WIKA IS-20-S Instructions page 2

Applications / Data for functional safety
Applications
The pressure transmitter models IS-20-S, IS-21-S, IS-20-F and IS-21-F are suitable for
SIL2 applications in process industry for operating modes with low demand rate.
MTTF values for defining the performance level (PL) are available for applications in machine
d
building.
Data for functional safety
Data for functional safety in the process industry
Applied standards
Device type
HFT Hardware Fault Tolerance
SFF Safe Failure Fraction
l
Total Failure Rate
total
l Safe Undetected Failure Rate
no effect
l Safe Detected Failure Rate
LOW
l
Safe Detected Failure Rate
HIGH
l
Dangerous Undetected Failure Rate
DU
PFD Average Probability of Failure on Demand
a
T Proof Test Intervall
proof
Suitable for Safety Integrity Level
Data for functional safety in machine building
Applied standards
MTTF Mean Time To Dangerous Failure
d
2 WIKA Additional instructions Safety related data Intrnsically Safe Pressure Transmitter IS-2X
EN 61508:2001 and EN 61511:2004; SN29500
B
0
% 62
FIT 101
FIT 30
FIT 23
FIT 10
FIT 38
1.66 x 10 -4
years 1
SIL 2
(according to IEC 61511-1 section 11.4.4 under conside-
ration of proven in use)
ISO 13849-1:2006; SN29500
years 1938
GB
Operating conditions for process industry / Operating conditions for machine building
Operating conditions for the process industry
All values apply at mean ambient temperature of max. 40 °C.
The pressure transmitters are suitable for SIL2 applications assuming that the sensors
contribute approx. 35 % of the PFD
The environment of the pressure transmitter must comply with the following criteria:
no damage to the pressure transmitter housing
„
„ electromagnetic environment in accordance with EN 61326-1:2006 and EN 61326-2-3:2006
„ use of a shielded cable grounded at least at one end
The following assumptions were made for a fail-safe operation of the pressure transmitter:
„ the maximum measurement error may range from -2.5 % to 10 % of the span
„ the process connection is suitable for the measuring range
„ wetted parts are suitable for the medium
no pressure peaks nor static pressures are higher than the values indicated in the data
„
sheet
Operating conditions for machine building
The MTTF value applies at a mean ambient temperature of max. 40 °C.
d
The MTTF value also applies to the following operating conditions:
d
„ no strong vibrations
„ no damage to the pressure transmitter housing
„ electromagnetic environment in accordance with EN 61326-1:2006, EN 61326-2-3:2006
and EN 61326-3-1:2008
the process connection is suitable for the measuring range
„
wetted parts are suitable for the medium
„
no pressure peaks nor static overpressures are higher than the values indicated in the data
„
sheet
WIKA Additional instructions
of the whole safety chain.
a
Safety related data Intrnsically Safe Pressure Transmitter IS-2X
GB
3