Abstract
The focus of this study is the behaviour of the lift-off point of intersection (LOI) under various test conditions: lift-off, thickness and conductivity of metallic layers with and without a ferromagnetic substrate. The pulsed eddy current (PEC) signal response is analyzed and a lift-off independent method to measure the thickness of conductive layers over ferromagnetic substrates is presented. This approach is tested by scanning specimens with varying lift-off and conductive layer thickness. The test articles have different substrate permeabilities, but identical lift-off and conductive layer conditions. The results demonstrate that the LOI feature can be used to measure the thickness of conductive layers over ferromagnetic substrates.
Get full access to this article
View all access options for this article.