Industry's use of electromagnetic impedance for this purpose has been limited because the conventional procedure comes with a risk. The structure being tested could be damaged due to the effort required to remove the attached piezoelectrical converter needed to establish electromagnetic coupling. The measuring system developed by Fraunhofer researchers allows automated inspection of structural components without that risk.

Innovative measuring head for non-destructive structure monitoring. Source: Fraunhofer LBFThe measuring head developed at Fraunhofer LBF is simply pressed up against the test structure in order to simulate the test structure and measure the electromagnetic impedance at the same time. In addition, the adjustable and highly sensitive measuring head has a lower electrical power demand (less than 500 mW) than other non-destructive measurement procedures. Other important benefits include reference-based measurements, short measuring times and flexible adjustment to various positioning units for faster and more reliable conclusions regarding quality deviations or local structural changes, compared to acoustic or optical systems.

A key component of the new process is integrating the measuring system into the industry production environment. The researchers accounted for all relevant hardware and software interfaces of a real production facility and were able to show the functional capacity of the system in the facility.