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(3) Do not use PEMS for laboratory measurements if it prevents you from demonstrating compliance with the applicable standards. Some of the PEMS requirements in this part 1065 are less stringent than the corresponding laboratory requirements. Depending on actual PEMS performance, you might therefore need to account for some additional measurement uncertainty when using PEMS for laboratory testing. If we ask, you must show us by engineering analysis that any additional measurement uncertainty due to your use of PEMS for laboratory testing is offset by the extent to which your engine's emissions are below the applicable standards. For example, you might show that PEMS versus laboratory uncertainty represents 5% of the standard, but your engine's deteriorated emissions are at least 20% below the standard for each pollutant.
§ 1065.905 General provisions.
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(a) General. Unless the standard-setting part specifies deviations from the provisions of this subpart, field testing and laboratory testing with PEMS must conform to the provisions of this subpart.
(b) Field-testing scope. Field testing conducted under this subpart may include any normal in-use operation of an engine.
(c) Field testing and the standard-setting part. This subpart J specifies procedures for field-testing various categories of engines. See the standard-setting part for specific provisions for a particular type of engine. Before using this subpart's procedures for field testing, read the standard-setting part to answer at least the following questions:
(1) How many engines must I test in the field?
(2) How many times must I repeat a field test on an individual engine?
(3) How do I select vehicles for field testing?
(4) What maintenance steps may I take before or between tests?
(5) What data are needed for a single field test on an individual engine?
(6) What are the limits on ambient conditions for field testing? Note that the ambient condition limits in §1065.520 do not apply for field testing.
(7) Which exhaust constituents do I need to measure?
(8) How do I account for crankcase emissions?
(9) Which engine and ambient parameters do I need to measure?
(10) How do I process the data recorded during field testing to determine if my engine meets field-testing standards? How do I determine individual test intervals? Note that “test interval” is defined in subpart K of this part 1065.
(11) Should I warm up the test engine before measuring emissions, or do I need to measure cold-start emissions during a warm-up segment of in-use operation?
(12) Do any unique specifications apply for test fuels?
(13) Do any special conditions invalidate parts of a field test or all of a field test?
(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?
(15) Do results of initial field testing trigger any requirement for additional field testing or laboratory testing?
(16) How do I report field-testing results?
(d) Field testing and this part 1065. Use the following specifications for field testing:
(1) Use the applicability and general provisions of subpart A of this part.
(2) Use equipment specifications in §1065.101 and in the sections from §1065.140 to the end of subpart B of this part. Section 1065.910 specifies additional equipment specific to field testing.
(3) Use measurement instruments in subpart C of this part, except as specified in §1065.915.
(4) Use calibrations and verifications in subpart D of this part, except as specified in §1065.920. Section 1065.920 also specifies additional calibrations and verifications for field testing.
(5) Use the provisions of the standard-setting part for selecting and maintaining engines in the field instead of the specifications in subpart E of this part.
(6) Use the procedures in §§1065.930 and 1065.935 to start and run a field test. If you use a gravimetric balance for PM, weigh PM samples according to §§1065.590 and 1065.595.
(7) Use the calculations in subpart G of this part to calculate emissions over each test interval. Note that “test interval” is defined in subpart K of this part 1065, and that the standard setting part indicates how to determine test intervals for your engine.
Section 1065.940 specifies additional calculations for field testing. Use any calculations specified in the standard-setting part to determine if your engines meet the field-testing standards. The standard-setting part may also contain additional calculations that determine when further field testing is required.
(8) Use a typical in-use fuel meeting the specifications of §1065.701(d).
(9) Use the lubricant and coolant specifications in §1065.740 and §1065.745.
(10) Use the analytical gases and other calibration standards in §1065.750 and §1065.790.
(11) If you are testing with oxygenated fuels, use the procedures specified for testing with oxygenated fuels in subpart I of this part.
(12) Apply the definitions and reference materials in subpart K of this part.
(e) Laboratory testing using PEMS. Use the following specifications when using PEMS for laboratory testing:
(1) Use the applicability and general provisions of subpart A of this part.
(2) Use equipment specifications in subpart B of this part. Section 1065.910 specifies additional equipment specific to testing with PEMS.
(3) Use measurement instruments in subpart C of this part, except as specified in §1065.915.
(4) Use calibrations and verifications in subpart D of this part, except as specified in §1065.920. Section 1065.920 also specifies additional calibration and verifications for PEMS.
(5) Use the provisions of §1065.401 for selecting engines for testing. Use the provisions of subpart E of this part for maintaining engines, except as specified in the standard-setting part.
