[Home](/)/[Resources](/resources)/Measuring Instruments Directive (MID) EUDirective guide # Measuring Instruments Directive (MID) 2014/32/EU MID-regulated meters carry two marks — the standard CE mark and the supplementary M metrology mark. These two marks represent two separate demonstrations of conformity: product safety and metrological accuracy. A meter with CE but without M cannot legally be used in commercial measurement applications in the EU. Copy Link[Share on WhatsApp](https://wa.me/?text=https%3A%2F%2Fkrono-labs.com%2Fguides%2Fmeasuring-instruments-directive) At a glance Instrument categories (MI) 10 Key standards 5 FAQs 4 ## Measuring instrument categories (MI-001 to MI-010) MI-001Water meters Measurement of volume of clean cold water and hot water for domestic and industrial use (commercial transactions). MI-002Gas meters and volume conversion devices Measurement of gas volume at domestic, commercial, and industrial metering points. MI-003Active electrical energy meters Electricity consumption measurement in residential and commercial settings — smart meters. MI-004Heat meters Measurement of heat energy in heating and cooling circuits in buildings. MI-005Measuring systems for liquids other than water Fuel dispensers at filling stations, milk delivery systems, LPG dispensers. MI-006Automatic weighing instruments Belt weighers, catchweighers, gravimetric filling machines, discontinuous totalising automatic weighing instruments. MI-007Taximeters Installed in taxis to calculate fare based on distance and time. MI-008Material measures Length measures (rulers, tapes), capacity measures, and dimensional gauges used in trade. MI-009Dimensional measuring instruments Instruments for measuring linear dimensions where measurement is the basis for commercial transactions. MI-010Exhaust gas analysers Vehicle emissions testing at roadworthiness testing stations. ## Key harmonised and OIML standards EN 14154 Water meters — accuracy classes, test conditions, and installation requirements EN 1434 Heat meters — general requirements, test conditions, and calibration EN 62053-21 Electricity metering equipment — static meters for active energy (Class 1 and 2) OIML R 49 Water meters for cold potable water and hot water — international recommendation OIML R 117 Dynamic measuring systems for liquids other than water ## Frequently asked questions ### What is the M mark on a MID-certified meter? MID-certified meters carry both the CE mark and the M mark — a supplementary metrology mark consisting of a capital M followed by the last two digits of the year of affixing (e.g., M23 for 2023). This combination tells the user and authorities that the meter has been assessed both for product safety (CE) and for metrological performance (M). The CE mark alone is not sufficient for MID-regulated instruments in commercial use. ### Does MID apply to meters used only for internal monitoring? No. MID applies to measuring instruments used in regulated measurement applications — primarily where measurement results form the basis of commercial transactions, invoicing, or legally mandated reporting. Meters used purely for internal process monitoring or engineering purposes are outside MID scope, though they may still need CE marking under other directives (EMC, LVD). ### Is a smart electricity meter covered by MID? Yes. Smart electricity meters (AMI meters) used for billing fall under MID category MI-003 (active electrical energy meters). The wireless communication module in a smart meter also needs RED compliance for its radio transmitter. The CE technical file must address both the MID metrological requirements and the RED radio equipment requirements separately. ### Which conformity modules are typically used for water meters? For water meters (MI-001), the most common routes are Module B+D (EU type-examination by a Notified Body, followed by NB-supervised production quality assurance) or Module B+F (type examination followed by product verification). Module H1 (comprehensive quality assurance with design examination) is also available. Module A alone is not available for most MID instrument categories. **Disclaimer:** Educational resource only. MID conformity routes vary by instrument category and Notified Body. Always verify the specific modules available for your MI category and work with an accredited Notified Body for type examination. 🇪🇺 CE Marking roadmap for your product Every standard, document, and test that applies — free, no account required. See your free roadmap[ Want an expert to take your product through 🇪🇺 CE Marking compliance for you? One consultant from Krono's compliance team takes your product from requirements to legal sale, with a fixed quote before any work starts. 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