The Ohaus STORP1 Gel Plastic ORP Electrode is an Oxidation-Reduction Potential (ORP) electrode that tests for the overall availability of electrons in a medium, specifically the ratio of positive and negative ions in the solution. They are also sometimes referred to as Redox electrodes.
ORP is the only practical method used to electronically monitor sanitizer effectiveness and it is also commonly tested in water, such as swimming pools and aquariums.
ORP is expressed in millivolts (mV). -1000 mV to 1000mV is a common range for ORP tests. The pH value influences the ORP value significantly.
The STORP1 uses a gel for its reference electrolyte, and uses a ceramic pin junction type.