https://doi.org/10.1351/goldbook.08261
Absorbance in the absence of reflection, scattering or luminescence.
Notes:
- Internal absorbance is a rarely used term in quantitative absolute intensity studies to emphasize that the necessary corrections of the transmittance for reflection and other cell effects have been made. Instrument manufacturers usually use the raw, uncorrected transmittance when calculating the absorbance. See experimental absorbance.
- Formally, \(A_{\rm{i}} = –\log_{10}(1 - \alpha_{\rm{i}})\), \(A_{\rm{i}} = –\log_{10}(T_{\rm{i}})\) for a sample that does not scatter or luminesce, where \(A_{\rm{i}}\) is the internal absorptance and \(T_{\rm{i}}\) is the internal transmittance.