FT-IR PAS measurements have been made of the optical properties of powdered samples at temperatures up to 350° C. These indicate that sample emission must be taken into account and that photoacoustic emission spectroscopy can be used to obtain spectral data. The experiments are discussed in terms of a model of an ideal FT-IR. It is shown that the high temperature spectra must be interpreted in terms of an absorption and sample emission signal that have a relative phase difference of 180°.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics