VEGA VEGASON 51V…53V - Manual (Page 32)

32 VEGASON 51 V … 53 V
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
,,,
Mounting and installation - False echoes
4.6 False echoes
The installation place of the ultrasonic sensor
must be selected such that no installations or
inflowing material cross the ultrasonic im-
pulses. The following examples and instruc-
tions show frequent meas. problems and
how they can be avoided.
Shoulders
Vessel forms with flat shoulder can aggravate
the measurement due to the strong false
echoes. Shields above these flat shoulders
spread the false echoes and ensure reliable
measurement.
Inlets, e.g. for material mixing with flat upper
side pointing to the sensor, should be cov-
ered by an angle shield. The false echo is
hence gated out.
Shoulders
Shoulder (inlet)
Vessel installations
Vessel installations such as e.g. a ladder
often cause false echoes. Note when plan-
ning your measurement loop that the ultra-
sonic signals should reach the product with-
out problems.
Struts
Struts such as vessel installations can cause
strong false echoes which can overlay the
useful echo. Small shields avoid a direct false
echo reflection. The false echoes are diffused
and filtered out by the meas. electronics as
"echo noise".
Vessel installations
Struts
Correct Wrong
Correct Wrong
Correct Wrong
Correct Wrong
Ladder
Ladder
Shields