An ion meter is a device used to measure specific ions in water with the use of an ion selective electrode. In most cases, an ion meter also allows simultaneous measurement of pH, mV and temperature, because this additional function is needed during ion measurement. The molar weight and valence of the measured ion are automatically included after selecting the specific ion. This allows to calculate the result for the selected unit and also allows to change one unit to another with automatic recalculation. Due to the complexity of sample preparation and measurement methods, the use of an ion meter for field measurements is not recommended. Ion-selective electrodes are usually supplied as a set of 2 separate electrodes: the measurement and reference electrode connected to separate terminals in the meter. Some electrodes are also available as units that combine the measurement and reference electrodes in one housing.
