Siemens SITRANS P DS III Operating Instructions Manual page 139

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Image 8-7
Procedure for monitoring a maximum pressure
Checking monitoring of the maximum pressure
1. Check the monitoring of the maximum pressure with the threshold defined in the system.
2. Apply an input pressure value that is below the threshold.
3. Apply an input pressure value that is ≥ 10% of the maximum measuring range above the
threshold.
Note
Step 3 can only be performed if the maximum limit value is ≥ 10% below the maximum
full scale value. Otherwise, check only up to full scale value.
However, the test range must be 50% of the maximum measuring range.
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Image 8-8
Result
The two-point measurements are successful when the deviation between input pressure and
transferred value is ≤ 0.2%.
SITRANS P DS III/P410 with PROFIBUS PA
Operating Instructions, 02/2016, A5E00053276-08
Threshold
Example of monitoring of a minimum pressure
Threshold
Example of monitoring of a maximum pressure
Functional safety
8.5 Maintenance/check
139