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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 Dissolved Oxygen (DO)?

Many gases mix with water like nitrogen and oxygen without chemically reacting with it. Some gases chemically react with water e.g. ammonia, CO2, and HCl. Oxygen does not react with water. Dissolved Oxygen (DO) is really a physical distribution of oxygen molecules in water. There are two main sources of DO in water: atmosphere and photosynthesis. Waves and tumbling water mix air into water where oxygen readily dissolves until saturation occurs. Oxygen is also produced by aquatic plants and algae as a by-product of photosynthesis.

For more information on Dissolved Oxygen Measurement, please visit our technical area

How Can Dissolved Oxygen be Measured?

Dissolved Oxygen can be measured in the laboratory using a bench Dissolved Oxygen analyzer, in outdoor and field applications a portable DO Meter would be used and for plant and process applications an online DO controller would be used. Dissolved Oxygen can be measured using the Polarographic (Clark Cell) Method or the Galvanic Cell Method.

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

Portable Hand Held Instruments:

The R.M.S DO 6 Portable Dissolved Oxygen Meter offers the user an economical, accurate and reliable portable DO2 meter that delivers superior reliability and accuracy at very competitive prices.

Please Click on the picture below to view in detail:







Outdoor & Field Applications: 

The CyberScan DO300 Waterproof Dissolved Oxygen Meter is the ideal choice for anyone requiring to take DO measurements in rugged outdoor field work i.e. Fish farming or in situ Plant and Process applications.

Please Click on the picture below to view in detail:







Laboratory Applications: 

The R.M.S DO1500 Laboratory Bench Dissolved Oxygen meter offers the user an extremely accurate and reliable Benchtop DO Metre.

Please Click on the picture below to view in detail:







Plant & Process Applications:

The Alpha DO1000 in line Dissolved Oxygen Monitor/Controller offers the user the facility to measure dissolved oxygen levels in oxygenated water using powerful programmable functions and enhanced performance that simplify complicated procedures associated with continuous in line Dissolved Oxygen measurements. Advanced user-customizable features in the Alpha Do1000'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 DO1000 controller offers 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 DO2 sensors for both Industrial and Laboratory applications that are compatible with all modern instruments. All of our electrochemical sensors can be supplied with or with out temperature compensation. When it becomes necessary to change the membrane of our Do probes, it is a simple task to unscrew the membrane cap, fill a new one with the filling solution provided and screw on to the probe. All we need is the make and model of your DO 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:







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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 



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