The development of a transient magnetic field measurement technique for implementation on a fuselage-like test setup

The susceptibility of airborne vehicles to electromagnetic (EM) transients has been studied for many years. In the case of lightning attachment, the current may flow along the surface of the conducting fuselage and disperse around the circumference. A portion of it can penetrate through the fuselage (by diffusion) resulting in transient EM fields on the inside that can result in EM interference to onboard electronics. In the laboratory, an aluminum test cylinder, representative in size and construction of a fighter-type aircraft fuselage, was subjected to high current pulses. An improved technique, the use of new two-dimensional magnetic flux density (B) probes is being developed to determine the magnitude of magnetic flux density outside and inside the cylinder as a result of transient currents flowing along the cylinder. The mating of these probes with a wide bandwidth fiber optic system for transient data acquisition and the overall system calibration procedures are presented.