International Standard Iso 14253 1.pdf [best] -

ISO 14253-1 provides a global, standardized framework for assessing conformity or nonconformity of manufactured products by formally accounting for measurement uncertainty. The standard, updated in 2017 to utilize a 95% conformance probability, defines crucial "guard bands" near tolerance limits to eliminate ambiguity and reduce disputes between suppliers and customers. For complete details on the standard, visit ISO. ISO 14253-1:2017 - Geometrical product specifications (GPS)

2.3 Measured value ((y))

The result obtained from a measurement procedure (e.g., the average of repeated readings). INTERNATIONAL STANDARD ISO 14253 1.pdf

The standard outlines decision rules for proving conformity or nonconformity with specifications. These rules are based on the measurement uncertainty and the specified tolerance limits. ISO 14253-1 provides a global, standardized framework for

• Conformance (pass): measured value between 10.02 and 10.08 mm
• Indeterminate zone (upper): between 10.08 and 10.12 mm — cannot decide pass/fail
• Non‑conformance (fail): measured value ≥ 10.12 mm
• (Lower side symmetric: 9.98 to 10.00 indeterminate, <9.98 fail)

• Formula: $y - U > USL$ (for upper limit)
• Formula: $y + U < LSL$ (for lower limit)

If indeterminate, options: