About REFEX™ pH Sensors

Refex products represent a revolutionary advance in pH and ORP measurement technology that solves the key weakness of the reference electrode in traditional probe designs. These traditional designs depend upon having a porous junction to provide electrochemical connection between the probe’s reference electrode and the process flow being measured. This necessary contact with process fluid allows interaction with the [stable] internal liquid in the reference half-cell, commonly diluting and/or poisoning it and causing measurement drift while leading to eventual sensor failure. In harsh applications, this interaction can lead to rapid failure.

Refex pH and ORP sensors are reliable, accurate, stable, and give exceptionally long life (even in harsh petrochemical applications, probes can be expected to last 5 times longer than conventional designs) providing real savings in maintenance costs while dramatically increasing process quality. REFEX sensors are available in a industry standard sizes and will retro-fit to your existing systems and housings perfectly. For those with specific requirements, REFEX will design and manufacture unique sensors to customer specifications.

pH and ORP Combination Probes

REFEX combination probes are available in industry standard sizes and designed to fit in any existing or new “socket” where pH or ORP measurement is made.

REFEX reference sensors can be used in all applications, particularly those where fouling or poisoning conditions exist. REFEX sensors have a usable lifetime of 5 times longer than conventional sensors. REFEX reference utilizes a patented, highly stable, non-porous polymeric interface instead of a traditional porous liquid junction as used by conventional reference electrodes. The active reference area is the whole of the outside surface of the electrode and this super large contact area means that electrode performance is supremely resistant to coating. Poisoning effects are eliminated because the polymeric reference material is conductive to ions but not porous; the reference can operate electrically but electrolyte and process fluids are not exchanged.

pH/ORP Combination Probe Line-up

12mm Separates – pH, ORP and Reference Probes

REFEX 12mm separates are available in all industry standard lengths and a variety of connector/integral cable styles to ensure they will fit in any 12mm “socket” where pH or ORP measurement is made. REFEX sensors work will all popular pH/ORP transmitters with high impedance inputs.

REFEX reference sensors are a tremendous upgrade to traditional porous/flowing junction reference probes and can be used in all applications, especially those where fouling or poisoning conditions exist. With lifetimes expected to be 5 times or more than existing designs, REFEX reference electrodes represent significant savings in maintenance and replacement costs.

REFEX sensors are available in a variety of packages to suit all pH and ORP applications:

  • pH glass sensors
  • Platinum ORP sensors
  • Reference sensors
12mm Separate Probe Line-up

What is Refex?

REFEX reference junctions are manufactured from an electrochemically conductive, salt loaded, polymeric matrix. When installed in an electrode, there is no porous junction to allow liquid contact between process fluids and the internal (sealed for life) Ag/AgCl reference half-cell. REFEX provides a stable mV output for measurement and ensures that process fluids do not poison or deplete reference cell electrode or electrolyte.

REFEX continues to perform even when completely coated as long as the coating remains wet and is conductive. Even when severe coating of the sensor inevitably slows electrode response, pH measurement remains accurate. Proven applications range from clean, cold river water to crude oil, sewage sludge and nasty chemical streams – all are solved with a REFEX reference interface.

The REFEX electrode is the reliable sensor the market has been waiting for – almost maintenance free with exceptionally long life and superb stability.

All REFEX reference sensor separates and combination probes are built using REFEX reference junction technology and have these very real benefits:


Advantages of Refex non-porous sensors:

  • Resistant to fouling and poisoning
  • Protected Ag/AgCl reference half-cell – Refex barrier/interface prevents all liquid contact/exchange.
  • Resistant to high and changing temperatures between 0 – 100°C
  • Resistant to high and changing pressures between full vacuum and 20 bar pressure.
  • Instant response to pH change
  • Constant Eo zero – no continuous drift over time
  • Long, long electrode life – many times longer than all others
  • Compatible with all standard, modern pH instruments with dual high impedance inputs
  • No diffusion potential errors in low ionic water applications
  • No KCl electrolyte loss due to dilution
  • No refilling of KCl electrolyte – sealed for life.

Have an application?

Let REFEX give you a solution – download an application data sheet, fill in your process specifications and send it to us.  We’ll come back to you with a configuration that will suit your needs

Application Data Sheet

Need Support?

Need additional information or help with your REFEX pH or ORP probe?

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Typical Applications Include:

Refex Industry Solutions


REFEX also offer direct replacement electrodes with REFEX technology to upgrade and improve installations where other brands are already in use. Replacements are available for:

  • BAT (Barben Analytical Technologies)
  • Broadley James
  • E+H
  • Ingold/Mettler Toledo
  • Yokogawa
  • Sensorex
  • Rousemount Analytical
  • Foxboro
  • Van London/Phoenix

Others – call us with your requirements

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