CFR > Title 40 - Protection of Environment > CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY > SUBCHAPTER U—AIR POLLUTION CONTROLS (Parts 1027–1074) > PART 1065—ENGINE-TESTING PROCEDURES > SUBPART F—Performing an Emission Test Over Specified Duty Cycles (§1065.501 to §1065.595) > 1065.520—Pre-test verification procedures and pre-test data collection.

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 at some point before the test that ambient conditions are within the tolerances specified in this paragraph (b). For purposes of this paragraph (b), “before the test” means any time from a point just prior to engine starting (excluding engine restarts) to the point at which emission sampling begins.
(1) Ambient temperature of (20 to 30) °C. See § 1065.530(j) for circumstances under which ambient temperatures must remain within this range during the test.
(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. You are not required to verify atmospheric pressure prior to a hot start test interval for testing that also includes a cold start.
(3) Dilution air conditions as specified in § 1065.140, except in cases where you preheat your CVS before a cold start test. We recommend verifying dilution air conditions just prior to the start of each test interval.
(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 8 hours before the start of the first test interval of each duty-cycle 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 O[=E T=8052]2 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 C3 H8 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 inlet or into a tee near the probe outlet.
(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., bag) 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, x THC[THC-FID]init, and use it to correct measured values as described in § 1065.660.
(7) If any of the x THC[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.

Code of Federal Regulations

[73 FR 37320, June 30, 2008, as amended at 73 FR 59330, Oct. 8, 2008; 75 FR 23043, Apr. 30, 2010]