WAVELET ANALYSIS ON PHOTOACOUSTIC SPECTRA OF DEGRADED PVC

Wavelet transform (WT) is introduced successfully to filter simultaneo usly the noise and the base line in complicated photoacoustic (PA) spe ctra. As the noise is often at very high frequency and the base line a t very low frequency, WT can fully demonstrate its capability of decom posing the signal according to the frequency. After wavelet transform, the relative strength of photoacoustic bands can be easily determined . Thus, WT can be expected as a powerful method in PA spectroscopy for analyzing the formation of polyenes with various conjugated numbers d uring degradation process.