Vega VEGAPULS 61, Руководство по безопасности

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PFH <
0
.
358
x
10
-
6
/ h
T
he chronological sequence of
PFD
avg
is nearly linear to the
operating time over a period up to
10
years . T he above values
apply only to the T
P roof
interval after which a recurring function
test must be carried out .
1 5 10
T
Proof
PFD
avg
1
2
3
4
F ig . 1 : C hronological sequence of PFD
avg
( fi gures see above charts )
1 PFD
avg
=
0
2
PFD
avg
after
1
year
3 PFD
avg
after 5 years
4 PFD
avg
after 10 years
M ultiple channel architecture
I f the measuring system is used in a multiple channel
architecture , the safety - relevant characteristics of the selected
structure of the meas . chain must be calculated speci fi cally for
the selected application according to the above failure rates .
A suitable C ommon C ause F actor must be taken into account .
T he measuring system must only be used in a diversitary
redundant architecture !
T ime - dependent process of
PFD
avg
S peci fi c characteristics
12
VEGAPULS series
60
-
4
…
20
m A / HART
F unctional safety
31338
-
EN
-
070510