An ORP meter (oxidation reduction potential meter, also called a redox meter) measures the tendency of a water sample to gain or lose electrons, reported in millivolts (mV). It is the fastest way to confirm that a disinfectant such as chlorine is actively sanitising — which is why ORP testing is essential for drinking water, swimming pools and spas, aquaculture,cooling towers, food and beverage processing, and wastewater treatment.
Pacific Sensor Tech supplies a full range of ORP meters and redox potential testers from Hanna Instruments, Milwaukee and Gondo — from low-cost pocket testers to professional data-logging bench meters and inline ORP controllers. Every meter measures ORP in mV, and our combination models add pH (and on some units EC, TDS and temperature) so you can check water quality with a single instrument.
An ORP meter (oxidation reduction potential meter, also called a redox meter) measures...
Pocket-size pH / ORP / Temperature Meter with rep…
ORP and Temperature Meter is designed to accurate…
pH and ORP meter for swimming pool, hot tub, or s…
Waterproof pH, ORP and temperature meter
-2…
Pocket ORP meter : Range ±1999 mV, Resolution 1 …
pH, ORP, Conductivity, TDS, Salt, Temperature Met…
pH / ORP / Temperature MAX Portable Meter
pH / ORP / Temperature MAX Portable Meter, Data L…
pH / ORP / Temp Laboratory Bench Meter
pH / ORP / Temperature Laboratory Bench Meter
…
pH/ORP/ISE/Temp Logging Bench Meter
pH/ ORP/ Conductivity/ TDS/ NaCl/ Temp
Set point: 4 to 8 pH, -200 to 600 mV
Redox ORP Controller, Set Point Range: 0 – …
Portable & handheld ORP meters are ideal for spot-checks and fieldwork around pools, tanks and treatment plants — pick a waterproof model with a replaceable double-junction electrode and automatic calibration for the longest service life. Benchtop ORP meters suit laboratory and QC work where you need higher resolution, GLP data logging and printout or USB output.
ORP / pH controllers continuously monitor redox and switch dosing pumps to hold a set point automatically. If you also need acidity readings, choose a combination pH/ORP meter.
Accurate redox readings depend on a clean, well-maintained ORP sensor. We stock replacement ORP probes and electrodes, ORP calibration and test solutions (for example 600 mV standard), and storage solution to keep the platinum sensor responsive. Calibrate against a known ORP standard regularly and replace the electrode when readings drift or slow — this is the single biggest factor in reliable oxidation reduction potential measurement.
Not sure which ORP meter is right for your application?
Our water quality specialists can help you match a meter, probe and calibration kit to your water type and budget — contact us for advice, or browse the ORP meters above.
An ORP meter measures oxidation reduction potential (ORP), also known as redox potential — the net tendency of a solution to oxidise or reduce, expressed in millivolts (mV). In water treatment it indicates how effectively a disinfectant such as chlorine is sanitising the water. A higher positive ORP value means stronger oxidising (disinfecting) power.
ORP meters are used to verify disinfection and water quality in drinking water, swimming pools and spas, aquaculture and aquariums, cooling towers, food and beverage production, hydroponics, and wastewater treatment. Because ORP responds instantly to changes in sanitiser level, it is often used to automatically control chlorine or chlorine-dioxide dosing.
For drinking water and swimming pools, the World Health Organization references an ORP of at least 650–700 mV as effective for disinfection. Pools and spas are commonly maintained around 650–750 mV. Always follow your local guideline and your sanitiser manufacturer's recommendation — an ORP meter lets you confirm you are within range in seconds.
A pH meter measures acidity or alkalinity, while an ORP meter measures redox (oxidising/reducing) potential in millivolts. They are related — pH affects how effective a given sanitiser is — so many users buy a combination pH/ORP meter that measures both with one instrument.
An ORP meter is the complete handheld or benchtop instrument with a display. An ORP probe or electrode is the sensor that contacts the water; it is replaceable and wears over time. An ORP controller is a fixed/inline unit that continuously monitors redox and switches a dosing pump to hold a target value automatically.
Rinse the electrode, then immerse it in a known ORP calibration standard (for example a 470 mV or 240 mV solution) and adjust the meter to match. Calibrate regularly, keep the platinum sensor clean, and store it in the correct storage solution. If readings drift or respond slowly, it is time to clean or replace the ORP electrode.
Choose a portable/handheld ORP meter for field spot-checks, a benchtop ORP meter for laboratory accuracy and data logging, and an ORP controller for continuous monitoring and automatic dosing. For general water and pool testing, a waterproof handheld redox meter with a replaceable double-junction electrode offers the best value.
Yes. Pacific Sensor Tech dispatches ORP meters, probes and calibration solutions Australia-wide, including Sydney, Melbourne, Brisbane, Perth and Adelaide. Contact our team for stock, lead times and help selecting the right oxidation reduction potential meter for your application.
