To measure the 'spot concentrations' of alcohol for use with an Accuro pump.

Cross sensitivity Alcohol 100/a: The tube does not differentiate between different alcohols. Higher molecular weight alcohols are indicated with a markedly reduced sensitivity. Aldehydes, ethers, ketones, esters are indicated but with different sensitivity. Aromates, petroleum, halogenated hydrocarbons are not indicated.

One stroke is equivalent to a volume of 100 ±5 ml of gas passing through the tube.