Overview
EN ISO 139:2005/A1:2011 is an amendment to ISO 139:2005 that updates the requirements for standard atmospheres for conditioning and testing of textiles. Approved by CEN in 2011, the amendment clarifies atmosphere definitions, introduces the term rapid conditioning, and specifies equilibrium criteria and measurement intervals to ensure repeatable, comparable textile test results across laboratories.
Key topics and requirements
- Standard atmosphere: temperature 20.0 °C and relative humidity 65.0 %.
- Alternative atmospheres (may be used only when agreed by the parties and must be reported):
- Specific standard atmosphere: 23.0 °C / 50.0 % RH
- Tropical standard atmosphere: 27.0 °C / 65.0 % RH
- Tolerance zones: temperature ±2.0 °C; relative humidity ±4.0 % RH.
- Rapid conditioning (definition): an accelerated conditioning system that lets specimens reach equilibrium with the standard atmosphere significantly faster than static exposure.
- Equilibrium criterion: specimens are considered in equilibrium when successive weighings show no progressive change in mass greater than 0.25 %.
- Weighing intervals:
- In a conditioned laboratory: successive weighings every 2 hours.
- For accelerated/rapid conditioning systems: successive weighings every 2 to 10 minutes.
- Note: Annex A of the standard provides guidance for control of standard atmospheres (see the standard for details).
Practical applications
- Ensures consistent specimen conditioning prior to physical tests (e.g., dimensional, mechanical, or other textile performance tests) so results are comparable between labs.
- Supports quality control and production testing by defining reproducible environmental conditions and tolerances.
- Enables rapid conditioning workflows where throughput or fast turnaround is required while maintaining valid equilibrium criteria.
- Useful in test method preparation, inter-laboratory studies, accreditation, and reporting-particularly when alternative atmospheres are used (they must be agreed upon and documented).
Who uses this standard
- Textile testing laboratories and quality-control departments
- Textile manufacturers and suppliers preparing samples for testing
- Standards bodies and conformity assessment organizations
- Research and development teams working on textile material properties
Related standards and context
- Amendment to ISO 139:2005 (textiles - standard atmospheres for conditioning and testing).
- Prepared by ISO/TC 38 (Textiles), Subcommittee SC 24 (Conditioning atmospheres and physical tests).
Keywords: EN ISO 139:2005/A1:2011, textiles standard atmospheres, conditioning and testing, 20 °C 65 % RH, rapid conditioning, equilibrium 0.25%, tolerance ±2 °C ±4 % RH.
