A special-purpose computer for particle-size analysis

An analogue computer is described which operates in conjunction with the Karl Zeiss particle-size analyser. The analyser is used to measure the diameter distribution of bubbles in a photograph of a column of foam, and the computer makes use of this information to provide simultaneous and separate indications proportional to total surface area and volume as the analysis proceeds. These indications enable an immediate determination of the mean surface area of foam per unit volume of contained air for the sample. The computer may also be used with the analyser for the total area analysis of particles of approximately circular shape, or for total area and volume analysis of particles of approximately spherical shape