Time‐of‐Flight Measurements from Eddy Current Tests

Data fusion techniques are based on the premise that two or more carefully designed NDE tests are potentially capable of offering additional information concerning the test object relative to what can be garnered from a single test. However, information from a heterogeneous set of transducers cannot be fused unless the data is mapped onto a common ‘format’. The eddy current method cannot, for example, provide time‐of‐flight information that can be combined from estimates derived from ultrasonic tests. This paper presents a simple solution to address the problem by employing the so‐called Q‐transform to relate diffusive fields, such as those generated by eddy current probes, and propagating wave fields generated by ultrasonic NDT sensors. The paper illustrates how the distance between a defect and a source can be extracted from eddy current data generated using carefully selected excitation signals. Numerical results and comparisons with analytical predictions are presented.