declared value. For 

example, if your engine is directly 

connected to a propeller, it may have a 

minimum power called idle power. In 

this case, you may use this declared 

minimum power as a reference power 

value instead of any reference power 

value generated per paragraph (e)(1) of 

this section that is from zero to this 

declared minimum power. 

■ 111. Section 1065.640 is amended by 

revising paragraphs (a) and (e) and 

redesignating the second ‘‘Table 3’’ as 

‘‘Table 4’’ to read as follows: 

§ 1065.640 Flow meter calibration 

calculations. 

* * * * * 

(a) Reference meter conversions. The 

calibration equations in this section use 

molar flow rate, n ̇ ref, as a reference 

quantity. If your reference meter outputs 

a flow rate in a different quantity, such  ̇ as standard volume rate, Vstdref, actual

volume rate, V ̇ actref, or mass rate, m ̇ ref, 

convert your reference meter output to 

a molar flow rate using the following 

equations, noting that while values for 

volume rate, mass rate, pressure, 

temperature, and molar mass may 

change during an emission test, you 

should ensure that they are as constant 

as practical for each individual set point 

during a flow meter calibration: 

of the active venturi throat diameters 

(dt) to the diameter of the common 

entrance to all of the venturis (D). To 

determine the Cd for a single venturi or 

a single combination of venturis, 

perform the following steps: 

(1) Use the data collected at each 

calibration set point to calculate an 

individual Cd for each point using Eq. 

1065.640–4. 

(2) Calculate the mean and standard 

deviation of all the Cd values according 

to Eqs. 1065.602–1 and 1065.602–2. 

(3) If the standard deviation of all the 

Cd values is less than or equal to 0.3% 

of the mean Cd, use the mean Cd in Eq. 

1065.642–6, and use the CFV only down 

to the lowest r measured during 

calibration using the following equation: 

∆p r = −1 Eq. 1065.640 -13 

pin 

(4) If the standard deviation of all the 

Cd values exceeds 0.3% of the mean Cd, 

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Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 37327 

omit the Cd values corresponding to the 

data point collected at the lowest r 

measured during calibration. 

(5) If the number of remaining data 

points is less than seven, take corrective 

action by checking your calibration data 

or repeating the calibration process. If 

you repeat the calibration process, we 

recommend checking for leaks, applying 

tighter tolerances to measurements and 

allowing more time for flows to 

stabilize. 

(6) If the number of remaining Cd 

values is seven or greater, recalculate 

d f Z Mmix ⋅ ⋅ R

Example: 	 R = 8.314472 J/(mol·K) 

A Tin = 298.15 K t = 0.01824 m2 

Re# = 7.232·10 pin = 99132 Pa 

y = 1.399 Z = 1 b = 0.8 Mmix = 28.7805 g/mol = 0.0287805 kg/mol Dp = 2.312 kPa 

n ̇ = 58.173 mol/s 

* * * * * 

■ 113. A new § 1065.644 is added to 

read as follows: 

§ 1065.644 Vacuum-decay leak rate. 

This section describes how to 

calculate the leak rate of a vacuumdecay leak verification, which is 

described in § 1065.345(e). Use Eq. 

1065.644–1 to calculate the leak rate, 

n ̇ leak, and compare it to the criterion 

specified in § 1065.345(e). 

■ 114. Section 1065.645 is revised to 

read as follows: 

� = t in nCC ⋅ ⋅ 

n� = 0 990 . ⋅ 0 274 . ⋅

the mean and standard deviation of the 

remaining Cd values. 

(7) If the standard deviation of the 

remaining Cd values is less than or equal 

to 0.3% of the mean of the remaining Cd, 

use that mean Cd in Eq. 1065.642–6, and 

use the CFV values only down to the 

lowest r associated with the remaining 

Cd. 

(8) If the standard deviation of the 

remaining Cd still exceeds 0.3% of the 

mean of the remaining Cd values, repeat 

the steps in paragraph (e)(4) through (8) 

of this section. 

A p⋅ Eq. 1065.642-3 ⋅Tin 

0 01824 99132 . ⋅

1 0 0287805 8 314472 298 15 ⋅ ⋅ ⋅ . . . 

■ 112. Section 1065.642 is amended by 

revising paragraph (b) to read as follows: 

§ 1065.642 SSV, CFV, and PDP molar flow 

rate calculations. 

* * * * * 

(b) SSV molar flow rate. Based on the 

Cd versus Re# equation you determined 

according to § 1065.640, calculate SSV 

molar flow rate, n ̇ during an emission 

test as follows: 

Using Eq. 1065.640–7, 


rssv = 0.997 


Using Eq. 1065.640–6, 


Cf = 0.274 


Using Eq. 1065.640–5, 


Cd = 0.990 


 p2 p1    − V T T vac  2 1  n�leak = ⋅ Eq. 1065.644-1 R (tt 2 1 − )

Where: 

Vvac = geometric volume of the vacuum-side 

of the sampling system. 

R = molar gas constant. 

p2 = Vacuum-side absolute pressure at time 

t2. 

T2 = Vacuum-side absolute temperature at 

time t2. 

p1 = Vacuum-side absolute pressure at time 

t1. 

 50600 25300   −  0 0002 .  293 15 . 293 15 .  n�leak = 8 314472 . ⋅

(10 57 3 : 5 : 10 56 25 − : : ) 

0 00200 . 86 304 . n� = ⋅ leak 8 314472 . 70

�n leak = 0 00030 m / s . mol 

§ 1065.645 Amount of water in an ideal 

gas. 

This section describes how to 

determine the amount of water in an 

ideal gas, which you need for various 

performance verifications and emission 

T1 = Vacuum-side absolute temperature at 

time t1. 

t2 = time at completion of vacuum-decay leak 

verification test. 

t1 = time at start of vacuum-decay leak 

verification test. 

Example: 

Vvac = 2.0000 L = 0.00200 m3 

R = 8.314472 J/(mol·K) 

p2 = 50.600 kPa = 50600 Pa 

T2 = 293.15 K 

p1 = 25.300 kPa = 25300 Pa 

T1 = 293.15 K 

t2 = 10:57:35 AM 

t1 = 10:56:25 AM 

calculations. Use the equation for the 

vapor pressure of water in paragraph (a) 

of this section or another appropriate 

equation and, depending on whether 

you measure dewpoint or relative 

humidity, perform one of the 

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37328 Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 

calculations in paragraph (b) or (c) of 

this section. 

(a) Vapor pressure of water. Calculate 

the vapor pressure of water for a given 

saturation temperature condition, Tsat, 

as follows, or use good engineering 

 T sat   2

sat 

. 

−4 



  273 16 . 



 −log10 ( pH O2 10 79574. ⋅ −1 + 5 02800 ⋅ log10   ) = . + 1 50475 10 . ⋅ ⋅ 10 −1

273 16 

 273 16 .   − 4 76955 1 . − 

+ . ⋅ −3 ⋅1−10 



 Tsat 



  0 42873 10 + 0 21386 Eq. 1065.645-1 .     

Where: Tsat = saturation temperature of water at Tsat = 9.5 °C 

pH20 = vapor pressure of water at saturation measured conditions, K. Tdsat= 9.5 + 273.15 = 282.65 K 

temperature condition, kPa. Example: 

 282 65 .   −8 2969 . ⋅ −1   273 16.   282. 65    −4 273 16  −log10 ( 2 ) = 10 79574. ⋅ −1 + 5 02800 ⋅ log10   + . ⋅ ⋅ 10 

 pHO . 1 50475 10 

  . −1 

 273 16 .   T 

 282 65.   273 16 . 

  −4 76955 1 − −3  + . ⋅ ⋅



1− . 0 42873 10 10 

 

¥log10(pH20) = ¥0.073974 

pH20 = 100.073974 = 1.18569 kPa 

 273 16 .  sat −log ( p ) = 9 09685 . ⋅ −1 . 3 56654 ⋅ 0 87682 . ⋅  + log  + 1 + 0 21386 Eq. 1065.645 .-2 10 sat  10   T T 273 16 .  sat   sat   

Example: 

Tice = ¥15.4 °C 

Tice = ¥15.4 + 273.15 = 257.75 K 

273 16 −log10 ( psat . ⋅ 

 . ) = 9 09685  257 75 .

 273.16  3 56654. ⋅ log10   +  257 75 . 

 257 75.  

 − 1 + 

0 87682 . ⋅ − 1 . 0 21386   +  273 16 . 

¥log10(pH2O) =¥0.79821 

pH2O = 100.79821 = 0.15914 kPa 

(b) Dewpoint. If you measure 

humidity as a dewpoint, determine the 

amount of water in an ideal gas, xH2O, 

as follows: 

judgment to use a different relationship 

of the vapor pressure of water to a given 

saturation temperature condition: 

(1) For humidity measurements made 

at ambient temperatures from 

(0 to 100) °C, or for humidity 

273 16 . 

  282 65 .  

 + 0 21386 . 

 

(2) For humidity measurements over 

ice at ambient temperatures from (¥100 

to 0) °C, use the following equation: 

 273 1. 6   T 

measurements made over super-cooled 

water at ambient temperatures from 

(¥50 to 0) °C, use the following 

equation: 

 Tsat   −8 2969 . ⋅ −1  

  

 − 

p 2 xHO = HO Eq. 1065.645-3 2 pabs 

Where: 

xH2O = amount of water in an ideal gas. 

pH2O = water vapor pressure at the measured 

dewpoint, Tsat = Tdew. 

pabs = wet static absolute pressure at the 

location of your dewpoint measurement. 

Example: 

pabs = 99.980 kPa 

Tsat = Tdew = 9.5 °C 

Using Eq. 1065.645–2, 

pH2O = 1.18489 kPa 

xH2O = 1.18489/99.980 

xH2O = 0.011851 mol/mol 

(c) Relative humidity. If you measure 

humidity as a relative humidity, RH %, 

determine the amount of water in an 

ideal gas, xH2O, as follows: 

RH % ⋅ pH O xHO = 2 Eq. 1065.645-4 2 pabs 

Where: 

xH2O = amount of water in an ideal gas. 

RH % = relative humidity. 

pH2O = water vapor pressure at 100% relative 

humidity at the location of your relative 

humidity measurement, Tsat = Tamb. 

pabs = wet static absolute pressure at the 

location of your relative humidity 

measurement. 

Example: 

RH % = 50.77% 

pabs = 99.980 kPa 

Tsat = Tamb = 20 °C 

Using Eq. 1065.645–2, 

pH2O = 2.3371 kPa 

xH2O = (50.77% ·2.3371)/99.980 

xH2O = 0.011868 mol/mol 

■ 115. Section 1065.650 is revised to 

read as follows: 

§ 1065.650 Emission calculations. 

(a) General. Calculate brake-specific 

emissions over each test interval in a 

duty cycle. Refer to the standard-setting 

part for any calculations you might need 

to determine a composite result, such as 

a calculation that weights and sums the 

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Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 37329 

results of individual test intervals in a 

duty cycle. For summations of 

continuous signals, each indexed value 

(i.e., ‘‘i’’) represents (or approximates) 

the mean value of the parameter for its 

respective time interval, delta-t. 

(b) We specify three alternative ways 

to calculate brake-specific emissions, as 

follows: 

(1) For any testing, you may calculate 

the total mass of emissions, as described 

in paragraph (c) of this section, and 

divide it by the total work generated 

over the test interval, as described in 

paragraph (d) of this section, using the 

following equation: 

m 

e = Eq. 1065.650-1 W 

Example: 

mNOx = 64.975 g 

W = 25.783 kW·hr 

eNOx = 64.975/25.783 

eNOx = 2.520 g/(kW·hr) 

(2) For discrete-mode steady-state 

testing, you may calculate the ratio of 

emission mass rate to power, as 

described in paragraph (e) of this 

section, using the following equation: 

m� e= Eq. 1065.650-2 P 

(3) For field testing, you may calculate 

the ratio of total mass to total work, 

where these individual values are 

determined as described in paragraph (f) 

of this section. You may also use this 

approach for laboratory testing, 

consistent with good engineering 

judgment. This is a special case in 

which you use a signal linearly 

proportional to raw exhaust molar flow 

rate to determine a value proportional to 

total emissions. You then use the same 

linearly proportional signal to 

determine total work using a chemical 

balance of fuel, intake air, and exhaust 

as described in § 1065.655, plus 

information about your engine’s brakespecific fuel consumption. Under this 

method, flow meters need not meet 

accuracy specifications, but they must 

meet the applicable linearity and 

repeatability specifications in subpart D 

or subpart J of this part. The result is a 

brake-specific emission value calculated 

as follows: 

m� e= Eq. 1065.650-3 W 

Example: 

m ̃ = 805.5 ~g 

W ̃ = 52.102 ~kW·hr 

eCO = 805.5/52.102 

eCO = 2.520 g/(kW·hr) 

(c) Total mass of emissions. To 

calculate the total mass of an emission, 

multiply a concentration by its 

respective flow. For all systems, make 

preliminary calculations as described in 

paragraph (c)(1) of this section, then use 

the method in paragraphs (c)(2) through 

(4) of this section that is appropriate for 

your system. Calculate the total mass of 

emissions as follows: 

(1) Concentration corrections. Perform 

the following sequence of preliminary 

calculations on recorded concentrations: 

(i) Correct all THC and CH4 

concentrations, including continuous 

readings, sample bags readings, and 

dilution air background readings, for 

initial contamination, as described in 

§ 1065.660(a). 

(ii) Correct all concentrations 

measured on a ‘‘dry’’ basis to a ‘‘wet’’ 

basis, including dilution air background 

concentrations, as described in 

§ 1065.659. 

(iii) Calculate all THC and NMHC 

concentrations, including dilution air 

background concentrations, as described 

in § 1065.660. 

(iv) For emission testing with an 

oxygenated fuel, calculate any HC 

concentrations, including dilution air 

background concentrations, as described 

in § 1065.665. See subpart I of this part 

for testing with oxygenated fuels. 

(v) Correct all the NOX 

concentrations, including dilution air 

background concentrations, for intakeair humidity as described in § 1065.670. 

(vi) Compare the background 

corrected mass of NMHC to background 

corrected mass of THC. If the 

background corrected mass of NMHC is 

greater than 0.98 times the background 

corrected mass of THC, take the 

background corrected mass of NMHC to 

be 0.98 times the background corrected 

mass of THC. If you omit the NMHC 

calculations as described in 

§ 1065.660(b)(1), take the background 

corrected mass of NMHC to be 0.98 

times the background corrected mass of 

THC. 

(vii) Calculate brake-specific 

emissions before and after correcting for 

drift, including dilution air background 

concentrations, according to § 1065.672. 

(2) Continuous sampling. For 

continuous sampling, you must 

frequently record a continuously 

updated concentration signal. You may 

measure this concentration from a 

changing flow rate or a constant flow 

rate (including discrete-mode steadystate testing), as follows: 

(i) Varying flow rate. If you 

continuously sample from a changing 

exhaust flow rate, time align and then 

multiply concentration measurements 

by the flow rate from which you 

extracted it. Use good engineering 

judgment to time align flow and 

concentration data to match t50 rise or 

fall times to within ±1 s. We consider 

the following to be examples of 

changing flows that require a 

continuous multiplication of 

concentration times molar flow rate: raw 

exhaust, exhaust diluted with a constant 

flow rate of dilution air, and CVS 

dilution with a CVS flowmeter that does 

not have an upstream heat exchanger or 

electronic flow control. This 

multiplication results in the flow rate of 

the emission itself. Integrate the 

emission flow rate over a test interval to 

determine the total emission. If the total 

emission is a molar quantity, convert 

this quantity to a mass by multiplying 

it by its molar mass, M. The result is the 

mass of the emission, m. Calculate m for 

continuous sampling with variable flow 

using the following equations: 

N 

mM ⋅∑ xi ⋅ ni = � ⋅ ∆t Eq. 1065.650-4 i=1 

Where: 

∆t = 1/f Eq. 1065.650-5 record 

Example: 

MNMHC = 13.875389 g/mol 

N = 1200 

xNMHC1 = 84.5 μmol/mol = 84.5 · 10¥6 mol/ 

mol 

xNMHC2 = 86.0 μmol/mol = 86.0 · 10¥6 mol/ 

mol 

n ̇ exh1 = 2.876 mol/s 

n ̇ exh2 = 2.224 mol/s 

frecord = 1 Hz 

Using Eq. 1065.650–5, 

Dt = 1/1 =1 s 

mNMHC = 13.875389 · (84.5 · 10¥6 · 2.876 + 

86.0 · 10¥6 · 2.224 + ... + xNMHC1200 · n ̇ exh) 

· 1 

mNMHC = 25.53 g 

(ii) Constant flow rate. If you 

continuously sample from a constant 

exhaust flow rate, use the same 

emission calculations described in 

paragraph (c)(2)(i) of this section or 

calculate the mean or flow-weighted 

concentration recorded over the test 

interval and treat the mean as a batch 

sample, as described in paragraph 

(c)(3)(ii) of this section. We consider the 

following to be examples of constant 

exhaust flows: CVS diluted exhaust 

with a CVS flowmeter that has either an 

upstream heat exchanger, electronic 

flow control, or both. 

(3) Batch sampling. For batch 

sampling, the concentration is a single 

value from a proportionally extracted 

batch sample (such as a bag, filter, 

impinger, or cartridge). In this case, 

multiply the mean concentration of the 

batch sample by the total flow from 

which the sample was extracted. You 

may calculate total flow by integrating 

a changing flow rate or by determining 

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37330 Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 

the mean of a constant flow rate, as 

follows: 

(i) Varying flow rate. If you collect a 

batch sample from a changing exhaust 

flow rate, extract a sample proportional 

to the changing exhaust flow rate. We 

consider the following to be examples of 

changing flows that require proportional 

sampling: Raw exhaust, exhaust diluted 

with a constant flow rate of dilution air, 

and CVS dilution with a CVS flowmeter 

that does not have an upstream heat 

exchanger or electronic flow control. 

Integrate the flow rate over a test 

interval to determine the total flow from 

which you extracted the proportional 

sample. Multiply the mean 

concentration of the batch sample by the 

total flow from which the sample was 

extracted. If the total emission is a molar 

quantity, convert this quantity to a mass 

by multiplying it by its molar mass, M. 

The result is the mass of the emission, 

m. In the case of PM emissions, where 

the mean PM concentration is already in 

units of mass per mole of sample, MPM,  ̄ 

simply multiply it by the total flow. The 

result is the total mass of PM, mPM. 

Calculate m for batch sampling with 

variable flow using the following 

equation: 

N 

m M= ⋅ ⋅ x ∑n t �i ⋅ ∆ Eq. 1065.650-6 i=1 

Example: 

MNOx = 46.0055 g/mol 

N = 9000 

x ̄ NOx = 85.6 μmol/mol = 85.6 · 10¥6 mol/mol 

n ̇ dexh1 = 25.534 mol/s 

n ̇ dexh2 = 26.950 mol/s 

frecord = 5 Hz 

Using Eq. 1065.650–5, 

Dt = 1/5 = 0.2 

mNOx = 46.0055 · 85.6 · 10¥6 · (25.534 + 

26.950 + ... + n ̇ exh9000) · 0.2 

mNOx = 4.201 g 

(ii) Constant flow rate. If you batch 

sample from a constant exhaust flow 

rate, extract a sample at a proportional 

or constant flow rate. We consider the 

following to be examples of constant 

exhaust flows: CVS diluted exhaust 

with a CVS flow meter that has either 

an upstream heat exchanger, electronic 

flow control, or both. Determine the 

mean molar flow rate from which you 

extracted the constant flow rate sample. 

Multiply the mean concentration of the 

batch sample by the mean molar flow 

rate of the exhaust from which the 

sample was extracted, and multiply the 

result by the time of the test interval. If 

the total emission is a molar quantity, 

convert this quantity to a mass by 

multiplying it by its molar mass, M. The 

result is the mass of the emission, m. In 

the case of PM emissions, where the 

mean PM concentration is already in 

units of mass per mole of sample, M ̄ PM, 

simply multiply it by the total flow, and 

the result is the total mass of PM, mPM. 

Calculate m for sampling with constant 

flow using the following equations: 

m M= ⋅⋅⋅ x n � ∆ t Eq. 1065.650-7 

and for PM or any other analysis of a 

batch sample that yields a mass per 

mole of sample, 

M = M ⋅ x Eq. 1065.650-8 

Example: 

M ̄ PM = 144.0 μg/mol = 144.0 · 10¥6 g/mol 

n ̄ dexh = 57.692 mol/s 

Dt = 1200 s 

mPM = 144.0 · 10¥6 · 57.692 · 1200 

mPM = 9.9692 g 

(4) Additional provisions for diluted 

exhaust sampling; continuous or batch. 

The following additional provisions 

apply for sampling emissions from 

diluted exhaust: 

(i) For sampling with a constant 

dilution ratio (DR) of diluted exhaust 

versus exhaust flow (e.g., secondary 

dilution for PM sampling), calculate m 

using the following equation: 

m m= ⋅ DR Eq. 1065.650-9 dil () 

Example: 

mPMdil = 6.853 g 

DR = 6:1 

mPM = 6.853 · (6) 

mPM = 41.118 g 

(ii) For continuous or batch sampling, 

you may measure background emissions 

in the dilution air. You may then 

subtract the measured background 

emissions, as described in § 1065.667. 

(d) Total work. To calculate total work 

from the engine’s primary output shaft, 

numerically integrate feedback power 

over a test interval. Before integrating, 

adjust the speed and torque data for the 

time alignment used in § 1065.514(c). 

Any advance or delay used on the 

feedback signals for cycle validation 

must also be used for calculating work. 

Account for work of accessories 

according to § 1065.110. Exclude any 

work during cranking and starting. 

Exclude work during actual motoring 

operation (negative feedback torques), 

unless the engine was connected to one 

or more energy storage devices. 

Examples of such energy storage devices 

include hybrid powertrain batteries and 

hydraulic accumulators, like the ones 

illustrated in Figure 1 of § 1065.210. 

Exclude any work during reference zeroload idle periods (0% speed or idle 

speed with 0 N·m reference torque). 

Note, that there must be two 

consecutive reference zero load idle 

points to establish a period where this 

applies. Include work during idle points 

with simulated minimum torque such as 

Curb Idle Transmissions Torque (CITT) 

for automatic transmissions in ‘‘drive’’. 

The work calculation method described 

in paragraphs (b)(1) though (7) of this 

section meets these requirements using 

rectangular integration. You may use 

other logic that gives equivalent results. 

For example, you may use a trapezoidal 

integration method as described in 

paragraph (b)(8) of this section. 

(1) Time align the recorded feedback 

speed and torque values by the amount 

used in § 1065.514(c). 

(2) Calculate shaft power at each point 

during the test interval by multiplying 

all the recorded feedback engine speeds 

by their respective feedback torques. 

(3) Adjust (reduce) the shaft power 

values for accessories according to 

§ 1065.110. 

(4) Set all power values during any 

cranking or starting period to zero. See 

§ 1065.525 for more information about 

engine cranking. 

(5) Set all negative power values to 

zero, unless the engine was connected 

to one or more energy storage devices. 

If the engine was tested with an energy 

storage device, leave negative power 

values unaltered. 

