Weighing scale
A weighing scale is one of 8 classes the finder reads in the mass and force group. Scales, balances, test weights, torque tools, force gauges and load cells: where an as-found reading out of tolerance usually means product was weighed, torqued or loaded against the wrong figure.
Calibrating a weighing scale
vendor-neutral, no interval given- What a calibration usually checks
- Readings with test weights across the range, eccentric loading, repeatability.
- Common as-found problems
- Load cell drift, damage from shock loads, debris under the platform.
- Calibration, and the routine check
- A calibration compares it with a reference traceable to national or international standards and records the as-found result; the routine check (a check weight before use) confirms it is working on the day and does not replace the calibration. Your procedure sets both, and the interval.
- What the register row should carry
- The asset ID on the instrument and its label, the last calibration date and the certificate reference, who did it (in house against which reference standard, or which external provider), the as-found result and, if it was out of tolerance, the impact assessment reference, and the due date worked out from your interval.
What the calibration register should record for it
| Column | What goes in it |
|---|---|
| Asset ID | the number on the instrument and its label, unique in the register |
| Type and description | what it is and its range, in the words your register uses |
| Location and owner | where it lives and who answers for it, so the recall list can find it |
| Control type | optional: calibration, verification, intermediate check, qualification or mapping; the wording of the due date follows it |
| Last calibration | the date of the last calibration or verification |
| Interval | the interval your procedure sets, in months, weeks or days, or before each use |
| Due date | optional: the finder works it out and shows where yours disagrees |
| Cal by | in house or external |
| Lab accredited to ISO/IEC 17025 | yes, no or unknown, for an external lab |
| Certificate number | the index to the calibration record |
| Traceable to a national standard | yes or no |
| As found | in tolerance or out of tolerance at the last calibration |
| Used for product acceptance | yes or no |
| Status | in service, out of service, reference only, lost, quarantined or retired |
| Impact assessment | yes, no, or a reference, for any out-of-tolerance reading |
The due date
worked out, never setThe due date is the last calibration plus the interval in your register, shown with its arithmetic. The interval is yours to set and review; the finder never suggests one, and no typical interval enters any arithmetic on this site.
A line that places here
exampleA-015 | platform scale 300 kg | 12/03/2025 | 12 months | Inspection | yes | in tolerance
What the finder reads on these lines
12 findings- 1. Overdue: the due date worked out is earlier than the as-at date: Is it out of use until it is done, and who books it?
- 2. Due before the audit, or inside the warning window: Book it: which slot, and does the lab turnaround land before the audit?
- 3. No due date can be worked out: no interval or no last calibration recorded: What is the interval, and when was it last done?
- 4. Out of tolerance as found, with no impact assessment recorded: Which parts or lots were measured with it between the calibration before and this one, and what was decided about them?
- 5. Overdue and used for product acceptance: Which lots were measured with it since the due date, and are they held until it is checked?
- 6. External lab not accredited, or its accreditation unknown: Is the service inside an accreditation scope, or is there customer acceptance or a stated alternative on file? Without IATF 16949: does a customer, a contract or your supplier procedure ask for an accredited lab?
- 7. Traceability not recorded in this register: What does the certificate trace to, or what basis was recorded, and should the register say so?
- 8. Calibrated in house with no procedure named: Which procedure is it done to, and is that procedure inside the internal lab's scope?
- 9. Certificate reference not recorded in this register: Where is the certificate for the last calibration, and can it be retrieved in the audit?
- 10. Lost, quarantined or out of service but marked for product acceptance, or lost with no impact assessment: Is the acceptance mark on the register wrong, or was it used? For a lost instrument, what did it measure since its last calibration?
- 11. The register's own due date disagrees with last calibration plus interval: Which is right: the interval, the last calibration date or the due date?
- 12. Two rows with one asset ID: Which instrument carries the number, and what is the other one's own ID?
Clauses, by standard
10 cited| Standard | Clause | Applies to |
|---|---|---|
| ISO 9001 | ISO 9001 7.1.5 Monitoring and measuring resources | a manufacturer holding ISO 9001 certification |
| AS9100D | AS9100D 7.1.5 Monitoring and measuring resources | an aerospace supplier holding AS9100 certification |
| ISO 13485 | ISO 13485 7.6 Control of monitoring and measuring equipment | a medical device maker holding ISO 13485 certification |
| ISO/IEC 17025 | ISO/IEC 17025 6.4 Equipment | a testing or calibration laboratory accredited to ISO/IEC 17025 |
| ISO/IEC 17025 | ISO/IEC 17025 6.5 Metrological traceability | a testing or calibration laboratory accredited to ISO/IEC 17025 |
| IATF 16949 | IATF 16949 7.1.5.2.1 Calibration and verification records | an automotive supplier holding IATF 16949 certification |
| 21 CFR 211 | 21 CFR 211.68 Automatic, Mechanical, and Electronic Equipment | a drug maker under 21 CFR 211 |
| 21 CFR 58 | 21 CFR 58.63 Maintenance and Calibration of Equipment | a laboratory running nonclinical studies under 21 CFR 58 |
| IATF 16949 | IATF 16949 7.1.5.1.1 Measurement systems analysis | an automotive supplier holding IATF 16949 certification |
| 21 CFR 211 | 21 CFR 211.160 Laboratory controls: general requirements | a drug maker under 21 CFR 211 |
The calibration clause, set out
ISO 9001 7.1.5Monitoring and measuring resourcesWhere monitoring or measurement is used to check that products and services conform, the organization identifies and provides the resources needed for results to be valid and reliable. It makes sure those resources suit the kind of monitoring and measurement done and are maintained so they stay fit for purpose, and it retains documented information as evidence that they are. Where traceability of measurement is required, or the organization judges it essential to confidence in the results, measuring equipment is: calibrated or verified, or both, at set intervals or before use, against standards traceable to international or national ones (and where none exist, the basis used is recorded); identified so its status is known; and protected from adjustment, damage or deterioration that would make its calibration status or later results invalid. If equipment proves unfit for its purpose, the organization judges whether earlier results remain valid and acts as needed.