Endress+Hauser Prosonic S FMU90 - Page 43

Prosonic S FMU90 Flow Measurement PROFIBUS Commissioning
Endress+Hauser 43
Blocking distance
5.6.2 Interference echo suppression: Basic principles
Parameter Remarks
"blocking distance" Indicates the blocking distance of the respective sensor. The blocking distance is
measured from the reference point of the respective sensor.
For more information and details see the Technical Information TI00396F.
Parameter Remarks
"check value"
"distance mapping"
The "flow N check value" and "flow N mapping" parameter sets are used to configure the
interference echo suppression of the Prosonic S.
The following picture shows the operating principle of the interference echo suppression:
L00-FMU90xxx-19-00-00-yy-030
A The envelope curve (a) contains the level echo and an interference echo. Without interference echo suppression, the
interference echo is evaluated.
B The interference echo suppression generates the mapping curve (b). This curve suppresses all echoes within the range
of mapping (c).
C From now on, only those echoes are evaluated, which are higher than the mapping curve. The interference echo is
below the mapping curve and is therefore ignored.
In order to include all interference echoes, the interference echo suppression should be
performed with the level as low as possible (ideal: channel empty). If during
commissioning the channel can not be sufficiently emptied, it is advisable to repeat the
interference echo suppression at a later point of time (as soon as the level reaches
nearly 0%).
(a) (a)
(b)
(c)
(a)
(b)
A
B
C