Automation and instrumentation components and systems must often be installed in process plant areas classified as hazardous according to IEC or NEC. These projects present challenges in terms of design, installation and maintenance.
For all such installations, there are four main options as shown in the table: explosion-proof, intrinsically safe, non-incendive or purged. Each approach has its advantages and drawbacks, and many installations will be best served by a combination of two or more methods.