WIKA T32.xS - Manual (Page 14)

GB
14
11583631.03 08/2014 GB/D/F/E
WIKA safety manual temperature transmitter T32.xS
2.8 Commissioning and recurring tests
The operability and error signalling current of the model T32.xS temperature
transmitter must be tested both during commissioning and at appropriate intervals.
Both the nature of the testing as well as the chosen intervals are the responsibility of
the user. The interval usually conforms to the PFD
avg
value given in the standard (for
values and key data see Appendix 1: “SIL declaration of conformity”). Normally the
proof test takes place every year. The PFD
avg
value conforms almost linearly to the
proof test interval, T
proof
. Depending on the available PFD
avg
value for the “sensor”
system component of the safety instrumented system, the proof test interval can be
increased or decreased.
2.8.1 Proof test of the transmitter's complete signal processing chain
1. If required, 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). (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 instrument off, or disconnect from the power supply.
9. Restart the instrument and wait at least 15 seconds from the switch-on time.
10. Check the current output with reference temperature 1) at 2 points. For the initial
value select (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 characteristic curve, this must be checked at a
minimum of three points.
12. Remove the bypass on the safety controller system or restore the normal operating
condition in a different way.
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 sources, 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).
2. Safety