Capacitive sensor array for nondestructive evaluation applications
Electromagnetic sensors come in different versions: capacitive, inductive, microwave, optics, etc. Eddy current probes (inductive sensors) have been used for decades in nondestructive evaluation (NDE) applications to detect flaws in conducting objects. Inductive probes are discussed by Rosegreen and Cooley (Bahr, and Rosegreen, 1987; Bahr, 1982; Bahr, and Cooley, 1983; Bahr, 1985). Capacitive sensors have been widely used for many decades also, but these applications have been based on extremely simple physical concepts; there has been no attempt to exploit the sophisticated sensing capabilities of generalized electric field probes. In NDE, there is a requirement to know not only how a probe behaves analytically under different probe geometry transformations, but also how a probe interacts with objects of different shapes and material properties.