While correcting a CFSP exam, I read a question which went something like this:
If you purchase all IEC 61508 certified equipment for a low demand safety instrumented function, then to meet the requirements of IEC 61511:
A. No other design verification is needed
B.…
There have been passionate debates in email and meetings about “Proven In Use” versus IEC 61508 certification. Most debates characterize these evaluation techniques as competing methods. In 2000 when IEC 61511 was being written there were few IEC 61508 certified products on the market. The…
One of the objectives of new performance based standards like IEC 61508 is to allow performance metrics (like PFDavg for low demand systems) to identify the weak links in any proposed design. Obviously, it is not necessary to put effort into design and spend money on areas…