Multifunctional mixed gas photoacoustic detection device and method

According to the multifunctional mixed gas photoacoustic detection device and method, a signal generator modulates the frequency according to gas to be detected and sends out a rectangular wave voltage signal, a quantum cascade laser device sets the temperature through temperature control according to the corresponding signal and generates infrared laser with a certain wavelength, the laser wavelength corresponds to the type of the detected gas, and the detection result is accurate. And the erbium-doped fiber amplifier is used for enhancing the laser power generated by the laser. The to-be-detected gas in the photoacoustic cell and the infrared laser generate a photoacoustic effect to cause the air pressure change in the photoacoustic cell, a sound pressure signal in the photoacoustic cell is detected through the microphone, the sound pressure signal is amplified by the corresponding preamplifier and then transmitted to the lock-in amplifier, the lock-in amplifier converts the sound pressure signal into a pho