Endress+Hauser Levelflex M FMP40 Brief Operating Instructions page 8

Mounting
2.3.5 Engineering hints for level measurement in bulk solids and fluids
• Normally, rope probes should be used for bulk solids, rod probes are only suitable for short
measuring ranges up to approx. 2 m in bulk solids. This applies above all to applications in
which the probe is installed laterally at an angle and for light and pourable bulk solids.
• Normally use rod or coax probes for liquids. Rope probes are used in liquids for measuring
ranges > 4 m and with restricted ceiling clearance which does not allow the installation of
rigid probes.
• Coax probes are suited to liquids with viscosities of up to approx. 500 cSt.
Coax probes can measure most liquefied gases, as of dielectric constant 1.4. Moreover,
installation conditions, such as nozzles, tank internal fittings etc., have no effect on the
measurement when a coax probe is used. A coax probe offers maximum EMC safety when
used in plastic tanks.
• In the case of large silos, the lateral pressure on the rope can be so high that a rope with plastic
jacketting must be used. We recommend PA-coated ropes be used for cereal products wheat,
flour etc.
Mounting location
• Do not mount rod or rope probes in the
filling curtain (2).
• Mount rod and rope probes away from the
wall (B) at such a distance that, in the
event of build-up on the wall, there is still
a minimum distance of 100 mm between
the probe and the build-up.
• Mount rod and rope probes as far away as
possible from installed fittings. "Mapping"
must be carried out during commissioning
in the event of distances < 300 mm.
• When installing rod and rope probes in
plastic containers, the minimum distance
of 300 mm also applies to metallic parts
outside the container.
• Rod and rope probes may not, at times,
contact metallic container walls or floors.
• Minimum distance of probe end to the
container floor (C):
– Rope probe: 150 mm
– Rod probe: 50 mm
– Coax probe: 10 mm
• When installing outdoors, it is
recommended that you use a protective
cover (1), see Operating Instruction on the
CD-ROM.
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Levelflex M FMP40 FOUNDATION Fieldbus
1
B
C
2
L00-FMP4xxxx-17-00-00-xx-003
Endress+Hauser