TDS meter is the abbreviation of 'Total Dissolved Solid', which refers to the total amount of inorganic salts and organic substances dissolved in water. Its main components include calcium, magnesium, sodium, potassium ions, as well as carbonate ions, bicarbonate ions, chloride ions, sulfate ions, and nitrate ions. Therefore, a TDS meter is a device used to measure the total amount of dissolved solids. The unit of TDS is ppm (i.e., mg/L), and the value is defined as a certain percentage of the conductivity, typically around 0.7. TDS meters have automatic temperature compensation, with a reference temperature of 25°C and a temperature coefficient of 2%/℃.
A 139 series of pen gauges are reliable, simple, and fast. This pen TDS allows for handheld measurements, and the LCD displays the measurement readings.