Analog Signal Transmitters Im35-**Ex-Hi/24Vdc - turck IM35-11Ex-Hi/24VDC Bedienungsanleitung

5.2 Analog Signal Transmitters IM35-**Ex-Hi/24VDC

The FMEDA carried out on the Analog Signal Transmitter IM35-22Ex-Hi/24VDC leads under
the assumptions described in section 4.2.3 and 5 to the following failure rates:
λ = 0,00E-00 1/h
sd
λ = 4,60E-09 1/h
su
λ = 0,00E-00 1/h
dd
λ = 4,09E-08 1/h
du
λ = 6,18E-08 1/h
high
λ = 2,53E-07 1/h
low
λ = 3,25E-07 1/h
no effect
λ = 6,85E-07 1/h
total
λ = 2,02E-08 1/h
not part
MTBF = MTTF + MTTR = 1 / (λ
Under the assumptions described in section 5 and the definitions given in section 4.1 the
following tables show the failure rates according to IEC 61508:
λ λ λ λ
safe
583 FIT
The PFD was calculated for three different proof test times using the Markov model as
AVG
described in Figure 4.
T[Proof] = 1 year
PFD = 4,50E-04
AVG
The boxes marked in yellow (
allowed range for SIL 2 according to table 2 of IEC 61508-1 and table 3.1 of ANSI/ISA–84.01–
1996 but do not fulfill the requirement to not claim more than 10% of this range, i.e. to be better
than or equal to 1,00E-03. The boxes marked in green (
values are within the allowed range for SIL 2 according to table 2 of IEC 61508-1 and table 3.1
of ANSI/ISA–84.01–1996 and do fulfill the requirement to not claim more than 10% of this
range, i.e. to be better than or equal to 1,00E-03. Figure 6 shows the time dependent curve of
PFD .
AVG
exida.com
© GmbH
Stephan Aschenbrenner
more@turck.com • www.turck.com • 2015/04
Anhang – EXIDA-Report FMEDA Turck 04/07-14 R001
+ λ ) + 8 h = 162 years
total not part
λ λ λ λ
dangerous
103 FIT
T[Proof] = 5 years
PFD = 2,25E-03
AVG
) mean that the calculated PFD
TURCK 04-07-14 R001 V2R0.doc; February 8, 2013
SFF
85,01%
T[Proof] = 10 years
PFD = 4,48E-03
AVG
values are within the
AVG
) mean that the calculated PFD
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AVG
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