... concentration of HC,CO, CO2, O2 in the Automobile Exhaust Gas. Main Technical Parameter: Measurement RangeCO: 0~10.0 10-2 ... the concentration of HC,CO,CO2,O2in the Automobile Exhaust Gas.2. Two kinds of test function: General and Two-speed ... 500 groups of data, built-in printer11. Measurable with liquefied gas (LG), liquefied natural gas (LNG) and gasoline and other alternative fuel vehicles.