Gas detector, used for detecting trace gases, comprises resonator, photo-acoustic detection cell, phase-sensitive rectifier and/or output device, modulator and receiver

摘要

Gas detector comprises a resonator into which gas to be detected is introduced and light emission is coded with the absorption spectrum of the gas; a photo-acoustic detection cell, a phase-sensitive rectifier and/or an output device for measuring the absorption signal and the gas concentration; a device for modulating the emission spectrum of the laser and/or the absorption of the sample gas in the resonator and/or in an external cell; and a device for receiving the measuring signal based on the modulation frequency. An independent claim is also included for a process for detecting a gas using the gas detector. Preferred Features: The emission spectrum of a multiple mode laser is adjusted on the region of selected strong absorption lines of the sample gas and regulated.