GAS SENSOR FOR A MOTOR VEHICLE AIR-CONDITIONING UNIT

摘要

The invention relates to a gas sensor for measuring gas concentration, in particular for a motor vehicle air conditioning unit. The aim of said invention is to obtain a reliable detection of a high dynamic gas concentration by means of simple equipment in an advantageous manner without an additional fan and forced convection. For this purpose, the inventive gas sensor comprises an infrared radiation source (2) for emitting infrared radiation, an infrared detection device (10) for receiving said infrared radiation, an absorption area (11, 30, 40, 50, 60, 70, 80) for receiving a gas whose concentration is to be measured, said area being arranged along an optical axis (A) between the infrared radiation source (2) and the infrared detection device (10), a first film (6) preferably in the form of a gas-impermeable, smudge-resistant film which is infrared-transparent at least within a wavelength range relevant in terms of measure and separates the absorption area (11, 30, 40, 50, 60, 70, 80) from the infrared radiation source (2), and a second film (18) in the form of a gas-impermeable, smudge-resistant film which is more or less transparent for infrared radiation (9) at least within a wavelength range relevant in terms of measure and separates the infrared detection device from the absorption area (11, 30, 40, 50, 60, 70, 80).