(6) Use the procedures in subpart F of this part and in the standard-setting part to start and run a laboratory test.
(7) Use the calculations in subpart G of this part to calculate emissions over the applicable duty cycle. Section 1065.940 specifies additional calculations for testing with PEMS.
(8) Use a fuel meeting the specifications of subpart H of this part, as specified in the standard-setting part.
(9) Use the lubricant and coolant specifications in §1065.740 and §1065.745.
(10) Use the analytical gases and other calibration standards in §1065.750 and §1065.790.
(11) If you are testing with oxygenated fuels, use the procedures specified for testing with oxygenated fuels in subpart I of this part.
(12) Apply the definitions and reference materials in subpart K of this part.
(f) Summary. The following table summarizes the requirements of paragraphs (d) and (e) of this section:
Table 1 of § 1065.905_Summary of Testing Requirements That are
Specified Outside of This Subpart J \1\
------------------------------------------------------------------------
Applicability for
Subpart Applicability for laboratory testing
field testing with PEMS
------------------------------------------------------------------------
A: Applicability and general Use all............. Use all.
provisions.
B: Equipment for testing.... Use § 1065.101 Use all. §
and § 1065.140 1065.910 specifies
through the end of equipment specific
subpart B. § to laboratory
1065.910 specifies testing with PEMS.
equipment specific
to field testing.
C: Measurement instruments.. Use all............. Use all.
§ 1065.915 § 1065.915
allows deviations. allows deviations.
D: Calibrations and Use all............. Use all.
verifications.
§ 1065.920 § 1065.920
allows deviations, allows deviations,
but also has but also has
additional additional
specifications. specifications.
E: Test engine selection, Do not use.......... Use all.
maintenance, and durability. Use standard-setting
part.
F: Running an emission test Use §§ Use all.
in the laboratory. 1065.590 and
1065.595 for PM.
§ 1065.930 and
§ 1065.935 to
start and run a
field test..
G: Calculations and data Use all............. Use all.
requirements.
Use standard-setting Use standard-setting
part. part.
§ 1065.940 has § 1065.940 has
additional additional
calculation calculation
instructions. instructions.
H: Fuels, engine fluids, Use fuels specified Use fuels from
analytical gases, and other in § subpart H of this
calibration materials. 1065.701(d). part as specified
in standard-setting
part.
Use lubricant and Use lubricant and
coolant coolant
specifications in specifications in
§ 1065.740 and subpart H of this
§ 1065.745. part.
Use analytical gas Use analytical gas
specifications and specifications and
other calibration other calibration
standards in § standards in §
1065.750 and § 1065.750 and §
1065.790. 1065.790.
I: Testing with oxygenated Use all............. Use all.
fuels.
K: Definitions and reference Use all............. Use all.
materials.
------------------------------------------------------------------------
\1\ Refer to paragraphs (d) and (e) of this section for complete
specifications.
§ 1065.910 PEMS auxiliary equipment for field testing.
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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 will likely route engine exhaust to a raw-exhaust flow meter and sample probes. Route the engine exhaust as follows:
(1) Flexible connections. Use short flexible connectors at the end of the engine's exhaust pipe.
(i) You may use flexible connectors to enlarge or reduce the exhaust-pipe diameter to match that of your test equipment.
(ii) Use flexible connectors that do not exceed a length of three times their largest inside diameter.
(iii) Use four-ply 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 Nomex TM coverings or linings for durability. You may also use any other material with equivalent permeation-resistance and durability, as long as it seals tightly around tailpipes and does not react with exhaust.
(iv) Use stainless-steel hose clamps to seal flexible connectors to the outside diameter of tailpipes, or use clamps that seal equivalently.
(v) You may use additional flexible connectors to connect to flow meters and sample probe locations.
(2) Raw exhaust 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 exhaust from multiple tailpipes, or you may cap or plug redundant tailpipes if the engine manufacturer recommends it.
(3) Exhaust back pressure. Use connectors and tubing that do not increase back pressure so much that it exceeds the manufacturer's maximum specified exhaust restriction. You may verify this at the maximum exhaust flow rate by measuring back pressure at the manufacturer-specified location with your system connected. You may also perform an engineering analysis to verify proper back pressure, 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 passenger might sit. Follow PEMS manufacturer instructions for installing PEMS in vehicle cargo spaces, vehicle trailers, or externally such that PEMS is directly exposed to the outside environment. Locate 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) Mounting hardware. Use mounting hardware as required for securing flexible connectors, exhaust tubing, ambient sensors, and other equipment. Use structurally sound mounting points such as vehicle frames, trailer hitch receivers, and payload tie-down fittings. We recommend mounting hardware such as clamps, suction cups, and magnets that are specifically designed for vehicle applications. We also recommend considering mounting hardware such as commercially available bicycle racks, trailer hitches, and luggage racks.
