Study on Denoising Method of Photoionization Detector Based on Wavelet Packet Transform

Aiming at the task of noise suppression caused by photoionization detector (PID) monitoring signal volatile organic compounds (VOCs) due to local non-uniformity photocathode surface PID in ionization chamber, this paper proposes an analytical method a with adaptive weight small wave package decomposition node. The is transmitted upper machine software through single-chip microcontroller. appropriate wavelet packet level determined according time frequency characteristics original PID, and optimal base selected polynomial fitting quality evaluation index. By comparing signals processed traditional denoising presented paper, superiority proposed was verified. This can eliminate generated on chamber high humidity environment, which lays foundation for accurate VOCs environment.