3
1 Functional safety
VEGACAL series 60 • Two-wire 4 … 20 mA/HART
35593-EN-181129
1 Functional safety
1.1 General information
This safety manual applies for measuring systems consisting of
the capacitive sensor VEGACAL series 60 in the version two-wire
4 … 20 mA/HART:
VEGACAL 62, 63, 64, 65, 66, 69
Valid hardware and software versions:
•
Serial number of the electronics > 14557661
•
Sensor software from Rev. 1.01
The measuring system can be used for level measurement of liquids
and solids that meets the special requirements of safety engineering.
Due to the service-proven reliability, implemention is possible in a sin-
gle channel architecture up to SIL2 and in a multi-channel, diversitary
redundant architecture up to SIL3.
The use of the measuring system in a multiple channel, homogene-
ous redundant architecture is excluded.
The SIL conformity is confirmed by the verification documents in the
appendix.
SIL
Safety Integrity Level
HFT
Hardware Fault Tolerance
SFF
Safe Failure Fraction
PFD
avg
Average Probability of dangerous Failure on Demand
PFH
Probability of a dangerous Failure per Hour
FMEDA
Failure Mode, Effects and Diagnostics Analysis
λ
sd
Rate for safe detected failure
λ
su
Rate for safe undetected failure
λ
dd
Rate for dangerous detected failure
λ
du
Rate for dangerous undetected failure
DC
S
Diagnostic Coverage of safe failures; DC
S
= λ
sd
/(λ
sd
+λ
su
)
DC
D
Diagnostic Coverage of dangerous failures; DC
D
= λ
dd
/(λ
dd
+λ
du
)
FIT
Failure In Time (1 FIT = 1 failure/10
9
h)
MTBF
Mean Time Between Failure
MTTF
Mean Time To Failure
MTTR
Mean Time To Repair
Further abbreviations and terms are stated in IEC 61508-4.
•
IEC 61508
– Functional safety of electrical/electronic/programmable elec-
tronic safety-related systems
•
IEC 61511-1
Scope
Application area
SIL conformity
Abbreviations, terms
Relevant standards
Summary of Contents for VEGACAL 60 Series
Page 1: ...Safety Manual VEGACAL series 60 Two wire 4 20 mA HART Document ID 35593...
Page 11: ...11 2 Supplement VEGACAL series 60 Two wire 4 20 mA HART 35593 EN 181129 2 Supplement...
Page 12: ...12 2 Supplement VEGACAL series 60 Two wire 4 20 mA HART 35593 EN 181129...
Page 13: ...13 Notes VEGACAL series 60 Two wire 4 20 mA HART 35593 EN 181129...
Page 14: ...14 Notes VEGACAL series 60 Two wire 4 20 mA HART 35593 EN 181129...
Page 15: ...15 Notes VEGACAL series 60 Two wire 4 20 mA HART 35593 EN 181129...