(d) Electrical power. 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, up to the highest power level, such that all the following are true:
(i) The vehicle power system is capable of safely supplying your power, such that your demand does not overload the vehicle's power system.
(ii) The engine emissions do not change significantly when you use vehicle power.
(iii) The power you demand 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. However, you must not supply power to the vehicle's power system under any circumstances.
§ 1065.915 PEMS instruments.
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(a) Instrument specifications. We recommend that you use PEMS that meet the specifications of subpart C of this part. For field testing of for laboratory testing with PEMS, the specifications in the following table apply instead of the specifications in Table 1 of §1065.205.
Table 1 of § 1065.915_Recommended Minimum PEMS Measurement Instrument Performance
--------------------------------------------------------------------------------------------------------------------------------------------------------
Measured Rise time and Recording update
Measurement quantity symbol fall time frequency Accuracy \1\ Repeatability \1\ Noise \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Engine speed transducer.......... fn.............. 1 s............. 1 Hz means...... 5.0% of pt. or 1.0% 2.0% of pt. or 1.0% 0.5% of max.
of max. of max
Engine torque estimator, BSFC T or BSFC....... 1 s............. 1 Hz means...... 8.0% of pt. or 5% of 2.0% of pt. or 1.0% 1.0% of max.
(This is a signal from an max. of max
engine's ECM).
General pressure transducer (not p............... 5 s............. 1 Hz............ 5.0% of pt. or 5.0% 2.0% of pt. or 0.5% 1.0% of max.
a part of another instrument). of max. of max
Atmospheric pressure meter....... patmos.......... 50 s............ 0.1 Hz.......... 250 Pa.............. 200 Pa 100 Pa.
General temperature sensor (not a T............... 5 s............. 1 Hz............ 1.0% of pt. K or 5 K 0.5% of pt. K or 2 K 0.5% of max 0.5 K.
part of another instrument).
General dewpoint sensor.......... Tdew............ 50 s............ 0.1 Hz.......... 3 K................. 1 K 1 K.
Exhaust flow meter............... nb.............. 1 s............. 1 Hz means...... 5.0% of pt. or 3.0% 2.0% of pt 2.0% of max.
of max.
Dilution air, inlet air, exhaust, nb.............. 1 s............. 1 Hz means...... 2.5% of pt. or 1.5% 1.25% of pt. or 1.0% of max.
and sample flow meters. of max. 0.75% of max
Continuous gas analyzer.......... x............... 5 s............. 1 Hz............ 4.0% of pt. or 4.0% 2.0% of pt. or 2.0% 1.0% of max.
of meas. of meas
Gravimetric PM balance........... mPM............. N/A............. N/A............. See § 1065.790. 0.5 µg N/A
Inertial PM balance.............. mPM............. 5 s............. 1 Hz............ 4.0% of pt. or 4.0% 2.0% of pt. or 2.0% 1.0% of max.
of meas. of meas
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Accuracy, repeatability, and noise are all determined with the same collected data, as described in § 1065.305, and based on absolute values.
``pt.'' refers to the overall flow-weighted mean value expected at the standard; ``max.'' refers to the peak value expected at the standard over any
test interval, not the maximum of the instrument's range; ``meas'' refers to the actual flow-weighted mean measured over any test interval.
(b) Redundant measurements. For all PEMS described in this subpart, you may use data from multiple instruments to calculate test results for a single test. If you use redundant systems, use good engineering judgment to use multiple measured values in calculations or to disregard individual measurements. Note that you must keep your results from all measurements, as described in §1065.25. This requirement applies whether or not you actually use the measurements in your calculations.
(c) Field-testing ambient effects on PEMS. PEMS must be only minimally affected by ambient conditions such as temperature, pressure, humidity, physical orientation, mechanical shock and vibration, electromagnetic radiation, and ambient hydrocarbons. Follow the PEMS manufacturer's instructions for proper installation to isolate PEMS from ambient conditions that affect their performance. If a PEMS is inherently affected by ambient conditions that you cannot control, you must monitor those conditions and adjust the PEMS signals to compensate for the ambient effect. The standard-setting part may also specify the use of one or more field-testing adjustments or “measurement allowances” that you apply to results or standards to account for ambient effects on PEMS.
(d) ECM signals. You may use signals from the engine's electronic control module (ECM) in place of values measured by individual instruments within a PEMS, subject to the following provisions:
(1) Recording ECM signals. If your ECM updates a broadcast signal more frequently than 1 Hz, take one of the following steps:
(i) Use PEMS to sample and record the signal's value more frequently—up to 5 Hz maximum. Calculate and record the 1 Hz mean of the more frequently updated data.
