Development of a MHz RF leak detector technique for aircraft hardness surveillance

A technique for electromagnetically exciting aircraft that produces surface magnetic and electric field distribution similar to those resulting from exposure to plane waves is presented. Surface magnetic fields in the range of 1 to 10 mA/m are easily produced for frequencies between 1 and 10 MHz. Measurement of the magnetic field at a prescribed distance from the outside and inside surfaces of hardened apertures, such as window screens and gasketed doors, using a small loop sensor and a battery-operated field-strength meter allows the shielding effectiveness of these hardening elements to be determined. When a current probe is substituted for the loop, this technique can also be used to characterized conductive penetrations. This technique has great potential as an aircraft hardness surveillance tool because it is simple to implement, quantitative and capable of not only characterizing each hardening element, but also finding the electromagnetic hot spots.<>