Skip to main content

EVS-EN ISO 6976:2016

Natural gas - Calculation of calorific values, density, relative density and Wobbe indices from composition (ISO 6976:2016)

General information

Valid from 04.10.2016
Base Documents
EN ISO 6976:2016; ISO 6976:2016
Directives or regulations

Standard history

This International Standard specifies methods for the calculation of gross calorific value, net calorific value, density, relative density, ross Wobbe index and net Wobbe index of natural gases, natural gas substitutes and other combustible gaseous fuels, when the composition of the gas by mole fraction is known. The methods specified provide the means of calculating the properties of the gas mixture at commonly used reference conditions. For the purpose of this International Standard the input mole fractions shall sum to unity exactly. Guidance on the achievement of this requirement is available in ISO 6974-1 and ISO 6974-2. All components with mole fractions greater than 0,000 05 shall be accounted for. If the composition of the gas is known by volume fractions, these shall first be converted to mole fractions in accordance with ISO 14912 (subclause 5.1.2). Note, however, that these derived mole fractions will have uncertainties greater than those of the original volume fractions. The methods of calculation require values for various physical properties of the pure components; these values, together with associated uncertainties, are provided in tables and their sources are identified. Methods are given for estimating the uncertainties of calculated properties. The methods of calculation of the values of properties on either a molar, mass or volumetric basis are applicable to any natural gas, natural gas substitute or other combustible fuel that is normally gaseous, except that for properties on the volumetric basis the method is restricted to mixtures for which the compression factor at reference conditions is greater than 0,9. Example calculations are given in annex D for the recommended methods of calculation.

Required fields are indicated with *

31.72 € incl tax
31.72 € incl tax
Browse standard from 2.44 € incl tax
Standard monitoring

Customers who bought this item also bought


EVS-EN ISO 16923:2018

Natural gas fuelling stations - CNG stations for fuelling vehicles (ISO 16923:2016)
Newest version Valid from 16.04.2018

EVS-EN 16726:2015+A1:2018

Gas infrastructure - Quality of gas - Group H
Newest version Valid from 01.08.2018

EVS-EN ISO 18086:2020

Corrosion of metals and alloys - Determination of AC corrosion - Protection criteria (ISO 18086:2019)
Newest version Valid from 31.12.2020

EVS-EN IEC 60079-10-1:2021

Explosive atmospheres - Part 10-1: Classification of areas - Explosive gas atmospheres (IEC 60079-10-1:2020)
Newest version Valid from 01.03.2021