(ii) Use PEMS to electronically filter the ECM signals to meet the rise time and fall time specifications in Table 1 of this section. Record the filtered signal at 1 Hz.
(2) Omitting ECM signals. Replace any discontinuous or irrational ECM data with linearly interpolated values from adjacent data.
(3) Aligning ECM signals with other data. You must perform time-alignment and dispersion of ECM signals, according to PEMS manufacturer instructions and using good engineering judgment.
(4) ECM signals for determining test intervals. You may use any combination of ECM signals, with or without other measurements, to determine the start-time and end-time of a test interval.
(5) ECM signals for determining brake-specific emissions. You may use any combination of ECM signals, with or without other measurements, to estimate engine speed, torque, and brake-specific fuel consumption (BSFC, in units of mass of fuel per kW-hr) for use in brake-specific emission calculations. We recommend that the overall performance of any speed, torque, or BSFC estimator should meet the performance specifications in Table 1 of this section. We recommend using one of the following methods:
(i) Speed. Use the engine speed signal directly from the ECM. This signal is generally accurate and precise. You may develop your own speed algorithm based on other ECM signals.
(ii) Torque. Use one of the following:
(A) ECM torque. Use the engine-torque signal directly from the ECM, if broadcast. Determine if this signal is proportional to indicated torque or brake torque. If it is proportional to indicated torque, subtract friction torque from indicated torque and record the result as brake torque. Friction torque may be a separate signal broadcast from the ECM or you may have to determine it from laboratory data as a function of engine speed.
(B) ECM %-load. Use the %-load signal directly from the ECM, if broadcast. Determine if this signal is proportional to indicated torque or brake torque. If it is proportional to indicated torque, subtract the minimum %-load value from the %-load signal. Multiply this result by the maximum brake torque at the corresponding engine speed. Maximum brake torque versus speed information is commonly published by the engine manufacturer.
(C) Your algorithms. You may develop and use your own combination of ECM signals to determine torque.
(iii) BSFC. Use one of the following:
(A) Use ECM engine speed and ECM fuel flow signals to interpolate brake-specific fuel consumption data, which might be available from an engine laboratory as a function of ECM engine speed and ECM fuel signals.
(B) Use a single BSFC value that approximates the BSFC value over a test interval (as defined in subpart K of this part). This value may be a nominal BSFC value for all engine operation determined over one or more laboratory duty cycles, or it may be any other BSFC that we approve. If you use a nominal BSFC, we recommend that you select a value based on the BSFC measured over laboratory duty cycles that best represent the range of engine operation that defines a test interval for field-testing.
(C) You may develop and use your own combination of ECM signals to determine BSFC.
(iv) Other ECM signals. You may ask to use other ECM signals for determining brake-specific emissions, such as ECM fuel flow or ECM air flow. We must approve the use of such signals in advance.
(6) Permissible deviations. ECM signals may deviate from the specifications of this part 1065, but the expected deviation must not prevent you from demonstrating that you meet the applicable standards. For example, your emission results may be sufficiently below an applicable standard, such that the deviation would not significantly change the result. As another example, a very low engine-coolant temperature may define a logical statement that determines when a test interval may start. In this case, even if the ECM's sensor for detecting coolant temperature was not very accurate or repeatable, its output would never deviate so far as to significantly affect when a test interval may start.
§ 1065.920 PEMS Calibrations and verifications.
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(a) Subsystem calibrations and verifications. Use all the applicable calibrations and verifications in subpart D of this part, including the linearity verifications in §1065.307, to calibrate and verify PEMS. Note that a PEMS does not have to meet the system-response specifications of §1065.308 if it meets the overall verification described in paragraph (b) of this section.
(b) Overall verification. We require only that you maintain a record showing that the particular make, model, and configuration of your PEMS meets this verification. We recommend that you generate your own record to show that your specific PEMS meets this verification, but you may also rely on data and other information from the PEMS manufacturer. If you upgrade or change the configuration of your PEMS, your record must show that your new configuration meets this verification. The verification consists of operating an engine over a duty cycle in the laboratory and statistically comparing data generated and recorded by the PEMS with data simultaneously generated and recorded by laboratory equipment as follows:
(1) Mount an engine on a dynamometer for laboratory testing. Prepare the laboratory and PEMS for emission testing, as described in this part, to get simultaneous measurements. We recommend selecting an engine with emission levels close to the applicable duty-cycle standards, if possible.
