What is ORP?

Oxidation reduction potential, commonly referred to as REDOX, is a measured in millivolts of the tendency of a chemicals substance to either oxidize or reduce another chemical substance.

Oxidation is classified as the loss of electrons by an atom or ion while reduction is the net gain of electrons by an atom or ion.

Accurate ORP Sensor

How is ORP Measured?

ORP is measured by using an electrochemical ORP (REDOX) sensor. Very similar to a pH sensor, the orp sensor is normally a combination type which contains a measuring electrode and reference electrode.

The measuring cell, typically a noble metal such as platinum or gold, detects changes in REDOX potential while the reference provides a stable comparison signal. ORP is expressed in millivolts and is typically a pH instrument while using the mV scaleto to display the readings.


Why is the ORP measurement necessary?

ORP measurements are used as a cost effective method to control various processes. Effective disinfection using chlorine, ozone, or bromine are commonly used. It is also used in the process applications in order to control the destruction of chromate or cyanide, as well as bleach production and wet scrubbers.

Common Applications:

  • Prechlorination and dechlorination in water/wastewater treatment
  • Cyanide destruction and chromate reduction in metal finishing
  • Ozone treatment process control
  • Bleach production
  • Poultry processing
  • Fruit and vegetable washing
  • Pulp bleaching
  • Chlorine addition in commercial swimming pools & spas