Definition:
An Instrument in functional safety is any sensor or device used to detect a condition to trigger the SIF into performing its action.
Key Points:
- Includes all types of instruments. Such as with transmitters or simple switches
- Can be very high end to very low tech instruments.
- The most high tech instruments are essentially computers with their own diagnostics.
Example:
A high-level switch on a separator vessel is an instrument.
See also: Final Element, Logic Solver
Cited Source:
- IEC 61511-1:2016, Clause 3.2.12.