(2) Select or create a duty cycle that has all the following characteristics:
(i) Engine operation that represents normal in-use speeds, loads, and degree of transient activity. Consider using data from previous field tests to generate a cycle.
(ii) A duration of (20 to 40) min.
(iii) At least 50% of engine operating time must include at least 10 valid test intervals for calculating emission levels for field testing. For example, for highway compression-ignition engines, select a duty cycle in which at least 50% of the engine operating time can be used to calculate valid NTE events.
(3) Starting with a warmed-up engine, run a valid emission test with the duty cycle from paragraph (b)(2) of this section. The laboratory and PEMS must both meet applicable validation requirements, such as drift validation, hydrocarbon contamination validation, and proportional validation.
(4) Determine the brake-specific emissions for each test interval for both laboratory and the PEMS measurements, as follows:
(i) For both laboratory and PEMS measurements, use identical values to determine the beginning and end of each test interval.
(ii) For both laboratory and PEMS measurements, use identical values to determine total work over each test interval.
(iii) Apply any “measurement allowance” to the PEMS data. If the measurement allowance is normally added to the standard, subtract the measurement allowance from the PEMS brake-specific emission result.
(iv) Round results to the same number of significant digits as the standard.
(5) Repeat the engine duty cycle and calculations until you have at least 100 valid test intervals.
(6) For each test interval and emission, subtract the lab result from the PEMS result.
(7) If for each constituent, the PEMS passes this verification if any one of the following are true:
(i) 91% or more of the differences are zero or less than zero.
(ii) The entire set of test-interval results passes the 95% confidence alternate-procedure statistics for field testing (t-test and F-test) specified in subpart A of this part.
§ 1065.925 PEMS preparation for field testing.
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Take the following steps to prepare PEMS for field testing:
(a) Verify that ambient conditions at the start of the test are within the limits specified in the standard-setting part. Continue to monitor these values to determine if ambient conditions exceed the limits during the test.
(b) Install a PEMS and any accessories needed to conduct a field test.
(c) Power the PEMS and allow pressures, temperatures, and flows to stabilize to their operating set points.
(d) Bypass or purge any gaseous sampling PEMS instruments with ambient air until sampling begins to prevent system contamination from excessive cold-start emissions.
(e) Conduct calibrations and verifications.
(f) Operate any PEMS dilution systems at their expected flow rates using a bypass.
(g) If you use a gravimetric balance to determine whether an engine meets an applicable PM standard, follow the procedures for PM sample preconditioning and tare weighing as described in §1065.590. Operate the PM-sampling system at its expected flow rates using a bypass.
(h) Verify the amount of contamination in the PEMS HC sampling system as follows:
(1) Select the HC analyzers' ranges for measuring the maximum concentration expected at the HC standard.
(2) Zero the HC analyzers using a zero gas introduced at the analyzer port. When zeroing the FIDs, use the FIDs' burner air that would be used for in-use measurements (generally either ambient air or a portable source of burner air).
(3) Span the HC analyzers using span gas introduced at the analyzer port. When spanning the FIDs, use the FIDs' burner air that would be used in-use (for example, use ambient air or a portable source of burner air).
(4) Overflow zero air at the HC probe or into a fitting between the HC probe and the transfer line.
(5) Measure the HC concentration in the sampling system:
(i) For continuous sampling, record the mean HC concentration as overflow zero air flows.
(ii) For batch sampling, fill the sample medium and record its mean concentration.
(6) Record this value as the initial HC concentration, xHCinit, and use it to correct measured values as described in §1065.660.
(7) If the initial HC concentration exceeds the greater of the following values, determine the source of the contamination and take corrective action, such as purging the system or replacing contaminated portions:
(i) 2% of the flow-weighted mean concentration expected at the standard or measured during testing.
(ii) 2 µmol/mol.
(8) If corrective action does not resolve the deficiency, you use a contaminated HC system if it does not prevent you from demonstrating compliance with the applicable emission standards.
§ 1065.930 Engine starting, restarting, and shutdown.
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Unless the standard-setting part specifies otherwise, start, restart, and shut down the test engine for field testing as follows:
(a) Start or restart the engine as described in the owners manual.
(b) If the engine does not start after 15 seconds of cranking, stop cranking and determine the reason it failed to start. However, you may crank the engine longer than 15 seconds, as long as 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 a required warm-up before emission sampling begins, restart the engine and continue warm-up.
(2) If the engine stalls at any other time after emission sampling begins, restart the engine and continue testing.
(d) Shut down and restart the engine according to the manufacturer's specifications, as needed during normal operation in-use, but continue emission sampling until the field test is complete.
