Micropilot S FMR531 with HART/4...20 mA
Commissioning
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6.5
Mounting calibration with VU331
6.5.1
Function group "mounting calibr." (03)
Function "tank gauging" (030)
Using this function, you can either enter a dip table or carry out an auto correction.
Function "auto correction" (031)
When measuring levels with radar systems, so-called "multipath reflections" can affect the level
signal giving rise to serious measuring errors. "Multipath reflections" also include radar beams which
are received by the radar system, which have not been reflected directly by the medium surface.
They may reach the antenna via the basin wall and the medium surface. This phenomenon is
particularly noticeable with devices mounted near to walls, as soon as the conical radar beam strikes
the basin wall.The Micropilot S can automatically discover and correct measuring errors due to this
"multiple path" propagation. This is because it uses two independent sets of information when
evaluating reflection signals:
• Firstly, it evaluates the
amplitude
of the reflected energy using the so-called envelope curve
system.
• Secondly, it evaluates the
phase
of the reflected energy.
The decisive factor for a constant output signal is to assign the phase values to the associated level
values. This assignment is ensured using a correspondence table (index correction table). The
Micropilot S learns this for the specific application after installation (learning period). Therefore,
after mounting the device, and
after
completing the basic calibration, a
history reset
(must be
performed (enter "
yes
" in the "
history reset
"
(009)
function in the "
basic setup
"
(00)
) function
group. Do not switch off the radar system during filling and emptying operations during the teach-
in phase. Switching off when there are only negligible level changes produces no error.
"
Caution!
During the learning period, fast filling/emptying or turbulent surfaces can result in switching off and
on the phase evaluation. Subsequently observed measurement errors will disappear as soon as tank
levels come back to areas measured by Micropilot S previously with activated phase evaluation. If
the observed measurement errors are correted by dip table entries, the Micropilot S will take care
of these corrections and automatically adjust the index correction table. Do
NOT
correct any
settings in the basic calibration or the extended calibration.
!
Note!
Immediately after installation, the Micropilot S measures with the specified mm-accuracy. Until the
level range has been completely covered by the medium (setting up the correction table), the
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Summary of Contents for Micropilot S FMR531
Page 4: ...Brief overview Micropilot S FMR531 with HART 4 20 mA 4 Endress Hauser ...
Page 87: ...Micropilot S FMR531 with HART 4 20 mA Technical data Endress Hauser 87 ...
Page 98: ...Micropilot S FMR531 with HART 4 20 mA Index 98 Endress Hauser ...
Page 100: ...www endress com worldwide BA207F 00 en 04 09 71093754 CCS FM SGML 6 0 ProMoDo 71093754 ...
