YOKOGAWA DPharp EJXC40A, Руководство пользователя

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<Appendix1. Safety Instrumented Systems Installation>
A1-3
IM 01C25W05-01EN
A1.2.10 Lifetime Limits
The expected lifetime of the transmitter is 50
years. The reliability data listed the FMEDA report
is only valid for this period. The failure rates of the
transmitter may increase sometime after this period.
Reliability calculations based on the data listed in
the FMEDA report for transmitter lifetimes beyond
50 years may yield results that are too optimistic,
i.e. the calculated Safety Integrity Level will not be
achieved.
A1.2.11 Environmental Limits
The environmental limits of the transmitter are
specified in the user’s manual IM 01C25.
A1.2.12 Application Limits
The application limits of the transmitter are specified
in the user’s manual IM 01C25. If the transmitter is
used outside of the application limits, the reliability
data listed in A1.2.9 becomes invalid.
A1.3 Definitions and
Abbreviations
A1.3.1 Definitions
Safety
Freedom from unacceptable risk of harm
Functional Safety
The ability of a system to carry out the actions
necessary to achieve or to maintain a defined
safe state for the equipment/machinery/plant/
apparatus under control of the system
Basic Safety
The equipment must be designed and
manufactured such that it protects against risk
of damage to persons by electrical shock and
other hazards and against resulting fire and
explosion. The protection must be effective
under all conditions of the nominal operation
and under single fault condition
Verification
The demonstration for each phase of the life-
cycle that the (output) deliverables of the phase
meet the objectives and requirements specified
by the inputs to the phase. The verification is
usually executed by analysis and/or testing
Validation
The demonstration that the safety-related
system(s) or the combination of safety-related
system(s) and external risk reduction facilities
meet, in all respects, the Safety Requirements
Specification.
The validation is usually executed by testing
Safety Assessment
The investigation to arrive at a judgment -based
on evidence- of the safety achieved by safety-
related systems
Further definitions of terms used for safety
techniques and measures and the description of
safety related systems are given in IEC 61508-4.
A1.3.2 Abbreviations
FMEDA Failure Mode, Effects and Diagnostic
Analysis
SIF Safety Instrumented Function
SIL Safety Integrity Level
SIS Safety Instrumented System
SLC Safety Lifecycle