NGA Extension is a software module for Natural Gas and Liquefied Petroleum Gas Data Processing. You no longer need an external tool for gas properties calculations since the Clarity contains the complete workflow of data acquisition, peak calibration, gas properties calculations based on supported norms and reporting. It is possible to perform summary calculations of gas properties from multiple signals and chromatograms.

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Calculations in the NGA Extension currently support these norms:

Natural Gas

  • ISO 6976-95 Natural gas - Calculation of calorific values, density, relative density and Wobbe index from composition.
  • ASTM D 3588-98 Standard Practice for Calculating Heat Value, Compressibility Factor, and Relative Density of Gaseous Fuels.
  • GPA 2172-09 Calculation of Gross Heating Value, Relative Density and Compressibility Factor for Natural Gas Mixtures From Compositional Analysis.

Liquefied Petroleum Gas

  • ASTM D 2421-02 Standard Practice for Interconversion of Analysis of C5 and Lighter Hydrocarbons to Gas-Volume, Liquid-Volume, or Weight Basis.
  • ASTM D 2598-02 Standard Practice for Calculation of Certain Physical Properties of Liquefied Petroleum (LP) Gases from Compositional Analysis.
  • ISO 8973-97 / EN589-04 Liquefied petroleum gases - Calculation method for density and vapour pressure

Calculated Gas Properties

ISO 6976-95

  • Compression Factor (for real gas only)
  • Mean Molecular Weight
  • Relative Density
  • Density
  • Superior Calorific Value
  • Inferior Calorific Value
  • Wobbe Index

ASTM D 3588-98 and GPA 2172-09

  • Molar Mass
  • Molar Mass Ratio
  • Compressibility Factor
  • Relative Density
  • Ideal Heating Value (incl.calculations in BTU - British Thermal Units)
  • Real Heating Value (incl.calculations in BTU - British Thermal Units)

ASTM ASTM D 2421-02 and D 2598-02

  • Vapour Pressure
  • Relative Density
  • Motor Octane Number

ISO 8973-97 / EN589-04

  • Absolute Vapour Pressure (for Molar and Mass Percent only)
  • Gauge Vapour Pressure (for Molar and Mass Percent only)
  • Octane Number


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