A large number of salts such as carbonates, bicarbonates, chloride, sulphates, phosphates & nitrates of calcium, magnesium, sodium, potassium, iron and manganese etc., are found dissolved in natural water. Similarly coastal marine water contains substantial quantity of these salts. A high content of dissolved solids elevates the density of water, influences Osmoregulation of fresh water organism and reduces solubility of gases thereby reducing the utility of water for drinking, irrigation and industrial purposes. Therefore, determination of Total Dissolved solids is one of the important parameters in water analysis. SANSEL make digital TDS meter TDS 100 is extremely useful for fast and accurate determination of Total Dissolved Solids in a liquid. The use of solid state technology and IC circuitry makes this instrument versatile and reliable. The multi position selector switch quickly sets the digital display to the desired test range. The instrument is ideal for testing of natural water, drinking water, waste water, brine solution, sea water and soluble salts, etc.,