What is the primary purpose of a high-pass filter in eddy current testing?

The primary purpose of a high-pass filter in eddy current testing is to minimize low-frequency noise. In this context, low-frequency noise can mask or obscure the signals of interest that are generated by the eddy currents in the material being tested. By allowing only signals above a certain frequency threshold to pass through, a high-pass filter effectively reduces the impact of this low-frequency noise, improving the clarity and accuracy of the desired signals. This enhancement is crucial for the reliable detection of flaws and variations in material properties during eddy current testing.

While factors such as signal strength and harmonics are important in the overall context of testing and signal analysis, they are not the primary focus of a high-pass filter’s function. Similarly, filtering out unwanted high frequencies is not relevant to the primary role of a high-pass filter, which is specifically designed to allow higher frequencies to pass while attenuating lower frequencies.