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Entries tagged with: Safety Instrumented Function

Back to Basics 05 – What is a Safety Function?

Back to Basics 05 – What is a Safety Function?

A Safety Function is the action of a collection of equipment to implement automatic mitigation of a particular hazard. It is the job of the Safety Instrumented Function (SIF).

Some examples of common Safety Functions: 

  • Car brake stop
  • ESD valve – Shutdown process
  • Sprinkler system 
  • High…

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How to Calculate Proof Test Coverage
  • by Dr. William Goble, CFSE
  • Thursday, October 16, 2014
  • Certification

How to Calculate Proof Test Coverage

Most engineers who design and verify safety instrumented functions (SIFs) understand how hard it is to design a manual proof test with high effectiveness (also called high proof test coverage). Those folks who understand that a proof test is not likely to detect all failures never use simplified equations…

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I Don’t Want No D*** Diagnostics!

After a false trip incident, I heard a control engineer express his displeasure with the automatic diagnostics in a new safety rated transmitter.  The transmitter diagnostics were annunciated by sending the analog current out of range.  In this case, the current went to 3.6 milliamps.  The problem was that…

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