What factor does NOT affect defect detection in ET?

In the context of eddy current testing (ET), defect detection is influenced by various factors that can impact the effectiveness of the inspection process. The choice indicating that manual data entry does not affect defect detection stands out because it pertains more to data interpretation than to the detection of defects themselves.

Material thickness, surface coating, and technician skill level are all critical factors that can significantly affect the outcome of an ET inspection. For instance, variations in material thickness can impact the penetration depth of the eddy currents, affecting the ability to detect flaws. Similarly, surface coatings can mask defects or alter the electrical conductivity of the material, making detection more challenging. The technician's skill level is essential, as it directly relates to their ability to set up equipment correctly, interpret signals, and identify defects accurately.

Manual data entry, while important for maintaining records and results documentation, does not influence the direct process of defect detection during the ET inspection. Therefore, it is not a variable that affects how effectively defects are identified in the material itself.