Particle size analyzers and particle count analyzers are used to determine the physical makeup of samples, specifically the size and count of particles in a sample or process stream.  Particle size analyzers use one of six principal techniques to determine the size of particles in the sample including, dynamic light scattering, electrozone sensing, laser diffraction (LALLS), microscopy, sedimentation and sieving.  Particle count analyzers use one of two main techniques for determining the count of particles in a sample, light blockage and filter blockage.  Commonly particle size analyzers and particle count analyzers will measure zeta potential, a measure of the magnitude of the repulsion or attraction between particles.