Last week we were discussing various methods of dealing with fire dangers in our aircraft.  I decided to try out the Hamamatsu UV Tron flame sensor, and promised to report my findings to the Fly Rotary group. 

 

I located a pre-assembled circuit board from Superdroid Robots, a company that supplies a variety of parts for robots.  They were the only place I could find that carried the Hamamatsu C3704 flame detector and driver card.   So, I ordered both along with a relay board.  (Attached is a picture of the boards.)  The UV Tron sensor is the clear glass “bulb” in the foreground.  The small board on the left is a voltage converter, allowing it to be connected directly to 14v. 

 

I hooked it up to a 12v cordless drill battery and tested it using a propane fire starter.  It could easily “see” a flame from 6’ away (maybe more, but I didn’t test it beyond 6’) and up to 90* right or left.  I didn’t test up/down, but the spec sheet indicates that it is about the same in the vertical and horizontal planes.  I could not get it to false trip by using a fluorescent or a halogen light.  There is about a .5 second delay before it trips the relay.  The tech rep at Superdroid Robots indicated that the UV Tron sensor could be remotely mounted up to 3’ away from the board.  I plan on mounting it in a small box on the firewall with the leads running though the firewall to the circuit boards inside the cabin, wired to a big red flashing LED on the panel.  Everything in the picture (including s&h) ran $150.  I look at it as cheap insurance.  Hopefully, I will never need it.

 

Mark S.