Non-dispersive IR gas analyser - has detector consisting of two chamber, with interference filter between them and before first chamber

摘要

The analyser has a measurement light path with a cell containing the tested gas, and a reference light path with a cell filled with a reference gas. A radiation detector consists of two chambers, one behind the other, filled pref. with the gas component to be measured. Pressure difference due to radiation absorption gives the amount of the component in the tested gas. Interference from gas components between the chambers (6, 7), whose absorption bands overlap with that of the measured component, is eliminated by an interference (16), whose absorption limit is in the overlap area, and its pass band in the measured component absorption band. A similar but tiltable filter (17) is provided before the first chamber (6).