Measuring Ranges Resolution 0 - 100% LEL * 0 - 100% Volume Gas * 0 - 25% Oxygen (O2) 0 - 100ppm Hydrogen Sulphide (H2S) 0 - 20% Carbon Dioxide (CO2) * 0 - 1000 ppm Carbon Monoxide (CO) ( * Infrared Detection) LEL Vol Gas O2 H2S CO2 CO 0 - 100% 0 - ...