Section 23 of 55
22. Datums and Physical Reference Geometry
Stable section ID: S05-CON-011-SECTION-23 · 25 content blocks
System05 shall establish stable datum systems that allow humans, robots, manufacturing equipment, scanners, and inspection tools to interpret component position and orientation consistently.
A datum hierarchy may include:
- Primary datum plane.
- Secondary datum plane or axis.
- Tertiary datum point or feature.
- Component coordinate system.
- Interface coordinate system.
- Node coordinate system.
- Zone coordinate system.
- Building coordinate system.
- Site coordinate system.
Datums shall be connected to stable structural or Interface geometry. They shall not rely solely on removable finishes, flexible seals, temporary labels, irregular material edges, or replaceable covers.
Datum definitions shall include:
- Reference feature.
- Coordinate orientation.
- Nominal location.
- Applicable tolerance.
- Measurement method.
- Calibration requirements.
- Accessibility.
- Expected lifecycle stability.
- Permitted replacement or repair.
Physical datum features may include machined surfaces, locating holes, bosses, slots, pins, geometric targets, or protected measurement references.
The transformation between coordinate systems shall be documented and traceable. When measured conditions differ from nominal geometry, the applicable task shall use the verified physical transform rather than silently assuming the design position.
Damage, corrosion, coating buildup, deformation, or obstruction of a datum shall trigger inspection, alternate localization, or task suspension according to consequence.