ELECTRIC SWITCH TESTER
April 11, 1943
Time required to check the maze of electrical installations in warplanes is cut from about 18 hours to 15 minutes by a recent invention.
It checks hundreds of wires for proper wiring and shorts, indicating which ones are bad and where.
Operating principle of the tester is based on the fact that the main switch box is the heart of a plane's circuit.
photo # Y8386 similar but not identical to 039.002