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Figure 18.
Magnitude and phase signals versus frequency calculated for thin
free-standing films of different thicknesses.
The magnitude ratio is relative to the signal of a 2-mm-thick sample.
The phase scale zero is coincident with the excitation waveform zero.
The FT-IR PAS technique is used extensively in industrial and other
laboratories on a wide range of applications.
Its main value for the majority of users is the ease by which FT-IR
spectra can be measured on nearly any sample without sample preparation.
The second important value to the user is the ability of FT-IR PAS to
provide a better understanding of materials with depth varying compositions.
1.
Process characterization. In
this case following paint cure as a function of baking temperature.
Six applications will be presented, with each one typical of a particular
area of application or of an important consideration in FT-IR PAS measurements.
The applications include:
2.
Qualitative and quantitative analysis of woods of various tree species.
3.
Increasing surface specificity by linearizing the FT-IR PAS signal to
observe a surface treatment on fibers.