Cross Sensitivity

We recommend that sensors should be calibrated using the gas for which they are intended to monitor as this method is more accurate than cross calibration. However, where this is not possible, cross calibration is a less accurate alternative method.

The following table lists theoretical K factors by which the signal with a cross-calibration gas should be multiplied to give the signal for other gases.

The information is provided in good faith but responsibility cannot be accepted for errors or omissions

For example: To cross-calibrate an instrument to monitor %LEL propane in air, using a cylinder of 50% LEL methane gas in air.

K-METHANE = 112 K-PROPANE = 62

Adjust the SPAN potentiometer on the instrument to read 50(112/62) = 90.3% LEL

The instrument should now read the approximate %LEL concentration of propane at the sensor when the sensor is exposed to a concentration of propane in air.

Cross Sensitivity:

Gas			K		Gas			K		Gas			K
Acetaldehyde			67		n-Decane			37		Dimethyl Ether			70
Acetic Acid			61		Diethylamine			55		Methylethylether			49
Acetic Anhydride			52		Dimethylamine			65		Methylethylketone			46
Acetone			58		Dimethylpentane			45		Methyl Formate			75
Acetylene			64		Dimethylpropane			44		Methylmercaptan			68
Alkyl Alcohol			57		Dimethylsulphide			49		Methylpropionate			57
Ammonia			142		Dioxane			50		Methyl n-propylketone			45
n-Amyl Alcohol			37		Ethane			76		Naphthalene			38
Aniline			44		Ethyl Acetate			57		Nitromethane			65
Benzene			46		Ethyl Alcohol			82		n-Nonane			35
Biphenyl			28		Ethylamine			59		n-Octane			42
Butadiene			63		Ethyl Benzene			40		n-Pentane			51
n-Butane			66		Ethylcyclopentane			44		iso-Pentane			52
iso-Butane			58		Ethylene			79		Propane			62
Butene-1			51		Ethyleneoxide			58		n-Propyl Alcohol			53
Cis-Butene-2			54		Diethyl Ether			52		n-Propylamine			54
trans-Butene-2			57		Ethyl Formate			50		Propylene			58
n-Butyl Alcohol			38		Ethylmercaptan			63		Propyleneoxide			51
iso-Butyl Alcohol			59		n-Heptane			43		iso-Propylether			49
tert-Butyl Alcohol			83		n-Hexane			41		Propyne			47
n-Butyl Benzene			35		Hydrazine			50		Toluene			45
iso-Butyl Benzene			36		Hydrogencyanide			53		Triethylamine			45
n-Butyric Acid			43		Hydrogen			86		Trimethylamine			54
Carbon Disulphide			20		Hydrogen Sulphide			46		Vinylethylether			47
Carbon Monoxide			84		Methane			112		Vinylchloride			45
Carbon Oxysulphide			105		Methyl Acetate			56		o-Xylene			40
Cyanogen			100		Methyl Alcohol			96		m-Xylene			44
Cyclohexane			46		Methylamine			87		p-Xylene			44
Cyclopropane			70		Methylcyclohexane			49