NDT is a wide group of analysis techniques used in science and industry to evaluate the properties of a material, component or system without causing damage. Because NDT does not permanently alter the article being inspected, it is a highly valuable technique that can save both money and time in product evaluation, troubleshooting, and research.

This book chapter aims to give an overview of the wide range of techniques available to measure forces. The most common measurement principles of force transducers are introduced with special focus on strain gauge load cells and piezoelectric crystal force transducers. Furthermore, the characteristics of force measurement systems are discussed, as well as the importance of calibration.

In this book chapter it is shown that the LFE is an interesting alternative to the well-established ECT technique when in nonferromagnetic conductors deep internal defects/anomalies have to be identified. In such cases, complicated structures with moving components lead to very high computational costs, i.e. it is highly preferably to apply fast numerical models for solving the forward problem. Solving the inverse problem, i.e. the identification of defects or conductivity anomalies, requires efficient solution strategies. In most cases, the number of optimization methods that can be applied for this purpose is limited because usually only derivative-free methods can be used.