How does Single Particle Optical Sizing (SPOS) work?
Particles in a gas or liquid suspension pass through a narrow, slab-like region (photozone) of uniform illumination produced by light from a laser diode or incandescent bulb. The particle suspension is sufficiently dilute so that particles pass one at a time through the photozone. The particle causes a detected pulse where its magnitude depends on the diameter of the particle. The particle size distribution is constructed one particle at a time. Pulse heights are calibrated with a standard calibration curve obtained from a set of uniform particles of known diameters. The SPOS technique is ideal for measuring particle size distributions of a wide variety of particle suspensions, emulsions, and dispersions.
