Note:
The ordinate quantity is usually the percentage of the incident radiation that is transmitted, usually called the percent transmission, with range \(\pu{0}\) to \(\pu{100 \%}\). If the ordinate quantity is the fraction transmitted, i.e., the transmittance, the ordinate range is \(\pu{0}\) to \(\pu{1}\) and the spectrum may be called a transmittance spectrum.