(6) Set all power values to zero during 

idle periods with a corresponding 

reference torque of 0 N·m. 

(7) Integrate the resulting values for 

power over the test interval. Calculate 

total work as follows: 

N 

W = ∑P t i ⋅ ∆ Eq. 1065.650-10 i=1 

P f T = ⋅ Eq. 1065.650-11 i ni i 

Example: 

N = 9000 

fn1 = 1800.2 rev/min 

fn2 = 1805.8 rev/min 

T1 = 177.23 N·m 

T2 = 175.00 N·m 

Crev = 2 · π rad/rev 

Ct1 = 60 s/min 

Cp = 1000 (N·m·rad/s)/kW 

frecord = 5 Hz 

Ct2 = 3600 s/hr 

1800 2 177 23 2 3 14159 . ⋅ . ⋅⋅ . P1 = 60 1000 ⋅ 

P1 = 33.41 kW 

P2 = 33.09 kW 

Using Eq. 1065.650–5, 

Dt = 1⁄5 = 0.2 s 

. + 33 09 ++ ... P9000 (33 41 . ) ⋅ 0 2 . W = 3600 

W = 16.875 kW·hr 

(8) You may use a trapezoidal 

integration method instead of the 
⋅⋅ 


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Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 37331 

rectangular integration described in this multiply it by the mean molar flow rate, m ̄ = 28.0101·0.01200·1.530 

n. The result is the mass rate of PM, 

m ̇ PM. Calculate m

Ô

Ô paragraph (b). To do this, you must 

integrate the fraction of work between m ̄ = 0.514 g/s = 1850.4 g/hr using the following P ̄ = 121.5·375.37 points where the torque is positive. You equation: 

may assume that speed and torque are P ̄ = 45607 

linear between data points. You may not m = ⋅ ⋅ M x n� Eq. 1065.650-12 W = 45.607 kW

set negative values to zero before 

running the integration. 

(e) Steady-state mass rate divided by 

power. To determine steady-state brakespecific emissions for a test interval as 

described in paragraph (b)(2) of this 

section, calculate the mean steady-state 

(2) Calculate P ̄ using the following 

equation: 

P f T = ⋅ Eq. 1065.650-13 n 

(3) Divide emission mass rate by 

power to calculate a brake-specific 

eCO = 1850.4/45.61 

eCO = 40.57 g/(kW·hr) 

(f) Ratio of total mass of emissions to 

total work. To determine brake-specific 

emissions for a test interval as described 

in paragraph (b)(3) of this section, 

calculate a value proportional to the mass rate of the emission, m


mean steady-state power, P ̄ as follows: paragraph (b)(2) of this section. 


Ô, and the emission result as described in total mass of each emission. Divide each 

proportional value by a value that is

(1) To calculate m (4) The following example shows how

concentration, x ̄ , by its corresponding 

Ô, multiply its mean similarly proportional to total work. to calculate mass of emissions using (1) Total mass. To determine a value 

mean molar flow rate, n mean mass rate and mean power: . If the result is 

a molar flow rate, convert this quantity MCO = 28.0101 g/mol emission, determine total mass as 

to a mass rate by multiplying it by its described in paragraph (c) of this x ̄ CO = 12.00 mmol/mol = 0.01200 mol/ molar mass, M. The result is the mean section, except substitute for the molar mol mass rate of the emission, m Ô Ô

Ô proportional to the total mass of an 

. In the case flow rate, n ̇ , or the total flow, n, with a n = 1.530 mol/s

 ̄

fn = 3584.5 rev/min = 375.37 rad/s 

of PM emissions, where the mean PM signal that is linearly proportional to Õ molar flow rate, n, or linearly 

T ̄ = 121.50 N·m proportional to total flow, n ̃ as follows: 

concentration is already in units of mass

per mole of sample, M ̄ PM, simply 

1 M nx C i Ccombdryi m = ⋅ Eq . . 1065 650­ 14 fueli w 1+ x fuel H2Oexhdryi 

(2) Total work. To calculate a value fuel, intake air, and exhaust as the value proportional to total work to 

proportional to total work over a test described in § 1065.655. In the chemical determine brake-specific emissions, as 

interval, integrate a value that is balance, you must use concentrations described in paragraph (b)(3) of this 

proportional to power. Use information from the flow that generated the signal section. 

, in Õ proportional to molar flow rate, n

consumption of your engine, efuel, to paragraph (e)(1) of this section. 

about the brake-specific fuel (4) Example. The following example 

shows how to calculate mass of convert a signal proportional to fuel Calculate a value proportional to total 

flow rate to a signal proportional to work as follows: emissions using proportional values: 

N = 3000 power. To determine a signal frecord = 5 Hz proportional to fuel flow rate, divide a N 

signal that is proportional to the mass ∑ � W = P t i ∆ Eq. 1065.650-15 efuel = 285 g/(kW.

hr) ⋅ wfuel = 0.869 g/g i=1 rate of carbon products by the fraction Mc = 12.0107 g/mol of carbon in your fuel, w Where: c.. For your fuel, n ̇ 1 = 3.922 ∼mol/s = 14119.2 mol/hr you may use a measured wc or you may xCcombdry1 = 91.634 mmol/mol = 0.091634

use the default values in Table 1 of 

§ 1065.655. Calculate the mass rate of 

m mol/mol fueli P =
 Eq. 1065.650-16 i xH2Oexh1 = 27.21 mmol/mol = 0.02721 mol/ efuel carbon from the amount of carbon and mol 

water in the exhaust, which you (3) Brake-specific emissions. Divide Using Eq. 1065.650–5, 

determine with a chemical balance of the value proportional to total mass by Dt = 0.2 s 

3 922 0 091634 . ⋅ . nx ⋅ n ⋅ x  2 Ccombdry2 3000 Ccombdry3000 12 0107 .  + ++ ...  ⋅ 0 2.

�  + 0 02721 1+ x 2 1+ xH Oexh 2  1 . H Oexh 23000  W = 285 0⋅ .869 

W ̃ = 5.09 ∼(kW·hr) ■ 116. Section 1065.655 is revised to their flows, and the wet concentration of 

read as follows: constituents in their flows. With one (g) Rounding. Round emission values flow rate of either fuel, intake air, or only after all calculations are complete § 1065.655 Chemical balances of fuel, exhaust, you may use chemical balances and the result is in g/(kW·hr) or units intake air, and exhaust. to determine the flows of the other two. equivalent to the units of the standard, (a) General. Chemical balances of fuel, For example, you may use chemical such as g/(hp·hr). See the definition of intake air, and exhaust may be used to balances along with either intake air or ‘‘Round’’ in § 1065.1001. calculate flows, the amount of water in fuel flow to determine raw exhaust flow. 

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37332 Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 

(b) Procedures that require chemical 

balances. We require chemical balances 

when you determine the following: 

(1) A value proportional to total work, 

W ̃ , when you choose to determine 

brake-specific emissions as described in 

§ 1065.650(e). 

(2) The amount of water in a raw or 

diluted exhaust flow, xH2Oexh, when you 

do not measure the amount of water to 

correct for the amount of water removed 

by a sampling system. Correct for 

removed water according to 

§ 1065.659(c)(2). 

(3) The flow-weighted mean fraction 

of dilution air in diluted exhaust, xdil/exh, 

when you do not measure dilution air 

flow to correct for background 

emissions as described in § 1065.667(c). 

Note that if you use chemical balances 

for this purpose, you are assuming that 

your exhaust is stoichiometric, even if it 

is not. 

(c) Chemical balance procedure. The 

calculations for a chemical balance 

involve a system of equations that 

require iteration. We recommend using 

a computer to solve this system of 

equations. You must guess the initial 

values of up to three quantities: The 

amount of water in the measured flow, 

xH2Oexh, fraction of dilution air in 

diluted exhaust, xdil/exh, and the amount 

of products on a C1 basis per dry mole 

of dry measured flow, xCcombdry. You 

may use time-weighted mean values of 

combustion air humidity and dilution 

air humidity in the chemical balance; as 

long as your combustion air and 

dilution air humidities remain within 

tolerances of ± 0.0025 mol/mol of their 

respective mean values over the test 

interval. For each emission 

concentration, x, and amount of water, 

xH2Oexh, you must determine their 

completely dry concentrations, xdry and 

xH2Oexhdry. You must also use your fuel’s 

atomic hydrogen-to-carbon ratio, a, and 

oxygen-to-carbon ratio, b. For your fuel, 

you may measure a and b or you may 

use the default values in Table 1 of 

§ 1065.650. Use the following steps to 

complete a chemical balance: 

(1) Convert your measured 

concentrations such as, xCO2meas, 

xNOmeas, and xH2Oint, to dry 

concentrations by dividing them by one 

x = x + x Ccombdry CO2dry COdry THCdry CO2dil dil exhdry CO / 2int int/ exhdry

a
 

x = ( x − x ) + x ⋅ x + x ⋅ x H2Oexhdry Ccombdry THCdry H2Odil / dil exhdry H2Oint int/exhdry 2 

minus the amount of water present 

during their respective measurements; 

for example: xH2OxCO2meas, xH2OxNOmeas, 

and xH2Oint. If the amount of water 

present during a ‘‘wet’’ measurement is 

the same as the unknown amount of 

water in the exhaust flow, xH2Oexh, 

iteratively solve for that value in the 

system of equations. If you measure 

only total NOX and not NO and NO2 

separately, use good engineering 

judgment to estimate a split in your total 

NOX concentration between NO and 

NO2 for the chemical balances. For 

example, if you measure emissions from 

a stoichiometric spark-ignition engine, 

you may assume all NOX is NO. For a 

compression-ignition engine, you may 

assume that your molar concentration of 

NOX, xNOx, is 75% NO and 25% NO2. 

For NO2 storage aftertreatment systems, 

you may assume xNOx is 25% NO and 

75% NO2. Note that for calculating the 

mass of NOX emissions, you must use 

the molar mass of NO2 for the effective 

molar mass of all NOX species, 

regardless of the actual NO2 fraction of 

NOX. 

(2) Enter the equations in paragraph 

(c)(4) of this section into a computer 

program to iteratively solve for xH2Oexh, 

xCcombdry, and xdil/exh. Use good 

engineering judgment to guess initial 

values for xH2Oexh, xCcombdry, and xdil/exh. 

We recommend guessing an initial 

amount of water that is about twice the 

amount of water in your intake or 

dilution air. We recommend guessing an 

initial value of xCcombdry as the sum of 

your measured CO2, CO, and THC 

values. We also recommend guessing an 

initial xdil/exh between 0.75 and 0.95, 

such as 0.8. Iterate values in the system 

of equations until the most recently 

updated guesses are all within ± 1% of 

their respective most recently calculated 

values. 

(3) Use the following symbols and 

subscripts in the equations for this 

paragraph (c): 

xdil/exh = Amount of dilution gas or excess air 

per mole of exhaust. 

xH2Oexh = Amount of water in exhaust per 

mole of exhaust. 

xCcombdry = Amount of carbon from fuel in the 

exhaust per mole of dry exhaust. 

