Saturday, 27 January 2018

Safety Instrumented Function (SIF) - Explained

What is a Safety Instrumented Function - SIF?

The term “safety instrumented function” or SIF is becoming common in the world of safety instrumented systems (SISs). It is one of the increasing number of Swords— SIS, SIL, SRS, SLC, etc.—that are coming into our safety system terminology. The definition of a SIF as provided in IEC standard 61511, “Functional safety: Safety Instrumented Systems for the process industry sector,” leaves a bit to be desired as a practical definition, and the application of the term leaves
many people confused. IEC standard 61511 defines a safety instrumented function as a “safety function with a specified safety integrity level which is necessary to achieve functional safety. A safety instrumented function can be either a safety instrumented protection function or a safety instrumented control function.” A safety function is further defined in 61511 as a “function to be implemented by a SIS, other technology safety-related system, or external risk reduction facilities, which is intended to achieve or maintain a safe state for the process, with respect to a specific hazardous event.” The standard 61511, however, uses the terms SIS and SIF somewhat interchangeably
in places.

1 comment:

  1. Harrahs Casino - Jordan 16 Retro
    Harrahs Casino has a huge air jordan 18 retro men blue for sale range where to find air jordan 18 retro yellow suede of slot machines in the rooms. They have a show to buy air jordan 18 retro men selection of how can i get air jordan 18 retro red suede over 700 titles that have different types of game. You can play at Harrah's air jordan 18 retro red suede discount


What is the difference between IEC 61511 and IEC 61508

A lot of engineers and functional safety practitioners struggle to understand the difference between the two most popular standards for func...