Paul L Leach

US Patent:

41729935, Oct 30, 1979

Filed:

Sep 13, 1978

Appl. No.:

5/941758

Inventors:

Paul W. Leach - East Orange NJ

Assignee:

The Singer Company - Little Falls NJ

International Classification:

G01R 3102
G01N 2500

US Classification:

324158F

Abstract:

In order to permit probing access to a printed circuit board while the printed circuit board is under test in a cold controlled environment, a doubled walled environmental hood is provided, the inner and outer walls spaced apart by rings containing orifices therein, a probe hole formed in the center of the ring and the outer wall cut away in the area of the ring, with a cold gas supplied to the inside of the inner wall and a hot gas supplied to the space between the walls, whereby the hot gas escaping through the orifices in the rings will raise the temperature of the cold gas escaping from the probe hole to prevent frosting and permit viewing of the printed circuit board under test for probing.