Knowledge Bank

“The accuracy of spectrosopic absorptance measurements can be seriously affected by the presence of absorbing species in the atmosphere anywhere in the optical train The error is due to the baud-pass nature of a monochromator and is just as severe when a double beam spectrometer is $used1$ as when a single-beam spectrometer is used. Using the method of $Sakei2$ for the calculation of the integrated absorptance at a pair of over- absorption lapping absorption lines, we have calculated the error in the measured integrated absorptance of a sample gas which contains $H2O$ or $CO2$. A number of experimentally important cases have been considered with the object of correcting the measured absorptance. The calculations are compared with experiment. 255 (1960). “