Electro-optical soil porosity investigation by means of Quantimet-B equipment

Abstract

Conventional micromorphometrical methods of soil porosity characterization are very laborious. The measurements, however, can be accelerated considerably by application of an electro-optical image analysis system (image plane scanning). Therefore, the authors used a Quantimet-B equipment. It consists of a microscope, an epidiascope (magnification on screen X 2.9 to X4700), a television camera, a closed-circuit monitor, a detector unit and a computer. The main parameters to be measured are: A, the total area of features; P, the projection value, i.e., the total horizontally projected length of features; N, the number of features. A minimum chord control device enables to measure the features in several diameter classes. By investigating a number of samples of different soils the authors demonstrated the usefulness of Quantimet-B for micromorphometrical examination of soil porosity. For that purpose the apparatus can be used in two ways, viz: (1) the measurement of total porosity at the magnification used and the determination of pore size distribution; (2) a quantitative morphological characterization of soil porosity; for this purpose a classification of void complexes according to size, shape and spatial distribution has been developed which is based on A P - ratios .