DUI Metrology Dictionary

Disappearing alcohol

A strange phenomenon whereby some of the ethyl alcohol vapour concentration introduced into the breath tube from a subject or some of the ethyl alcohol vapour concentration introduced into the Intoxilyzer inlet from the wet-bath simulator or dry gas/air gas seems to disappear. The phenomenon is a result of zero for instrument purposes being elevated during prior air blanks.

Ambient Conditions Change Baseline 0 on an IR Breath instrument - Disappearing Alcohol