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 (<0.25%) over successive 2-hour intervals.

• Test Reporting

  • Test reports should include sample identification, reference to ISO 139:2005, details of conditioning atmosphere, and any deviations from the standard.

• Tolerance Zones and Uncertainty

  • The standard innovatively incorporates uncertainty of measurement in tolerance zones, ensuring laboratories maintain environmental control within practical and metrologically sound limits.

Applications

ISO 139:2005 is vital for quality assurance and product development in the textile industry, facilitating:

• Reliable Textile Testing
  Standardized conditioning atmospheres ensure that textile testing results, such as tensile strength, elongation, and dimensional stability, are reproducible and comparable across different labs and markets.

• Quality Control Laboratories
  Textile manufacturers and laboratories use ISO 139 atmospheres to maintain consistent environmental conditions, crucial for compliance with testing specifications and international trade.

• Research and Development
  R&D teams establish baseline conditions following ISO 139 to conduct physical and mechanical textile property testing under controlled, replicable environments.

• Certification and Compliance
  Compliance with ISO 139 enhances credibility of test data and supports certifications related to textile performance and safety, impacting global supply chains.

Related Standards

• ISO 14253-1 - Geometrical Product Specifications - Provides decision rules for product conformity considering measurement uncertainty, referenced for tolerance zone definitions and statistical control in ISO 139.

• ISO 3534-2 - Statistics - Defines terms like tolerance, tolerance limits, and zones applied in this standard.

• International Vocabulary of Metrology (VIM) - Offers foundational terminology related to measurement uncertainty and resolution.

• ISO 9001/QMS Standards - While not specific to textiles, these quality management standards often integrate ISO 139 conditioning atmospheres as part of quality control processes.

By adhering to ISO 139:2005, textile professionals ensure accurate, consistent, and internationally recognized conditioning and testing environments that underpin reliable evaluation of textiles’ physical and mechanical properties. This fosters product quality, global trade confidence, and scientific rigor in textile testing laboratories.