I.S. EN ISO 14912:2007

Foreword
Introduction
1 Scope
2 Terms and definitions
3 Symbols and units
4 Basic principles
  4.1 Expression of gas mixture composition
  4.2 Conversion between different quantities
  4.3 Conversion between different state conditions
5 Main procedures
  5.1 Conversion between different quantities of composition
  5.2 Conversion to reference conditions
6 Practical implementation
  6.1 Conversion between quantities of composition
  6.2 Conversion of single analyte contents
  6.3 Conversion of complete compositions
  6.4 Conversion between state conditions
  6.5 Simple approximations applicable to conversion
7 Input quantities and their uncertainties
  7.1 Pure gas data
  7.2 Gas mixture data
  7.3 Rough uncertainty estimates
8 Conversion uncertainty
  8.1 General considerations
  8.2 Conversion of single analyte contents
  8.3 Conversion of complete compositions
  8.4 Uncertainty calculation using numerical differentiation
  8.5 Variances and covariances of input composition data
9 Application recommendations
Annex A (normative) Assessment of state conditions
Annex B (normative) Summation relations for the expression
                      of mixture properties
Annex C (informative) Mixture component data
Annex D (informative) Examples
Annex E (informative) Computer implementation of recommended
                      methods
Bibliography

Specifies quantities commonly used to express the composition of gas mixtures: mole fraction, mass fraction and volume fraction, as well as mole concentration, mass concentration and volume concentration. Applicable to homogeneous and stable gas mixtures.