+ x − x ⋅ x − x ⋅ x 

xH2Oexhdry = Amount of water in exhaust per 

dry mole of dry exhaust. 

xprod/intdry = Amount of dry stoichiometric 

products per dry mole of intake air. 

xdil/exhdry = Amount of dilution gas and/or 

excess air per mole of dry exhaust. 

xint/exhdry = Amount of intake air required to 

produce actual combustion products per 

mole of dry (raw or diluted) exhaust. 

xraw/exhdry = Amount of undiluted exhaust, 

without excess air, per mole of dry (raw 

or diluted) exhaust. 

xO2int = Amount of intake air O2 per mole of 

intake air. 

xCO2intdry = Amount of intake air CO2 per 

mole of dry intake air. You may use 

xCO2intdry = 375 μmol/mol, but we 

recommend measuring the actual 

concentration in the intake air. 

xH2Ointdry = Amount of intake air H2O per 

mole of dry intake air. 

xCO2int = Amount of intake air CO2 per mole 

of intake air. 

xCO2dil = Amount of dilution gas CO2 per 

mole of dilution gas. 

xCO2dildry = Amount of dilution gas CO2 per 

mole of dry dilution gas. If you use air 

as diluent, you may use xCO2dildry = 375 

μmol/mol, but we recommend measuring 

the actual concentration in the intake air. 

xH2Odildry = Amount of dilution gas H2O per 

mole of dry dilution gas. 

xH2Odil = Amount of dilution gas H2O per 

mole of dilution gas. 

x[emission]meas = Amount of measured emission 

in the sample at the respective gas 

analyzer. 

x[emission]dry = Amount of emission per dry 

mole of dry sample. 

xH2O[emission]meas = Amount of water in sample 

at emission-detection location. Measure 

or estimate these values according to 

§ 1065.145(d)(2). 

xH2Oint = Amount of water in the intake air, 

based on a humidity measurement of 

intake air. 

a = Atomic hydrogen-to-carbon ratio in fuel. 

b = Atomic oxygen-to-carbon ratio in fuel. 

(4) Use the following equations to 

iteratively solve for xdil/exh, xH2Oexh, and 

xCcombdry: 

x raw/exhdry x / = −1 Eq. 1065.655-1 dil exh 1+ xH2Oexhdry 

xH2Oexhdry x 2 = Eq. 1065.655-2 H Oexh 1+ xH2Oexhdry 

Eq. 1065.655-3 

Eq. 1065.655-4 

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Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 37333 

xdil exh x / = / Eq. 1065.655-5 dil exhdry 1− x H Oexh 2

1  a   x = 

 − + 2 ⋅( x − x − x int/exhdry  b  Ccombdry THCdry ) ( COdry − xNOdry − 2xNO2dry ) Eq. 1065.655-6 2 ⋅ x 2 O2int   

1 a   x raw exhdry / =  + b ⋅( xCcombdry − xTHCdry ) + (2xTHCdry + xCOdry − xNO2dry ) + xint/exhdry Eq. 1065.655-7 2  2  


0 209820 . − x
CO2intdry x = Eq. 1065.655-8 O2int 1+ x H O2 intdry 

xCO2intdry x = Eq. 1065.655-9 CO2int 1+ x H O2 intdry 

xH Oint x 2 = 2 Eq. 1065.655-10 H Ointdry 1− x H O2 int 

xCO2dildry x = Eq. 1065.655-11 CO2dil 1+ x H O2 dildry 

xH Odil x 2 = 2 Eq. 1065.655-12 H Odildry 1− x H Odil 2

xCOmeas x = Eq. 1065.655-13 COdry 1− xH2OCOmeas 

xCO2meas x = Eq. 1065.655-14 CO2dry 1− xH 2OCO2meas 

xNOmeas x = Eq. 1065.655-15 NOdry 1− xH 2ONOmeas 

xNO2meas x = Eq. 1065.655-16 NO2dry 1− xH 2ONO2meas 

xTHCmeas x = Eq. 1065.655-17 THCdry 1− xH 2OTHCmeas 

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37334 Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 

(5) The following example is a 0 182. 35 18 . solution for xdil/exh, xH2Oexh, and xCcombdry xdil/exh =− = 0 824mol/mol x 1 . 2 = = 33 98 . mmol/mol H Oexh 35 18. 35 18 . using the equations in paragraph (c)(4) 1+ 1+ 

1000 1000 of this section: 

29 3 47 6 0 371. . . 0.369 

x = 0 025 . + + − ⋅ 0 853 . − ⋅ 0 171 . . = 0 0247mol/mol Ccombdry 1000000 1000000 1000 1000 

1 8.  47 6.  x = 0 0247. − + 0 012 . 0 853 . ⋅ . + 0 017 . ⋅ 0 171 . = 0 035mol/mol H O2 exhdry   2  1000000 

0 824 . x = = 0 853 . mol/mol dil/exhdry 1− 0 034 .

1 8.   47 6.    − 0 050 . + 2   ⋅ 0 0247 . − −  1  2   1000000  x   0 171mol/mol int/exhdry = = . ⋅ .  29 3 . 12 1  2 0 206  . 50 4 .   − − ⋅ 2    1000000 1000000 1000000   

18 .   47 6.      + 0 050 . . ⋅ 0 0247 − +  1  2   1000000  x =   + 0 1. 71 .= 0 182mol/mol raw/exhdry 2  4 . 29 3 .  47 6 . 12 1   2 ⋅ + −    1000000 1000000 1000000   

0 209820 . . − 0 000375

x = = 0 206 . mol/mol O2int 17 22 . 1+ 

1000 

0 000375 . ×1000

x = = 0 371 . mmol/mol CO2int 17 22 . 1+ 

1000 

16 93. 29 0 . 12 0. x = =17 22 . mmol/mol x = = 29 3 . mmol/mol x = =12 1. mmol/mol H O2 intdry COdry NO2dry 16 93. 8 601 . 8 601 . 1− 1− 1− 1000 1000 1000 

0 375 . 24 98 . 46

x = = 0 37 . mmol/mol x = = 25 2 . mmol/mol x = = 47 6. mmol/mol CO2dil CO2dry THCdry 12 01. 8 601 . 33 98 . 1+ 1− 1− 1000 1000 1000 

a = 1.8 

b = 0.05 

11 87. 50 0. 

x = =12 01 . mmol/mol x = = 50 4. mmol/mol H O2 dildry NOdry 11 87. 8 601 . 1− 1− 1000 1000 

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Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 37335 

TABLE 1 OF § 1065.655.—DEFAULT VALUES OF ATOMIC HYDROGEN-TO-CARBON RATIO, a, ATOMIC OXYGEN-TO-CARBON
 

RATIO, b, AND CARBON MASS FRACTION OF FUEL, wC, FOR VARIOUS FUELS
 

Atomic Carbon mass hydrogen and concentration, Fuel oxygen-to-carbon wC ratios g/g CHaOb 

Gasoline .....................................................................................................................................................
 CH1.85O0 0.866

#2 Diesel ....................................................................................................................................................
 CH1.80O0 0.869

#1 Diesel ....................................................................................................................................................
 CH1.93O0 0.861

Liquified Petroleum Gas ............................................................................................................................
 CH2.64O0 0.819

Natural gas .................................................................................................................................................
 CH3.78O0.016 0.747

Ethanol .......................................................................................................................................................
 CH3O0.5 0.521

Methanol ....................................................................................................................................................
 CH4O1 0.375 

(d) Calculated raw exhaust molar flow 

rate from measured intake air molar 

flow rate or fuel mass flow rate. You 

may calculate the raw exhaust molar 

flow rate from which you sampled 

emissions, n ̇ exh, based on the measured 

intake air molar flow rate, n ̇ int, or the 

measured fuel mass flow rate, n ̇ fuel, and 

the values calculated using the chemical 

balance in paragraph (c) of this section. 

Note that the chemical balance must be 

based on raw exhaust gas 

n�exh = 

Where: 

n ̇ exh = raw exhaust molar flow rate from 

which you measured emissions. 

n ̇ int = intake air molar flow rate including 

humidity in intake air. 

Example: 

n ̇ int = 3.780 mol/s 

xint/exhdry = 0.69021 mol/mol 

n�exh 

Where: 

n ̇ exh = raw exhaust molar flow rate from 

which you measured emissions. 

m ̇ fuel = fuel flow rate including humidity in 

intake air. 

Example: 

m ̇ fuel = 7.559 g/s 

wC = 0.869 g/g 

MC = 12.0107 g/mol 

xCcombdry = 99.87 mmol/mol = 0.09987 mol/ 

mol 

xH20exhdry = 107.64 mmol/mol = 0.10764 mol/ 

mol 

concentrations. Solve for the chemical 

balance in paragraph (c) of this section 

at the same frequency that you update 

and record n ̇ intor n ̇ fuel. 

(1) Crankcase flow rate. If engines are 

not subject to crankcase controls under 

the standard-setting part, you may 

calculate raw exhaust flow based on 

n ̇ intor n ̇ fuel using one of the following: 

(i) You may measure flow rate 

through the crankcase vent and subtract 

it from the calculated exhaust flow. 

n�

(ii) You may estimate flow rate 

through the crankcase vent by 

engineering analysis as long as the 

uncertainty in your calculation does not 

adversely affect your ability to show 

that your engines comply with 

applicable emission standards. 

(iii) You may assume your crankcase 

vent flow rate is zero. 

(2) Intake air molar flow rate 

calculation. Based on n ̇ int, calculate n ̇ exh 

as follows: 

int Eq. 1065.655-18  ( x − x )  int/exhdry raw/exhdry 1+    (1+ xH2Oexhdry )   

xraw/exhdry = 1.10764 mol/mol 3 780 . xH20exhdry = 107.64 mmol/mol = 0.10764 mol/ n� = 

mol 

exh 

1+ ( . 0 69021− 1 10764) .    (1+ 0 10764) .  

n ̇ exh = 6.066 mol/s 

(3) Fuel mass flow rate calculation. 

Based on mfuel, calculate n ̇ exh as follows: 

m w � ⋅ ⋅ 1 x fuel c ( + H2Oexhdry ) = Eq. 1065.655-19 M x⋅ c Ccombdry 

7 559 0 869 ( . ⋅ . ⋅ 1 . ) + 0 10764

n�exh = 12 0107 0 09987 . ⋅ .

n ̇ exh = 6.066 mol/s 

■ 117. Section 1065.659 is revised to 

read as follows: 

§ 1065.659 Removed water correction. 

(a) If you remove water upstream of a 

concentration measurement, x, or 

upstream of a flow measurement, n, 

correct for the removed water. Perform 

this correction based on the amount of 

water at the concentration 

measurement, xH2O[emission]meas, and at 

the flow meter, xH2Oexh, whose flow is 

used to determine the concentration’s 

total mass over a test interval. 

(b) When using continuous analyzers 

downstream of a sample dryer for 

transient and ramped-modal testing, you 

must correct for removed water using 

signals from other continuous analyzers. 

When using batch analyzers 

downstream of a sample dryer, you 

must correct for removed water by using 

signals either from other batch analyzers 

or from the flow-weighted average 

concentrations from continuous 

analyzers. Downstream of where you 

removed water, you may determine the 

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37336 Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 

amount of water remaining by any of the correction in paragraph (d) of this (1) Use any of the techniques 

following: section results in a corrected value that described in paragraph (b) of this 

is greater than the measured value, your section. (1) Measure the dewpoint and saturation assumption is invalid and absolute pressure downstream of the (2) If the measurement comes from

water removal location and calculate the you must determine the water content raw exhaust, you may determine the according to paragraph (b)(1) of this amount of water remaining as described amount of water based on intake-air 

section. in § 1065.645. humidity, plus a chemical balance of (3) You may also use a nominal value fuel, intake air and exhaust as described (2) When saturated water vapor of absolute pressure based on an alarm in § 1065.655. conditions exist at a given location, you set point, a pressure regulator set point, may use the measured temperature at (3) If the measurement comes from or good engineering judgment. that location as the dewpoint for the (4) Set xH2O[emission]meas equal to that of diluted exhaust, you may determine the 

downstream flow. If we ask, you must the measured upstream humidity amount of water based on intake-air 

demonstrate how you know that humidity, dilution air humidity, and a condition if it is lower than the dryer saturated water vapor conditions exist. chemical balance of fuel, intake air, and saturation conditions. 

