ABSTRACT
The determination of natural gas composition by gas chromatography using reduced pressure techniques enables the gas analyst, by close monitoring of sample loop pressures, to ensure that very accurately reproducible sample volumes are injected into the analysis system. The selection of multi-column analytical system in conjunction with reduced pressure sampling technique has afforded analysts greater resolution and reproducibility well within Gas Producers Association tolerance limits. This degree of reliability is demonstrated by the results of biennial inter laboratory test programs in which error of heating value from compositional calculation has been reduced to 0.1%. Precise gas analysis technique is essential in order to obtain compositional analysis data for the reliable determination of natural gas heating values. Any gas chromatography by a reputable manufacturer, fitted with a thermal conductivity detector and suited to multi column operation, may be used.
