Why should inspection surfaces not be modified during VT?

• A. Modifications can create artificial indications or mask real ones, compromising data integrity
• B. Modifications can improve detection
• C. Modifications are harmless
• D. Modifications reduce inspection time

Answer: (A)

In visual testing, you must observe the surface in its original condition under standardized lighting and viewing angles. Any modification to the surface changes how light interacts with it, which can create artificial indications or hide real ones. Scraping, polishing, repainting, or abrasive cleaning can add or erase features, alter surface texture, or blur cracks and corrosion, leading to false positives or false negatives. This compromises data integrity because the inspection results no longer reflect the actual as-found condition and cannot be trusted for repair decisions or trend analysis. Modifications are not allowed unless a clearly defined, approved cleaning or alteration procedure exists that does not affect defect indicators.