Research on Infrared Breath Alcohol Test Based on Differential Absorption

An infrared alcohol testing system based on differential absorption is presented. The technique relies on the fact that the breath alcohol gas has a unique, well-defined absorption characteristic within the infrared region of electromagnetic spectrum. It is used to detect the present and concentration of alcohol gas. The non-dispersive infrared gas detection principle is introduced in detail. Experiments show that the testing system has high precision, good environment adaptability, and its indication error and repeatability reach the China National Standards.