KROHNE DK 32-DK 34-DK 37 Safety V1 EN - Manual (Page 16)

7
SAFETY-RELATED CHARACTERISTICS
16
DK32 - DK34 - DK37
www.krohne.com 02/2012 - 4000574702 MA DK32 34 37 SIL R02 en
DK37/M8E DK37/M8E DK37/M8E DK37/M8E...-SE with 4...20mA current output
DK37/M8E DK37/M8E DK37/M8E DK37/M8E/R*...-SE with 4...20mA current output and dp-regulator
Fail safe Fail dangerous
detected undetected detected undetected
λ
SD
λ
SU
λ
DD
λ
DU
SFF 2 DC
D
SIL AC
3
Stress profile 2 0 FIT 258 FIT 150 FIT 200 FIT 67.1% 43% SIL1
Stress profile 4 0 FIT 317 FIT 150 FIT 220 FIT 67.9% 41% SIL1
T[Proof] 4 1 year 5 years 10 years
PFD
AVG
5 9.58*10 -4 4.43*10 -3 8.76*10 -3
Fail safe Fail dangerous
detected undetected detected undetected
λ
SD
λ
SU
λ
DD
λ
DU
SFF 2 DC
D
SIL AC
3
Stress profile 2 0 FIT 395 FIT 150 FIT 288 FIT 65.3% 34% SIL1
Stress profile 4 0 FIT 543 FIT 150 FIT 338 FIT 67.2% 31% SIL1
T[Proof] 4 1 year 5 years 10 years
PFD
AVG
5 1.38*10 -3 6.37*10 -3 1.26*10 -2
2 The number listed is for reference only. The SFF must be determined for the complete
subsystem.
3 SIL AC (architectural constraints) means that the calculated values are within the range
for hardware architectural contraints for the corresponding SIL level.
4 It is assumed that proof testing is performed with a proof test coverage of 99%.
5 The PFD
AVG
was calculated for profile 2 using the Markov modelling. The results must
be considered in combination with PFD
AVG
values of other devices of the Safety
Instrumented Function (SIF) in order to determine suitability for a specific Safety
Integrity Level (SIL)
For SIL1 applications, the PFD
AVG
value needs to be < 10 -1 .
For SIL2 applications, the PFD
AVG
value needs to be < 10 -2 .
MA_DK32_34_37_SIL_R02_en_574702_PRT.book Page 16 Thursday, March 1, 2012 9:53 AM