This calculates calorific values, density, relative density and Wobbe index from a gas composition.
Kelton calculation reference C111
KIMS calculation K143
International standard, Natural Gas – Calculation of calorific values, density, relative density and Wobbe index (ISO 6976:editions 1983, 1989 and 1995)
Select the edition of the reference standard (ISO 6976) for the calculation
- No Tail
- C6 Tail
- C7 Tail
- C9 Tail
Select the appropriate hydrocarbon tail. Where a tail is selected the percentage split of each component is entered, this is generally obtained from laboratory analysis.
This gives the option to select the combustion and metering temperatures. the choice will depend upon the edition of the standard.
- Full precision
This option gives the choice to use the rounded molecular weights as shown in Table 1, or calculate the molecular weights with full precision using the elemental molars masses shown beneath Table 1.
Ideal gas calorific value (mass) method
This option is used to select whether the mass calorific value is calculated using the alternative or definitive tables.
Ideal gas calorific value (volumetric) method
This option is used to select whether the volumetric calorific value is calculated using the alternative or definitive tables.
If the 1995 edition of the standard is chosen the options to select an extended analysis or to include refinery or trace gasses are available
Refer to the appropriate standard for the calculation details.