Influence Of Ambient Temperature; Operating Conditions: Installation With Level Measurement; General Information On Level Measurement - Endress+Hauser Levelflex M FMP40 Series Technical Information

Influence of ambient
temperature
General information on level
measurement
Mounting location
• Do not mount rod or cable probes in the filling curtain (2)
• Mount rod and cable probes away from the wall (B) at such a
distance that, in the event of buildup on the wall, there is still
a minimum distance of 4" (100 mm) between the probe and
the buildup.
• Mount rod and cable probes as far away as possible from
installed fittings. "Mapping " must be carried out during
commissioning in the event of distances < 12" (300 mm).
• When installing rod and cable probes in plastic containers, the
minimum distance of 12" (300 mm) also applies to metallic
parts outside the container.
• Rod and cable probes may not, at times, contact metallic
container walls or floors.
• Minimum distance of probe end to the container floor (C):
– Cable probe: 6" (150 mm)
– Rod probe: 2" (50 mm)
– Coax probe: 0.4" (10 mm)
• When installing outdoors, it is recommended that you use a
protective cover (1) see "Accessories" on page 47.
• Avoid buckling the cable probe during installation or operation
(e.g. through product movement against silo wall) by selecting
a suitable mounting location.
18
The measurements are carried out in accordance with EN 61298-3:
• digital output (HART, PROFIBUS PA, FOUNDATION Fieldbus):
– FMP40
Average T : 0.023"/10K (0.6 mm/10 K), max. ±0.14" (3.5 mm) over the entire temperature range
K
-40 to +176°F (-40°C to +80°C)
2-wire:
• Current output (additional error, in reference to the span of 16 mA):
– Zero point (4 mA)
Average T : 0.032 %/10 K, max. 0.35 % over the entire temperature range
K
-40 to +176°F (-40°C to +80°C)
– Span (20 mA)
Average T : 0.05 %/10 K, max. 0.5 % over the entire temperature range -40 to +176°F (-40°C to +80°C)
K
4-wire:
• Current output (additional error, in reference to the span of 16 mA):
– Zero point (4 mA)
Average T : 0.02 %/10 K, max. 0.29 % over the entire temperature range
K
-40 to +176°F (-40°C to +80°C)
– Span (20 mA)
Average T : 0.06 %/10 K, max. 0.89% over the entire temperature range
K
-40 to +176°F (-40°C to +80°C)

Operating conditions: installation with level measurement

Probe selection (see overview on page 6-7)
• Normally, cable probes should be used for bulk solids, rod probes are only suitable for short measuring ranges
up to approx. 6.5 ft (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. Cable probes are used in liquids for measuring ranges > 15 ft
(4m) 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 a dielectric constant of 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 cable can be so high that a cable with plastic jacketing
must be used. We recommend PA-coated cables be used for cereal products wheat, flour etc..
Levelflex M FMP40
1 2
B
C
L00-FMP4xxxx-17-00-00-xx-003
Endress+Hauser