Why might a technician adjust the frequency during ET?

Adjusting the frequency during eddy current testing (ET) is crucial for optimizing defect detection based on the characteristics of the material being inspected. Different materials and their unique electromagnetic properties can respond differently to various frequencies. By selecting the appropriate frequency, a technician can enhance the system's sensitivity to specific types of flaws or defects, such as cracks or corrosion, that may be present in the material.

For instance, higher frequencies may be more effective for detecting smaller defects or flaws in thinner materials, while lower frequencies might be better suited for thicker materials or larger defects. This adaptability allows for more accurate and reliable testing results, ensuring that the detection set-up is aligned with the material's properties and the expected fault characteristics.

Understanding the connection between frequency adjustment and material response is fundamental in ensuring that inspections are thorough and that faults are not missed. This level of attention to detail is what makes ET an effective non-destructive testing technique.