Use good engineering judgment to exhaust as described in § 1065.655. (c) For a corresponding concentration 

measure the temperature at the or flow measurement where you did not (d) Perform a removed water 

appropriate location to accurately reflect remove water, you may determine the correction to the concentration 

the dewpoint of the flow. Note that if amount of initial water by any of the measurement using the following 

you use this option and the water following: equation: 

  1− xH Oexh x x = ⋅  2  Eq. 1065.659-1 [ ] emission meas  1− xH2O emission meas ]   [  

Example: § 1065.660 THC and NMHC determination.  1− 0 03404 .  xCOmeas = 29.0 μmol/mol xCO = 29 0 . ⋅   (a) THC determination and THC/CH4 1− 0 008601 . xH2OCOmeas = 8.601 mmol/mol = 0.008601   initial contamination corrections. (1) If 


mol/mol xCO = 28.3 μmol/mol we require you to determine THC 


xH2Oexh = 34.04 mmol/mol = 0.03404 mol/mol emissions, calculate xTHC[THC–FID] using 
 ■ 118. Section 1065.660 is revised to the initial THC contamination 

read as follows: concentration xTHC[THC–FID]init from 

§ 1065.520 as follows: 

x = x − x Eq. 1065.660-1 0 THC THC [ ] -FID cor THC THC [ ] -FID uncor THC THC [ -FID ]init 

Example: contamination of the CH4 sample train penetration fractions (PF) of CH4 and 

xTHCuncor = 150.3 μmol/mol using Eq. 1065.660–1, substituting in C2H6 from § 1065.365, and using the HC 

xTHCinit = 1.1 μmol/mol CH4 concentrations for THC. contamination and wet-to-dry corrected 

xTHCcor = 150.3 ¥ 1.1 (b) NMHC determination. Use one of THC concentration xTHC[THC–FID]cor as xTHCcor = 149.2 μmol/mol the following to determine NMHC determined in paragraph (a) of this concentration, xNMHC: section. (2) For the NMHC determination (1) If you do not measure CH4, you 

described in paragraph (b) of this may determine NMHC concentrations as (i) Use the following equation for

section, correct xTHC[THC–FID] for initial described in § 1065.650(c)(1)(vi). penetration fractions determined using 

HC contamination using Eq. 1065.660– (2) For nonmethane cutters, calculate an NMC configuration as outlined in 

1. You may correct for initial xNMHC using the nonmethane cutter’s § 1065.365(d): 

x − x ⋅ RF THC THC [ -FID ]cor THC NMC [ -FID ] CH 4[THC -FID ] xNMHC = Eq. 1065.660-2 

1− RFPF ⋅ RF C2 6 H NMC [ ] -FID CH 4[THC -FID ] 

Where: RFCH4[THC–FID] = response factor of THC FID 150 3 . − 20 5 . ⋅ 1 05 . to CH4, according to § 1065.360(d). = xNMHC = concentration of NMHC. xNMHC 

RFPFC2H6[NMC . –FID] = nonmethane cutter 1− 0 019 . ⋅ 1 05 xTHC[THC–FID]cor = concentration of THC, HC combined ethane response factor and contamination and dry-to-wet corrected, xNMHC = 130.4 μmol/mol penetration fraction, according to as measured by the THC FID during § 1065.365(d).
 sampling while bypassing the NMC. (ii) For penetration fractions
 Example: xTHC[NMC–FID] = concentration of THC, HC determined using an NMC configuration xTHC[THC–FID]cor = 150.3 μmol/mol contamination (optional) and dry-to-wet as outlined in § 1065.365(e), use the xTHC[NMC–FID] = 20.5 μmol/mol corrected, as measured by the THC FID following equation: RFPFC2H6[NMC–FID] = 0.019 

during sampling through the NMC. RFCH4[THC–FID] = 1.05 

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Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 37337 

x ⋅ PF − x THC THC [ -FID]cor CH4 NMC [ -FID] THC NMC [ -FID] xNMHC =	 Eq. 1065.660-3 PF − PF CH4 NM [ C-FID] C H2 6[NMC-FID ]

Where: 	 corrected, as measured by the THC FID 150 3 . 20 5 . ⋅ 0 990 − . xNMHC = concentration of NMHC. during sampling through the NMC. xNMHC = 0 990. − 0 020 . xTHC[THC–FID]cor = concentration of THC, HC PFC2H6[NMC–FID] = nonmethane cutter ethane 

contamination and dry-to-wet corrected, penetration fraction, according to xNMHC = 132.3 μmol/mol as measured by the THC FID during § 1065.365(e).


sampling while bypassing the NMC. 
 Example: 	 (iii) For penetration fractions PFCH4[NMC–FID] = nonmethane cutter CH4 

xTHC[THC–FID]cor = 150.3 μmol/mol 	 determined using an NMC configuration penetration fraction, according to as outlined in § 1065.365(f), use the § 1065.365(e). PFCH4[NMC–FID] = 0.990 

xTHC[NMC–FID] = concentration of THC, HC xTHC[NMC–FID] = 20.5 μmol/mol following equation: 

contamination (optional) and dry-to-wet PFC2H6[NMC–FID] = 0.020 

x ⋅ PF − x ⋅ RF THC THC [ -FID]cor CH 4 NMC [ -FID] THC [	NMC-FID]	 CH4 TH [C -FID] xNMHC =	 Eq. 1065.660-4 

PF − RFPF ⋅ RF CH4 NMC-FID [ ] C H NMC 2 6[ -FID] CH4[THC-FID]

Where: 	 RFPFC2H6[NMC-FID] = nonmethane cutter CH4 150 3. ⋅ 0 990 . 20 5 − . . ⋅ 0 980 xNMHC = concentration of NMHC. combined ethane response factor and xNMHC = 0 990 . 0 980 . − 0 019 ⋅ . xTHC[THC-FID]cor = concentration of THC, HC penetration fraction, according to 

contamination and dry-to-wet corrected, § 1065.365(f). xNMHC = 132.5 μmol/mol 

as measured by the THC FID during RFCH4[THC-FID] = response factor of THC FID (3) For a gas chromatograph, calculate sampling while bypassing the NMC. 	 to CH4, according to § 1065.360(d). xNMHC using the THC analyzer’s PFCH4[NMC-FID] = nonmethane cutter CH4 Example: penetration fraction, according to response factor (RF) for CH4, from

§ 1065.365(f). xTHC[THC-FID]cor = 150.3 μmol/mol § 1065.360, and the HC contamination 

xTHC[NMC-FID] = concentration of THC, HC PFCH4[NMC-FID] = 0.990 and wet-to-dry corrected initial THC xTHC[NMC-FID] = 20.5 μmol/mol contamination (optional) and dry-to-wet concentration xTHC[THC-FID]cor as 
 RFPFC2H6[NMC-FID] = 0.019
 corrected, as measured by the THC FID determined in section (a) above as RFCH4[THC-FID] = 0.980 during sampling through the NMC. 	 follows: 

x = x − RF ⋅ x Eq. 1065.660-5 NMHC THC THC [ ] -FID cor CH4 [ ] THC-FID CH4

Where: 	 RFCH4[THC-FID] = 0.970 sample was taken (raw or diluted xCH4 = 18.9 μmol/mol xNMHC = concentration of NMHC. 	 exhaust), and convert this into a C1- xNMHC = 145.6¥0.970 · 18.9 xTHC[THC-FID]cor = concentration of THC, HC 	 equivalent molar concentration. Add xNMHC = 127.3 μmol/mol contamination and dry-to-wet corrected, these C1-equivalent molar as measured by the THC FID. ■ 119. Section 1065.665 is revised to concentrations to the molar xCH4 = concentration of CH4, HC read as follows: 	 concentration of NOTHC. The result is contamination (optional) and dry-to-wet the molar concentration of THCE. corrected, as measured by the gas § 1065.665 THCE and NMHCE Calculate THCE concentration using the chromatograph FID. determination. 

RFCH4[THC-FID] = response factor of THC-FID following equations, noting that (a) If you measured an oxygenated to CH4. 	 hydrocarbon equation 1065.665–3 is only required if ’s mass concentration, first 

Example: calculate its molar concentration in the you need to convert your OHC 

xTHC[THC-FID][cor = 145.6 μmol/mol exhaust sample stream from which the concentration from mass to moles: 

N 

xTHCE = xNOTHC + ∑( xOHCi − xOHCi-init ) Eq. 1065.665-1 i=1 

x = x [ − ∑ 

N ( x ⋅ RF ) Eq. 1065.665-2 NOTHC THC THC-FID]cor OHCi OHCi[THC-FID] i=1 

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37338 Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 

mdexhOHCi 

M n OHCi dexhOHCi x = = Eq. 1065.665-3 OHCi 

Where: 

xTHCE = The C1-equivalent sum of the 

concentration of carbon mass 

contributions of non-oxygenated 

hydrocarbons, alcohols, and aldehydes. 

xNOTHC = The C1-equivalent sum of the 

concentration of nonoxygenated THC. 

xOHCi = The C1-equivalent concentration of 

oxygenated species i in diluted exhaust, 

not corrected for initial contamination. 

xOHCi-init = The C1-equivalent concentration of 

the initial system contamination 

x 

m dexh ndexh 

Mdexh 

(optional) of oxygenated species i, dryto-wet corrected. 

xTHC[THC-FID]cor = The C1-equivalent response 

to NOTHC and all OHC in diluted 

exhaust, HC contamination and dry-towet corrected, as measured by the THCFID. 

RFOHCi[THC-FID] = The response factor of the 

FID to species i relative to propane on a 

C1-equivalent basis. 

C# = The mean number of carbon atoms in 

the particular compound. 

= x − RF ⋅ x Eq. 1065.665-4 

Where: 

xNMHCE = The C1-equivalent sum of the 

concentration of carbon mass 

contributions of non-oxygenated NMHC, 

alcohols, and aldehydes. 

RFCH4[THC–FID] = response factor of THC–FID 

to CH4. 

xCH4 = concentration of CH4, HC 

contamination (optional) and dry-to-wet 

corrected, as measured by the gas 

chromatograph FID. 

(c) The following example shows how 

to determine NMHCE emissions based 

on ethanol (C2H5OH), methanol 

(CH3OH), acetaldehyde (C2H4O), and 

formaldehyde (HCHO) as C1-equivalent 

molar concentrations: 

xTHC[THC–FID]cor = 145.6 μmol/mol 

xCH4 = 18.9 μmol/mol 

xC2H5OH = 100.8 μmol/mol 

xCH3OH = 1.1 μmol/mol 

xC2H4O = 19.1 μmol/mol 

xHCHO = 1.3 μmol/mol 

RFCH4[THC–FID] = 1.07 

RFC2H5OH[THC–FID] = 0.76 

RFCH3OH[THC–FID] = 0.74 

RFH2H4O[THC–FID] = 0.50 

RFHCHO[THC–FID] = 0.0 

xNMHCE = xTHC[THC–FID]cor¥(xC2H5OH · 

RFC2H5OH[THC–FID] + xCH3OH · 

RFCH3OH[THC–FID] + xC2H4O · 

RFC2H4O[THC–FID] + xHCHO · 

RFHCHO[THC–FID] + xC2H5OH + xCH3OH 

+ xC2H4O + xHCHO¥(RFCH4[THC-FID] · 

xCH4) 

xNMHCE = 145.6¥(100.8 · 0.76 + 1.1 · 

0.74 + 19.1 · 0.50 + 1.3 · 0) + 100.8 

+ 1.1 + 19.1 + 1.3¥(1.07 · 18.9) 

xNMHCE = 160.71 μmol/mol 

■ 120. Section 1065.667 is amended by 

revising paragraph (b) to read as follows: 

§ 1065.667 Dilution air background 

emission correction. 

