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European Measuring Instruments Directive – What Progress?

European Measuring Instruments Directive – What Progress?

In Issue 1 2000 of Metering International, Roger Ford provided an overview of the Measuring Instruments Directive (MID) and its potential impact on the market for meters. He thought then that its completion was imminent. In fact, the ‘final’ version was not submitted as a proposal until late last year, and even that was just the start of a new phase which is still under way.

This article looks back to the processes by which the Directive was developed and through which it is now proceeding, and attempts to give a flavour of the complex and frustrating business of producing European law.

Overall Process

The European Commission – effectively the civil service of the European Union – is responsible for drafting new European legislation. This legislation is in the form of directives which, when agreed in an appropriate forum, must be adopted by member states into their system of law. Commission officials are skilled at drafting legislation, but do not necessarily have detailed knowledge of the subject being dealt with. They therefore submit proposals which are discussed among appropriate representatives who have the required expertise. When the latest draft is considered suitably ‘mature’ it is proposed to the body which will give it final approval.

The Commission can write its own directives, but the majority are council directives, where the European Council (the main decision-making body of the EU) approves them. Such approval is then ratified in the European Parliament. 


One problem with the MID is its scope, in that it applies to such a wide range of instruments. Also, because it deals with instruments subject to legal metrology, the consultation has been predominantly with representatives of national metrology bodies, many of whom do not necessarily have expertise relating to all instruments covered by the MID. For instance, the UK’s National Weights and Measures Laboratory, which is the official contact with the Commission, does not deal with gas or electricity meters (although they have closely liaised with Ofgem, the UK regulator, which does). For this reason the Commission allowed additional representation by ‘industry federations’, ie European trade associations (listed below for tariff metering). 

The consultation process was somewhat strange. The federation representatives, often the only people who knew what they were talking about on points of detail, were viewed by the Commission as second class participants, only allowed to speak when the metrology members had nothing more to say. Commission officials would not necessarily respond to a point or agree to changes immediately – the only way of knowing whether a change had been accepted was when the next draft was produced. 

The fact that the MID applied to all instruments meant it was essential to ensure that requirements were not put in which, although sensible for one class of instrument, would cause great problems for others. This was eased by the eventual decision to have instrument-specific essential requirements for some instruments in separate annexes.

Current Process

The final Commission version of the MID was proposed to Council in September 2000. Council is now discussing the proposals stage by stage to reach consensus, so that Parliament is able to ratify the Directive without any embarrassing objections from individual member states. Council is being assisted in this process by WELMEC – the Western European Legal Metrology Committee – which is advising on ‘technical’ aspects of the MID (ie the annexes). 

What is the MID?

The MID is a new approach directive, which means that it should lay down broad 

The MID comprises the following:

  • An explanatory memorandum, providing background information and describing the expected impact on various sectors.
  • The body, comprising chapters covering scope, legal metrology control, assessment and presumption of conformity, committees, markings, general and final provisions. The 20 articles of the Directive are within these chapters.
  • Annex I, giving generic ERs applying to all instruments.
  • Annex II, giving details of test programmes.
  • Annex III, listing the criteria to be satisfied by bodies overseeing conformity testing.
  • Annex IV, listing technical documentation required.
  • Annexes A – H1, providing details of conformity procedures.
  • Annexes MI-XXX, giving specific ERs applying to particular classes (types) of instrument.

Annex MI-001 refers to water meters, MI-002 to gas meters, MI-003 to electricity meters and MI-004 to heat meters.

Essential requirements (ERs) which are then interpreted by European standards in its support, compliance with which is a ‘fast track’ to conformity with the Directive. Having set the requirements, the Commission gives a mandate to a relevant body to prepare such standards. This may be a good approach for a ‘green field’ situation, but in the case of electricity meters adequate and appropriate IEC and CENELEC standards already exist. The situation is broadly similar for gas meters, although standards for water meters and heat meters are not so well defined.

Concerns have been compounded by the Commission’s apparent signal at one stage that it would mandate OIML (the Organisation Internationale de Metrologie Legale) – which has not been active in the electricity meter sector – rather than CEN/CENELEC. This could lead to duplication of work which has already been done. There has also been a Commission view that a manufacturer should be able to prove conformity solely to the ERs, without having to comply with standards, thus raising the possibility of two different classes of meter. However, recent dialogue between the various groups and a memorandum of understanding between OIML and CENELEC have clarified matters and, for instance for electricity meters, CENELEC has prepared a document relating the ERs of the MID to clauses in standards which apply, as a prelude to any required modification.

Present Work

Working Group 8 of WELMEC has held meetings to which federations have been invited, and there has been discussion on generic annexes of the MID for feeding into Council meetings. It has also reactivated working sub-groups to review the instrument-specific annexes. The intention is to have final drafts for approval at the next WG8 meeting in September. In the case of electricity meters, the draft MI-003 in the Commission proposal was unsatisfactory on several points, but this has now been amended in line with a joint proposal by EURELECTRIC and CITEF for a more suitable version. Working groups in the gas, water and heat sectors have taken the opportunity to do likewise.

As regards the MID in total, the intention was that it would be ready for adoption by mid-2002. This might now be an ambitious target, but it is certainly expected that adoption will be no later than the end of that year. Work then begins in each member state to translate it into law.