In simple terms, a continuity test verifies that current will flow in an electrical circuit (i.e. that the circuit is continuous). The test is performed by placing a small voltage between 2 or more endpoints of the circuit. The flow of current can be verified qualitatively (e.g. by observing a light or buzzer in series with the circuit actuates) or quantitatively (e.g. by using a multimeter to measure the resistance between the endpoints).
Nearly all military aerospace platforms InterConnect manufactures for, from the F-16 and F-22, to C-130 and UH-60, require a qualitative test to confirm the integrity of the EWIS (Electrical Wiring Interconnect System). These tests require the resistance between circuit endpoints to fall below a certain value, typically from 2 to 4 ohms. The values can be higher for circuits containing coax or thermocouple wire, inline resistors or similar components.
InterConnect utilizes wiring analyzers and automated test programs to not only verify the resistance of circuits, but also to confirm our products are wired according to the wiring diagrams or similar engineering requirements. In many cases when InterConnect rewires military aircraft, the entire EWIS is tested after installation but prior to applying power to the aircraft. Here is a photo of a United States Army National Guard UH-60 that InterConnect Wiring completely rewired and is performing continuity and other tests on, prior to operational flight check.
Do you learn better from watching videos? Check out our Vlog on Testing a Wiring Harness to DoD Standards!