§ 1065.935 Emission test sequence for field testing.
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(a) Time the start of field testing as follows:
(1) If the standard-setting part requires only hot-stabilized emission measurements, operate the engine in-use until the engine coolant, block, or head absolute temperature is within ±10% of its mean value for the previous 2 min or until an engine thermostat controls engine temperature with coolant or air flow.
(2) If the standard-setting part requires hot-start emission measurements, shut down the engine after at least 2 min at the temperature tolerance specified in paragraph (a)(1) of this section. Start the field test within 20 min of engine shutdown.
(3) If the standard-setting part requires cold-start emission measurements, proceed to the steps specified in paragraph (b) of this section.
(b) Take the following steps before emission sampling begins:
(1) For batch sampling, connect clean storage media, such as evacuated bags or tare-weighed PM sample media.
(2) Operate the PEMS according to the instrument manufacturer's instructions and using good engineering judgment.
(3) Operate PEMS heaters, dilution systems, sample pumps, cooling fans, and the data-collection system.
(4) Pre-heat or pre-cool PEMS heat exchangers in the sampling system to within their tolerances for operating temperatures.
(5) Allow all other PEMS components such as sample lines, filters, and pumps to stabilize at operating temperature.
(6) Verify that no significant vacuum-side leak exists in the PEMS, as described in §1065.345.
(7) Adjust PEMS flow rates to desired levels, using bypass flow if applicable.
(8) Zero and span all PEMS gas analyzers using NIST-traceable gases that meet the specifications of §1065.750.
(c) Start testing as follows:
(1) Before the start of the first test interval, zero or re-zero any PEMS electronic integrating devices, as needed.
(2) If the engine is already running and warmed up and starting is not part of field testing, start the field test by simultaneously starting to sample exhaust, record engine and ambient data, and integrate measured values using a PEMS.
(3) If engine starting is part of field testing, start field testing by simultaneously starting to sample from the exhaust system, record engine and ambient data, and integrate measured values using a PEMS. Then start the engine.
(d) Continue the test as follows:
(1) Continue to sample exhaust, record data and integrate measured values throughout normal in-use operation of the engine.
(2) Between each test interval, zero or re-zero any electronic integrating devices, and reset batch storage media, as needed.
(3) The engine may be stopped and started, but continue to sample emissions throughout the entire field test.
(4) Conduct periodic verifications such as zero and span verifications on PEMS gas analyzers, as recommended by the PEMS manufacturer or as indicated by good engineering judgment. Results from these verifications will be used to calculate and correct for drift according to paragraph (g) of this section. Do not include data recorded during verifications in emission calculations.
(5) You may periodically condition and analyze batch samples in-situ, including PM samples; for example you may condition an inertial PM balance substrate if you use an inertial balance to measure PM.
(6) You may have personnel monitoring and adjusting the PEMS during a test, or you may operate the PEMS unattended.
(e) Stop testing as follows:
(1) Continue sampling as needed to get an appropriate amount of emission measurement, according to the standard setting part. If the standard-setting part does not describe when to stop sampling, develop a written protocol before you start testing to establish how you will stop sampling. You may not determine when to stop testing based on measured values.
(2) At the end of the field test, allow the sampling systems' response times to elapse and then stop sampling. Stop any integrators and indicate the end of the test cycle on the data-collection medium.
(3) You may shut down the engine before or after you stop sampling.
(f) For any proportional batch sample, such as a bag sample or PM sample, verify for each test interval whether or not proportional sampling was maintained according to §1065.545. Void the sample for any test interval that did not maintain proportional sampling according to §1065.545.
(g) Take the following steps after emission sampling is complete:
(1) As soon as practical after the emission sampling, analyze any gaseous batch samples.
(2) If you used dilution air, either analyze background samples or assume that background emissions were zero. Refer to §1065.140 for dilution-air specifications.
(3) After quantifying all exhaust gases, record mean analyzer values after stabilizing a zero gas to each analyzer, then record mean analyzer values after stabilizing the span gas to the analyzer. Stabilization may include time to purge an analyzer of any sample gas, plus any additional time to account for analyzer response. Use these recorded values to correct for drift as described in §1065.550.
(4) Invalidate any test intervals that do not meet the range criteria in §1065.550. Note that it is acceptable that analyzers exceed 100% of their ranges when measuring emissions between test intervals, but not during test intervals. You do not have to retest an engine in the field if the range criteria are not met.
(5) Invalidate any test intervals that do not meet the drift criterion in §1065.550. For test intervals that do meet the drift criterion, correct those test intervals for drift according to §1065.672 and use the drift corrected results in emissions calculations.
