Yokogawa EJX440A - Manual (Page 39)

IM 01C25T03-01E A-3
APPENDIX 1. SAFETY INSTRUMENTED SYSTEMS INSTALLATION
A1.2.11 Environmental Limits
The environmental limits of the EJX are specified in
the user’s manual IM 01C25.
A1.2.12 Application Limits
The application limits of the EJX 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 Abbrevia-
tions
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 opera-
tion 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 combina-
tion of safety-related system(s)
and external risk reduction
facilities meet, in all respects, the
Safety Requirements Specifica-
tion. 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