Patent ID: 11940375
Assignee: DALIAN UNIVERSITY OF TECHNOLOGY
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 3:
4. The sensing system according to claim 3, wherein a working process comprises the following steps:
step 1: turning off the photoacoustic excitation light source (3), wherein the detection light is reflected on a surface of the fiber-optic Fabry-Perot interferometer after entering the fiber-optic photoacoustic sensing probe (5), to output an interference signal;
step 2: performing demodulation and spectrum analysis on the output interference signal to obtain influence of ambient noise, and then determining a low-interference frequency as a working frequency;
step 3: driving the photoacoustic excitation light source (3) after determining a modulation frequency, wherein the excitation light is incident into the fiber-optic photoacoustic sensing probe (5) to cause a photoacoustic effect and generate a photoacoustic signal;
step 4: restoring the photoacoustic signal by using an interference-intensity demodulation method, and performing spectrum analysis on the signal; and
step 5: calculating a concentration of a to-be-measured gas based on an amplitude of the photoacoustic signal.