Optical instrument for measuring particle sizes.

摘要

In an optical instrument for measuring particles in the size range of 0.5 microns to 300 microns, a laser beam is caused to pass through a sample stream of liquid containing particles to be measured. A photodetector detects a portion of the direct laser beam passing through the sample stream and the amplitudes of the pulses generated by this first photodetector provide a measurement of particles in the size range of 10 to 50 microns. A second photodetector detects forward scattered light from the laser beam passing through the liquid sample stream. The amplitudes of pulses generated by the second photodetector provide a measurement of pulses in the size range of 0.5 microns to 10 microns and the durations of pulses generated by the second photodetector provide a measurement of pulses in the size range of 50 to 300 microns.