Update on the European measuring instruments directive


The Measuring Instruments Directive (MID) comes into force in October 2006, and this article gives an update on activities being carried out in preparation.

The MID will establish a Measuring Instruments Committee which has powers to agree normative references which presume conformity and to amend the requirements of the instrument-specific Annexes. As a precursor to the committee being formed, a ‘working group’ has been convened by the European Commission. This met in January; its main purpose appears to be to co-ordinate and endorse guidelines being prepared by WELMEC.


The MID must be transposed into the laws of individual member states, and proposals should be ready for Commission agreement by April 2006. In the UK, work for gas and electricity meter legislation has been progressing through an advisory group to the regulator Ofgem, including utility and manufacturer representatives, and draft regulations are expected to be available for comment shortly. A metering group of EURELECTRIC – the trade association for the European electricity utilities – has been observing general progress in member states as regards legislation for electricity meters.


Assessment of conformity to the MID is assisted by reference either to European standards which interpret them, or to other international normative documents. Both CEN (for gas) and CENELEC (for electricity) are awaiting a formal mandate from the Commission to produce standards in support of the MID.CENELEC has produced drafts of three new standards for electricity meters, interpreting accuracy requirements of the MID, based on IEC 62052-11, 62053-11 and 62053-21, and these will shortly be available for national comment. As regards acceptance inspection, reference may be made to IEC standards which are now being reviewed by a working group of IEC TC13.

The other body able to produce normative references for the MID is OIML (an international organisation of legal metrology representatives) which has continued work on updating its Recommendation 46 on electricity meters. A second redraft of this is now available for comment.

WELMEC, the Western European Legal Metrology Co-operation, is a voluntary grouping of representatives of European legal metrology bodies whose role is to exchange information to promote consistency of legal metrology practice and, where appropriate, to issue guidelines. This role is assuming great importance as a vehicle for providing interpretations of the MID, and WELMEC has reviewed its structure and assigned various aspects of the MID to its working groups. From a metering point of view the more important of these are WG7 and WG11 (see below).

The MID has requirements about software used in measuring instruments – for instance to separate software relating to legal metrology functions and protect it from unauthorised access or attack. WELMEC’s WG7 has identified specific requirements and made recommendations about how software conformity can be assessed. These are in the form of a general guide and some specific proposals for simple electricity meters.


The brief of WELMEC WG11 is to deal with matters in the MID relating specifically to electricity, gas and water meters. It has carried out a review of applicable standards and normative references, endorsed WG7’s work and discussed the ways in which the scope of the MID might be defined. In order to seek a common interpretation, the UK has passed to WG11 a number of ‘European level’ issues identified during its work to produce national regulations.

Reports from some of the European regulators on the impact of the MID will be given in a session on ‘The Regulatory Framework’ at Metering Europe, to be held in Barcelona from 20-22 September 2005.