§1066.615. NO X intake-air humidity correction.
40 C.F.R. § 1066.615
You may correct NOX emissions for intake-air humidity as described in this section if the standard-setting part allows it. See § 1066.605(c) for the proper sequence for applying the NOX intake-air humidity correction.
For vehicles at or below 14,000 pounds GVWR, apply a correction for vehicles with reciprocating engines operating over specific test cycles as follows:
Calculate a humidity correction using a time-weighted mean value for ambient humidity over the test interval. Calculate absolute ambient humidity, H, using the following equation:
Use the following equation to correct measured concentrations to a reference condition of 10.71 grams H2O vapor per kilogram of dry air for the FTP, US06, LA-92, SC03, and HFET test cycles:
For vehicles above 14,000 pounds GVWR, apply correction factors as described in 40 CFR 1065.670.
Notes, amendments, and revision history
Amendments
[80 FR 9121, Feb. 19, 2015, as amended at 81 FR 74207, Oct. 25, 2016]
Authority
Authority: 42 U.S.C. 7401-7671q.
Source
Source: 79 FR 23823, Apr. 28, 2014, unless otherwise noted.
Amendments
[80 FR 9121, Feb. 19, 2015, as amended at 81 FR 74207, Oct. 25, 2016]