What is required by law – and what you need to pay attention to
Anyone who uses scales in business or medical applications must be familiar with the topic of calibration . But what exactly does this mean, when is calibration required, and what is the difference between calibration and adjustment? Here you'll find everything you need to know in a concise and understandable format.
What is the calibration of a scale?
Calibration is a legally required, official test that checks the measuring accuracy of a scale. If the scale passes this test, it is issued with a calibration mark. This ensures that the scale measures within the legal tolerance limits.
The goal: consumer protection – particularly important when pricing is based on weight or in medical applications.
Initial verification, conformity assessment and re-verification – an overview
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Initial calibration: Previously carried out by the calibration office, today mostly replaced by the manufacturer's conformity assessment (according to EU Directive NAWI 2014/31/EU)
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Conformity assessment: The manufacturer declares that the scale complies with all legal requirements – often already ex works
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Recalibration: Recurring calibration after expiry of the calibration period, only by authorized testing centers
Calibration, adjustment – what is the difference?
These terms are often confused, but mean different things:
| Expression | Meaning |
|---|---|
| oaks | Official, legally regulated testing with marking – only by authorized bodies |
| Calibrate | Documentation of the deviation – without intervention in the device |
| Adjust | Technical adjustment to improve accuracy |
In summary:
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Calibration checks
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Adjustment corrected
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Eichen confirms the legally permissible accuracy
When does a scale need to be calibrated?
Calibration is mandatory whenever a scale is used in the following areas:
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Commercial transactions (e.g. sales by weight)
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Medical and pharmaceutical applications (e.g. doctor's offices, pharmacies)
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Official tasks or production of prepackaged goods
How often is calibration required?
The calibration intervals depend on the scale type and application. Here are the most important rules:
| Area of application / scale type | Calibration period |
|---|---|
| Standard commercial and industrial scales (up to 3,000 kg) | 2 years |
| Vehicle scales and industrial scales (3,000 kg or more) | 3 years |
| Personal scales in hospitals (except bed scales) | 4 years |
| Baby scales | 4 years |
| Medical scales in doctor's offices | mostly unlimited |
| Livestock scales | 4 years |
Note: The deadline always runs until December 31st of the last year of validity – regardless of the calibration month.
How to recognize a calibrated scale
Calibrated scales carry certain legally required markings:
Explanation of the calibration marks:
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A Year mark in a square with inwardly curved edges shows the year in which the calibration period begins.
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Additional markings (information marks) may contain further information on calibration.
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At first-calibrated scales (conformity assessed by the manufacturer) is behind the "M" the year of placing on the market – also the start of the calibration period.
Practical examples
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One Counter scale with the marking “16” must be issued no later than 2018 be recalibrated.
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One vehicle scale with the manufacturer’s marking “M14” must be 2019 be recalibrated.
Apply for recalibration in good time
The calibration validity always ends on December 31st of the last year of validity.
Example: A vehicle scale with calibration mark “25” is valid until 31.12.2028.
Important deadlines:
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Apply for recalibration by mid-October of the expiry year at the latest
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At least 10 weeks before the end of the year
If the application is submitted too late, the scale may only be used with a special permit – otherwise, fines may be imposed.
Summary – your to-dos at a glance
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Regularly check the expiration year on the calibration mark or sticker
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Apply for recalibration in a timely manner. If you wish, we can take care of the recalibration. Feel free to contact us!
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Pay attention to complete and visible markings (CE, M-mark, seal)
Checklist: Is your scale legal?
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CE and M marks available
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Validity date not exceeded
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Calibration seal or sticker present
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Recalibration requested in good time
Conclusion:
If you use scales in areas subject to legal metrology, you bear responsibility – both legally and to your customers. A correctly calibrated scale is not only a requirement, but also a sign of accuracy and trust.
Do you need support?
Please feel free to contact us! We will answer your questions and, if you wish, take care of the entire calibration process – professionally, on time and reliably.