An out-of-tolerance result means the gage did not meet the defined acceptance criteria when evaluated. It does not automatically prove that every prior measurement or product is unacceptable—but it does require controlled, competent review rather than simply adjusting the gage and filing a passing certificate.
Understand exactly what was out of tolerance
Start with the actual as-found data. Identify the point, range, direction, and magnitude of the deviation; the acceptance limit used; the reported uncertainty or decision rule where relevant; and whether the result occurred before any adjustment or repair.
The gage condition before adjustment or repair; essential for evaluating prior use
The condition after calibration, adjustment, or repair; used to decide future availability
The defined limits used to decide whether the gage was suitable
The measurement points, direction, function, or range where the deviation occurred
The technical values and affected range determine how the organization can evaluate prior measurements. Preserve the complete certificate or internal calibration data.
Take immediate control actions
- 1Identify and segregate the gage
Prevent unintended use through physical status, electronic status, location control, or another method defined by procedure.
- 2Preserve the as-found evidence
Do not adjust, repair, or overwrite the record before the original condition and result are captured.
- 3Notify the responsible functions
Inform the quality owner and the operational area that used or controls the gage.
- 4Open a review record
Assign an owner and unique reference for containment, potential impact, disposition, and closure.
- 5Identify the last known acceptable point
Use the previous acceptable calibration, verification, check-standard result, or other justified evidence.
The exact actions depend on your documented system and applicable requirements. If uncertainty exists about the scope, use a conservative boundary until evidence supports narrowing it.
Evaluate potential impact on previous measurements
The review asks whether the gage’s condition could have changed an earlier decision. It should be performed by people with the authority and technical knowledge to understand the measurement, tolerance, product, process, and available evidence.
- Which characteristic, range, direction, or function was affected?
- When was the gage last known to be acceptable?
- Which jobs, batches, products, tests, or inspections used it since that point?
- Could the observed error change a pass/fail or conformity decision?
- Was the error conservative or non-conservative for the actual measurement direction?
- Are independent measurements, process data, check standards, or final tests available?
- Can affected items be identified, contained, remeasured, retested, or otherwise evaluated?
- Do customer, regulatory, or reporting obligations apply?
Document both the conclusion and the reasoning. “No impact” is a conclusion, not an explanation. A credible record identifies the population considered, evidence reviewed, assumptions made, and authorized decision.
NIST’s Engineering Metrology Toolbox FAQ notes that a serious out-of-calibration condition may require review of prior judgments. FDA inspection guidance similarly explains that an out-of-calibration finding can call the validity of results into question. Apply the requirements relevant to your own organization and industry.
Decide the gage disposition separately
The decision about previous measurements and the decision about the gage’s future are related but separate. A gage can be repaired and pass calibration while the prior-use review remains open. It must not return to normal service merely because a new as-left result passes.
Adjustment is authorized, the gage meets acceptance criteria, and required review is complete
A defect is corrected and satisfactory calibration evidence is obtained
Use is restricted to a documented range or application with clear identification and authorization
The gage moves to a less demanding, defined application after technical approval
The item is permanently removed from the controlled active population
Do not close the event until equipment disposition and the potential product or test impact have each been addressed according to procedure.
Records to retain for an out-of-tolerance event
- Gage ID, calibration event ID, date, provider, and certificate.
- As-found and as-left data, acceptance criteria, and affected range.
- Immediate containment and status-control actions.
- Last known acceptable point and the potential-use window.
- Affected records, product, batches, tests, or processes considered.
- Evidence, calculations, assumptions, and technical review conclusion.
- Customer or regulatory communication, when required.
- Repair, adjustment, restriction, revalidation, or retirement decision.
- Approvals, completion dates, and effectiveness follow-up.
Use the event to improve the calibration system
Look beyond the individual failure. Review whether the calibration interval, handling, storage, protection, training, method, provider instructions, acceptance limits, or interim checks need to change. Trending similar events by equipment family, department, damage type, or provider can reveal a systemic problem.
If the event shows that the gage can drift between scheduled calibrations, consider whether a shorter interval, check standard, pre-use verification, environmental control, or different measurement method provides better protection.
This is a general quality-workflow guide, not a universal regulatory procedure. Use your approved procedures and competent technical judgment, and involve customers or regulatory specialists where applicable.