This International Standard contains requirements and methods for measuring the properties of natural gas used primarily for volume calculation and volume conversion: density at reference and operating conditions, pressure, temperature and compressibility factor (real gas factor). Only those methods and measuring devices that are suitable for on-site operation under the conditions of long-distance natural gas transport and distribution and are either integrated into the pipeline or installed on the pipeline but do not require the determination of the gas composition are taken into account. This International Standard provides examples of currently used measuring instruments that are commercially available and of interest to the natural gas industry. NOTE Reference is made to the requirements for approval by national authorities and to national regulations for the use of these devices for commercial and official trade purposes. Density at reference conditions (sometimes called norm, standard, or even basic density) is needed for converting volume data and can be used for other physical properties. Density at operating conditions is measured for mass flow measurement and volume conversion using the density determined in the line and can be used for other physical properties. This International Standard covers density (measured) transducers based on vibrating elements, which are normally suitable for measuring ranges from 5 kg/m3 to 250 kg/m3. The pressure measurement uses differential pressure, gauge pressure and absolute pressure transmitters. Analogue and intelligent transmitters (i.e. microprocessor-based meters) are considered and, unless otherwise specified, the relevant paragraphs refer to differential pressure, gauge pressure and absolute pressure transmitters without distinction. The temperature measurements in natural gas are within the range of the conditions
EN ISO 15970:2014 Referenced Document
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EN ISO 15970:2014 history
2014EN ISO 15970:2014 Natural gas - Measurement of properties - Volumetric properties: density@ pressure@ temperature and compression factor