Excitation and Emission

Abstract

In order to obtain quantitative results from arc analysis, one must measure line intensities in spectra, but before doing this it is advisable to consider the extent to which the luminous vapour of the arc resembles the original sample in its composition. It is necessary to examine the formulae of the relationships which govern the entry of elements into the excited state in the core of the arc. These formulae are briefly stated in Section 2.1 and they permit the derivation of factors called K-factors (and Q-factors) which are then used to work out numerical values of the analyses. It should be understood that these are not two independent variables, but are factors related to two different ways of photographing part of the radiation from the arc, which are appropriate for different samples. The factors are defined in Section 2.2.