Endress+Hauser Levelflex FMP51 Operating Instructions Manual page 23

Levelflex FMP51, FMP52, FMP54
Feature 610 - Accessory mounted
Application
Interface measurement
• Pipe diameter: > 40 mm (1.6") for rod probes
• Rod probe installation can take place up to a diameter size of 100 mm. In the event of larger
diameters, a coax probe is recommended.
• Side disposals, holes or slits and welded joints that protrude up to approx. 5 mm (0.2") inwards
do not influence the measurement.
• The pipe may not exhibit any steps in diameter.
• The probe must be 100 mm longer than the lower disposal.
• Within the measuring range, the probe must not get into contact with the pipe wall. If
necessary, use a center washer (see feature 610 of the product structure).
• If the center washer is mounted at the end of the probe, it enables a reliable recognition of the
end-of-probe signal (see feature 610 of the product structure).
Note: For interface measurements only use the nonmetallic center washers made of PEEK or
PFA (feature 610, options OD or OE) .
• Coax probes can always be applied if there is enough mounting space.
For bypasses with condensate formation (water) and a medium with low dielectric constant
(e.g. hydrocarbons):
In the course of time the bypass is filled with condensate up to the lower disposal and for
low levels the the level echo is superimposed by the condensate echo. Thus in this range
the condensate level is measured instead of the correct level. Only higher levels are
measured correctly. To prevent this, position the lower disposal 100 mm (4 in) below the
lowest level to be measured and apply a metallic centering disk at the height of the lower
edge of the lower disposal.
With heat insulated tanks the bypass should also be insulated in order to prevent condensate
formation.
Endress+Hauser
Option Type of probe
OD Rod probe
OE Rope probe
Center washer
Æ d [mm (in)] Material
48...95 PEEK
(1,89...3,74)
37 (1,46) PFA
Mounting
Pipe
Æ D [mm
(in)]
³ 50 mm
(2")
³ 40 mm
(1.57")
23