(a) Application. Use a diluted exhaust flow meter to determine instantaneous diluted exhaust flow rates or total diluted exhaust flow over a test interval. You may use the difference between a diluted exhaust flow meter and a dilution air meter to calculate raw exhaust flow rates or total raw exhaust flow over a test interval.
CFR 40-1065.240-2014 history
2014CFR 40-1065.240-2014 Protection of Environment. Part1065:Engine-testing procedures. Section1065.240:Dilution air and diluted exhaust flow meters.