Sampling by Photoacoustic Detection

The basics of photoacoustic spectroscopy (PAS) are described in Chapter 5. PAS is useful for examining highly absorbing samples that are difficult to analyze by other IR techniques. Minor or even no sample preparation is required here. The size and shape of the sample are not critical. PA spectra can be obtained from a wide variety of samples such as powders, polymer pellets, viscous glues, single crystals, and single fibres. 

PA spectra are generally similar to conventional IR spectra except that strong spectral bands will often be saturated (truncated). However, the presence of such truncated bands does not appreciably limit the practical use of PAS. Depth resolved 

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