A device that measures alcohol content of a person's breath; SYN. breathalyser.
Trademark for an instrument for on-the-spot checking by police of the amount of alcohol consumed by a suspect driver. The driver breathes into a plastic bag connected to a tube containing a chemical (such as a diluted solution of potassium dichromate in 50% sulfuric acid) that changes color in the presence of alcohol. Another method is to use a gas chromatograph, again from a breath sample. Breath-a-lyzer.