What is a significant cause of false indications in NDT?

Surface roughness or spatter is a significant cause of false indications in nondestructive testing (NDT) because these surface conditions can scatter, reflect, or absorb the testing signal in unpredictable ways. When defects are present, surface roughness can create reflections that mimic indications of flaws. Similarly, spatter from surface treatments or processes can create additional signals that can confuse the technician interpreting the results, leading to false positives or negatives.

In contrast, other factors, while they may contribute to the overall quality of testing, do not directly result in false indications as prominently as surface roughness or spatter. For instance, excessive illumination may affect visibility but does not inherently create misleading signals related to the actual integrity of the material being inspected. Poor training of technicians can lead to misinterpretation of data rather than a production of false indications from the testing itself. Using outdated equipment may influence the reliability and sensitivity of the results but does not necessarily produce misleading indications in the same direct manner that surface roughness or spatter does.