81
Safety Manual
00809-0200-5100, Rev GB
Dry-run Configuration
February 2017
Dry-run Configuration
Appendix G Dry-run Configuration
This section describes the recommended procedure to configure the SIL Safety System for
Dry-run applications.
Prior to setting up the SIL Safety System for Dry-run it
has to be installed and configured as normal.
The Dry-run configuration aims at specifying the SIL
Low Alarm Limit as well as optimizing the SIL Used
Hold Off Distance and SIL Amplitude Thresholds.
The Hold Off Distance should be as large as possible
to avoid impact from noise in the upper part of the
tank. By adjusting SIL Amplitude Thresholds to
appropriate values, noise will be filtered out to ensure
that the product surface is detected at all times.
1. Define the Minimum Operation Distance for the
application. This is the Distance from the bottom of
the flange to the maximum filling point of the Tank
in normal operation.
2. Specify a safety margin to ensure that there will be a
sufficient gap between the SIL Hold Off Distance
and the Minimum Operation Distance. A margin of
50 -100 mm should be sufficient in most cases. This
will make sure that no false alarms will be triggered
in case of minor measurement errors near the
maximum filling point.
3. Calculate the recommended new SIL Used Hold Off
Distance by subtracting the safety margin from the
Minimum Operation Distance:
SIL Used Hold Off Distance C= D - safety margin
SIL Hold Off Distance Adjustment B = C- A
Tip! SIL Antenna Hold Off A can be found in the Safety
Alarm window.
A=SIL Used Hold Distance - SIL Hold Off Distance
Adjustment
1. SIL Amplitude threshold
2. SIL High Alarm Limit
3. Product surface
Distance
Amplitude
3
1
2
1. Minimum operation distance
Distance
Amplitude
1
C
A
B
A. SIL Antenna Hold Off
B. SIL Hold Off Distance Adjustment
C. SIL Used Hold Off Distance
D. Minimum operation distance
E. Measurement range
ED
Distance
Amplitude
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