Preliminary studies using digital images and tomography in atomic spectrometry

Abstract

Three techniques for studying spatial emission from sources used in analytical atomic spectrometry are described. Photographic evaluation using digitisation by (i) a microdensitometer with a computerised interface and (ii) a television camera digitiser, were compared with computerised tomography using a filtered back projection algorithm. The photographic methods were used to study a direct current plasma and although useful information on plasma structure could be obtained, details of the internal structure were obscured as the images presented the sum of the signal in the direction viewed. There were also limitations to quantification of data. A tomographic system using a self-scanning linear photodiode array interfaced to a laboratory computer is described which should overcome these limitations. The application of this system is illustrated using a laminar flow air-acetylene flame.