Siemens SITRANS F M TRANSMAG 2, Руководство по эксплуатации, Страница: 20 / 114

Installing
4.2 Sensor installation
SITRANS F M TRANSMAG 2
18
Operating Instructions, 11/2009, A5E00102775-07
4.2.1 Potential equalization of sensor (refence potential)
The sensor must be at the same potential as the medium for an accurate measurement.
This is guaranteed when the connecting flange of the pipe is made of metal and a perfect
electrical connection is established to the sensor through the fastening screws. In this case
the medium, pipe and transmitter are connected with each other in the sense of a potential
equalization.
Figure 4-7 Reference potential in electrically conductive pipes
In the case of internally electrically isolated pipes, the medium in the pipe must be applied to
a reference potential by additional measures (e.g. by grounding rings). Grounding rings
serve to establish the reference potential of the sensor in electrically isolated pipes.
Figure 4-8 Reference potential in electrically isolated pipes by grounding rings
Grounding rings are offered as accessories.