Absorption Spectrum Definition:
In IR spectroscopy as well as UV-VIS spectroscopy, a plot that measures the percent transmittance or absorption as a function of frequency.
Absorption Spectrum Explained:
An IR spectrometer is designed to measure the % transmittance or intensity. As a result, the plot formed has the “% transmittence” on the Y axis, while the wavenumber is in the x-axis.
Uses of IR Absorption Spectrum:
The IP absorption spectrum provides important information on functional groups within a compound. Different functional groups have different absorption frequencies. Here is a sample chart: