JUMO 14597 safetyM STB/STW Ex - Safety Temperature Limiter and Safety Temperature Monitor Operating Manual - Manual (Page 45)

6 Safety Manual
39 2013-04-01
Lambda:
λ
SD
Rate of detected safe failures per hour
Lambda:
λ
SU
Rate of undetected safe failures per hour
BPCS Basic Process Control System
DC
Diagnostic Coverage
FIT Failures In Time (1 × 10
-9
per h)
HFT Hardware Fault Tolerance
PFD Probability of Failure on Demand
PFD
avg
Average Probability of Failure on Demand
MooN Architecture with M out of N channels
MTBF Mean Time Between Failures
MTTR Mean Time To Repair
SFF Safe Failure Fraction
SIL Safety Integrity Level
Table 3: Terms and abbreviations according to DIN EN 61508 and DIN EN 61511
Name Description