What is a disadvantage of electrical resistance probes?

Electrical resistance probes are commonly used for measuring the thickness of materials, often in the context of monitoring corrosion or wear in metal structures. However, one of the significant disadvantages of these probes is that they do not measure pitting accurately. Pitting corrosion involves the formation of small, localized areas of corrosion that can significantly reduce the effective thickness of a material without a corresponding change in overall thickness that would be detected by standard resistance probes. This limitation means that while these probes can provide a general idea of material thickness, they are not suitable for detecting and quantifying the specific damage caused by pitting.

The focus on pitting is crucial because it can compromise the structural integrity of components more than uniform corrosion, which is what resistance probes are typically designed to assess. Thus, even if a resistance probe shows an acceptable thickness reading, it may not account for areas where the metal has developed pitting, leading to potential failures.

Understanding this limit helps users select the appropriate tools for monitoring material integrity, especially in applications where the presence of pitting is critical. Each option presents different considerations, but the failure to effectively measure pitting stands out as a prominent drawback of electrical resistance probes.