Patent ID: 7355395
Filing Date: 2008-04-08
Classification: G01N,G01R

Abstract:
1. A method of non-destructive non-contact quality inspection of dry electrode units of energy storage, including the steps of: providing an eddy current-based inspection system comprising a conveyor belt, and a hollow dielectric shell, an outer surface of said shell having a plurality of measuring transducers thereon, each of said transducers including a feed-through eddy current probe and at least two strap capacitors spatially linked therewith; placing an electrode unit to be inspected on said conveyor belt, wherein said electrode unit enters and moves through said dielectric shell; exciting said electrode unit using a magnetic field from said eddy current probe as it passes by each of said plurality of transducers while in said shell, wherein eddy currents at a plurality of frequencies are induced; measuring modulation characteristics of impedance at said plurality of frequencies using said eddy current probes, and determining whether said electrode unit is defective based on said modulation characteristics of said impedance.