Honeywell Krom Schroder BCU 580 - 19.14 Safe failure fraction SFF; 19.15 Probability of dangerous failure PFHD; 19.16 Mean time to dangerous failure MTTFd

BCU 580 · Edition 11.15l 130
Glossary
19.14 Safe failure fraction SFF
Fraction of safe failures related to all failures, which are
assumed to appear
from EN 13611/A2:2011
19.15 Probability of dangerous failure PFH
D
Value describing the likelihood of dangerous failure per
hour of a component for high demand mode or con-
tinuous mode. Unit: 1/h.
from EN 13611/A2:2011
19.16 Mean time to dangerous failure
MTTF
d
Expectation of the mean time to dangerous failure
from EN ISO 138491:2008