Explosion Proof Detection

["Bob La Londe" <none@xxxxxxxx>]

Ok...  what is there that meets a weatherproof and explosion proof criteria,
and has any chance of detecting in intruders in a fenced yard.

Yes I said explosion proof.

I was thinking stacked photo beams for coverage, but I can not find any that
meet the explosion proof rating.  Suggestions?  Ideas?  Just walk away....
I actually quoted them a video system and found explosion proof rated
cameras for a reasonable price, but they were not willing to pay what it
costs.

Now they want me to quote them some kind of detection system.  Their fence
is way to loose and out of tune to even consider a microphone cable on the
fence.  Its in town with walking traffic on two sides anyway.