(6) Unless you weighed PM in-situ, such as by using an inertial PM balance, place any used PM samples into covered or sealed containers and return them to the PM-stabilization environment and weigh them as described in §1065.595.
§ 1065.940 Emission calculations.
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Perform emission calculations as described in §1065.650 to calculate brake-specific emissions for each test interval using any applicable information and instructions in the standard-setting part.
Subpart K—Definitions and Other Reference Information
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§ 1065.1001 Definitions.
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The definitions in this section apply to this part. The definitions apply to all subparts unless we note otherwise. All undefined terms have the meaning the Act gives them. The definitions follow:
300 series stainless steel means any stainless steel alloy with a Unified Numbering System for Metals and Alloys number designated from S30100 to S39000. For all instances in this part where we specify 300 series stainless steel, such parts must also have a smooth inner-wall construction. We recommend an average roughness, Ra, no greater than 4 µm.
Accuracy means the absolute difference between a reference quantity and the arithmetic mean of ten mean measurements of that quantity. Determine instrument accuracy, repeatability, and noise from the same data set. We specify a procedure for determining accuracy in §1065.305.
Act means the Clean Air Act, as amended, 42 U.S.C. 7401–7671q.
Adjustable parameter means any device, system, or element of design that someone can adjust (including those which are difficult to access) and that, if adjusted, may affect emissions or engine performance during emission testing or normal in-use operation. This includes, but is not limited to, parameters related to injection timing and fueling rate. In some cases, this may exclude a parameter that is difficult to access if it cannot be adjusted to affect emissions without significantly degrading engine performance, or if it will not be adjusted in a way that affects emissions during in-use operation.
Aerodynamic diameter means the diameter of a spherical water droplet that settles at the same constant velocity as the particle being sampled.
Aftertreatment means relating to a catalytic converter, particulate filter, or any other system, component, or technology mounted downstream of the exhaust valve (or exhaust port) whose design function is to decrease emissions in the engine exhaust before it is exhausted to the environment. Exhaust-gas recirculation (EGR) and turbochargers are not aftertreatment.
Allowed procedures means procedures that we either specify in this part 1065 or in the standard-setting part or approve under §1065.10.
Alternate procedures means procedures allowed under §1065.10(c)(7).
Applicable standard means an emission standard to which an engine is subject; or a family emission limit to which an engine is certified under an emission credit program in the standard-setting part.
Aqueous condensation means the precipitation of water-containing constituents from a gas phase to a liquid phase. Aqueous condensation is a function of humidity, pressure, temperature, and concentrations of other constituents such as sulfuric acid. These parameters vary as a function of engine intake-air humidity, dilution-air humidity, engine air-to-fuel ratio, and fuel composition—including the amount of hydrogen and sulfur in the fuel.
Atmospheric pressure means the wet, absolute, atmospheric static pressure. Note that if you measure atmospheric pressure in a duct, you must ensure that there are negligible pressure losses between the atmosphere and your measurement location, and you must account for changes in the duct's static pressure resulting from the flow.
Auto-ranging means a gas analyzer function that automatically changes the analyzer digital resolution to a larger range of concentrations as the concentration approaches 100% of the analyzer's current range. Auto-ranging does not mean changing an analog amplifier gain within an analyzer.
Auxiliary emission-control device means any element of design that senses temperature, motive speed, engine RPM, transmission gear, or any other parameter for the purpose of activating, modulating, delaying, or deactivating the operation of any part of the emission-control system.
Brake power has the meaning given in the standard-setting part. If it is not defined in the standard-setting part, brake power means the usable power output of the engine, not including power required to fuel, lubricate, or heat the engine, circulate coolant to the engine, or to operate aftertreatment devices. If the engine does not power these accessories during a test, subtract the work required to perform these functions from the total work used in brake-specific emission calculations. Subtract engine fan work from total work only for air-cooled engines.
C1 equivalent (or basis) means a convention of expressing HC concentrations based on the total number of carbon atoms present, such that the C1 equivalent of a molar HC concentration equals the molar concentration multiplied by the mean number of carbon atoms in each HC molecule. For example, the C1 equivalent of 10 µmol/mol of propane (C3H8) is 30 µmol/mol. C1 equivalent molar values may be denoted as “ppmC” in the standard-setting part.
Calibration means the process of setting a measurement system's response so that its output agrees with a range of reference signals. Contrast with “verification”.
Certification means relating to the process of obtaining a certificate of conformity for an engine family that complies with the emission standards and requirements in the standard-setting part.
Compression-ignition means relating to a type of reciprocating, internal-combustion engine that is not a spark-ignition engine.
