... -computer analysis, directly measure the thickness of HC, CO and CO2 in the exhaust gas of vehicles and inspect the density ... -6(ppm)vol CO: 0-10.0 10-2(%)vol CO2: 0-20.0 10-2 (%) vol O2: 0-25.0 ... :10mins5.resolution:CO: 0.01%vol HC:1ppmvolnormal hexane equivalent CO2: 0.01%vol O2: 0.01%vol NO:1ppmvol rate ... automobile exhaust gas analyzer SHENGWEI Tester Meter Detector 5gas CO,CO2, HC, O2, NOx