Use this sensitive measurement board to determine the quality of water based on its total dissolved solids or TDS. Find out wether your tap water is clean, or keep an eye on your aquarium water, and more! This set includes the measurement board as well as a detachable water-proof measurement probe of 60 cm. The board has a standard 3-pin header interface connector and has a simple analog voltage readout. The TDS measurement ranges from 0 - 1000 ppm, and has an accuracy of ± 10 % full-scale at 25 °C.