Functional safety for SITRANS P, series DS III PROFIsafe
Product information, 07/2006, A5E00849297-01
2-1
General safety instructions
2
2.1
Safety-instrumented system
Definition: Safety-instrumented system
A safety-instrumented system executes the safety functions that are required to achieve or
maintain a safe status in a system. It consists of a sensor, logic unit/control system and final
controlling element.
Example:
A safety-instrumented system is made up of a pressure transmitter, a limit signal sensor and
a control valve.
Definition: Safety function
Defined function executed by a safety-instrumented system with the objective of achieving or
maintaining a safe system status taking into account a defined dangerous occurrence.
Example:
Limit pressure monitoring
Definition: Dangerous failure
Failure with the potential to bring the safety-instrumented system into a dangerous or non-
functional status.
Description
The sensor, logic unit/control system and final controlling element combine to form a safety-
instrumented system, which executes a safety function.
Note
This document deals with the SITRANS P pressure transmitter exclusively as a part of a
safety function.