top of page


4-electrode sensors 551

The 551 four-electrode conductivity sensor is designed for sample line installations. Sensor mounts with a Barben 1-inch NPT Nut Lock union adaptor._cc781905-5cde-3194-bb3b -136bad5cf58d_This allows threadless installation and removal of the sensor for cleaning and calibration.

  • Quick Change 1 Inch NPT Nut Lock Adapter Installation
  • Conductivity measurements up to 2 Siemens (depending on cell constant)
  • Kynar body and PEEK insulation
  • Autocompensation for corrosion and scale buildup (depends on analyzer)
  • Well suited for sample line installations
  • Electrode options in 316 stainless steel, titanium and Hastelloy


As the name suggests, four-electrode sensors add an additional pair of electrodes to the two-electrode sensor design. This second pair of electrodes provides sensor diagnostics that can then be used to compensate the measurement if scale or particles accumulate on the electrodes. Four-electrode conductivity sensors can resist coating and scale that could otherwise foul a traditional two-electrode sensor._cc781905-5cde -3194-bb3b-136bad5cf58d_Typical applications include the following:

  • leak detection
  • condensate return
  • Salinity
  • chemical concentration
  • on-site cleaning
bottom of page