Accurate measurement of Aluminum layer thickness in a multilayer material using eddy current sensor

This paper presents an eddy current sensor based system that allows thickness measurement of an Aluminum layer in multilayer material. An electromagnetic analytical model is used to give the relationship between the response of the eddy current sensor and the Aluminum layer thickness for different frequencies, and then looking for the optimal working frequency according to a given criterion. The measurement system is performed and controlled by a Labview application in which the analytical relationship is integrated. Some experimental samples of multilayer material containing an Aluminum layer with different thicknesses are used to verify the measurement system. A good accuracy and agreement is observed between the measured thicknesses and the exact thickness of the samples.