The increasing demand for energy and emission set to achieve climate goals, leads to growing attention on gas as an environmentally friendly energy carrier. In the trade of gas, both gas meters that measure gas in gaseous form and liquid meters that measure gas compressed into liquid are used. Weighing instruments are also used in gas transactions.
At the Norwegian Metrology Service, we measure the mass flow of hydrogen gas under pressure using a hydrogen test rig developed in our laboratory. This rig is the only one of its kind in Norway and one of about ten in Europe. The hydrogen rig is EX-certified and in the process of being pressure-certified.
At the Norwegian Metrology Service, our current focus is on the measurement of hydrogen gas under pressure, as this is the form used by vehicles in operation today. Such vehicles are commercially available, both as passenger cars and lorries.
There are several metrological challenges associated with hydrogen, the most important of which are quality assurance and flow measurement. The Norwegian Metrology Service has developed and owns one of the few standards for testing and calibrating hydrogen gas flow under pressure, consisting of a Coriolis meter in combination with a gravimetric calibration.
The gravimetric standard consists of three hydrogen tanks with a total capacity of around 4 kg at 700 bar. A flow meter is located within the frame, and the manual controls are mounted at the front of the frame for easy access. A precision scale is placed under the tanks, with a capacity of 600 kg and a resolution of 0.1 g. The standard can be transported on a specially built trailer, allowing calibrations to be performed in the field, for example at hydrogen refuelling stations. The standard is approved in accordance with ATEX and pressure-certified (in accordance with §9 of the Regulation on the handling of flammable, reactive and pressurised substances).
Hydrogen measurements at the Norwegian Metrology Service form part of our research and development activities and are included in the MetroHyVe projects. We welcome questions and opportunities for collaboration and also offer several master’s thesis topics related to this field.
The requirements in Norwegian metrological regulations for flow meters for liquids and weighing instruments are based on EEA-relevant directives: the Measuring Instruments Directive (MID) and the Non-Automatic Weighing Instruments Directive (NAWID).
Any new requirements for flow meters for gases in gaseous form used in households, business premises and light industry will be based on the relevant instrument-specific annex in the MID.
If requirements are introduced for compressed gas for vehicles, such as CNG or hydrogen, these will be based on international normative documents (for example, OIML).
Sider: