Proficiency Testing — Vernier Caliper(Interlaboratory Comparison — Dimensional)
ISO/IEC 17043-aligned proficiency testing scheme for vernier caliper calibration — circulated reference artefacts, ISO 13528 statistical evaluation (En / z-scores), and confidential performance reports for NABL-accredited and aspiring calibration laboratories.
What is the Proficiency Testing — Vernier Caliper Scheme?
Under ISO/IEC 17025:2017 (clause 7.7), every accredited calibration laboratory must monitor the validity of its results by participating in proficiency testing (PT) — and NABL expects documented, satisfactory PT participation across the accredited scope. Global Lab operates an ISO/IEC 17043:2023-aligned interlaboratory comparison scheme for vernier caliper calibration: a characterised artefact travels between participating labs, each calibrates it by their normal method, and results are evaluated statistically against the assigned reference value.
The humble caliper is the most-calibrated instrument in India — and the volume makes consistent technique across labs matter more, not less. The scheme measurand covers calibration of vernier/digital calipers against gauge references, with results reported at defined points across the measuring range including jaw checks. Each participant receives a confidential performance report — En numbers and z-scores per ISO 13528 — through our Live PT Program portal, with anonymised group statistics and corrective-action guidance where performance flags arise.
How the Proficiency Testing — Vernier Caliper is Conducted
- 1
Enrolment
The laboratory enrols for the vernier caliper scheme round through the Live PT Program portal and receives the scheme protocol. - 2
Artefact Receipt
The characterised artefact arrives per the circulation schedule with handling instructions and condition-check requirements. - 3
Calibration by Your Method
Your lab calibrates the circulated caliper by its normal gauge-block-based method and reports errors with uncertainties. - 4
Result Submission
Results with claimed uncertainties are submitted through the portal by the round deadline. - 5
Statistical Evaluation
Submissions are evaluated against the assigned value per ISO 13528 — En numbers and z-scores computed per measurement point. - 6
Performance Report
A confidential report with your performance flags and anonymised group statistics is issued; corrective-action guidance follows any unsatisfactory result.
Applicable Test Standards
| Standard | Title | Scope | Type |
|---|---|---|---|
| ISO/IEC 17043:2023 | Conformity Assessment — General Requirements for the Competence of Proficiency Testing Providers | PT Scheme Operation | International |
| ISO 13528:2022 | Statistical Methods for Use in Proficiency Testing by Interlaboratory Comparison | En / z-Score Evaluation | International |
| ISO/IEC 17025:2017 | Competence of Testing and Calibration Laboratories (Clause 7.7) | Participation Requirement | International |