Vega VEGAPULS 63 Operating Instructions Manual page 36

6 Set up with the display and adjustment module PLICSCOM
Diagnosis - Curve pres-
entation
Service - False signal
suppression
36
The "False echo curve" displays the saved false echoes (see menu
"Service") of the empty vessel as signal strength in "dB" over the
measuring range.
Up to 3000 measured values are recorded (depending on the sensor)
when starting a "Trend curve". Then the values can be displayed on
a time axis. The oldest measured values are always deleted.
In the menu item "Choose curve", the respective curve is selected.
Curve selection
▼
Echo curve
Information:
The trend recording is not activated when being shipped. It must be
started by the user via the menu item "Start trend curve".
A comparison of the echo curve and the false echo curve allows a
more detailled evaluation of measurement reliability. The selected
curve is updated continuously. With the [OK] key, a submenu with
zoom functions is opened.
The following functions are available with "Echo and false echo
curve":
•
"X-Zoom": Zoom function for the meas. distance
•
"Y-Zoom": 1, 2, 5 and 10x signal magnification in "dB"
•
"Unzoom": Reset the presentation to the nominal measuring range
without magnification
In the menu item "Trend curve" the following are available:
•
"X-Zoom": Resolution
– 1 minute
– 1 hour
– 1 day
•
"Stop/Start": Interrupt a recording or start a new recording
•
"Unzoom": Reset the resolution to minutes
As default setting, the recording pattern has 1 minute. With the adjust-
ment software PACTware, this pattern can be also set to 1 hour or 1
day.
Echo curve
High sockets or vessel installations, such as e. g. struts or agitators as
well as buildup and weld joints on the vessel walls, cause interfering
reflections which can impair the measurement. A false echo storage
detects and marks these false echoes, so that they are no longer
taken into account for the level measurement. A false echo memory
should be created with low level so that all potential interfering reflec-
tions can be detected.
VEGAPULS 63 • Profibus PA