Introduction

Electroresistance particle size analyzers (e.g., the Coulter Counter or the Elzone [Particle Data Inc.]) have long proven suitable for grain size analysis of sediment in the size range 0.5–1,000 µm. Very small amounts of material are required to perform a highly accurate size analysis based on the volume of the individual particles in the sample. The same analytical method can be applied both to unconsolidated bottom sediments and to material sampled from a suspension, thus providing a single method of analysis that can be used to study sediment from source materials to deposition.

This chapter describes the principles of electroresistance counters and discusses the techniques developed by the Sediment Dynamics Lab, Physical and Chemical Sciences Branch, Department of Fisheries and Oceans, Bedford Institute of Oceanography for the analysis of naturally occurring sediments of divers origin. It does not discuss detailed operation and calibration of the instrument or its accuracy and precision; such information is available in manufacturers' handbooks and in earlier works on electroresistance techniques (see, e.g., Coulter, 1957; Berg, 1958; Wales & Wilson, 1961, 1962; Sheldon & Parsons, 1967; Allen, 1968; Walker & Hutka, 1971; McCave & Jarvis, 1973; Shideler, 1976; Kranck & Milligan, 1979).

Our methods were designed for a model TAII Coulter Counter, with population control accessory, interfaced to an HP85 microcomputer using software developed in our laboratory (Fig. 8.1). Interfacing of the multichannel particle analyzers with computers has now become standard, and manipulation of the raw data has been facilitated (see, e.g., Muerdter et al., 1981).