Wellon ORP Meter, TDS Meter, pH Meter and pH Liquid Drop for Water Testing – 4 Pcs
An ORP meter measures very small voltages generated with a probe placed in ozonated water. The electrode is made of platinum or gold, which reversibly looses its electrons to the oxidizer. A voltage is generated which is compared to a silver (reference) electrode in a silver salt solution, similar to a pH probe. The approximate range of ORP values this meter can show is -1900 to 1900 mv.