Aiming to the disadvantages of the normalized measuring technology of trace gas

and according to the feature of absorption spectrum of the trace gas between 4 000～400 cm-1

based on the infrared pyroelectric effect a trace gas detecting technology was presented.A prototype was set up which uses thermopile as a detector.A steel gas absorption cell is also as a infrared reflector.The system was tested using the gas CH4 as a sample trace gas. It has the ability to detect various gas by changing the corresponding optic-filter

or to detect number kinds of gases at same time with detect matrix.