KROHNE OPTISWITCH 3x00C Contactless SIL EN - Manual (Page 9)

For a higher average temperature of 60 °C (140 °F), the failure
rates should be multiplied by a factor of 2.5. A similar factor
applies if frequent temperature fluctuations are expected.
The calculations are also based on the specifications stated in
chapter "Planning".
After 8 to 12 years, the failure rates of the electronic
components will increase, whereby the derived PFD and PFH
values will deteriorate (IEC 61508-2, 7.4.7.4, note 3).
Overflow protection
(max. operation)
Dry run protection
(min. operation)
λ
sd
0 FIT 0 FIT
λ
su
506 FIT 481 FIT
λ
dd
124 FIT 135 FIT
λ
du
41 FIT 56 FIT
DC
S
0 % 0 %
DC
D
75 % 71 %
MTBF = MTTF + MTTR 1.45 x 10 6
h 1.45 x 10 6
h
Diagnosis test period < 100 sek.
Single channel architecture (1oo1D)
SIL SIL 2
HFT 0
Sensor type Type B
Overflow protection
(max. operation)
Dry run protection
(min. operation)
SFF 94 % 92 %
PFD
avg
T
Proof
= 1 year
T
Proof
= 5 years
T
Proof
= 10 years
< 0.018 x 10 -2
< 0.089 x 10 -2
< 0.178 x 10 -2
< 0.024 x 10 -2
< 0.122 x 10 -2
< 0.243 x 10 -2
PFH < 0.041 x 10 -6 /h < 0.056 x 10 -6 /h
Service life
Failure rates
Fault reaction time
Specific characteristics
OPTISWITCH series 3000 • - contactless electronic switch 9
Functional safety
32741
-
EN
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080414