* * * * * 

(b) You may determine the total flow 

of dilution air by a direct flow 

measurement. In this case, calculate the 

total mass of background as described in 

§ 1065.650(b), using the dilution air 

flow, ndil. Subtract the background mass 

from the total mass. Use the result in 

brake-specific emission calculations. 

* * * * * 

■ 121. Section 1065.670 is amended by 

revising the introductory text to read as 

follows: 

§ 1065.670 NOX intake-air humidity and 

temperature corrections. 

See the standard-setting part to 

determine if you may correct NOX 

emissions for the effects of intake-air 

humidity or temperature. Use the NOX 

intake-air humidity and temperature 

corrections specified in the standardsetting part instead of the NOX intakeair humidity correction specified in this 

part 1065. If the standard-setting part 

does not prohibit correcting NOX 

emissions for intake-air humidity 

according to this part 1065, first apply 

any NOX corrections for background 

emissions and water removal from the 

Mdexh = The molar mass of diluted exhaust as 

determined in § 1065.340. 

mdexhOHCi = The mass of oxygenated species 

i in dilute exhaust. 

MOHCi = The C1-equivalent molecular weight 

of oxygenated species i. 

mdexh = The mass of diluted exhaust. 

ndexhOHCi = The number of moles of 

oxygenated species i in total diluted 

exhaust flow. 

ndexh = The total diluted exhaust flow. 

(b) If we require you to determine 

NMHCE, use the following equation: 

NMHCE THCE CH4[THC-FID] CH4 

exhaust sample, then correct NOX 

concentrations for intake-air humidity. 

You may use a time-weighted mean 

combustion air humidity to calculate 

this correction if your combustion air 

humidity remains within a tolerance of 

± 0.0025 mol/mol of the mean value 

over the test interval. For intake-air 

humidity correction, use one of the 

following approaches: 

* * * * * 

■ 122. Section 1065.675 is revised to 

read as follows: 

§ 1065.675 CLD quench verification 

calculations. 

Perform CLD quench-check 

calculations as follows: 

(a) Calculate the amount of water in 

the span gas, xH2Ospan, assuming 

complete saturation at the span-gas 

temperature. 

(b) Estimate the expected amount of 

water and CO2 in the exhaust you 

sample, xH2Oexp and xCO2exp, 

respectively, by considering the 

maximum expected amounts of water in 

combustion air, fuel combustion 

products, and dilution air 

concentrations (if applicable). 

(c) Set xH2Oexp equal to xH2Omeas if you 

are using a sample dryer that passes the 

sample dryer verification check in 

§ 1065.342. 

(d) Calculate water quench as follows: 

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Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 37339 


 xNOwet 
  

 








 

 








x −
x − H2Omeas 1
 x x x H O2 exp +
 CO
 

CO2
 

NO CO , 2 NO N , 2 2 −
1
 ⋅
 ⋅
 exp quench =
 Eq. 1065.675-1

x x x x NOdry H Omea 2 s NO N, 2 meas 

Where: 

quench = amount of CLD quench. 

xNOdry = measured concentration of NO 

upstream of a bubbler, according to 

§ 1065.370. 

xNOwet = measured concentration of NO 

downstream of a bubbler, according to 

§ 1065.370. 

xH2Oexp = expected maximum amount of 

water entering the CLD sample port 

during emission testing. 

xH2Omeas = measured amount of water 

entering the CLD sample port during the 

quench verification specified in 

§ 1065.370. 

xNO,CO2 = measured concentration of NO 

when NO span gas is blended with CO2 

span gas, according to § 1065.370. 

xNO,N2 = measured concentration of NO when 

NO span gas is blended with N2 span 

gas, according to § 1065.370. 

xCO2exp = expected maximum amount of CO2 

entering the CLD sample port during 

emission testing. 

xCO2meas = measured amount of CO2 entering 

the CLD sample port during the quench 

verification specified in § 1065.370. 

Example: 

xNOdry = 1800.0 μmol/mol 

xNOwet = 1760.5 μmol/mol 

xH2Oexp = 0.030 mol/mol 

xH2Omeas = 0.017 mol/mol 

xNO,CO2 = 1480.2 μmol/mol 

xNO,N2 = 1500.8 μmol/mol 

xCO2exp = 2.00% 

xCO2meas = 3.00% 


 1760 5. 
  

 








 

 








1
−
0 017 . 0 030 . 1480 2. −
1500 8.
 2 00 . quench = −
1
 ⋅
 +
 ⋅
 1800 0.
 0 017. 1500 8. 3 00 . 

quench = ¥0.00888¥0.00915 = ¥1.80% 	 § 1065.690 Buoyancy correction for PM (e) Correction calculation. Correct the 

sample media. PM sample media for buoyancy using 

■ 123. Section 1065.690 is amended by * * * * * the following equations: revising paragraph (e) to read as follows: 


 r
 
 air 1
−
  

 

 






 

 

 






r
 weight m =
 m ⋅
 Eq. 1065.690-1 cor uncor r
air 1
 −
 r
media 

Where: Mmix = 28.83563 g/mol (ix) Warm-idle speed value. mcor = PM mass corrected for buoyancy. R = 8.314472 J/(mol · K) * * * * * muncor = PM mass uncorrected for buoyancy. Tamb = 20 °C 

rair = density of air in balance environment. Subpart H—[Amended] rweight = density of calibration weight used to 99 980 . ⋅
28 83563 . span balance. rair =
 ■ 125. Section 1065.701 is amended by r 8 314472 . ⋅
293 15 . media = density of PM sample media, such as revising paragraphs (b), (c), and (e) to 

read as follows: a filter. rair = 1.18282 kg/m3 

⋅ 

⋅ 

muncorr = 100.0000 mg 

p M rweight = 8000 kg/m3 § 1065.701 General requirements for test abs mix 

RT Eq.1065.690-2 rmedia = 920 kg/m3	 r =
 fuels. air 

amb * * * * * 
 1 18282 . 
 (b) Fuels meeting alternate 

specifications. We may allow you to use 

a different test fuel (such as California 

Where: 1
−
 




 






 

pabs = absolute pressure in balance 8000
 m =
100 0000 . ⋅
 environment. 1 18282 . cor 

1
 −
 Phase 2 gasoline) if it does not affect 

your ability to show that your engines 

Mmix = molar mass of air in balance 

environment. 
 920
 


R = molar gas constant. 


Tamb = absolute ambient temperature of 


balance environment. 

Example: 

pabs = 99.980 kPa 

Tsat = Tdew = 9.5 °C 

Using Eq. 1065.645–2, 

pH20 = 1.1866 kPa 

Using Eq. 1065.645–3, 

xH2O = 0.011868 mol/mol 

Using Eq. 1065.640–9, 

mcor 100.1139 mg 

■ 124. Section 1065.695 is amended by 

revising paragraph (c)(7)(ix) to read as 

follows: 

§ 1065.695 Data requirements. 

* * * * * 

(c) * * * 

(7) * * * 

would comply with all applicable 

emission standards using the fuel 

specified in this subpart. 

(c) Fuels not specified in this subpart. 

If you produce engines that run on a 

type of fuel (or mixture of fuels) that we 

do not specify in this subpart, you must 

get our written approval to establish the 

appropriate test fuel. See the standardsetting part for provisions related to 
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37340 Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 

fuels and fuel mixtures not specified in 

this subpart. 

(1) For engines designed to operate on 

a single fuel, we will generally allow 

you to use the fuel if you show us all 

the following things are true: 

(i) Show that your engines will use 

only the designated fuel in service. 

(ii) Show that this type of fuel is 

commercially available. 

(iii) Show that operating the engines 

on the fuel we specify would be 

inappropriate, as in the following 

examples: 

(A) The engine will not run on the 

specified fuel. 

(B) The engine or emission controls 

will not be durable or work properly 

when operating with the specified fuel. 

(C) The measured emission results 

would otherwise be substantially 

unrepresentative of in-use emissions. 

(2) For engines that are designed to 

operate on different fuel types, the 

provisions of paragraphs (c)(1)(ii) and 

(iii) of this section apply with respect to 

each fuel type. 

(3) For engines that are designed to 

operate on different fuel types as well as 

continuous mixtures of those fuels, we 

may require you to test with either the 

worst-case fuel mixture or the most 

representative fuel mixture, unless the 

standard-setting part specifies 

otherwise. 

* * * * * 

(e) Service accumulation and field 

testing fuels. If we do not specify a 

service-accumulation or field-testing 

fuel in the standard-setting part, use an 

appropriate commercially available fuel 

such as those meeting minimum 

specifications from the following table: 

TABLE 1 OF § 1065.701.—EXAMPLES OF SERVICE-ACCUMULATION AND FIELD-TESTING FUELS 

Fuel category Subcategory Reference procedure 1 

Diesel .................................................................................. 

Intermediate and residual fuel ............................................ 

Gasoline .............................................................................. 

Alcohol ................................................................................ 

Aviation fuel ........................................................................ 

Gas turbine fuel .................................................................. 

Light distillate and light blends with residual ..................... 

Middle distillate .................................................................. 

Biodiesel (B100) ................................................................. 

All ....................................................................................... 

Motor vehicle gasoline ....................................................... 

Minor oxygenated gasoline blends .................................... 

Ethanol (Ed75–85) ............................................................. 

Methanol (M70–M85) ......................................................... 

Aviation gasoline ................................................................ 

Gas turbine ........................................................................ 

Jet B wide cut .................................................................... 

General .............................................................................. 

ASTM D975–07b. 

ASTM D6751–07b. 

ASTM D6985–04a. 

See § 1065.705. 

ASTM D4814–07a. 

ASTM D4814–07a. 

ASTM D5798–07. 

ASTM D5797–07. 

ASTM D910–07. 

ASTM D1655–07e01. 

ASTM D6615–06. 

ASTM D2880–03. 

1 ASTM specifications are incorporated by reference in § 1065.1010. 

■ 126. Section 1065.703 is amended by § 1065.703 Distillate diesel fuel. 

revising Table 1 to read as follows: * * * * * 

TABLE 1 OF § 1065.703.—TEST FUEL SPECIFICATIONS FOR DISTILLATE DIESEL FUEL 

Item Units Ultra low 

sulfur Low sulfur High sulfur Reference procedure 1 

Cetane Number ........................................................... 

Distillation range .......................................................... 

.................. 

°C ............ 

40–50 40–50 40–50 ASTM D613–05. 

Initial boiling point ................................................ .................. 171–204 171–204 171–204 ASTM D86–07a. 

10 pct. point ......................................................... .................. 204–238 204–238 204–238 

50 pct. point ......................................................... .................. 243–282 243–282 243–282 

90 pct. point ......................................................... .................. 293–332 293–332 293–332 

Endpoint ............................................................... .................. 321–366 321–366 321–366 

Gravity ......................................................................... ° API ........ 32–37 32–37 32–37 ASTM D4052–96e01. 

Total sulfur .................................................................. mg/kg ....... 7–15 300–500 2000–4000 ASTM D2622–07. 

Aromatics, min. (Remainder shall be paraffins, 

naphthalenes, and olefins). 

g/kg .......... 100 100 100 ASTM D5186–03. 

Flashpoint, min. ........................................................... °C ............ 54 54 54 ASTM D93–07. 

Kinematic Viscosity ..................................................... cSt ........... 2.0–3.2 2.0–3.2 2.0–3.2 ASTM D445–06. 

