Emerson Rosemount 8800D Series - Page 24

Unit subjected to either no proof test or a comprehensive proof test
every 5 years
Figure 3-3:
A
B
D
E
E
E
C
0 2 4 6 8 10
A. PFD (Probability of failure on demand)
B. Mission time (years)
C. PFD
AVG
(average probability of failure on demand)
D. Predicted PFD
E. Predicted PFD + CPT (comprehensive proof test)
Unit subjected to a partial proof test every year and a comprehensive
proof test every 3 years
Figure 3-4:
A
B
D
D
C
0 2 4 6 8 10
A. PFD (Probability of failure on demand)
B. Mission time (years)
C. PFD
AVG
(average probability of failure on demand)
D. Predicted PFD + PPT (partial proof test) + CPT (comprehensive proof test)
Proof tests
20 Rosemount
™
8800D Safety Manual