Particle counters operate based on different principles, including light scattering, electrical sensing zone (Coulter principle), and condensation particle counting. Light scattering involves directing a laser beam at the particles and measuring the scattered light, which helps determine the particle size and count. The Coulter principle measures changes in electrical resistance as particles pass through a small aperture, while condensation particle counters grow nanoparticles to a detectable size using a supersaturated vapor.
