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Safety-related characteristics – KROHNE DK 32-DK 34-DK 37 Safety V2 EN User Manual

Page 17

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SAFETY-RELATED CHARACTERISTICS

7

17

DK32 - DK34 - DK37

www.krohne.com

06/2013 - 4000574703 MA DK32 34 37 SIL R03 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

0 FIT

150 FIT

200 FIT

42%

42%

-

Stress profile 4

0 FIT

0 FIT

150 FIT

220 FIT

40%

40%

-

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

0 FIT

150 FIT

288 FIT

34%

34%

-

Stress profile 4

0 FIT

0 FIT

150 FIT

338 FIT

30%

30%

-

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_R03_en_574703_PRT.book Page 17 Wednesday, June 26, 2013 9:17 AM