Electronic Scanning for Flat Bed Densitometry

Abstract

The paper discusses the advantages and disadvantages of replacing the traditional optical scanning methods used in densitometers for the evaluation of 1D and 2D flat bed separations (Chromatography as well as electrophoresis) by electronic devices. The main advantage expected from such a replacement are lower hardware cost and much higher data acquisition speed. Disadvantages are spectral limitations and a more difficult optical design.

Electronic scanning can be performed by vacuum tubes (vidicons) and solid state devices. The trend goes to increased use of the latter. Solid state sensors can in turn be divided into line and matrix sensors. Only devices in large scale integrated design are considered. The relative advantages and disadvantages of the various types of sensors are briefly discussed also in comparison to optical scanning. Briefly mentioned are high resolution laser scanning and pyroelectric arrays with flat spectral response. In the final paragraph are outlined specific problems associated with sampling, analog to digital conversion and storage for the high speed, high volume data flow produced by electronic scanning.