A rapid method of spectrographic analysis

Abstract

A process has been developed to enable Spectrographic analyses to be carried out in approximately ten minutes. This speed has been attained chiefly through attention to the methods of processing the photographic plates, “which are developed and fixed in ultra rapid reagents, washed for a minimum time and dried in an oven designed for the purpose. A single analysis can be carried out in 8 1/2 minutes with an error of ± 4% using fast photographic plates or in 9 1/2 minutes with an error of ± 3% using a slower plate. An addition of about 2 minutes to either of these times permits duplicate determinations to be made with a reduction of some 30% in the analytical error. It is suggested that in routine practice duplicate determinations should be carried out wherever time permits; this precaution is particularly desirable, apart from the increase in accuracy it allows, in applications where the method is to be used for controlling the composition of molten metal prior to casting. In this case any delay in the release of the analytical result, due to a blemish on the photographic emulsion or a scratched or dirty plate due to faulty manipulation during processing, may cause serious inconvenience in the casting shop or refinery.