The airknife pressure we use is 42 psi at approximately .25 inch from 
the board bottom surface. I can't tell you what the temperature is 
because I do not monitor it.  The preheating is achieved by a coil of 
aluminum tubing arranged in the bottom of the preheating box below 
the quartz lamps. The airknife supply air is routed through this coil 
first and then into the airknife.  This is an inexpensive way of 
heating the air, but provides varying output temperatures depending 
on the preheat profile being used.  Nonetheless, the air has never 
been dangerously hot and we have had good success with the system.

Jason Spera
General Atronics Corp.