CMM (Coordinate Measuring Machine)
Definition: A coordinate measuring machine (CMM) is a tactile or optical measuring system for the three-dimensional acquisition of a workpiece’s geometric features. It determines coordinate points in space and uses these to calculate dimensions as well as form and position tolerances. The accuracy requirements are governed by DIN EN ISO 10360.
Practical relevance: CMMs are used to inspect complex geometries, positional and profile tolerances within the framework of the GPS standards (e.g. DIN EN ISO 1101). Dimensional deviations, flatness, roundness or positional tolerances are assessed. Measurement uncertainty, temperature stability and calibration status have a decisive influence on the quality of the results.
Decision-making perspectives:
- Technical decision-makers: Ensuring function-critical tolerances and series suitability.
- Purchasing/project management: Definition of inspection plans, acceptance criteria and measurement strategies.
- Science: Analysis of measurement uncertainties and comparison of tactile versus optical systems.
- Insurance/law: Documented geometric verification in disputes over dimensions or fit.
Typical testing or verification methods: 3D point measurement, scanning, evaluation against the CAD data set, measurement report including uncertainty statement.
FAQ:
- Which standard governs the accuracy of a CMM?
- DIN EN ISO 10360 defines test procedures and accuracy requirements for coordinate measuring machines.
