Code of Federal Regulations Title 40. Protection of Environment § 40.89.416 Raw exhaust gas flow

(a) Measurement of the air flow and the fuel flow by suitable metering systems (for details see SAE J244. This procedure has been incorporated by reference. See § 89.6.) and calculation of the exhaust gas flow as follows:

G_EXHW=G_AIRW+G_FUEL (for wet exhaust mass)

or

V_EXHD = V_AIRD + (−.767) x G_FUEL (for dry exhaust volume)

or

V_EXHW=V_AIRW + .749 x G_FUEL (for wet exhaust volume)

(b) Exhaust mass calculation from fuel consumption (see § 89.415) and exhaust gas concentrations using the method found in § 89.418.