Non-dispersive infrared gas analyzer used for determining concentration of carbon dioxide in measuring gas has region of radiation between infrared radiation source and measuring cuvette together enclosed by housing

摘要

A non-dispersive infrared gas analyzer comprises an infrared radiation source (1); an orifice wheel (5); a measuring cuvette containing measuring gas and through which modulated infrared radiation passes; and a detector (11) arranged in the radiation direction behind the cuvette. The region of the radiation lying between the infrared radiation source and the measuring cuvette together with the wheel is enclosed by a housing (17) having a rinsing gas inlet (19) and a rinsing gas outlet (21). A gas source (20) with a gas which is free from carbon dioxide is connected to the rinsing gas inlet. Preferred Features: The rinsing gas is nitrogen or external air fed over a carbon dioxide absorber. The rinsing gas inlet has a perforated nozzle (22) which constantly holds the rinsing gas stream.