Water contains particles in it that can tell about the characteristics of the water. Knowing about the size and the distribution of the particles in water can help in knowing a number of things. The source of the water can be known such as from a stream or a river through these particles. Also it can be understood that how much purity the water has and what techniques should be used to treat such water. Normally, a number of filtration techniques and filters are used in such a method but there are four main approaches.

• 1. Optical microscopy is the method to count the particles in the water directly under a microscope.
• 2. Coulter counting is carried out by using instruments with electrical sensing zones.
• 3. At times also some light blockage instruments are used.
• 4. Again the water particles can be analyzed by using a light scattering instrument that can be laser-based.

These methods are standardized as per the American Public Health Association, Water Environment Federation, and the American Water Works Association. Till now our laboratory experts have carried out such tests as per the standards for many industries and organizations.