WIKA T32.xS - Manual (Page 13)

GB
13 WIKA safety manual temperature transmitter T32.xS
11583631.02 11/2010 GB/D/F/E
2.8 Commissioning and periodic tests
The operability and error current of the model T32.xS temperature transmitter must
be tested both during commissioning and at reasonable intervals. Both the nature of
the tests as well as the chosen intervals are the responsibility of the user. The interval
usually conforms to the PFDavg value given in the standard (Values and key data see
"Appendix 1: SIL declaration of conformity"). Normally the repeated test happens every
year.
2.8.1 Proof test of the transmitter's complete signal processing chain
1. If required, bypass the safety controller system and/or take the appropriate action,
to prevent an alarm being triggered unintentionally.
2. Deactivate the device'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). (HART ® command 40: Enter Fixed Current-Mode)
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. Check the current output with reference temperature 1) at 2 points. Select for the
initial value, (4 mA to +20 % of the span) and for the final value (20 mA up to –20 %
of the span).
11. When using a customer-specific linearisation, this must be checked at a minimum
of three points.
12. Remove the bypass on the safety controller system or return to a normal operating
condition for other measures.
13. Following the tests, the results must be documented and archived accordingly.
1) checking transmitters without sensors can also be achieved with an appropriate sensor
simulator (Simulator, ref. voltage source, etc.). Here the sensor must be tested to the SIL
demands of the customer's application. The measuring or setting accuracy of the test
instruments used should be at least 0.2 % of the span of the current output (16 mA).
With the testing described above a diagnostic cover of 99% will be
achieved.
2. Safety