For applications where direct measurement in the process is required the Barben 547 "Hot Tap" Four Electrode Conductivity Sensor provides the solution. The 547 sensor can be fitted into the same retractable sheath as the 547 pH / ORP sensors thus providing 16 to 60 inches of length to fit into any process.
- Hot Tap installation uses same hardware as 547 pH/ORP sensors
- Conductivity measurements up to 2 Siemen (Dependent on cell constant)
- Kynar Body and PEEK insulator
- Self compensating for corrosion and scale build up (analyzer dependent)
- Insertion/retraction pressure up to 65 PSIG
- Electrode options in 316 Stainless, 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 which can then be used to compensate the measurement if scale or particulate build-up occur on electrodes. Four electrode conductivity sensors can withstand coating and scale which might otherwise foul a traditional two electrode sensor. Typical applications include the following:
- Leak Detection
- Condensate Return
- Salinity
- Chemical Concentration
- Clean-In-Place
Sensor Technology - How it works
Four-electrode sensor designs keep a constant current through two of the electrodes and let the drive voltage change. If fouling occurs then the drive voltage can be increased to compensate the measurement.
| Pros |
Cons |
- Compensation for coating and build-up
- Wide measurement range
- Sensor diagnostics if fouling is too great (analyzer dependent)
- No polarization affect
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- Not as accurate as two electrode sensors at low conductivity
- Susceptible to corrosion
- Limited availability of analyzers (ABB, Rosemount, Mettler Toledo, Knick)
- Conductive field can be distorted by pipe walls and flow cells
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