VEGA VEGAPULS series 60 Recurring function test - Manual (Page 11)

3 .4 Verification of echo data
For this test point, you require the sensor documentation of the setup
or a sensor documentation created at least 6 months ago.
If none of these sensor documentations is available, the described
recurring function test (λ
du
96 %) cannot be carried out.
Only the test at a detection rate of 88 % of all dangerous undetected
failures is possible. In this case, just skip this test point.
In this case, continue with the test point "Sensor reaction on level
change".
Use the two pdf files of the sensor documentation again for
assessment of the level echo.
Under chapter "Echo curve" you will find a short chart containing the
"E
cho data". The data of this chart are relevant for the assessment.
Compare the values of the two echo data charts. The echo curve itself
cannot be compared.
Proceed as follows:
1 Compare the distance [m] of the two level echoes (actual/setup).
2 Divide the distance [m] of the current level through the distance [m]
of the level echo during setup.
Round this ratio "V" mathematically to one decimal point.
3 Search in the following chart the correction value (dB) belonging to
the calculated ration "V".
4 Calculate with the correction value the corrected value of the
amplitude.
This corrected value of the amplitude [dB] of the actual level echo
can be higher, but only max. 6 dB lower than the amplitude of the
level echo during setup.
Ratio "V" Correction value (dB)
0.5 -6
0.6 -4.5
0.7 -3
0.8 -2
0.9 -1
1.0 -0
Calculation of the cor-
rection factor
Recurring function test • for VEGAPULS series 60 11
3 Sequence of the recurring function test
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