If the LSh value is very high (untuned case) and so can be neglected, expression (1) would be valid and simple linear expressions for VT can be deduced [7]. This hypothesis is not very often fulfilled because, in order to improve the sensitivity of NDE probes, they are usually loaded with an inductor, of rather low value [8]. Under these last working conditions, both impulsive responses—IrCH, IrSS—may not be linearly defined.