Metrics Instruments can help you design intrinsically
safe (I.S.) instruments for use in hazardous environments.
One of the challenges in designing electronic instruments
for areas where explosive gases are present is prevention
of sparks during product failure due to the storage
of excessive electrical energy in certain components.
Two ways to solve this problem are either to enclose
the entire instrument in an explosion-proof box, resulting
in more expensive and bulkier products, or to simply
design the circuitry at the board level such that no
section of the circuit is allowed to store enough energy
to generate sparks. The latter application typically
requires the use of an I.S. barrier that limits the
current consumption of the circuit.
There are different classifications for hazardous
locations depending on the potency of the explosive
gases present, and the European Community has a different
set of requirements than North America.