Which method is considered the most accurate for measuring pits?

• A. Visual inspection
• B. Routing
• C. Profilometry
• D. Caliper measurement

Answer: (B)

Accurate pit measurement comes from capturing the full geometry of the defect rather than relying on a single point or a qualitative view. Routing achieves this by tracing the pit along defined survey paths and recording depth and dimensions at many points, building a complete profile of the pit’s shape. This detailed, multi-point data lets you calculate true depth, cross-sectional area, and even estimated volume, which makes the measurement far more reliable for irregular pits than a single measurement or a rough visual check.

Visual inspection is qualitative and subjective, giving only a rough sense of size. Caliper work usually provides a single linear dimension and can miss variations along the pit’s length or width. Profilometry offers high-resolution surface maps but typically samples a small area and may not capture the full extent of an irregular pit unless multiple measurements are stitched together. Routing, by contrast, records the pit’s geometry across its entire footprint, delivering the most accurate overall assessment.