VEGA VEGAPULS SR 68 4 … 20 mA_HART - four-wire - Manual (Page 62)

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9 Diagnosis, Asset Management and service
VEGAPULS SR 68 • 4 … 20 mA/HART - four-wire
38295-EN-130624
Measurement error during emptying
Fault description Error pattern Cause Rectification
6. Measured value re-
mains unchanged in
the close range during
emptying
Level
time 0
– False echo larger than the level
echo
– Level echo too small
– Remove false echoes in the
close range. Check: Antenna
must protrude out of the socket
– Remove contamination on the
antenna
– Minimize interfering instal-
lations in the close range by
changing the polarization
direction
– After removing the false ech-
oes, the false signal suppres-
sion must be deleted. Carry out
a new false signal suppression
7. Measured value
jumps sporadically to-
wards 100 % during
emptying
Level
time 0
– Changing condensation or con-
tamination on the antenna
– Carry out false signal suppres-
sion or increase false signal
suppression in the close range
by editing
– With bulk solids use radar sen-
sor with purging air connection
or flexible antenna cover
8. Measured val-
ue fluctuates around
10 … 20 %
Level
time 0
– Various echoes from an uneven
product surface, e.g. an extrac-
tion funnel
– Check parameter "Medium
type" and adapt, if necessary
– Optimize installation position
and sensor orientation
– Reflections from the product
surface via the vessel wall
(deflection)
Depending on the reason for the fault and the measures taken, the
steps described in chapter "Setup" must be carried out again or must
be checked for plausibility and completeness.
Should these measures not be successful, please call in urgent cases
the VEGA service hotline under the phone no. +49 1805 858550.
The hotline is also available outside normal working hours, seven
days a week around the clock.
Since we offer this service worldwide, the support is provided in
English. The service itself is free of charge, the only costs involved are
the normal call charges.
9.5 Exchanging the electronics module
If the electronics module is defective, it can be replaced by the user.
In Ex applications only one instrument and one electronics module
with respective Ex approval may be used.
If there is no electronics module available on site, the electronics
module can be ordered through the agency serving you. The electron-
ics modules are adapted to the respective sensor and differ in signal
output or voltage supply.
The new electronics module must be loaded with the default settings
of the sensor. These are the options:
Reaction after fault recti-
fication
24 hour service hotline