1 ASTM procedures are incorporated by reference in § 1065.1010. See § 1065.701(d) for other allowed procedures. 

■ 127. A new § 1065.705 is added to 	 definition of residual fuel in 40 CFR the fuel that will be used by the engine 

read as follows: 	 80.2, including fuels marketed as in actual use. 

intermediate fuel. Residual fuels for (b) The fuel must meet the § 1065.705 Residual and intermediate service accumulation and any testing residual fuel. 	 specifications for one of the categories must meet the following specifications: in the following table: This section describes the (a) The fuel must be a commercially 

specifications for fuels meeting the available fuel that is representative of 
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Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 37341 

TABLE 1 OF § 1065.705.—SERVICE ACCUMULATION AND TEST FUEL SPECIFICATIONS FOR RESIDUAL FUEL 

Characteristic Unit 

Category ISO–F– 

Test method reference 1 

RMA RMB RMD RME RMF RMG RMH RMK RMH RMK 

30 30 80 180 180 380 380 380 700 700 

Density at 15 °C, kg/m 3 ......... 960.0 975.0 980.0 991.0 991.0 1010.0 991.0 1010.0 ISO 3675 or ISO 12185: 

max. 1996/Cor 1:2001 (see also 

ISO 8217:2005(E) 7.1). 

Kinematic viscosity 

at 50 °C, max. 

cSt .............. 30.0 80.0 180.0 380.0 700.0 ISO 3104:1994/Cor 1:1997. 

Flash point, min ..... °C ............... 60 60 60 60 60 ISO 2719 (see also ISO 

8217:2005(E) 7.2). 

Pour point (upper): 

Winter quality, 

max. 

°C ............... 0 24 30 30 30 30 ISO 3016. 

Summer quality, max. .................... 6 24 30 30 30 30 ISO 3016. 

Carbon residue, 

max. 

(kg/kg)% ..... 10 14 15 20 18 22 22 ISO 10370:1993/Cor 1:1996. 

Ash, max. ............... (kg/kg)% ..... 0.10 0.10 0.10 0.15 0.15 0.15 ISO 6245. 

Water, max ............ (m3/m3)% .... 0.5 0.5 0.5 0.5 0.5 ISO 3733. 

Sulfur, max ............ (kg/kg)% ..... 3.50 4.00 4.50 4.50 4.50 ISO 8754 or ISO 14596: 

1998/Cor 1:1999 (see also 

ISO 8217:2005(E) 7.3). 

Vanadium, max ...... mg/kg ......... 150 350 200 500 300 600 600 ISO 14597 or IP 501 or IP 

470 (see also ISO 

8217:2005(E) 7.8). 

Total sediment potential, max. (kg/kg)% ..... 0.10 0.10 0.10 0.10 0.10 ISO 10307–2 (see also ISO 

8217:2005(E) 7.6). 

Aluminium plus silicon, max. mg/kg ......... 80 80 80 80 80 ISO 10478 or IP 501 or IP 

470 (see also ISO 

8217:2005(E) 7.9). 

Used lubricating oil 

(ULO), max. 

Zinc ........................ 

Phosphorus ............ 

Calcium .................. 

.................... 

mg/kg ......... 

.................... 

.................... 

.................... 

Fuel shall be free of ULO. We consider a fuel to be free of ULO if one or more of the elements 

zinc, phosphorus, or calcium is at or below the specified limits. We consider a fuel to contain 

ULO if all three elements exceed the specified limits. 

15 

15 

15 

30 

IP 501 or IP 470 (see ISO 

8217:2005(E) 7.7). 

IP 501 or IP 500 (see ISO 

8217:2005(E) 7.7). 

IP 501 or IP 470 (see ISO 

8217:2005(E) 7.7). 

1 ISO procedures are incorporated by reference in § 1065.1010. See § 1065.701(d) for other allowed procedures. 

■ 128. Section 1065.710 is amended by § 1065.710 Gasoline. 

revising Table 1 to read as follows: * * * * * 

TABLE 1 OF § 1065.710.—TEST FUEL SPECIFICATIONS FOR GASOLINE 

Item Units General testing Low-temperature testing Reference 

procedure 1 

Distillation Range: 

Initial boiling point ................... 

10% point ................................ 

50% point ................................ 

90% point ................................ 

End point ................................. 

Hydrocarbon composition: 

Olefins ..................................... 

Aromatics ................................ 

Saturates ................................. 

Lead (organic) ................................ 

Phosphorous .................................. 

Total sulfur ...................................... 

°C ............ 

°C ............ 

°C ............ 

°C ............ 

°C ............ 

m3/m3 ...... 

.................. 

.................. 

g/liter ........ 

g/liter ........ 

mg/kg ....... 

24–35 2 ........................................... 

49–57 .............................................. 

93–110 ............................................ 

149–163 .......................................... 

Maximum, 213 ................................ 

Maximum, 0.10 ............................... 

Maximum, 0.35 ............................... 

Remainder ...................................... 

Maximum, 0.013 ............................. 

Maximum, 0.0013 ........................... 

Maximum, 80 .................................. 

24–36. 

37–48 .............................................. 

82–101. 

158–174. 

Maximum, 212. 

Maximum, 0.175 ............................. 

Maximum, 0.304. 

Remainder. 

Maximum, 0.013 ............................. 

Maximum, 0.005 ............................. 

Maximum, 80 .................................. 

ASTM D86–07a. 

ASTM D1319–03. 

ASTM 

D3237–06e01. 

ASTM D3231–07. 

ASTM D2622–07. 
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37342 Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 

TABLE 1 OF § 1065.710.—TEST FUEL SPECIFICATIONS FOR GASOLINE 

Item Units General testing Low-temperature testing Reference 

procedure 1 

Volatility (Reid Vapor Pressure) ..... kPa .......... 60.0–63.4 2, 3 ................................... 77.2–81.4 ........................................ ASTM D5191–07. 

1 ASTM procedures are incorporated by reference in § 1065.1010. See § 1065.701(d) for other allowed procedures. 2 For testing at altitudes above 1,219 m, the specified volatility range is (52.0 to 55.2) kPa and the specified initial boiling point range is (23.9 to 

40.6) °C. 3 For testing unrelated to evaporative emissions, the specified range is (55.2 to 63.4) kPa. 

■ 129. Section 1065.715 is revised to § 1065.715 Natural gas. must meet the specifications in the 

read as follows: (a) Except as specified in paragraph following table: 

(b) of this section, natural gas for testing 

TABLE 1 OF § 1065.715.—TEST FUEL SPECIFICATIONS FOR NATURAL GAS 

Item 

Methane, CH4 ...........................................................................................
 

Ethane, C2H6 ............................................................................................
 

Propane, C3H8 ..........................................................................................
 

Butane, C4H10 ...........................................................................................
 

Pentane, C5H12 .........................................................................................
 

C6 and higher ...........................................................................................
 

Oxygen .....................................................................................................
 

Inert gases (sum of CO2 and N2) .............................................................
 

Value 1 

Minimum, 0.87 mol/mol. 

Maximum, 0.055 mol/mol. 

Maximum, 0.012 mol/mol. 

Maximum, 0.0035 mol/mol. 

Maximum, 0.0013 mol/mol. 

Maximum, 0.001 mol/mol. 

Maximum, 0.001 mol/mol. 

Maximum, 0.051 mol/mol. 

1 All parameters are based on the reference procedures in ASTM D1945–03 (incorporated by reference in § 1065.1010). See § 1065.701(d) for 

other allowed procedures. 

(b) In certain cases you may use test specifications in paragraph (a) of this down to a concentration in air not more 

fuel not meeting the specifications in section, but only if using the fuel would than one-fifth the lower flammable 

paragraph (a) of this section, as follows: not adversely affect your ability to limit. 

(1) You may use fuel that your in-use demonstrate compliance with the ■ 130. Section 1065.720 is revised to 

engines normally use, such as pipeline applicable standards. read as follows: 

natural gas. (c) When we conduct testing using 

(2) You may use fuel meeting natural gas, we will use fuel that meets § 1065.720 Liquefied petroleum gas. 

alternate specifications if the standard- the specifications in paragraph (a) of (a) Except as specified in paragraph 

setting part allows it. this section. (b) of this section, liquefied petroleum 

(3) You may ask for approval to use (d) At ambient conditions, natural gas gas for testing must meet the 

fuel that does not meet the must have a distinctive odor detectable specifications in the following table: 

TABLE 1 OF § 1065.720.—TEST FUEL SPECIFICATIONS FOR LIQUEFIED PETROLEUM GAS 

Item Value Reference procedure 1 

Propane, C3H8 ......................................................................................... 

Vapor pressure at 38 °C ......................................................................... 

Volatility residue (evaporated temperature, 35 °C) ................................. 

Butanes ................................................................................................... 

Butenes ................................................................................................... 

Pentenes and heavier ............................................................................. 

Propene ................................................................................................... 

Residual matter (residue on evap. of 100 ml oil stain observ.) .............. 

Corrosion, copper strip ............................................................................ 

Sulfur ....................................................................................................... 

Moisture content ...................................................................................... 

Minimum, 0.85 m3/m3 .................... 

Maximum, 1400 kPa ...................... 

Maximum, ¥38 °C ........................ 

Maximum, 0.05 m3/m3 ................... 

Maximum, 0.02 m3/m3 ................... 

Maximum, 0.005 m3/m3 ................. 

Maximum, 0.1 m3/m3 ..................... 

Maximum, 0.05 ml pass3 ............... 

Maximum, No. 1 ............................ 

Maximum, 80 mg/kg ...................... 

pass ............................................... 

ASTM D2163–05. 

ASTM D1267–02 or 2598–022. 

ASTM D1837–02a. 

ASTM D2163–05. 

ASTM D2163–05. 

ASTM D2163–05. 

ASTM D2163–05. 

ASTM D2158–05. 

ASTM D1838–07. 

ASTM D2784–06. 

ASTM D2713–91. 

1 ASTM procedures are incorporated by reference in § 1065.1010. See § 1065.701(d) for other allowed procedures. 2 If these two test methods yield different results, use the results from ASTM D1267–02. 3 The test fuel must not yield a persistent oil ring when you add 0.3 ml of solvent residue mixture to a filter paper in 0.1 ml increments and examine it in daylight after two minutes. 

(b) In certain cases you may use test (2) You may use fuel meeting not adversely affect your ability to 

fuel not meeting the specifications in alternate specifications if the standard- demonstrate compliance with the 

paragraph (a) of this section, as follows: setting part allows it. applicable standards. 

(1) You may use fuel that your in-use (3) You may ask for approval to use (c) When we conduct testing using 

engines normally use, such as fuel that does not meet the liquefied petroleum gas, we will use 

commercial-quality liquefied petroleum specifications in paragraph (a) of this fuel that meets the specifications in 

gas. section, but only if using the fuel would paragraph (a) of this section. 
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Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 37343 

(d) At ambient conditions, liquefied (a) Subparts C, D, F, and J of this part concentration expected at the standard. 

petroleum gas must have a distinctive refer to the following gas specifications: For example, if you would expect a 

odor detectable down to a concentration (1) Use purified gases to zero flow-weighted CO concentration of 

in air not more than one-fifth the lower measurement instruments and to blend 100.0 μmol/mol, then you would be

flammable limit. with calibration gases. Use gases with allowed to use a zero gas with CO contamination no higher than the contamination less than or equal to ■ 131. Section 1065.750 is amended by highest of the following values in the 2.000 μmol/mol. revising paragraph (a) to read as follows: gas cylinder or at the outlet of a zero- (ii) Contamination as specified in the gas generator: § 1065.750 Analytical Gases. following table: 

* * * * * relative to the flow-weighted mean 

(i) 2% contamination, measured 

TABLE 1 OF § 1065.750.—GENERAL SPECIFICATIONS FOR PURIFIED GASES 

Constituent Purified synthetic air 1 Purified N2 1 

THC (C1 equivalent) ...................................................................................................... 

CO .................................................................................................................................. 

CO2 ................................................................................................................................ 

O2 ................................................................................................................................... 

