15
UK
13 Approvals/standards
The following standards and directives have been applied:
• 2006/42/EC European machinery directive
• 2004/108/EC EMC directive
• EN ISO 13849-1 PL d (2006) Safety of machinery - Safety-related parts of
control systems
• IEC 60947-5-2 (2008) low voltage switchgear and controlgear: control circuit
devices and switching elements - proximity switches
• IEC 61508 (2000)
• IEC 62061 (2005)
• UL 508
14 Terms and abbreviations
CCF
Common Cause Failure
DC
Diagnostic Coverage
MTTF
D
Mean Time To Dangerous
Failure
OSSD
Output Signal Switching Device
PFH
Probability of failure per Hour
PL
Performance Level
PL to EN ISO 13849-1
SIL
Safety Integrity Level
SIL 1-4 to IEC 61508� The higher the
SIL, the lower the probability that a safety
function will fail�
SIL
cl
Safety Integrity Level
Claim Limit
to IEC 62061
T
M
Mission Time
Lifetime
(= max� service life)
