Gas concentration detection device and method based on photoacoustic cell

A gas concentration detection device comprises a detection module 1, a sound source driving module and a data collecting and processing module 4. The detection module comprises an acoustic resonant cavity 125, a sound wave signal generating mechanism 127 e.g. buzzer, a sound wave signal collecting mechanism 126 e.g. microphone, a gas inlet 121 and a gas outlet 122. Sound signals with different frequencies are generated, and an amplitude-frequency curve graph (Fig.3) is drawn based on the collected sound wave signals. The resonant frequency of the cavity is determined based on the graph, and the concentration of the gas is determined based on a relationship between resonant frequency and gas concentration. The device does not use a laser as in traditional photoacoustic spectroscopy.