Abstract
Constructional features of the alcotest infrared breath alcohol analyzer are discussed, e.g. folding of the IR-beam in the measuring chamber in order to obtain a sufficiently long absorption path. Evaluation of the size of the measuring chamber to ensure the investigation of deep lung air. Necessity of heating of those parts which come into contact with breathing air. A special breath sampling technique which guarantees in a unique way that only alveolar air is analyzed.