Orientation and Location Testing
Definition: Orientation and location testing is the metrological determination of deviations of a geometrical feature with regard to its orientation or position relative to defined datum features. It assesses location tolerances such as parallelism, perpendicularity, angularity or position. The basis is geometrical product specifications according to DIN EN ISO 1101.
Practical relevance: Location deviations affect the assemblability, tightness and functional reliability of components. The assessment is carried out by comparing the measured geometry with defined tolerance zones, referenced to datum surfaces or axes. Measuring instruments are coordinate measuring machines (CMM), optical 3D scanners or special gauges. Measurement uncertainty and the correct selection of datums are decisive.
Decision-making perspectives:
- Technical decision-makers: Ensuring function-critical alignments and minimising wear or vibrations.
- Purchasing/project management: Unambiguous definition of datum and tolerance specifications in drawings.
- Science: Analysis of tolerance chains and the influence of manufacturing variation.
- Insurance/law: Proof of position or alignment errors in the event of complaints.
Typical testing or verification methods: CMM measurement, optical 3D metrology, evaluation according to the GPS framework of standards.
FAQ:
- What is the difference between form tolerance and location tolerance?
- Form tolerances concern the shape of a feature, location tolerances its orientation or position relative to a datum.
