Pneumatic detector for nondispersive infrared gas analyzers

摘要

A pneumatic detector for nondispersive infrared gas analyzers comprises two gas-filled chambers disposable one behind the colinearly with a source of infrared radiation and connected to one another by a gas conductive line containing a microflow sensor which generates an electrical signal indicative of the pressure difference between the two chambers. A third chamber is disposed on a side of the two chambers opposite the radiation source and is connected to a second of the two chambers via a gas conductive line. An adjustable aperture stop is arranged between the second and the third gas-filled chambers. The arrangement of chambers and the adjustable aperture stop serve to compensate and reduce to zero a negative cross-sensitivity.