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D.5 Air Shield - P/N 777161
The Air Shield enables you to install the detector in dirty areas and using compressed air,
keep the window clean. This prevents the accumulation of dirt on the window and enables
the detector to continue to operate under harsh conditions.
Figure 18: Air Shield
E SIL-2 Features
E.1 40/40I Flame Detector
This appendix details the special conditions to comply with the requirements of EN 61508
for SIL 2.
The 40/40I Flame Detector can only be used in low or high demand mode applications,
see IEC 61508.4, Chapter 3.5.12.
E.1.1 Safety Relevant Parameters
Perform the following functional checks of the detector:
•
Alternative 1 : Functional check of the detector every 180 days:
•
HFT : 0
•
PFD : 3.0 x 10 -4 (˜ 3% of SIL-2) if only Alarm Relay is used for alerting.
•
PFD : 3.2 x 10 -4 (˜ 3.2% of SIL-2) if 4-20mA – interface is used as alarm.
•
PFH : 1.5 x 10 –7 1/h (˜ 14.9% of SIL-2) for 4-20mA application.
•
SFF : 95% fulfils the conditions of EN 61508 for SIL2
•
Alternative 2 : Functional check of the detector every 365 days:
•
HFT : 0
•
PFD : 4.5 x 10 -4 (˜ 4.5% of SIL-2) if only Alarm Relay is used for alerting.
•
PFD : 4.9 x 10 -4 (˜ 4.9% of SIL-2) if 4-20mA – interface is used signal current as
alarm.
•
PFH : 1.5 x 10 –7 1/h (˜ 14.9% of SIL-2) for 4-20mA application.
•
SFF : 95% fulfils the conditions of EN 61508 for SIL2