Overview
ISO 139:2005, titled Textiles - Standard atmospheres for conditioning and testing, is an international standard developed by ISO/TC 38/SC 24, which defines the environmental conditions necessary for the conditioning and testing of textile materials. This standard prescribes standard atmospheres-specified temperature and relative humidity conditions-used to ensure reliable and repeatable measurement of the physical and mechanical properties of textiles.
The 2005 edition is a revision of the original 1973 standard, incorporating allowances for measurement uncertainty in temperature and humidity control, aligning with modern metrological practices. ISO 139:2005 facilitates consistent inter-laboratory testing by establishing reference atmospheres and tolerance zones critical to textile testing workflows.
Key Topics
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Standard Atmosphere Conditions
- Temperature: 20.0 °C ± 2.0 °C
- Relative Humidity: 65.0% ± 4.0%
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Standard Alternative Atmosphere (subject to agreement)
- Temperature: 23.0 °C ± 2.0 °C
- Relative Humidity: 50.0% ± 4.0%
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Measurement and Control Requirements
- Devices used to measure temperature and humidity must have a resolution of at least 0.1 °C and 0.1% RH respectively, with uncertainty of measurement ±0.5 °C and ±2.0% RH or better.
- Continuous monitoring is recommended to detect any deviations from tolerance limits.
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Preconditioning and Conditioning Procedures
- Textiles may require preconditioning at low humidity (10% to 25% RH) and not exceeding 50 °C prior to testing.
- Conditioning requires textiles to reach equilibrium in the standard atmosphere; equilibrium is defined as a negligible change in mass (
