Many ionic substances are easily measured by means of potentiometry using ion-selective electrodes (ISE). The potential between the ISE and a suitable reference electrode depends on the concentration of the ion-species to be measured. The most common ion-specific electrode is the pH-electrode.

This versatile measuring principle is used in the ISE-Analyser/Titrator to measure a variety of different parameters like halides, ammonium, sulphate, sulphide etc.