Note
For a safety-instrumented system, we recommend checking the device at regular intervals of
one year.
8.5.2.1
Checking temperature sensors
Procedure
● Read the sensor temperature and the electronics temperature via communication.
● Check whether the measured sensor temperature is within the range of -50 °C to 120 °C.
● Check whether the measured electronics temperature is within the range of -50 °C to
90 °C.
If the measured temperatures are not within this range, the temperature sensor is defective.
8.5.2.2
Check response time of pressure transmitter.
Procedure
To check whether the response time of the pressure transmitter meets the requirements of
the process plant, follow these steps:
● Change the pressure at the input abruptly from a base value by ≥ 10% of the maximum
measuring range and check the measured values that result from this.
Note that the set damping can affect the damping of the response time of the pressure
transmitter.
8.5.2.3
Two-point measurement ≥ 10% of the maximum measuring range
General procedure
Requirement
The difference between the first input pressure and the second input pressure is ≥ 10% of
the maximum measuring range.
Checking the measuring range
1. Apply an initial input pressure.
2. Check the transferred value.
SITRANS P DS III/P410 with PROFIBUS PA
Operating Instructions, 02/2016, A5E00053276-08
Functional safety
8.5 Maintenance/check
135