A device that provides the means for comparing a test surface to a standard surface finish is called:

• A. Measuring magnifier
• B. Surface calibrator
• C. Surface comparator
• D. Surface magnifier

Answer: (C)

Direct comparison of a test surface finish to a standard reference is accomplished with a surface comparator. This device provides a standard reference surface (or patches) that you view side-by-side with the test surface under the same lighting, allowing a quick, qualitative judgment of whether the finish matches the required spec. It’s designed specifically for comparing texture and roughness to a known standard, not for magnifying details or calibrating instruments. A measuring magnifier or surface magnifier only enlarges the view without a reference standard for comparison, and a surface calibrator is used to check or adjust measurement equipment rather than to compare finishes directly.