GIFSQ Tools · Module 15 — Metrology, Validation & Laboratory Accreditation · Tool 297 of 500
Check a balance with a certified test mass: the error, the percentage error, and a pass or fail against your tolerance — the daily check of ISO/IEC 17025 clause 6.4.
Try sample values — fills the form with the worked example below.
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Error
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Error (%)
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Result
Equation: Error = observed − nominal. Error (%) = error ÷ nominal × 100. Pass when |error| ≤ tolerance.
Method: Daily balance verification per ISO/IEC 17025 clause 6.4 (equipment) and OIML R 76 practice: weigh a certified test mass, compare the indication with the certified value, and accept the balance only inside the laboratory tolerance.
Assumptions: the test mass is certified and traceable; the balance is levelled, warmed up and free of draughts; the tolerance is the laboratory limit for this balance and use.
Limitations: a single-mass check does not prove linearity — check at least two masses across the working range periodically; temperature and draughts can shift a reading without the balance being at fault.
Rounding: error to 2 decimal places; error (%) to 2 decimal places; intermediates unrounded.
This is a calculation aid, not a laboratory report — confirm against your accredited method before citing a value.
Method: Daily balance verification per ISO/IEC 17025 clause 6.4 (equipment) and OIML R 76 practice: weigh a certified test mass, compare the indication with the certified value, and accept the balance only inside the laboratory tolerance.
Assumptions: the test mass is certified and traceable; the balance is levelled, warmed up and free of draughts; the tolerance is the laboratory limit for this balance and use.
Limitations: a single-mass check does not prove linearity — check at least two masses across the working range periodically; temperature and draughts can shift a reading without the balance being at fault.
Rounding: error to 2 decimal places; error (%) to 2 decimal places; intermediates unrounded.
This is a calculation aid, not a laboratory report — confirm against your accredited method before citing a value.
Worked example: Nominal 100 g, observed 100.02 g, tolerance 0.05 g: error = 0.02 g, error = 0.02% — pass, inside tolerance.
Enter values above to see results.
Pass is |error| at or under the tolerance. A fail means stop weighing, clean and level the balance, and re-check before use. Tool 297 of 500 — GIFSQ
