home site map contact


Instruments, Controllers & Sensors




Portable Turbidity meters

Bench Turbidity meters

Online Turbidity

Flame Photometry

BWB-1 Flame Photometer

Dissolved Oxygen (DO)

Handheld Dissolved Oxygen IP67 Dissolved Oxygen Meters

Bench Dissolved Oxygen Meters

Industrial Dissolved Oxygen 

Dissolved Oxygen Probes

DO Probe Conditioner


Portable pH Testers

Handheld pH Meters

Waterproof pH Meters

Bench pH Meters

Industrial pH Controllers

Replacement pH Electrodes


Free Chlorine

Total Chlorine

Cyanuric Acid

Redox (ORP)

Portable Redox Testers

Handheld Redox Meters

Waterproof ORP Meters

Bench ORP Meters

Industrial ORP Controllers

Replacement Metal ORP Probes

Conductivity (EC)

Portable Conductivity Testers

Handheld Conductivity Meters

Waterproof Conductivity Meters

Bench Conductivity Meters

Industrial Conductivity Meters

Replacement Conductivity Cells

Total Dissolved Solids (TDS)

Portable TDS Testers

Handheld TDS Meters

Waterproof TDS Meters

Bench TDS Meters

Industrial TDS Controllers

Replacement Cells

Ion Concentration

Handheld Ion Meters

Waterproof Ion Meters

Bench Ion Meters

Ion Selective Electrodes (ISE)


Portable Salinity Testers

Handheld Salinity Meters

Bench Salinity Meters

Salinity Sensors

Multi-parameter Bench Meters


Please click above to view this range


Multifunctional Controller


Chlorine Dioxide

Paracetic Acid

Hydrogen Peroxide 



Bench Resistivity Meters

Industrial Resistivity Controller

Resistivity Cells

Electrochemical Sensors

pH, Reference, Conductivity, Redox, Dissolved Oxygen, Ion Selective Electrodes, Calibration Solutions, Hollow Cathode Lamps and

Deuterium Lamps

What is Redox (ORP)?

Oxidation-Reduction Potential (ORP) or Redox potential measurements are used to monitor chemical reactions, to quantify ion activity, or to determine the oxidizing or reducing properties of a solution. ORP is a measurement of the electrical potential of a redox reaction and serves as a yardstick to judge how much oxidation or reduction takes place under existing conditions. ORP electrodes measure the voltage across a circuit formed by the measuring metal half cell and the reference half cell. When the ORP electrode is placed in the presence of oxidizing or reducing agents, electrons are constantly transferred back and forth on its measuring surface, generating a tiny voltage.

For more information on Redox Measurement, please visit our technical area

How Can Redox be Measured?

Redox can be measured using the millivolt mode of a pH meter. In the laboratory a bench pH Meter would be used, in outdoor and field applications a portable pH Meter is preferred and for plant and process applications an online pH controller would be used.

What products do R.M.S Ltd offer for Redox Measurement?

Portable Hand Held Instruments:

Our EcoScan compact palm-top ORP/pH meters are economically priced, user-friendly and simple-to-use features such as : Microprocessor based, easy and quick push button calibration, auto buffer recognition, automatic temperature compensation (ATC), easy to read custom LCD, hold function, auto power off and self diagnostic.

Please Click on the picture below to view in detail:







Outdoor & Field Applications: 


Our New large screen dual line display ORPTestr meters are the WORLD'S FIRST Redox testers to utilize user-replaceable Double Junction Electrodes giving significantly longer electrode life, especially when used in harsh environments. These feather-weight testers have extended measurement Range up to -999 to +1000 mV and are ideal for use in rugged outdoor and wet applications. 

Please Click on the picture below to view in detail:







Waterproof Portable:

The CyberScan ORP/pH Meters are an ideal choice for anyone requiring to take ORP measurements in rugged outdoor field work or in situ Plant and Process applications - being waterproof and robustly built, the chance of accidental damage is virtually eliminated.  Not only is this instrument waterproof but in the event of accidentally dropping it into liquid, it will float to facilitate easy retrieval.

Please Click on the picture below to view in detail:







Laboratory Applications: 

Choose from our wide range of Bench ORP/pH meters, from the low cost, high specification CyberScan pH510 through to our top of the range touch-screen CyberScan pH5000. Incorporating advanced programmable features to suit the demands of today's scientist these meters make laboratory ORP testing procedures routine with user-customisable options. Some top-of-the-line bench meters even automatically print or store measurements at timed intervals or when readings stabilise.

Please Click on the picture below to view in detail:







Plant & Process Applications:

Our Alpha 2000 is our top of the range industrial ORP/pH process control instrument. Advanced user-customizable features in the Alpha's powerful SETUP function include: Two Galvanically Isolated Scaleable 0-20/4-20 mA Outputs for fine control, 2 independent set-points with hysteresis protection, built-in proportional control, and noise grounding functions. Being menu-driven, the alpha range of controllers offer quick access and greater flexibility to configure measurement functions to suit the needs of process plants that demand high-end features at an economical price. 

Please Click on the picture below to view in detail:







Replacement Sensors and Ancillaries:

At R.M.S Ltd we can supply replacement Redox Electrodes for both Industrial and Laboratory applications that are compatible with all modern instruments. All of our electrochemical sensors can be supplied with or without temperature compensation. All we need is the make and model of your ORP/pH meter so that we can determine the correct connector etc - please email, phone or fax us with your requirements and one of our team will contact you. 

Please Click on the picture below to view in detail:








· Home
· Links of interest
· Contact Us



We are proud to announce the launch of the Worlds First CFR 21 Compliant - Windows CE Driven Multi-Parameter 6000 Range of Bench Meters. Ideal for use in industries such as Pharmaceutical, Food & Drug Manufacture and Health & Human Services. Please click here for details.

We accept all major credit/debit cards - please contact us for our best possible prices!; any questions? Why not try our Technical Area where you will find an in-depth explanation of many relevant aspects within the field of electrochemistry! more..


Russell Mainstream Supply Ltd.


Cameron House, 8 Crown Square, Kingskettle, Cupar, Fife, KY15 7PW


Phone: +44 (0)1337 831192

Fax: +44 (0)1337 371192


Email: Sales@rmprocesscontrol.co.uk 



home · links · contact us · site map
Copyright 2009 -- Russell Mainstream Supply Ltd