(9) Internal Revenue Code means the Internal Revenue Code of 1986 in effect for the federal tax year beginning on January 1, 2007, not including any changes made by federal law after that date, and any regulations adopted under that code applicable to that period.
Absorbance spectroscopy, commonly referred to as spectrophotometry, is the analytical technique based on measuring the amount of light absorbed by a sample at a given wavelength.
The goal of any absorption spectroscopy (FTIR, ultraviolet-visible (UV-Vis) spectroscopy, etc.) is to measure how well a sample absorbs light at each wavelength.TIR is a method of measuring an infrared absorption spectrum. For a discussion of why people measure infrared absorption spectra, i.e. why and how substances absorb infrared light, see the article: Infrared spectroscopy.