Reference
Glossary
Plain-language definitions of the standards and terms that govern conformant measurement, in German and English.
ISO GPS (Geometrical Product Specification)
The ISO standard system, known in German as Geometrische Produktspezifikation, that defines how the geometry of a part is specified on a drawing and verified by measurement. It is the dominant framework across the DACH region and the EU, in contrast to the North American ASME Y14.5 standard.
Learn moreISO-GPS matrix (ISO 14638)
The coordinating model that structures all GPS standards into chains linking a drawing indication to the final measurement result. ISO 14638 is the entry point for understanding which standard governs each step of specification and verification.
Learn moreDIN EN ISO 1101
The German adoption (DIN national, EN European, ISO international) of the standard for geometrical tolerancing, titled Tolerierung von Form, Richtung, Ort und Lauf. It governs form, orientation, location and run-out tolerances on technical drawings in the DACH region.
Learn moreISO 14405 (two-point size)
The ISO standard for dimensional tolerancing. It defines size specification operators such as the two-point size, which can differ from a software's default associated (Gaussian) size and is a common source of non-conformant evaluation if the CMM software is not configured for it.
Learn moreISO 14253-1 (decision rules)
The ISO standard defining decision rules (Entscheidungsregeln) for proving conformity or non-conformity with a specification, accounting for measurement uncertainty when accepting or rejecting parts.
Learn moreISO 5459 (datums)
The ISO standard for datums and datum systems (Bezüge), which establish the reference framework a geometrical tolerance is measured against. Incorrect datum alignment is one of the most frequent causes of wrong CMM results.
Learn moreASME Y14.5
The North American GD&T standard. It agrees with ISO GPS on the surface but diverges in roughly two thirds of practical cases. ASME Y14.5-2018 removed concentricity and symmetry tolerances, whereas ISO retains the coaxiality concept, making standard interpretation essential for export-facing work.
Learn moreCoordinate Measuring Machine (CMM)
A precision instrument, in German Koordinatenmessmaschine, that measures the geometry of a part by probing defined points on its surface. The measured data is compared against drawing tolerances. CMM acceptance and verification testing is governed by ISO 10360.
Learn moreMeasuring program
The set of instructions that tells a CMM which features to measure, in what sequence, with which probe strategy, datum alignment and evaluation method. A poorly written or non-conformant program can pass bad parts or reject good ones.
Learn moreMeasurement uncertainty (Messunsicherheit)
A quantified estimate of the range within which the true value of a measured quantity lies. It must be small relative to the part tolerance to allow confident accept or reject decisions, and is evaluated according to the GUM (Guide to the Expression of Uncertainty in Measurement).
Learn moreMeasurement System Analysis (MSA)
Statistical studies, in German Messsystemanalyse, that evaluate whether a measurement process is fit for purpose. They examine gauge capability, repeatability and reproducibility (Gage R&R). In the automotive supply chain, VDA 5 (Prüfprozesseignung) is the corresponding test process suitability method.
Learn moreErstmusterprüfbericht (EMPB) / First Article Inspection Report (FAIR)
A quality document that records the full inspection results of an initial sample before serial production begins. The German Erstmusterprüfbericht corresponds to the international First Article Inspection Report; both are part of the broader initial-sample release process.
Learn moreDIN EN ISO/IEC 17025 and DAkkS
ISO/IEC 17025 is the worldwide standard for the accreditation of testing and calibration laboratories. DAkkS is Germany's national accreditation body; the equivalents are SAS in Switzerland and Akkreditierung Austria. Calibration certificates underpinning measurement uncertainty trace back to 17025-accredited labs.
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