A flow ultramicroscope for particle counting and size distribution analysis

A machine is described which will count particles or droplets in suspension in a liquid down to 0.1 μm and which is capable of size measurements between 0.1 μm and 2.0 ,μm. It works on the basis of the flow ultramicroscope. A stream of particles is passed through a laser beam and as each one passes a pulse of scattered light is produced. The pulses are detected by a photomultiplier and can be counted. Additionally the intensity of the pulses can be measured and a size distribution built up for the particles.