Which statement is not applicable to spinning probe-type instruments?

The statement regarding the limitations of the size of the product to be inspected by spinning probe-type instruments being correlated to the dc saturation capability of the system is not applicable. Spinning probe instruments are designed to have a broad range of applications, allowing them to inspect various sizes and types of conductive materials without being strictly constrained by the saturation capability.

The other statements emphasize relevant features of spinning probe instruments. They can accommodate different frequencies, which is beneficial for inspecting various metals and alloys. This adaptability in frequency allows for effective detection of defects in different material properties. Furthermore, these instruments are versatile enough to be used on both straight and coiled wire products, making them practical for a wide range of inspection scenarios. Additionally, their ability to effectively detect seams is crucial in many manufacturing processes, especially in industries where the integrity of welds and seams is paramount.

Ultimately, the misconception about the size limitation due to dc saturation illustrates a misunderstanding of the capabilities of spinning probe instruments, which are designed to perform efficiently across a variety of conditions and materials.