Electricity meter certification

Certification

When an electricity meter design has been approved under the Meters (Approval of Pattern or Construction and Manner of Installation) Regulations 1998, a manufacturer can submit meters, manufactured in accordance with the type approval, for certification. It is a requirement of the Electricity Act 1989 that all domestic meters used for billing purposes by an authorised supplier are certified to show that, when tested following manufacture / refurbishment, they conform to the original type approval and operate within the prescribed levels of accuracy.

Certification is performed by meter examiners appointed by the Office for Product Safety and Standards (OPSS) or by authorised examiners employed by manufacturers / repairers of electricity meters that have been authorised to self-certify. This process is described in detail in the Meters (Certification) Regulations 1998 (SI 1998/1566). This prescribes that all meters, following approval, be allocated a certification life (i.e. the time a meter is allowed to remain on the wall from initial certification).

Meters for industrial and commercial customers are either certified, or the supplier reaches agreement with the customer for a meter with a similar level of accuracy to be installed. Certification periods are 10 years for newly approved induction meters and for periods of between 10 and 20 years for static meters. Certification periods greater than 10 years (for static meters) are subject to the submission and validation of a component reliability model based on the Siemens Norm SN29500.

Subsequent in-service surveillance monitoring is carried out through sample. Where certification is required meters must be removed from service when the certification period expires.

Secondary metering

Meters need not be certified where the supplier does not hold a supply licence. This provides for situations where the supplier might be a landlord selling electricity on to tenants, or a caravan park owner billing individual berth occupiers. However, a written agreement must be in place between the two parties to dispense with the requirement for certification and the meter owner is obliged to use an approved meter and keep the metrology of the meter accurate.

Self-certification

The Meters (Certification) Regulations 1998 allow OPSS to authorise manufacturers and repairers of electricity meters to ‘self-certify’ meters that have been manufactured or repaired. Formal authorisations are issued to the manufacturer / repairer; these are subject to regular audits performed by independent meter examiners appointed by OPSS.

Manufacturers and repairers authorised to self-certify meters must comply with the strict conditions under which the authorisation is issued. If these are breached, OPSS can withdraw the authorisation (see Section 5(5)(c) of the Electricity Act 1989 and Regulations 3(9) and 4(9) of The Meters (Certification) Regulations 1998.

Sealing

Prior to submission for certification, meters will have a uniquely marked seal attached. A seal is used to provide security by protecting the measuring elements from tamper, and to identify the manufacturer / repairer of the meter, the year of certification and the fact that the meter is certified. The seal can take the form of either a crimped security seal or an indelible inscription on the meter case.

If this seal is removed or tampered with in any way this should be reported to the supplier.

Contact us

If you have a specific enquiry regarding the accuracy of your gas and/or electricity meter, please email OPSS.enquiries@businessandtrade.gov.uk.

Alternatively you can contact the OPSS helpdesk on 0121 345 1201, open Monday to Friday 09.00 to 17.00.

Or in writing to: