Moore Industries. Intrinsic safety is increasing worldwide as a method of hazardous area protection with monitoring and measurement instruments. Significant savings, both initial installation and ongoing maintenance costs, can be realized in intrinsically-safe (IS) facilities or projects by selecting an associated apparatus that encompasses the required IS barrier protection for your system. Written by Tina Todd, Director of Engineering at Moore Industries, this paper explains the basic differences between simple apparatus with separate intrinsic safety barriers and associated apparatus with intrinsically-safe field connections. It addresses why selecting an associated apparatus which includes the IS barrier provides the most economic and effective use of IS technology. Additionally it addresses design, installation and maintenance considerations in selecting the best approach when choosing an intrinsic safety solution.