Kelilong pH,EC,TDS,ORP Testers,Redox readings in swimming pools,pH and ... Refractometer, Massager,etc KL-169A Waterproof Pen type ORP Tester Descriptions: ORP is Oxidation-Reduction Potential , it represents the ... solution of oxygen Of potential. The ORP value is a measure of the ability of an ... aqueous solution of redox. Its units are mV.ORP meter is a specialized instrument of the redox ...