Sealing

Why is sealing important?

Sealing ensures that the measuring instrument continues to comply with regulations after being placed in service. Without a valid seal, measurement results may be incorrect – either due to a technical change or deliberate tampering.

For this reason, Section 5-1 of the Regulation on Units of Measurement and Measurement requires that measuring instruments be sealed in accordance with their type approval certificate. Without a seal, the instrument is no longer legally permitted for use.

When must measuring instruments be sealed?

Always, when used for commercial transactions or in regulated control contexts.

• The sealing must comply with the requirements specified in the instrument’s approval.
• Any intervention affecting the seal requires re-sealing before use. 

Examples:

• Fuel dispensers, retail scales, taximeters, gas meters, and electricity meters.

Note: The Norwegian Metrology Service recommends the use of traceable seals, allowing seal breaks and re-sealing to be documented. This improves control and strengthens your position in the event of inspections or inquiries.

What happens in the event of a seal break?

A seal break occurs when the seal is removed or damaged – either intentionally (e.g. during repair) or accidentally. In such cases:

1. You must notify the Norwegian Metrology Service before the instrument is used again.
2. The seal must be reapplied by a qualified repairer or service provider.
3. A non-compliance fee may be imposed if the instrument is used without notification.

What must the notification include?

• New seal number (recommended: traceable seal).
• For electronic sealing: calibration number, configuration number, and/or checksum. 

Note: If the Norwegian Metrology Service discovers an issue during inspection and breaks the seal to check or require corrective action, you must still submit a notification after the repair – including for exempted instrument types. Notifications of seal breaks can be submitted via “Din side” (Your page).

Exceptions: When notification is not required

For certain measuring instruments, the obligation to report a seal break after repair no longer applies:

• Retail scales
• Fuel dispensers / energy stations 

The Norwegian Metrology Service has decided that, for these instruments, the costs and inconvenience to users outweigh the benefits of notification. The requirement remains stated in the regulation, but it is not enforced for these instruments.

Note: This exception does not apply to other types of measuring instruments – for all others, the notification requirement still applies.