Topic: Metrology and Inspection
For profile controls, datum is
- A. Allowed but not required
- B. Not allowed
- C. Required
- D. None of these
Answer: A. Allowed but not required
Explanation: For profile controls (like profile of a line or profile of a surface in GD&T), a datum is allowed but not strictly required. When no datum is specified, the tolerance controls only the form of the profile. If datums are specified, it controls form, orientation, and/or location.