VEGA VEGAPULS 54K enamel - Manual (Page 52)

52 VEGAPULS 54K enamel
24 101-EN-041227
SIL declaration of conformity
Supplement
Füllstand - Grenzstand - Druck
S I L d e c l a r a t i o n of c o n f o r m i t y
Functional safety according to IEC 61508 / IEC 61511
VEGA Grieshaber KG, Am Hohenstein 113, D-77761 Schiltach
declares as manufacturer, that for the radar sensors of the product families
VEGAPULS series 40 and 50 ( 4 ... 20 mA HART® )
the reliability (“proven in use”) was verified according to IEC 61508 / IEC 61511.
Therefore the devices are suitable for safety-related applications
e.g. overfill protection, dry run protection or recording of an arbitrary fill level.
The corresponding instructions of the safety manual must be considered. 1)
Safety related characteristics:
VEGAPULS 40 VEGAPULS 50
SIL Safety Integrity Level SIL 2 SIL 2
HFT Hardware Fault Tolerance 2) 0 0
SFF Safe Failure Fraction > 88 % > 86 %
< 0,10 x 10 -2 < 0,12 x 10 -2 T
Proof
1 year
PFD
avg
average Probability of dangerous
Failure on Demand 3)
(for low demand mode) < 0,50 x 10 -2 < 0,60 x 10 -2 T
Proof
5 years
PFH Probability of a dangerous Failure per
Hour
4)
[1/h] (for high demand or continuous mode)
< 0,22 x 10 -6 < 0,28 x 10 -6
Error response time
60sec
The failure rates were determined by a FMEDA ( Failure Modes, Effects and Diagnostics Analysis )
VEGAPULS 40 VEGAPULS 50
λ
sd
safe detected failure 107 FIT 111 FIT 5)
λ
su
safe undetected failure 494 FIT 518 FIT
λ
dd
dangerous detected failure 1090 FIT 1140 FIT
λ
du
dangerous undetected failure 221 FIT 277 FIT
MTTF Mean Time To Failure 60 years 56 years MTTR = 8h
1) Safety Manual see supplement of the operating instructions
2) HFT is reduced by one according to IEC 61511-1, section 11.4.4
3) PFD
avg
is valid only for the T
Proof
interval according to which a recurring function test must be carried out
4) PFH is constant over the time. According to the standard, a recurring function test is not necessary.
The failure tolerance time of the overall system must be higher than the error response time of the sensor.
5) FIT = failure in time [10 -9 h]
The assessment of the modification management was part of the proof for
reliability (“proven in use”).
Schiltach, 28.10.03
VEGA Grieshaber KG
i.V.
Frühauf i.A. Blessing
Head of Certification department Commissioner for functional safety
SIL-KE_PULS40+50_EN_031028