Posted for "Steitle, Mark R" <mark.steitle@austin.utexas.edu>:

 I used a UVtron based fire detector designed by the robotics guys to
 help robots find fires in burning buildings.  I mounted it in a small
 project box and wired it to a big red light on my panel.  It only
 detects actual fire (flames), not light.  So, it won't trigger based on
 glowing exhaust headers, sunlight, etc.  Attached is a picture of the
 unit with the box open. The heart of the unit is the UVtron bulb, which
 is the clear bulb you can see mounted on the circuit board & standing
 upright within the box.  The "warning light" is the small LED lying on
 top of the box.  I ended up using a much larger LED than what is shown
 here.  You can assemble what you see in the picture for about $150.
 Hopefully, I'll never have to find out how well it works.
 
 Mark S.
 LNCE 208TX
 
http://www.weslick.com/images/Mid-Winter%20Rotor-Fest%2006/target9.html