1.Measure the concentration of HC, CO, CO2, O2, NO. 2.Built-in printer 3.Full english menu operation ... 10-2(%)vol CO2: 0-20.0 10-2 (%)vol O2 : 0-25.0 10-2(%)vol rotate speed: 0-10000rpm ... % relative error CO2: ±0.5% vol or ±5% relative error O2: 0.1% vol or±5% relative error NO±25ppm vol ...