EN ISO 6145-10:2008

• Abstract:

  This part of ISO 6145 specifies a dynamic method using permeation membranes for the preparation of calibration; gas mixtures containing component mole fractions ranging from 10−9 and 10−6. A relative expanded uncertainty of; 2,5 % of the component mole fraction can be achieved using this method. In the mole fraction range considered, it; is difficult to maintain some gas mixtures, for example in cylinders, in a stable state. It is therefore desirable to; prepare the calibration gas immediately before use, and to transfer it by the shortest possible path to the place; where it is to be used. This technique has been successfully applied in generating low content calibration gas; mixtures of, for example, sulfur dioxide (SO2), nitrogen dioxide (NO2) and benzene (C6H6) in air.; If the carrier gas flow is measured as a gas mass-flow, the preparation of calibration gas mixtures using permeation; tubes is a dynamic-gravimetric method which gives contents in mole fractions.

• Status: Published
• Publication Date: 19-Aug-2008
• ICS: 71.040.40 - Chemical analysis
• Technical Committee: CEN/TC 238 - Test gases, test pressures and categories of appliances
• Drafting Committee: CEN/TC 238 - Test gases, test pressures and categories of appliances
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 20-Aug-2008
• Due Date: 28-Sep-2009
• Completion Date: 20-Aug-2008
• Ref Project: SIST EN ISO 6145-10:2008 - Gas analysis - Preparation of calibration gas mixtures using dynamic volumetric methods - Part 10: Permeation method (ISO 6145-10:2002)

• Refers: ISO 6145-1:2003 - Gas analysis — Preparation of calibration gas mixtures using dynamic volumetric methods — Part 1: Methods of calibration
• Effective Date: 25-Aug-2026
• Refers: EN 12790:2009 - Child use and care articles - Reclined cradles
• Effective Date: 28-Jan-2026
• Referred By: EN 14211:2024 - Ambient air - Standard method for the measurement of the concentration of nitrogen dioxide and nitrogen monoxide by chemiluminescence
• Effective Date: 28-Jan-2026
• Referred By: EN 14212:2012 - Ambient air - Standard method for the measurement of the concentration of sulphur dioxide by ultraviolet fluorescence
• Effective Date: 28-Jan-2026
• Referred By: EN 14662-3:2015 - Ambient air - Standard method for the measurement of benzene concentrations - Part 3: Automated pumped sampling with in situ gas chromatography
• Effective Date: 28-Jan-2026
• Referred By: EN 14211:2012 - Ambient air - Standard method for the measurement of the concentration of nitrogen dioxide and nitrogen monoxide by chemiluminescence
• Effective Date: 28-Jan-2026
• Referred By: EN 14212:2024 - Ambient air - Standard method for the measurement of the concentration of sulphur dioxide by ultraviolet fluorescence
• Effective Date: 28-Jan-2026

Overview

EN ISO 6145-10:2008 (ISO 6145-10:2002) - Gas analysis: Preparation of calibration gas mixtures using dynamic volumetric methods - Part 10: Permeation method.
This standard defines a dynamic permeation technique for producing very low concentration calibration gas mixtures (component mole fractions ≈ 10−9 to 10−6). It explains apparatus, procedures, measurement principles and uncertainty estimation. The method can achieve a relative expanded uncertainty of about 2.5 % of the component mole fraction.

Key topics and technical requirements

• Permeation principle: A calibration component permeates through a membrane from a temperature-controlled tube into a carrier gas; mixture concentration is determined from the permeation rate and carrier-gas flow.
• Concentration range: Target mole fractions between 10−9 and 10−6 - levels difficult to store stably in cylinders, so on-site generation is recommended.
• Uncertainty: The method supports an achievable relative expanded uncertainty of ~2.5 %; the standard includes procedures for estimating uncertainty (mass-loss determination, flow measurement, etc.).
• Apparatus modes:
  • Periodic-weighing mode: permeation tube removed periodically and weighed.
  • Continuous-weighing mode: permeation tube weighed continuously on a microbalance.
• Materials and design:
  • Use chemically inert, low-adsorption materials (glass housings preferred where possible).
  • Select permeation membranes (e.g., PTFE, polyethylene, polypropylene, FEP) compatible with the permeant and temperature.
  • Seal and junction quality to prevent leaks and adsorption artefacts.
• Measurement controls:
  • Temperature-controlled enclosure for stable permeation rates.
  • Accurate carrier-gas flow control and measurement (mass flow controllers/meters); if carrier flow is measured as mass-flow the technique becomes a dynamic-gravimetric method providing mole fractions.
  • Purity verification of carrier gas (recommended techniques: GC and/or FTIR).
• Reagents: High-purity permeant chemicals; if impurities exist their effects must be known and accounted for.

Applications and users

• Calibration gas generation for environmental monitoring, air quality labs, emissions testing, and analytical instrument calibration (e.g., gas analysers sensitive to SO2, NO2, benzene).
• Useful where ultra-low, short-lived or unstable gas mixtures are needed and must be prepared immediately before use and delivered by the shortest path to the analyser.
• Typical users: calibration laboratories, instrument manufacturers, regulatory agencies, and research institutions.

Related standards

• ISO 6145-1 (Methods of calibration) and other parts of ISO 6145 covering pumps, injection methods, capillaries, critical orifices, thermal mass-flow controllers, saturation method, etc. EN ISO 6145-10:2008 is the CEN adoption of ISO 6145-10:2002.

Keywords: EN ISO 6145-10:2008, ISO 6145-10, permeation method, calibration gas mixtures, gas analysis, permeation tubes, carrier gas, mole fraction, permeation membrane, dynamic volumetric methods, calibration uncertainty.