(a) General requirements.

(1) Ambient temperature levels encountered by the test engine throughout the test sequence may not be less than 20 °C nor more than 30 °C.

(2) Calculate all volumes and volumetric flow rates at standard conditions for temperature and pressure. Use these conditions consistently throughout all calculations. Standard conditions for temperature and pressure are 25 °C and 101.3 kPa.

(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 ps and expressed in kPa. Determine the parameter f according to the following provisions:

(1) Naturally aspirated and mechanically supercharged engines:

(2) Turbocharged engine with or without cooling of inlet air:

(3) For a test to be recognized as valid, the parameter f must be between the limits as shown below: