Measuring Ranges Resolution 0 - 1000 ppm Flammable 0 - 100% LEL Flammable 0 - 100% Volume Gas Flammable 0 - 25% Oxygen (O2) 0 - 1000 ppm Carbon Monoxide (CO) 0 - 100 ppm Hydrogen Sulphide (H2S) 0 - 1000 0 - 9.9% LEL 10 - 100% LEL 0 - 100% Vol Gas 0 ...