CFR > Title 40 - Protection of Environment > CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY > SUBCHAPTER C—AIR PROGRAMS (Parts 50–99) > PART 89—CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION-IGNITION ENGINES > SUBPART D—Emission Test Equipment Provisions (§89.301 to §89.331) > 89.331—Test conditions.

89.331—Test conditions.

(a) General requirements. Calculate all volumes and volumetric flow rates at standard conditions for temperature and pressure (0 °C and 101.3 kPa), and these conditions must be used consistently throughout all calculations.
(b) Engine test conditions. Measure the absolute temperature (designated as T and expressed in Kelvin) of the engine air at the inlet to the engine, and the dry atmospheric pressure (designated as p and expressed in kPa), and determine the parameter f according to the following provisions:
(1) Naturally aspirated and mechanically supercharged engines:
Pt. 89, Subpt. D, App. A
(2) Turbocharged engine with or without cooling of inlet air:
(c) For a test to be recognized as valid, the parameter f shall be between the limits as shown below:

Code of Federal Regulations

[59 FR 31335, June 17, 1994. Redesignated at 63 FR 56995, Oct. 23, 1998]