Toroidal Conductivity

Loop Powered 4-20mA Toroidal Electrode

The model C3254 Toroidal Conductivity Electrode is designed as a low cost, rugged, easy to install industrial sensor. The electrodeless conductivity electrode is coupled with a two wire loop powered 4-20mA output transmitter.

The toroidal, or “electrodeless” design eliminates any form of polarization, so accurate readings are possible in all types of fouling solutions. Utilizing a probe consisting of two toroid wound coils in close proximity, with one generating an electric field in the solution and the other acting as a receiver to pick up the small current which is proportional to the induced current from the ions moving in the conducting loop of solution. The entire assembly is encapsulated in plastic minimizing electrode contamination, and unlike conventional sensors, no metallic contact with the solution is involved.

With the loop power, the isolated 4-20mA output can be connected to a 4-20mA input control device for accurate conductivity control.


  • Installation: In-line or Submersible
  • Cell: Toroidal
  • Length: 207mm (Overall); 86mm (Insertion)
  • Body: CPVC or PVDF
  • Thread: 1 1/2″ MNPT
  • Max. Pressure: 44psig (3 Bar) at 25 °F (25 °C)
  • Max. Temperature: 104 °F (40 °C) wetted parts
  • Temperature Compensation Sensor: Pt100
  • Range: 0-10, 0-100 and 0-1000 mS
  • Cable length: Standard 10ft; other cable lengths available upon request
  • Temperature Coeff: TC of the liquid + 0.3%/°C
  • Power Supply: 24 VDC
  • Output: 4-20mA Isolated, 600 ohm max at 24 VDC