ORP electrodes deliver a sensitive voltage signal from reactions in aqueous solutions, where the reaction partners exchange charges on the metal surface of the electrode. The scale is comparable with that of pH measurement. Typical areas of use are the monitoring of the disinfection effect, the determination of ORP potentials in biochemical reactions, measuring in waters of different quality and more. The platinum electrodes can be used universally, the gold electrode is especially suited for strongly oxidizing media without the presence of chloride. The silver electrode is intended for argentometry.