Potential Equalization - Endress+Hauser Proline Promag 50H Manual

Proline Promag 50H, 53H

Potential equalization

Endress+Hauser
Perfect measurement is only ensured when the medium and the sensor have the same electrical potential.
Metal process connections
Potential matching usually takes place over the metallic process connection in contact with medium process
connections which are directly mounted on the measuring transmitter. This usually means that additional
potential matching measures are unnecessary.
Plastic process connections
For plastic process connections, potential matching must be ensured between sensor and medium using
additional ground rings. If these ground rings are missing, this can influence accuracy or destroy the measuring
transmitter through the electrochemical decomposition of electrodes.
1
1 Allen screw (process connection)
2 O-ring seals
3 Plastic washer (spacer) or ground ring
4 Sensor
When using ground rings, note the following points:
• Depending on the option ordered, plastic washers may be installed at the process connections instead of
ground rings. These plastic washers serve only as spacers and have no potential equalization function. In
addition, they provide a sealing function at the interface between the sensor and process connection.
For this reason, with process connections without ground rings, these plastic washers/seals must not be
removed, or must always be installed.
• Ground rings can be ordered separately from Endress+Hauser as an accessory.
Also make sure that the ground rings are compatible with the electrode material. Otherwise the danger exists
that the electrodes could be destroyed by electrochemical corrosion.
You can find material data on → ä 44.
• Ground rings, incl. seals, are mounted inside the process connection. This has no influence on the
installation length. You can find the dimensions of ground rings on → ä 35.
2 3 2 4
A0002651
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