International Standard Iso 14253 1.pdf ((install)) -

ISO 14253-1:2017 Geometrical product specifications (GPS) — Inspection by measurement of workpieces and measuring equipmentPart 1: ISO - International Organization for Standardization

The core principle of this standard is that Therefore, measurement results cannot be treated as absolute truth. The standard provides a mathematical and procedural framework for handling this uncertainty to ensure fair trade between the supplier and the customer. INTERNATIONAL STANDARD ISO 14253 1.pdf

The default rule favours the consumer (protects against accepting bad parts), which is typical for many safety‑critical industries. INTERNATIONAL STANDARD ISO 14253 1.pdf

. It is critical for industries that rely on high-precision manufacturing because it accounts for the inevitable measurement uncertainty that occurs in every inspection. ISO - International Organization for Standardization Core Concept: The "Golden Rule" The standard operates on a simple principle: uncertainty must work against the party making the claim HN Metrology Proving Conformity: INTERNATIONAL STANDARD ISO 14253 1.pdf

Conclusion: because uncertainty interval exceeds USL.