Siemens MAG 1100 F Operating Instructions Manual page 27

SITRANS F M
Inlet and outlet conditions
Potential equalization
Vacuum
Installation in large pipes
3. Project guidance
To achieve accurate flow measurement it is
essential to have straight lengths of inlet and
outlet pipes and a certain distance between
pumps and valves.
It is also important to centre the flowmeter in
relation to pipe flanges and gaskets.
The electrical potential of the liquid must always
be equal to the electrical potential of the sensor.
This can be achieved in different ways depend-
ing on the application:
A. Wire jumper between sensor and adjacent
flanges. (MAG 1100 and MAG 3100).
B. Direct metallic contact between sensor and
fittings. (MAG 1100 FOOD).
C. Built-in grounding electrodes. (MAG 3100
and MAG 5100 W).
D. Optional earthing/protection flanges/rings.
(MAG 1100 and MAG 3100).
E. Optional graphite gaskets on MAG 1100.
(Standard for MAG 1100 High temperature).
Avoid a vacuum in the measuring pipe, as this
can damage certain liners.
See "Technical data", chapter 2.
The flowmeter can be installed between two
reducers (e.g. DIN 28545). At 8° the following
pressure drop curves apply. The curves are
applicable to water.
Example:
A flow velocity of 3 m/s (V) in a sensor with a
diameter reduction from DN 100 to DN 80
(d /d = 0.8) gives a pressure drop of 2.9 mbar.
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