ORP Sensors - Oxidation Reduction Potential

Industrial ORP sensors for monitoring water oxidation and disinfection levels in aquaculture. Essential water quality sensors for maintaining healthy aquatic environments in fish farming operations.

How to choose an ORP sensor

An ORP sensor (also called an ORP probe or redox sensor) reads oxidation reduction potential in millivolts: how strongly the water oxidizes or reduces. It is the standard way to watch ozone, chlorine and other disinfection processes continuously. The three Agrinovo models differ in output signal, mounting and body material.

ModelOutputRange and accuracyMounting and bodyChoose it for
ORP-100 RS485 Modbus RTU-1999 to +1999 mV, ±3 mV3/4 in NPT thread, ABS exteriorGeneral water monitoring with a digital signal
ORP-110 RS485 Modbus RTU-1999 to +1999 mV, ±3 mV3/4 in NPT front and back, PTFE bodyIndustrial lines and tanks, immersed or threaded into a pipe
ORP-10 Analog-2000 to 2000 mV, ±1 mVPG13.5 thread, 12 mm diameterIn-line mounting on an existing ORP transmitter

Digital or analog

The ORP-100 and ORP-110 convert the signal inside the probe and send a finished reading over RS485 Modbus RTU, so long cables and electrical noise matter far less. Both hold a stability of 2 mV or better over 24 hours and connect to an Omni Genesis controller on the same bus as pH, dissolved oxygen and conductivity sensors. The ORP-10 is a slim analog electrode for a transmitter that is already in place.

All three are rated IP68. The ORP-110 adds four-layer isolation and a single-point offset calibration. For the selection in detail, read the ORP probe selection guide, and for ozone dosing in recirculating systems, ORP control of ozonation in RAS.

ORP sensor questions

What does an ORP sensor measure?

Oxidation reduction potential, in millivolts. A higher positive reading means the water is more oxidizing, which is why ORP is used to follow ozone and chlorine treatment.

Is an ORP probe the same as an ORP sensor?

Yes. Both names, and "redox sensor", describe the electrode that sits in the water.

Does an ORP sensor measure chlorine concentration?

No. ORP shows the oxidizing strength of the water, not the amount of a specific chemical. The same chlorine dose gives a different ORP reading at a different pH, so ORP is read together with pH.

Which ORP sensor connects to a controller or PLC over Modbus?

The ORP-100 and the ORP-110. Both output RS485 Modbus RTU.