TDS meter is the abbreviation of "Total Dissolved Solid" in English, meaning the total amount of dissolved solids. Total dissolved solids refer to the sum of inorganic salts and organic matter dissolved in water. Its main components include calcium, magnesium, sodium, potassium ions, and carbonate ions, bicarbonate ions, chloride ions, sulfate ions, and nitrate ions. Therefore, a TDS meter is an instrument for testing the total amount of dissolved solids. The unit of a TDS meter is ppm (i.e., mg/L), and its value is defined as a certain proportion of the conductivity value, generally taken as around 0.7. The reference temperature for automatic temperature compensation in a TDS meter is usually 25°C, and the temperature coefficient is generally 2%/°C.


KL-139A TDS meter is waterproof, with an IP55 waterproof rating.


KL-139B TDS meter can be wall-mounted or embedded, making it easy to install, operate, and maintain. It can be used with both AC and DC power sources.