Natural gas — Measurement of properties — Volumetric properties: density, pressure, temperature and compression factor

ISO 15970:2008 gives requirements and procedures for the measurement of the properties of natural gas that are used mainly for volume calculation and volume conversion: density at reference and at operating conditions, pressure, temperature and compression factor.

Only those methods and instruments are considered that are suitable for field operation under the conditions of natural gas transmission and distribution, installed either in-line or on-line, and that do not involve the determination of the gas composition.

ISO 15970:2008 gives examples for currently used instruments that are available commercially and of interest to the natural gas industry.

The density at reference conditions (sometimes referred to as normal, standard or even base density) is required for conversion of 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 observed line density and can be used for other physical properties. ISO 15970:2008 covers density transducers based on vibrating elements, normally suitable for measuring ranges of 5 kg/m3 to 250 kg/m3.

Pressure measurement deals with differ