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Image: Courtesy of CEM, Spain

The Spanish National Metrology Institute is an active member of the European Metrology Network (EMN) for Energy Gases

The Centro Español de Metrología (CEM) is an autonomous body attached to the State Secretariat for Industry of the Ministry of Industry and Tourism.

Created by the General State Budget Law of 1990, in accordance with Metrology Law 3/1985, CEM is, pursuant to Article 149 of the Spanish Constitution, the highest technical body for metrology in Spain and represents it in all international organisations of scientific and legal metrology.

In the chemistry area, CEM has a wide experience in the preparation of primary reference materials of gases (PRMs), interlaboratory comparisons under the BIPM CIPM-MRA framework, and in EURAMET's European Metrology Research Programmes driving new methods and standards.

Building Spain’s primary capabilities for energy gases

CEM’s Reference Gas Laboratory has consolidated internationally recognised competence to certify primary reference materials (PRM) for key components (CO, CO₂, O₂, C₃H₈, CH₄) and multi-component natural gas/biogas. These PRMs underpin custody transfer, calorific calculations and Wobbe index determinations across the gas value chain.

The PRMs are prepared gravimetrically (direct SI traceability to mass) and verified using chromatographic and spectroscopic analytical techniques, ensuring homogeneity and stability across batches.

Hydrogen quality for mobility and grids

To support the hydrogen economy, CEM has developed reference mixtures and analytical methods aligned with ISO 14687 fuel quality requirements. Developing capabilities include trace-level impurity determination (e.g., N₂, Ar, O₂, He and HCl) relevant to PEM fuel cell protection and station compliance.

This work has been accelerated through projects within the European Metrology Research Programmes, including:

• 15NRM03 Hydrogen and 16ENG01 MetroHyVe, targeting purity assurance for hydrogen at refuelling points and traceable impurity measurement methods.  
• 21GRD05 Met4H2 where CEM supplies gas mixtures and contributes to hydrogen gas quality work packages alongside European NMIs and industry.
• 20IND10 DECARB which delivered new methods and reference materials to support the development of flow metering specifications, gas composition, physical properties and safety (including leak monitoring), required for grid injection.

Biomethane & biogas measurement science

CEM has contributed to Europe’s coordinated push on biomethane measurement, building on work developed in the projects ENG01 GAS and ENG54 Biogas. Earlier collaborative research included characterising biomethane-like mixtures to support thermodynamic property data and instrumentation performance.

Working with the European Metrology Network for Energy Gases

CEM is an active member of the EMN for Energy Gases, the Europe-wide hub aligning metrology for hydrogen, biomethane, NG/H₂ blends, CO₂, ammonia and emerging fuels, including shared service directories and stakeholder workshops.

Partnerships that extend national capability

Through collaboration agreements, CEM connects primary standards with industrial facilities, e.g., supporting high-flow, high-pressure gas meter calibration activities in Spain’s gas sector, strengthening the national traceability chain for custody transfer.