Siemens SITRANS LG250 Operating Instructions Manual page 39

Setup - False signal sup-
pression
Unlock setup - adjust-
ment
PBD-51041387
The default setting is min. current 3.8 mA and max. current 20.5 mA.
The following circumstances cause interfering reflections and can
influence the measurement:
•
High sockets
•
Vessel internals such as struts
Note:
A false signal suppression detects, marks and saves these false
signals so that they are no longer taken into account for the level and
interface measurement. We generally recommend carrying out a false
signal suppression to achieve the best possible accuracy. This should
be done with the lowest possible level so that all potential interfering
reflections can be detected.
Proceed as follows:
Enter the actual distance from the sensor to the product surface.
All interfering signals in this section are detected by the sensor and
stored.
Note:
Check the distance to the product surface, because if an incorrect
(too large) value is entered, the existing level will be saved as a false
signal. The level would then no longer be detectable in this area.
If a false signal suppression has already been created in the sensor,
the following menu window appears when selecting "False signal
suppression":
The instrument carries out an automatic false signal suppression
as soon as the probe is uncovered. The false signal suppression is
always updated.
The menu item "Delete" is used to completely delete an already cre-
ated false signal suppression. This is useful if the saved false signal
suppression no longer matches the metrological conditions in the
vessel.
With this menu item you safeguard the sensor parameters against
unauthorized or unintentional modifications.
SITRANS LG250 - Operating Instructions
39