Det-Tronics PIRECL Infrared Hydrocarbon Gas Detector PointWatch Eclipse SAFETY MANUAL - Manual (Page 7)

5.1 95-8630 7
TErMS AND DEFiNiTioNS
AMS Asset Management System
DU Dangerous Undetected
FMEDA Failure Mode Effects and Diagnostics
Analysis
HART Highway Addressable Remote Transducer
HFT Hardware Fault Tolerance
LFL Lower Flammable Limit
PFD Probability of Failure on Demand
(Probability of Dangerous Failure)
PFDavg Average Probability of Failure on Demand
PIRECL Pointwatch Eclipse ® IR Gas Detector
SFF Safe Failure Fraction
SIF Safety Instrumented Function
SIL Safety Integrity Level
SIS Safety Instrumented System
UD20 FlexVu ® Model UD20 Universal Display
iEC 61508 Failure rates in FiT 1
Failure Category l sd l su 2 l dd l du SFF 3
PIRECL IR Gas Detector, Analog Output 0 46 1655 123 93.3
PIRECL IR Gas Detector, Relay Output 106 222 1335 130 92.7
PIRECL IR Gas Detector with UD20 Universal Display,
Analog Output
0 46 1691 142 92.5
PIRECL IR Gas Detector with UD20 Universal Display,
Relay Output
106 222 1371 149 91.9
1
FIT = 1 Failure / 10 9 Hours
2
It is important to realize that the No Effect failures are no longer included in the Safe Undetected Failure category according to IEC 61508,
ed2, 2010.
3
Safe Failure Fraction needs to be calculated on (sub)system level.