Sensor Selection for Safety Instrumented Systems | AIChE

Sensor Selection for Safety Instrumented Systems

     Safety instrumented systems are designed to be the last, and most critical, layer of protection in an operating facility. While the control system’s purpose is to keep the plant running and optimize profits, the safety instrumented system (SIS) works to keep the process, plant, and the company’s reputation safe. Its main purpose is to shut down the plant and prevent potentially catastrophic accidents. The key takeaway is that these are two independent systems, which, per SIS standards, should not share any common components. However, this is not always the case in the real world, as the standards can be open to interpretation.

     The safety instrumented system’s main job is to determine when the system becomes unsafe, and shut down the system, if necessary. The sensors within the safety instrumented system play an important role in detecting when a process has become unsafe. This article takes a look at sensors for safety instrumented systems, and explains methods for selection based on targeted safety integrity level (SIL).

Tags 

Sensors
Transmitters
Controllers

Date 

July, 2015