2. Safety
2.8.2 Reduced proof test - limited testing of the transmitter's signal
conditioning chain
1. Bypass the safety controller system and/or take the appropriate action, to prevent
an alarm being triggered unintentionally.
GB
2. Deactivate the device's write protection
3. With the aid of the HART
high alarm value (≥ 21.0 mA).
4. Test whether the current output signal reaches this value.
5. With the aid of the function in simulation mode, set the current output of the
transmitter to a low alarm value (≤ 3.6 mA)
6. Test whether the current output signal reaches this value.
7. Activate the write protection and wait for a minimum of 5 seconds.
8. Switch the device off, or disconnect from the power supply.
9. Restart the device and wait at least 15 seconds from the switch-on time.
10. Read the device status
11. Evaluate the device status and check it for conformity with the specifications in the
operating instructions.
12. Read the device diagnostics
13. Evaluate the device diagnostics and check it for conformity with the specifications
in the operating instructions.
14. Remove the bypass on the safety controller system or return to a normal operating
condition for other measures.
15. Following the tests, the results must be documented and archived accordingly
In contrast to the procedures described in 2.8.1., the signal conditioning chain is not tested here.
Its operational reliability should be ensured through reading and evaluating the device status and
device diagnostics.
With the testing described above, a diagnostic cover of 73 % will be
achieved.
WARNING!
Following the checking of the safety function, the device should be
secured against interference through write protection, since any change
in parameter can prejudice the safety function. The write protection should
be checked as follows: send a write instruction to the model T32.xS via a
HART
instruction with the message "Instrument is write protected".
WARNING!
The methods and procedures used for these tests (test scenarios) must
also be documented like the test results. If the outcome of the function test
is negative, the whole system must be shut down. The process must be
put into a safe condition using appropriate procedures.
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function in simulation mode, set the current output to a
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command. The temperature transmitter must acknowledge this
WIKA safety manual temperature transmitter T32.xS