Method and apparatus for measuring the loop self impedance of shielded wiring non-intrusively utilizing the current transformer ratio of a sense current probe and the current transformer ratio of a drive current probe

摘要

A method for non-intrusively measuring the shielding effectiveness of coaxial wiring by employing an inductive current probe which causes current to flow on the shield of the wiring. A second inductive current probe senses the current on the shield circuit and outputs a voltage which is a function of the shield current. The method employs loop self- impedance in contrast to transfer impedance.