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What is the Measuring Instruments Directive?

The Measuring Instruments Directive (MID) is the European law that sets down the essential requirements for a wide range of measuring instruments. It provides options for the manufacturer as to how the requirements are met and which organizations to apply to for conformity assessment.

The Directive is brought into Irish law through SI No 2 of 2018- Legal Metrology (European Conformity Assessment of Measuring Instruments) Regulations 2018. 

What is Conformity Assessment?

Conformity assessment is the procedure that must be applied to a measuring instrument before it can be put on the market for trade use. For more information Click here

What are Essential Requirements?

Essential requirements are the legal requirements that must be met by the instruments. In the MID, they are listed in Annex 1 and in the instrument-specific annexes, MI-001 to MI-0010.

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The optionality of MID means that each Member State in Europe can decide whether or not it regulates certain measuring instruments.

Where a measuring instrument is not used in significant enough numbers to be important in a country, that Member State does not need to establish legal controls over its use. However, where this happens, instruments that comply with the Directive must be allowed on the market without any restrictions and no other rules can be established that differ from MID.

The following instruments are regulated for trade use in Ireland under the MID:

  • Electricity meters
  • Water meters
  • Gas meters
  • Fuel dispensers and metering systems on fuel tankers and delivery depots
  • Metering systems for milk
  • Automatic weighing instruments, catchweighers, including checkweighers, weigh labellers and weigh/price labellers, gravimetric fillers, belt weighers and discontinuous totalizers
  • Length measures
  • Capacity-serving measures such as carafes, glasses or thimble measures
  • Dimensional measuring instruments
  • Taximeters
  • Exhaust gas analysers.

Requirements governing the use of most of these instruments are set out in the Legal Metrology (General) Regulations, 2008. The exceptions are exhaust gas analysers and electricity, water and gas meters, which are regulated by separate legislation.

The entry into the Irish market of Non-Automatic Weighing Instruments such as retail scales, industrial scales and weighbridges is regulated through the requirements set down in the Non-Automatic Weighing Instruments Directive

To find out more go to About the Non-Automatic Weighing Instruments Directive

The requirements these instruments must meet when in use can be found in the Legal Metrology (General) Regulations, 2008.

Other measuring instruments regulated for trade use are:

Information on the European standards, OIML recommendations (called "normative documents") and Welmec guidance documents adopted for use with the MID can be found on the European Commission website page on Metrology and Pre-packaging.