Infrared gas analyser

摘要

An infrared gas analyser comprises an infrared-radiation source, a measurement cell into which the gas to be analysed is introduced, and in which an infrared beam fed from the radiation source is absorbed by the gas to be analysed, and a detector device having two detector cells, connected together by a gas-flow channel, each of which has an infrared window, for detecting an intensity difference between infrared beams which have passed through the infrared window, through a pressure difference of a gas enclosed in the detector cells, the absorption wavelength range of which is equal to that of the gas to be analysed, the pressure difference being caused by a difference, between the detector cells, in the infrared absorption by the enclosed gas. The detector device comprises a multiplicity of thermally decoupled thermal sensors, each composed of a pair of thermally coupled thermal elements which are arranged in the gas-flow channel, in order to detect a gas flow, caused by the pressure difference, and convert the detected gas flow into an electrical signal.