ISO 139:2005

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

• Standard Atmosphere Conditions

  • Temperature: 20.0 °C ± 2.0 °C
  • Relative Humidity: 65.0% ± 4.0%

• Standard Alternative Atmosphere (subject to agreement)

  • Temperature: 23.0 °C ± 2.0 °C
  • Relative Humidity: 50.0% ± 4.0%

• 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.

• 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 (