Elettronica Santerno IRIS BLUE, Руководство по применению

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STO FUNCTION
APPLICATION MANUAL
SINUS PENTA
PENTA MARINE
IRIS BLUE
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9. TERMS AND ABBREVIATIONS
A
ccording to EN 61508-6, Table B.1:
Abbreviation Term (units)
T1
Proof-test interval (hour)
MTTR Mean time to restoration (hour)
DC Diagnostic coverage (expressed as a fraction in equation and as a percentage
elsewhere)

Fraction of undetected failures that have a common cause (expressed as a
fraction in equation and as a percentage elsewhere)

D

Fraction of detected failures that have a common cause (expressed as a fraction
in equation and as a percentage elsewhere)

Failure rate (per hour) of a channel in a subsystem
PFH
G

Probability of failure per hour for the group of voted channels

D
Dangerous failure rate (per hour) of a channel in a subsystem, equal to 0.5


DD

Detected dangerous failure rate (per hour) of a channel in a subsystem (sum of
all the detected dangerous failure rates within the channel of the subsystem)

DU

Undetected dangerous failure rate (per hour) of a channel in a subsystem (sum
of all the undetected dangerous failure rates within the channel of the
subsystem)

SD

Detected safe failure rate (per hour) of a channel in a subsystem (sum of all the
detected safe failure rates within the channel of the subsystem)

SU

Undetected safe failure rate (per hour) of a channel in a subsystem (sum of all
the undetected safe failure rates within the channel of the subsystem)
t
CE

Channel equivalent mean down time (hour) for 1oo1, 1oo2, 2oo2 and 2oo3
architectures (combined down time for all the components in the channel of the
subsystem)