How does multi-frequency testing improve Eddy Current Testing capabilities?

Multi-frequency testing enhances Eddy Current Testing (ECT) capabilities primarily by allowing for the distinction between different types of defects and thereby improving accuracy in detection. When several frequencies are employed during testing, the system can take advantage of how different materials and defects respond to varying frequencies of the eddy currents.

Different types of materials and geometric features present unique impedance characteristics at different frequencies. By analyzing the results across these frequencies, testing personnel can differentiate not only the presence of a defect but also its type, size, and shape. This is especially beneficial in complex situations where multiple defects might exist or where the materials being tested have varying electrical and magnetic properties.

In contrast, focusing solely on a single frequency may yield ambiguous results, particularly when defects are small or closely spaced. With multi-frequency capabilities, the overall reliability and precision of the testing process are significantly enhanced, leading to better decision-making in terms of maintenance and safety.