WIKA T32.xS - Manual (Page 15)

GB
15 WIKA safety manual temperature transmitter T32.xS
11583631.03 08/2014 GB/D/F/E
With the testing described above, a diagnostic coverage of 99 % will be
achieved.
2.8.2 Reduced proof test - limited testing of the transmitter's signal processing
chain
1. Bypass the safety controller system or take the appropriate action to prevent an
alarm being triggered unintentionally, respectively.
2. Deactivate the instrument's write protection.
3. With the aid of the HART ® function in simulation mode, set the current output to a
high alarm value (≥ 21.0 mA)
4. Test whether the current output signal reaches this value.
5. With the aid of the HART ® 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 instrument off, or disconnect from the power supply.
9. Restart the instrument and wait at least 15 seconds from the switch-on time.
10. Read the instrument status.
11. Evaluate the displayed error messages and check them for conformity with the
specifications in the operating instructions.
12. Remove the bypass on the safety controller system or restore the normal operating
condition in a different way.
13. Following the test, the results must be documented and archived accordingly.
In contrast to the procedures described in 2.8.1., the signal processing chain is not tested here.
Its operational reliability should be ensured through reading the instrument status and evaluating
the error messages.
With the testing described above, a diagnostic coverage of at least 60.4 %
for the transmitter without connected sensor is achieved.
WARNING!
Following the checking of the safety function, the instrument should be
secured against interference through write protection, since any change in
parameters 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 ® command. The temperature transmitter must acknowledge this
instruction with the message “Instrument is write protected”.
2. Safety