Conductivity meters, also known as electrical conductivity (EC) meters, measure the ability of a solution or material to conduct an electrical current. This measurement helps determine if the solution is, for example, contaminated or contains too much saline. In general, pure solutions, such as distilled water, have low conductivity. More saline- or nutrient-rich solutions, such as seawater or fertilizers, have high conductivity. Conductivity measurements are often used with total dissolved solids (TDS) measurements, which are typically expressed in ppm (parts per million). TDS consist of dissolved minerals and salts. To determine the amount of TDS, conductivity is measured, and the result is converted to a TDS measurement. Different meters provide results for conductivity, TDS, or both, and the application determines meter selection. Conductivity meters are used in research laboratories and a variety of industries, such as water-quality testing, waste-water treatment, hydroponics, agriculture, aquaculture, and cosmetics manufacturing.
YSI manufactures instruments, sensors, and software for environmental water quality monitoring and testing. The company, founded in 1948, is headquartered in Yellow Springs, OH.