NOX ................................................................................................................................ 

< 0.05 μmol/mol ................. 

< 1 μmol/mol ...................... 

< 10 μmol/mol .................... 

0.205 to 0.215 mol/mol ...... 

< 0.02 μmol/mol ................. 

< 0.05 μmol/mol. 

< 1 μmol/mol. 

< 10 μmol/mol. 

< 2 μmol/mol. 

< 0.02 μmol/mol. 

1 We do not require these levels of purity to be NIST-traceable. 

(2) Use the following gases with a FID 

analyzer: 

(i) FID fuel. Use FID fuel with a stated 

H2 concentration of (0.39 to 0.41) mol/ 

mol, balance He, and a stated total 

hydrocarbon concentration of 0.05 

μmol/mol or less. 

(ii) FID burner air. Use FID burner air 

that meets the specifications of purified 

air in paragraph (a)(1) of this section. 

For field testing, you may use ambient 

air. 

(iii) FID zero gas. Zero flameionization detectors with purified gas 

that meets the specifications in 

paragraph (a)(1) of this section, except 

that the purified gas O2 concentration 

may be any value. Note that FID zero 

balance gases may be any combination 

of purified air and purified nitrogen. We 

recommend FID analyzer zero gases that 

contain approximately the expected 

flow-weighted mean concentration of O2 

in the exhaust sample during testing. 

(iv) FID propane span gas. Span and 

calibrate THC FID with span 

concentrations of propane, C3H8. 

Calibrate on a carbon number basis of 

one (C1). For example, if you use a C3H8 

span gas of concentration 200 μmol/mol, 

span a FID to respond with a value of 

600 μmol/mol. Note that FID span 

balance gases may be any combination 

of purified air and purified nitrogen. We 

recommend FID analyzer span gases 

that contain approximately the flowweighted mean concentration of O2 

expected during testing. If the expected 

O2 concentration in the exhaust sample 

is zero, we recommend using a balance 

gas of purified nitrogen. 

(v) FID methane span gas. If you 

always span and calibrate a CH4 FID 

with a nonmethane cutter, then span 

and calibrate the FID with span 

concentrations of methane, CH4. 

Calibrate on a carbon number basis of 

one (C1). For example, if you use a CH4 

span gas of concentration 200 μmol/mol, 

span a FID to respond with a value of 

200 μmol/mol. Note that FID span 

balance gases may be any combination 

of purified air and purified nitrogen. We 

recommend FID analyzer span gases 

that contain approximately the expected 

flow-weighted mean concentration of O2 

in the exhaust sample during testing. If 

the expected O2 concentration in the 

exhaust sample is zero, we recommend 

using a balance gas of purified nitrogen. 

(3) Use the following gas mixtures, 

with gases traceable within ± 1.0% of 

the NIST-accepted value or other gas 

standards we approve: 

(i) CH4, balance purified synthetic air 

and/or N2 (as applicable). 

(ii) C2H6, balance purified synthetic 

air and/or N2 (as applicable). 

(iii) C3H8, balance purified synthetic 

air and/or N2 (as applicable). 

(iv) CO, balance purified N2. 

(v) CO2, balance purified N2. 

(vi) NO, balance purified N2. 

(vii) NO2, balance purified synthetic 

air. 

(viii) O2, balance purified N2. 

(ix) C3H8, CO, CO2, NO, balance 

purified N2. 

(x) C3H8, CH4, CO, CO2, NO, balance 

purified N2. 

(4) You may use gases for species 

other than those listed in paragraph 

(a)(3) of this section (such as methanol 

in air, which you may use to determine 

response factors), as long as they are 

traceable to within ± 3.0% of the NISTaccepted value or other similar 

standards we approve, and meet the 

stability requirements of paragraph (b) 

of this section. 

(5) You may generate your own 

calibration gases using a precision 

blending device, such as a gas divider, 

to dilute gases with purified N2 or 

purified synthetic air. If your gas 

dividers meet the specifications in 

§ 1065.248, and the gases being blended 

meet the requirements of paragraphs 

(a)(1) and (3) of this section, the 

resulting blends are considered to meet 

the requirements of this paragraph (a). 

* * * * * 

Subpart I—[Amended] 

■ 132. Section 1065.805 is amended by 

revising paragraphs (a), (b), and (c) to 

read as follows: 

§ 1065.805 Sampling system. 

(a) Dilute engine exhaust, and use 

batch sampling to collect proportional 

flow-weighted dilute samples of the 

applicable alcohols and carbonyls. You 

may not use raw sampling for alcohols 

and carbonyls. 

(b) You may collect background 

samples for correcting dilution air for 

background concentrations of alcohols 

and carbonyls. 

(c) Maintain sample temperatures 

within the dilution tunnel, probes, and 

sample lines high enough to prevent 

aqueous condensation up to the point 

where a sample is collected to prevent 

loss of the alcohols and carbonyls by 

dissolution in condensed water. Use 

good engineering judgment to ensure 

that surface reactions of alcohols and 

carbonyls do not occur, as surface 

decomposition of methanol has been 

shown to occur at temperatures greater 

than 120 °C in exhaust from methanolfueled engines. 

* * * * * 

■ 133. Section 1065.845 is amended by 

revising the introductory text to read as 

follows: 
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37344 Federal Register / Vol. 73, No. 126 / Monday, June 30, 2008 / Rules and Regulations 

§ 1065.845 Response factor determination. 

Since FID analyzers generally have an 

incomplete response to alcohols and 

carbonyls, determine each FID 

analyzer’s alcohol/carbonyl response 

factor (such as RFMeOH) after FID 

optimization to subtract those responses 

from the FID reading. You are not 

required to determine the response 

factor for a compound unless you will 

subtract its response to compensate for 

a response. Formaldehyde response is 

assumed to be zero and does not need 

to be determined. Use the most recent 

alcohol/carbonyl response factors to 

compensate for alcohol/carbonyl 

response. 

* * * * * 

Subpart J—[Amended] 

■ 134. Section 1065.901 is amended by 

revising paragraphs (b) introductory text 

and (b)(2) to read as follows: 

§ 1065.901 Applicability. 

* * * * * 

(b) Laboratory testing. You may use 

PEMS for any testing in a laboratory or 

similar environment without restriction 

or prior approval if the PEMS meets all 

applicable specifications for laboratory 

testing. You may also use PEMS for any 

testing in a laboratory or similar 

environment if we approve it in 

advance, subject to the following 

provisions: * * * 

(2) Do not apply any PEMS-related 

field-testing adjustments or 

measurement allowances to laboratory 

emission results or standards. 

* * * * * 

■ 135. Section 1065.905 is amended by 

revising paragraphs (c)(14) and (e) 

introductory text to read as follows: 

§ 1065.905 General provisions. 

* * * * * 

(c) * * * 

(14) Does any special measurement 

allowance apply to field-test emission 

results or standards, based on using 

PEMS for field-testing versus using 

laboratory equipment and instruments 

for laboratory testing? 

* * * * * 

(e) Laboratory testing using PEMS. 

You may use PEMS for testing in a 

laboratory as described in § 1065.901(b). 

Use the following procedures and 

specifications when using PEMS for 

laboratory testing: 

* * * * * 

■ 136. Section 1065.910 is revised to 

read as follows: 

§ 1065.910 PEMS auxiliary equipment for 

field testing. 

For field testing you may use various 

types of auxiliary equipment to attach 

PEMS to a vehicle or engine and to 

power PEMS. 

(a) When you use PEMS, you may 

route engine intake air or exhaust 

through a flow meter. Route the engine 

intake air or exhaust as follows: 

(1) Flexible connections. Use short 

flexible connectors where necessary. 

(i) You may use flexible connectors to 

enlarge or reduce the pipe diameters to 

match that of your test equipment. 

(ii) We recommend that you use 

flexible connectors that do not exceed a 

length of three times their largest inside 

diameter. 

(iii) We recommend that you use fourply silicone-fiberglass fabric with a 

temperature rating of at least 315 °C for 

flexible connectors. You may use 

connectors with a spring-steel wire 

helix for support and you may use 

NomexTM coverings or linings for 

durability. You may also use any other 

nonreactive material with equivalent 

permeation-resistance and durability, as 

long as it seals tightly. 

(iv) Use stainless-steel hose clamps to 

seal flexible connectors, or use clamps 

that seal equivalently. 

(v) You may use additional flexible 

connectors to connect to flow meters. 

(2) Tubing. Use rigid 300 series 

stainless steel tubing to connect 

between flexible connectors. Tubing 

may be straight or bent to accommodate 

vehicle geometry. You may use ‘‘T’’ or 

‘‘Y’’ fittings made of 300 series stainless 

steel tubing to join multiple 

connections, or you may cap or plug 

redundant flow paths if the engine 

manufacturer recommends it. 

(3) Flow restriction. Use flowmeters, 

connectors, and tubing that do not 

increase flow restriction so much that it 

exceeds the manufacturer’s maximum 

specified value. You may verify this at 

the maximum exhaust flow rate by 

measuring pressure at the manufacturerspecified location with your system 

connected. You may also perform an 

engineering analysis to verify an 

acceptable configuration, taking into 

account the maximum exhaust flow rate 

expected, the field test system’s flexible 

connectors, and the tubing’s 

characteristics for pressure drops versus 

flow. 

(b) For vehicles or other motive 

equipment, we recommend installing 

PEMS in the same location where a 

passenger might sit. Follow PEMS 

manufacturer instructions for installing 

PEMS in cargo spaces, engine spaces, or 

externally such that PEMS is directly 

exposed to the outside environment. We 

recommend locating PEMS where it will 

be subject to minimal sources of the 

following parameters: 

(1) Ambient temperature changes. 

(2) Ambient pressure changes. 

(3) Electromagnetic radiation. 

(4) Mechanical shock and vibration. 

(5) Ambient hydrocarbons—if using a 

FID analyzer that uses ambient air as 

FID burner air. 

(c) Use mounting hardware as 

required for securing flexible 

connectors, ambient sensors, and other 

equipment. Use structurally sound 

mounting points such as vehicle frames, 

trailer hitch receivers, walkspaces, and 

payload tie-down fittings. We 

recommend mounting hardware such as 

clamps, suction cups, and magnets that 

are specifically designed for your 

application. We also recommend 

considering mounting hardware such as 

commercially available bicycle racks, 

trailer hitches, and luggage racks where 

applicable. 

(d) Field testing may require portable 

electrical power to run your test 

equipment. Power your equipment, as 

follows: 

(1) You may use electrical power from 

the vehicle, equipment, or vessel, up to 

the highest power level, such that all the 

following are true: 

(i) The power system is capable of 

safely supplying power, such that the 

power demand for testing does not 

overload the power system. 

(ii) The engine emissions do not 

change significantly as a result of the 

power demand for testing. 

(iii) The power demand for testing 

does not increase output from the 

engine by more than 1% of its 

maximum power. 

(2) You may install your own portable 

power supply. For example, you may 

use batteries, fuel cells, a portable 

generator, or any other power supply to 

supplement or replace your use of 

vehicle power. You may connect an 

external power source directly to the 

vehicle’s, vessel’s, or equipment’s 

power system; however, during a test 

interval (such as an NTE event) you 

must not supply power to the vehicle’s 

power system in excess of 1% of the 

engine’s maximum power. 

■ 137. Section 1065.915 is amended by 

revising paragraph (a) before the table 

and paragraphs (c), (d)(1), and 

(d)(5)(iii)(B) to read as follows: 

§ 1065.915 PEMS instruments. 

(a) Instrument specifications. We 

recommend that you use PEMS that 

meet the specifications of subpart C of 

this part. For unrestricted use of PEMS 

in a laboratory or similar environment, 

use a PEMS that meets the same