4.1.0 Meters
   4.1.1 AGA 3 1992 Orifice
    4.1.2 ISO 5167 Orifice 1980
    4.1.3 ISO 5167 Orifice 1991
    4.1.4 ISO 5167 Orifice 1997
    4.1.5 ISO 5167 Orifice 2003
    4.1.6 ISO 5167 Venturi 1980
    4.1.7 ISO 5167 Venturi 1991
    4.1.8 ISO 5167 Venturi 1997
    4.1.9 ISO 5167 Venturi 2003

  4.2.0 Instruments

    4.2.1 Solartron Gas Densitometer
    4.2.2 RD Analyser – Solartron 3098/96
    4.2.3 RD Analyser Calibration Check – Solartron 3098/96
 4.3.0 Properties
    4.3.1 Density, Compressibility – AGA8: 1985/94

    4.3.2 Speed of Sound – AGA10: 2003

    4.3.3 Density, Compressibility, Calorific Value ISO 6976: 1983/95

    4.3.4 Density, Compressibility, Heating Value - GPA 2172/2145
    4.3.5 Density, Volume, Mass, PTZ - ISO6976, GPA2172

    4.3.6 Sampler Lag Time
    4.3.7 Murdock Wet Gas Correction  

4.3 Orifice/Venturi Uncertainty