Endress+Hauser Profi Bus Levelflex M FMP40 - Page 85

Levelflex M FMP40 with PROFIBUS PA Commissioning
Endress + Hauser 85
6.8.2 Envelope curve with the ToF Tool
After the basic setup, an evaluation of the measurement using the envelope curve is
recommended (→ ä 85).
L00-FMP4xxxx-20-00-00-en-007
!
Note!
For the optimization of the measurement the installation of the Levelflex in another place can be
executed when enterference echoes.
An evaluation of the measurement with the aid of the envelope curve
Typical curve shape:
The following examples display typical curve shapes for a rope or rod probe in an empty tank. For
all probe types, a negative probe end signal is shown. For rope probes, the end weight causes an
additional preliminary positive echo (see rope probe diagram).
L00-FMP40xxx-05-00-00-en-024
Level echoes are detected as positive signals in the envelope curve. Interference echoes can be both
positive (e.g. reflections from internals) and negative (e.g. nozzles). The envelope curve, the map
and the differential curve are used for the evaluation.Level echoes are searched for in the differential
curve.
400.00
400.00
[mV]
[mV]
300.00
300.00
200.00
200.00
100.00
100.00
0.00
0.00
-100.00
-100.00
-200.00
-200.00
-300.00
-300.00
-400.00
-400.00
-500.00
-500.00
0.00
0.00
0.20
0.20
0.40
0.40
0.60
0.60
0.80
0.80
1.00
1.00 1.20 1.40
[m]
[m]
LN
LN
E
E
F
F
(1.00 m, -143.00 mV)
(1.08 m, -115.00 mV)
Rod probe
Rope probe
Probe end signal
Launch pulse
Probe end signal
Launch pulse