Photoacoustic spectrum gases detecting technique can be well applied to on-line monitoring of dissolved gases in transformer oil.In order to improve the monitoring SNR

this paper combines wavelet thresholding denoising with chaotic detection to restrain strong noise interference in photoacoustic signal detecting process

and uses LabVIEW and Simulink to set up signal detection system and pick up weak photoacoustic signal.The test results show that this method is very sensitive to weak periodic signal submerged in strong noise

and can effectively restrain strong noise.