Siemens SITRANS LR200 HART Guía Para La Puesta En Marcha Rápida página 19

Using P837 and P838 (perform this function at low tank levels)
If SITRANS LR200 displays an incorrect full level, or if the reading fluctuates between a false
high level and a correct level, use P838 and P837 together to elevate the TVT (Time Varying
Threshold) in this region and de-sensitize the receiver from any 'base noise' caused by internal
antenna reflections, nozzle echoes, or other vessel false echoes
Notes:
• Use this function only if there is a minimum distance of 2 meters from SITRANS LR 200 to
the material.
• Set P837 and P838 during start up, if possible.
• If the vessel contains an agitator, the agitator should be running.
a. First rotate the instrument for best signal (lowest false echo amplitude).
b. Determine the distance from the reference point to the material level.
c. Select P838 and key in [distance to liquid level – 0.5 m].
d. Select P837, then press 2 (Learn) and ENTER
(use Learned TVT) after a few seconds.
9. Return to RUN
Press PROGRAM
SITRANS LR200 Communications: HART
mA Output with Level, Space, and Distance operation
See
Note:
illustration of the mA output with different modes of operation.
• You will need the full manual to acquire the list of applicable parameters.
• The HART Device Descriptor (DD) may be obtained from the HART Communication
Foundation at www.hartcomm.org
• We recommend that you use SIMATIC Process Device Manager (PDM) to program your
instrument.
Maintenance
SITRANS LR200 requires no maintenance or cleaning under normal operating conditions. If
cleaning becomes necessary under severe operating conditions:
1. Note the antenna material and the process medium, and select a cleaning solution that
will not react adversely with either.
2. Remove the instrument from service and wipe the antenna clean using a cloth and
suitable cleaning solution.
Unit Repair and Excluded Liability
For detailed information, please see the inside back cover.
1.
For more details on Auto False Echo Suppression, see the full manual.
Page EN-18 SITRANS LR200 (HART) – QUICK START MANUAL
to return to RUN mode: setup is complete.
1
.
. P837 will automatically revert to 1
on page 16 for an
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