What does SIL rating mean?

How do you define SIL level?

Safety integrity level (SIL) is defined as a relative levels of risk-reduction provided by a safety function, or to specify a target level of risk reduction. In simple terms, SIL is a measurement of performance required for a safety instrumented function (SIF).

What is a SIL rated device?

SIL certification is a tool to measure the amount of risk reduction provided by a Safety Instrumented Function. It assesses the tolerable/acceptable failure rate of an individual device. This is important when installing or retrofitting an instrument into a SIS.

What is the difference between SIL 1 and SIL 2?

The higher the SIL, the greater the risk of failure. And the greater the risk of failure, the stricter the safety requirements.
What Is SIL?

Safety Integrity Level	Probability of Failure on Demand	Risk Reduction Factor
SIL 1	≥102 to <101	100 to 10

What is the highest SIL level?

SIL 4

The Meaning of Safety Integrity Level (SIL)
99,999 in 100,000). There are four discrete integrity levels associated with SIL: SIL 1, SIL 2, SIL 3, and SIL 4. The higher the SIL level, the higher the associated safety level, and the lower probability that a system will fail to perform properly.

What is a SIL 2 rating?

SIL2 – Low statistical risk of failure that you do not know about in the product.

How is SIL rating calculated?

To determine a SIF’s SIL level, the SIF’s overall PFD must be calculated. This SIL calculation basically combines the Failure Rate data for each of the individual SIF components (i.e. the sensors, logic solvers and control elements) and accounts for test frequency, redundancy, voting arrangements, etc.

How do you increase your SIL level?

So to improve your SIL, you must improve one of the three compliance requirements:

1. Improve SIL Capability.
2. Improve Architectural Constraints.
3. Improve PFDavg.