New standards in fiscal metering - Better gas quality monitoring

摘要

In traditional fiscal metering, natural gas is valued based on its energy content. This energy content is calculated as a product of the calorific value (CV) per unit volume of the gas and its volumetric flow rate. CV values are outputted from a calorific value determining device (CVDD) which then combines data from a flow meter. CV can be calculated with sufficient accuracy given the composition. This requires accurate gas sampling and analysis to produce a breakdown of the gas composition into individual components. Analysis for natural gas and similar gaseous mixtures is typically performed by Gas Chromatography (GC). However, it is also possible, and often a faster alternative, to measure CV using one of several 'non-separative' techniques that do not require a compositional analysis but rely on inferential or correlative methods from direct measurements.