Beer’s Law and the Optimum Transmittance in Absorption Measurements

Beer’s law is used widely in the determination of cross sections and of unknown solution concentrations in the form τ = 10−A, where τ is the transmittance and A is the absorbance. By the criterion of minimum experimental error, the best value of the transmittance depends upon numerous parameters and varies between 2% and 90%. This paper considers the influence of the source, background, noise, counting time, and other parameters on the optimum transmittance.