Call: A.WIHARTA 081294124885 085778084789 087784022201 Oxidation reduction is a process by which a molecule or ion loses or gains electrons. This occurs most readily in water treatment and in pool and spa maintenance where an oxidizer, such as chlorine, is added to the water to destroy contaminants. The higher the ORP value, the greater the sanitizing power of your water. HI 98201 is ideal for swimming pools and spas and can provide a valuable indication of water quality. This tester utilizes a platinum electrode and HANNA unique renewable cloth junction, that can be pulled out when clogging occurs, reactivating the reference and restoring the electrode. * To be replaced by authorized technical personnel only. Order Information: HI 98201 ( ORP) is supplied with protective cap, batteries and instructions