Confidence interval means the range associated with a probability that a quantity will be considered statistically equivalent to a reference quantity.
Constant-speed engine means an engine whose certification is limited to constant-speed operation. Engines whose constant-speed governor function is removed or disabled are no longer constant-speed engines.
Constant-speed operation means engine operation with a governor that automatically controls the operator demand to maintain engine speed, even under changing load. Governors do not always maintain speed exactly constant. Typically speed can decrease (0.1 to 10)% below the speed at zero load, such that the minimum speed occurs near the engine's point of maximum power.
Coriolis meter means a flow-measurement instrument that determines the mass flow of a fluid by sensing the vibration and twist of specially designed flow tubes as the flow passes through them. The twisting characteristic is called the Coriolis effect. According to Newton's Second Law of Motion, the amount of sensor tube twist is directly proportional to the mass flow rate of the fluid flowing through the tube. See §1065.220.
Designated Compliance Officer means the Manager, Engine Programs Group (6405–J), U.S. Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460.
Dewpoint means a measure of humidity stated as the equilibrium temperature at which water condenses under a given pressure from moist air with a given absolute humidity. Dewpoint is specified as a temperature in °C or K, and is valid only for the pressure at which it is measured. See §1065.645 to determine water vapor mole fractions from dewpoints using the pressure at which the dewpoint is measured.
Discrete-mode means relating to a discrete-mode type of steady-state test, as described in the standard-setting part.
Dispersion means either:
(1) The broadening and lowering of a signal due to any fluid capacitance, fluid mixing, or electronic filtering in a sampling system. (Note: To adjust a signal so its dispersion matches that of another signal, you may adjust the system's fluid capacitance, fluid mixing, or electronic filtering.)
(2) The mixing of a fluid, especially as a result of fluid mechanical forces or chemical diffusion.
Drift means the difference between a zero or calibration signal and the respective value reported by a measurement instrument immediately after it was used in an emission test, as long as you zeroed and spanned the instrument just before the test.
Duty cycle means a series of speed and torque values (or power values) that an engine must follow during a laboratory test. Duty cycles are specified in the standard-setting part. A single duty cycle may consist of one or more test intervals. For example, a duty cycle may be a ramped-modal cycle, which has one test interval; a cold-start plus hot-start transient cycle, which has two test intervals; or a discrete-mode cycle, which has one test interval for each mode.
Electronic control module means an engine's electronic device that uses data from engine sensors to control engine parameters.
Emission-control system means any device, system, or element of design that controls or reduces the emissions of regulated pollutants from an engine.
Emission-data engine means an engine that is tested for certification. This includes engines tested to establish deterioration factors.
Emission-related maintenance means maintenance that substantially affects emissions or is likely to substantially affect emission deterioration.
Engine means an engine to which this part applies.
Engine family means a group of engines with similar emission characteristics throughout the useful life, as specified in the standard-setting part.
Engine governed speed means the engine operating speed when it is controlled by the installed governor.
Exhaust-gas recirculation means a technology that reduces emissions by routing exhaust gases that had been exhausted from the combustion chamber(s) back into the engine to be mixed with incoming air before or during combustion. The use of valve timing to increase the amount of residual exhaust gas in the combustion chamber(s) that is mixed with incoming air before or during combustion is not considered exhaust-gas recirculation for the purposes of this part.
Fall time, t90–10, means the time interval of a measurement instrument's response after any step decrease to the input between the following points:
(1) The point at which the response has fallen 10% of the total amount it will fall in response to the step change.
(2) The point at which the response has fallen 90% of the total amount it will fall in response to the step change.
Flow-weighted mean means 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 flow rate, divided by the sum of the recorded flow rates. 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.
Fuel type means a general category of fuels such as gasoline or LPG. There can be multiple grades within a single type of fuel, such as all-season and winter-grade gasoline.
Good engineering judgment means judgments made consistent with generally accepted scientific and engineering principles and all available relevant information. See 40 CFR 1068.5 for the administrative process we use to evaluate good engineering judgment.
HEPA filter means high-efficiency particulate air filters that are rated to achieve a minimum initial particle-removal efficiency of 99.97% using ASTM F 1471–93 (incorporated by reference in §1065.1010).
Hydraulic diameter means the diameter of a circle whose area is equal to the area of a noncircular cross section of tubing, including its wall thickness. The wall thickness is included only for the purpose of facilitating a simplified and nonintrusive measurement.
Hydrocarbon (HC) means THC, THCE, NMHC, or NMHCE, as applicable. Hydrocarbon generally means the hydrocarbongroup on which the emission standards are based for each type of fuel and engine. (continued)