Endress+Hauser Micropilot S FMR531, Руководство по эксплуатации

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Micropilot S FMR531 with HART/4...20 mA Mounting
E Hauser 17
Measuring conditions
• The measuring range begins where the beam hits the tank bottom. Particularly with dish bottoms
or conical outlets the level cannot be detected below this point.
• For overspill protection , it is possible to define a safety distance (SD) additionally to the
blocking distance (BD) .
• Depending on its consistence, foam can either absorb microwaves or reflect them off the foam
surface. Measurement is possible under certain conditions.
• Distance B defined the smallest recommended measurement range.
• Tank diameter and height should be at least dimensioned such that a reflection of the radar signal
on both sides of the tank can be ruled out (see »Beam angle« on Page 16).
• In case of media with a low dielectric constant (groups A and B), the tank bottom can be visible
through the medium at low levels (low height C ). Reduced accuracy has to be expected in this
range. If this is not acceptable, we recommend positioning the zero point at a distance C (see Fig.)
above the tank bottom in these applications.
• In principle it is possible to measure with the FMR531 up to the tip of the antenna. However, due
to considerations regarding accuracy corrosion and build-up, the end of the measuring range
should not be chosen any closer than
A (see Fig.) to the tip of the antenna.
• The safety distance (SD) is set to 0.1 m (4") by default and generating an alarm.
L00-FMR53xxx-17-00-00-en-011
Behaviour if measuring
range is exceeded
The behaviour in case of the measuring range being exceeded can be freely set: the default setting
is a current of 22 mA and the generation of a digital warning (E681).
reference: flange / BD
(cf. picture)
reference: antenna tip
(cf. picture)
Blocking
distance
Safety
distance
recommended additional settings
BD [m / ft] SD [m / ft] A [mm / inch] B [m / ft] C [mm / inch]
FMR531 0.39/1.3 or
0.54/1.8
0.1/0.3 50 / 2 0.5 /1.64 150...300/6...12
A
100%
0%
B
BD
SD
C
Ø D
max. level