ORP Sensors & Transmitters

ORP Sensors & Transmitters

ORP (oxidation-reduction potential) sensors and transmitters measure redox potential as a millivolt signal that reflects the aggregate electron activity in an aqueous medium. The measurement is inherently a sum parameter - highly effective for trend and endpoint behavior, but not a direct speciation or concentration readout for individual compounds. Systems typically include a noble metal measuring electrode and a stable reference system, paired with transmitters and assemblies suited to standard, hygienic, or hazardous areas.

ORP delivers process-relevant trend information in a compact signal, supporting control where redox state defines performance. Endress+Hauser positions ORP for disinfection ability trending in drinking water and pools, aeration control in wastewater treatment, and detoxification processes such as electroplating bath treatment or flue gas scrubbing. It is particularly useful where the process target is an oxidative or reductive condition rather than a specific analyte concentration.

Sensor selection is tied to redox chemistry and media behavior. Gold electrodes are cited as suitable for oxidation processes (e.g., cyanide oxidation or ozone measurement), while platinum electrodes are used in reducing processes such as chromate reduction or chlorine dosing. Reference junction design and diaphragm selection are critical where fouling, poisoning, or blocking risks exist, and must be matched to solids load, surfactants, and chemical aggressiveness.

Because ORP is temperature-dependent and comparative interpretation requires temperature context, robust systems incorporate temperature measurement and stable reference behavior. Portfolio elements include combination pH/ORP sensors for paired insight, calibration solutions and buffers, and a range of assemblies (fixed, immersion, flow, retractable). Automated calibration, cleaning, and maintenance concepts help sustain signal reliability where chemical films or deposits can compromise electrode response.

Typical applications include breakpoint control and residual management in disinfection, oxidation of cyanide and other hazardous species, reduction processes such as chromate reduction, control of redox conditions in biological treatment zones, monitoring of electroplating rinse and treatment systems, and trend control in chemical scrubber and wastewater neutralization/detox trains.

Miller Mechanical Specialties, an exclusive authorized representative of sales and service for Endress+Hauser.