ISO 14912-2003 PDF

Full title and description

ISO 14912:2003 — Gas analysis — Conversion of gas mixture composition data. This International Standard defines quantities commonly used to express the composition of gas mixtures (mole fraction, mass fraction, volume fraction, mole concentration, mass concentration and volume concentration) and gives methods for converting gas composition data between these quantities and between different state conditions (pressure and temperature).

Abstract

ISO 14912:2003 specifies definitions and mathematical methods for converting the numerical value of an analyte content expressed in one composition quantity to another composition quantity at the same state, and for converting a composition quantity between two sets of state conditions (pressure and temperature). The standard applies to homogeneous, stable gas mixtures and requires that state conditions be well outside the condensation region of the gas mixture and of each specified analyte.

General information

• Status: Withdrawn (replaced by a later edition).
• Publication date: March 2003 (ISO publication, Edition 1:2003).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 71.040.40 — Chemical analysis (gas analysis).
• Edition / version: Edition 1 (2003); Technical Corrigendum ISO 14912:2003/Cor 1:2006 issued.
• Number of pages: 58 pages.

Scope

Provides definitions of composition quantities for gas mixtures (mole fraction, mass fraction, volume fraction, and their corresponding concentrations) and mathematical procedures for converting measured or stated composition values between these quantities and between different thermodynamic state conditions (pressure and temperature). The standard is applicable only to homogeneous, stable gas mixtures and requires that conversions be made for state points well outside any condensation regions of the mixture and specified analytes.

Key topics and requirements

• Definitions of composition quantities: mole fraction, mass fraction, volume fraction, mole concentration, mass concentration, volume concentration.
• Mathematical methods and formulae for converting between different composition quantities at the same state.
• Procedures for converting composition data between different state conditions (changes in pressure and temperature), and combining quantity and state conversions.
• Applicability limited to homogeneous, stable gas mixtures; requirement to avoid condensation regions when selecting state conditions.
• Technical corrigendum published in 2006 to correct/clarify aspects of the 2003 text.

Typical use and users

Used by analytical laboratories, gas producers and suppliers, instrument and sensor manufacturers, calibration and metrology laboratories, standards bodies, and engineers working with gas composition data who need to convert results into different concentration or fraction units or between reference conditions. It is also used when reporting or comparing gas composition data across different measurement conditions.

Related standards

ISO 14912:2003 was issued with a Technical Corrigendum (ISO 14912:2003/Cor 1:2006). The 2003 edition has since been withdrawn and the series has been updated — a later edition (ISO 14912:2025) supersedes the 2003/2006 documents.

Keywords

gas analysis; gas mixtures; composition conversion; mole fraction; mass fraction; volume fraction; concentration; state conditions; pressure; temperature; condensation region.

FAQ

Q: What is this standard?

A: ISO 14912:2003 is an International Standard titled "Gas analysis — Conversion of gas mixture composition data" that defines composition quantities for gas mixtures and gives methods for converting composition data between quantities and between different state conditions.

Q: What does it cover?

A: It covers definitions (mole fraction, mass fraction, volume fraction, and concentrations) and provides mathematical procedures to convert composition values between these quantities and to convert values between different pressures and temperatures for homogeneous, stable gas mixtures. It also specifies the requirement to avoid state points within condensation regions.

Q: Who typically uses it?

A: Analytical and calibration laboratories, gas producers and suppliers, instrument manufacturers, metrology institutes, and engineers who need to compare, report or convert gas composition data across different units or reference conditions.

Q: Is it current or superseded?

A: The 2003 edition (including its 2006 corrigendum) has been withdrawn and superseded by a later edition (ISO 14912:2025). Users should refer to the most recent edition for current requirements.

Q: Is it part of a series?

A: It is a stand‑alone ISO standard within the gas analysis/chemical analysis subject area (ICS 71.040.40), but it is related to other ISO and regional standards concerned with gas analysis, calibration gases and analytical methods. The 2003 edition was maintained with a corrigendum and later revised by the 2025 edition.

Q: What are the key keywords?

A: Mole fraction, mass fraction, volume fraction, concentration, gas mixtures, conversion, pressure, temperature, condensation region.