Which of the following statements about eddy current testing is true?

Eddy current testing is indeed capable of differentiating between different materials. This is primarily due to the fact that the characteristics of the eddy currents induced in a conductive material can change based on the electrical conductivity and magnetic permeability of that material. Each material has unique properties that affect how eddy currents flow and how they interact with an external electromagnetic field, which can produce distinct responses in the testing equipment. Therefore, when subjected to eddy current testing, different materials will generate different signals, allowing technicians to identify and differentiate various materials effectively.

The capability to distinguish materials is particularly useful in applications where materials with similar physical appearances but different electrical properties need to be verified or monitored. This can include situations such as detecting the presence of an alloy versus a pure metal or differentiating between treated and untreated surfaces. Such functionality is a significant advantage of eddy current testing, reinforcing its utility in various industries for quality assurance and material characterization.