WIKA T32.xS - Manual (Page 6)

GB
6
11583631.03 08/2014 GB/D/F/E
WIKA safety manual temperature transmitter T32.xS
SC
Systematic capability
The systematic capability of an element (SC 1 to SC 4) states
that the systematic safety integrity for the corresponding SIL is
achieved.
SFF Safe Failure Fraction
SIL Safety Integrity Level, the international standard IEC 61508
defines four discrete safety integrity levels (SIL 1 to SIL 4).
Each level corresponds to a range of probability with which a
safety-related system performs the specified safety functions in
accordance with the requirements. The higher the safety integrity
level of the safety-related system, the greater the probability that
the safety function is executed.
T
1
or T
proof
Interval of the proof tests (in hours, typically one year (8760 h))
Following this interval, the proof test will be carried out.
Proof test Proof testing for the detection of hidden failures to danger in a
safety-related system so that, if necessary through repair, the
system can be placed, as far as possible, in an “as-new” condition.
For further relevant abbreviations, see IEC 61508-4.
2. Safety
2.1 Intended use in safety applications
All safety functions relate exclusively to the analogue output signal (4 … 20 mA). The
instrument is certified to SIL 2 (IEC 61508). Due to the systematic capability of the
transmitter for SC 3, it is possible, depending on the safety integrity of the hardware, to
use the instrument in homogenous redundant systems up to SIL 3.
Taking into account the error detection functions of the model T32.xS temperature
transmitter, the following temperature sensors connected to the transmitter achieve a
sufficient SFF (Safe Failure Fraction) for SIL 2 of > 60 %.
■ Thermocouples with internal or external Pt100 cold junction
(Type E, J, T, U, R, S, B, K, L, N)
■ Resistance temperature sensors with 2-, 3- or 4-wire connection
(Pt100, JPt100, Ni100, Pt1000, Pt500, Pt25, Pt10)
■ Dual thermocouples or dual resistance temperature sensors
Only permitted in the operating modes “Sensor 1 and sensor 2 redundant”, “Mean
value”, “Minimum value”, “Maximum value” and if both sensors are being used
for the monitoring of the same measuring point. The operating mode “Differential
measurement” is not permitted.
1. General information / 2. Safety