For accurate eddy current inspections, what must be considered regarding specimen geometry?

In eddy current testing, specimen geometry plays a crucial role in determining the accuracy and effectiveness of the inspection results. When the geometry of the test specimen is matched with the calibration standards used during the inspection, it ensures that the current flow and the eddy currents generated are consistent. This matching allows for reliable comparisons between the calibration and the test results.

If the geometry is not consistent, it can lead to variations in the sensitivity of the eddy currents, which may affect the test's ability to detect flaws or defects accurately. The shape and size of the specimen can influence the distribution of the electromagnetic field and, consequently, the responses received by the inspection equipment. Therefore, matching the geometry is essential for ensuring that the test results are valid and comparable across different inspections.

Considering the other options, the uniformity of the material or the interchangeability of geometry types or the idea that geometry only affects frequency does not capture the critical importance of matching geometry for producing consistent and reliable eddy current inspection results.