Terms used across the product and this site, defined the way the standards define them, with a note on where each one shows up in Metroliq.
| Term | Definition | In Metroliq |
|---|---|---|
| As-found / as-left | The reading before and after any adjustment during calibration. | Both stored per point; the interval review uses as-found. |
| CAPA | Corrective and preventive action: the record that fixes a cause, not a symptom. | Quality module; AI-drafted, human-owned, effectiveness check required to close. |
| CMC | Calibration and measurement capability: the smallest uncertainty a lab can claim on its accredited scope. | Uncertainty studies publish as CMC lines; authoritative at perform. |
| Conditional (verdict) | Specification met, but the result is not accepted under the decision rule because the uncertainty interval crosses the limit. | Third verdict state; wording prints the probability of non-conformance. |
| Coverage factor k / probability | Multiplier turning combined standard uncertainty into expanded uncertainty; k = 2 ≈ 95.45 %. | Taken from the t-distribution via effective degrees of freedom; printed on the certificate. |
| DCC | Digital Calibration Certificate, the PTB-led XML schema with D-SI units. | Exported for every certificate; imported from other labs. |
| Decision rule | The rule that turns a measured value, its uncertainty and a tolerance into a verdict. | Simple, guard-banded accept, guard-banded reject, PFA target; printed with the verdict. |
| Effective degrees of freedom | Welch–Satterthwaite combination of the degrees of freedom of the contributors. | Computed per budget; picks k. |
| En score / z score | Proficiency-testing performance statistics comparing a lab's result with the reference. | PT/ILC evaluation in the quality module. |
| FEFO | First expired, first out: issue the lot with the nearest valid expiry. | Inventory issue rule; expired lots refused. |
| Guard band | A margin inside the tolerance that offsets measurement uncertainty; ILAC-G8 uses w = U. | Acceptance limit = tolerance − U; shown per point. |
| GUM | Guide to the expression of uncertainty in measurement (JCGM 100). | The budget arithmetic: divisors, quadrature, Welch–Satterthwaite. |
| Hash chain | Each audit entry hashes the previous entry's hash with its own content, so history cannot be edited silently. | SHA-256 over canonical JSON; verify endpoint. |
| Idempotency key | A client-supplied token that makes a repeated write safe. | Header on POST/PUT/PATCH; replays return the stored response. |
| ILAC | International Laboratory Accreditation Cooperation; publishes P14 (uncertainty), G8 (decision rules), G24 (intervals). | Applied throughout the calibration module. |
| Intermediate check | A check between calibrations that a reference standard still performs. | Due list per standard. |
| MSA / Gage R&R | Measurement system analysis: how much variation comes from the gauge and the operators. | AIAG Gage R&R studies. |
| Monte Carlo (JCGM 101) | Propagating uncertainty by sampling the input distributions. | Seeded, reproducible, 10 k – 2 M trials; cross-checks the GUM budget. |
| NCR | Nonconformance report: something did not meet its requirement. | Raised at the bench with the failing point; escalates to CAPA. |
| PFA / PFR | Probability of false accept / false reject for a given reading, uncertainty and rule (JCGM 106). | Computed per point; printed. |
| Provenance (AI) | The record of which model produced a draft, from what prompt, and who approved it. | Ledger entry per draft; certificate states AI-assisted specs. |
| Reference standard | The calibrated artefact or instrument the unit under test is compared with. | Typed per-point accuracy, own certificate and due date; overdue refused. |
| Revision / amendment | A corrected certificate is a new revision with a reason; the old one is kept. | §7.8.8; verify page shows both. |
| Sensitivity coefficient | How much the output changes per unit change of an input; the partial derivative of the measurement equation. | Derived symbolically from the equation and cross-checked numerically. |
| Specification provenance | Where a tolerance came from: document, revision, clause, origin. | Stored with the spec; printed on the certificate. |
| Traceability | An unbroken chain of calibrations to the SI, each with stated uncertainty. | Standards chain and statement on the certificate. |
| TUR / TAR | Test uncertainty ratio: tolerance divided by expanded uncertainty (TAR uses the standard's accuracy). | Computed from the standard's typed accuracy; declared when below 4:1. |
| Type A / Type B | Uncertainty evaluated statistically from repeated readings (A) or by other means such as certificates and specifications (B). | Contributor types in the budget. |
| Validation (IQ/OQ/PQ) | Installation, operational and performance qualification of a computerised system. | Validation evidence; the OQ runs itself. |
The tour runs the working platform, not a mockup. Pilot on your own instruments with your own imported history — we set it up with you, and fixes ship in hours and days, not release cycles.