Safety; Intended Use In Safety Applications - WIKA T32. S Serie Manual De Seguridad

1. General information / 2. Safety
Abbreviation
T or T
1 proof
Proof test
EN
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.
The temperature transmitter achieves, for all recognised connections for temperature
sensors, an SFF (Safe Failure Fraction) sufficient for SIL 2 of > 90 %.
The instrument generates a current signal in the approved measuring mode of a nominal
4 ... 20 mA, that is dependent upon the sensor signal. The effective range of the output
signal limited to a minimum of 3.8 mA and a maximum of 20.5 mA (factory setting in basic
configuration).
6
Description
Interval of the proof tests (in hours, typically one year (8,760 h))
Following this interval, the proof test will be carried out.
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.
WIKA safety manual temperature transmitter T32.xS