DART Technology and FOUNDATION fieldbus

Dynamic Arc Recognition and Termination technology (DART) will have a big impact on the world of intrinsic safety, particularly IS implementations of fieldbus.

DART technology enables intrinsic safety of an electric circuit with dramatically increased available power during normal operation. In the case of an unwanted, potentially threatening condition such as opening or closing of the electric circuit, DART technology puts the circuit into a safe state before critical levels are reached. A spark caused by opening or closing an electric circuit has a very characteristic and easily detectable change of current and voltage. This change is detected by DART technology and the circuit switched off in only a few microseconds (µs). Thus, even at higher power levels, sparks never become incendive.

Pepperl+Fuchs in conjunction with PTB, the Physikalisch Technische Bundesanstalt in Germany and twelve other manufacturers is involved in introducing changes to international standard IEC 60079 (Electrical Installations in Hazardous Areas). In order to facilitate easier practical application and interoperability between manufacturers, the working group targets introducing regulations for test and approval of dynamically acting power supplies and equipment into IEC 60079.
There is an interesting white paper done by ARC Advisory Group on DART technology available for download here at the Control Global web site. 

Pepperl+Fuchs Page on DART Technology