IEC 60068-2-39:2015

Overview

IEC 60068-2-39:2015 is an international standard issued by the International Electrotechnical Commission (IEC) that describes environmental test methods and guidance. It focuses specifically on testing electrical and electronic equipment or components under combined environmental conditions involving temperature or temperature and humidity, alongside low air pressure. This second edition updates and replaces the earlier 1976 version, incorporating significant technical revisions such as preferred test severities consistent with the IEC 60068 series and combined temperature, humidity, and low air pressure scenarios.

The standard ensures that equipment can withstand and operate effectively in varied environmental conditions that simulate real-world operational, transport, and storage environments. It helps manufacturers and testing laboratories assess the resilience and performance reliability of components or systems exposed to such combined stresses.

Key Topics

• Combined Environmental Testing: The core focus is on combined temperature, humidity, and low air pressure testing. This approach evaluates the interaction effects between these parameters on equipment reliability and function.
• Test Parameters and Severities: IEC 60068-2-39 defines preferred severities for temperature ranges (from extreme cold to high heat), low air pressure conditions, and duration of exposure. These factors simulate environments such as high-altitude or aerospace conditions.
• Test Procedures: The standard outlines detailed procedures including preconditioning, exposure, stabilization, and measurement phases:
  • Preconditioning of specimens as required.
  • Controlled temperature cycles within chambers with a defined temperature change rate.
  • Reduction of chamber pressure to simulate low air pressure conditions.
  • Functional performance checks before, during, and after testing.
• Guidance on Interpretation: Annex A provides additional guidance on environmental effects, temperature measurement and combined testing strategies.
• Documentation Requirements: It specifies information that must be included in relevant specifications and test reports for transparency and consistency.

Applications

IEC 60068-2-39:2015 is highly valuable across industries where equipment is exposed to harsh or variable environmental conditions, including:

• Aerospace and Aviation: For testing equipment that operates at altitude where low air pressure and temperature variations coexist.
• Telecommunications: Ensuring robustness of outdoor components affected by temperature fluctuations and atmospheric pressure changes.
• Automotive and Transportation: Verification of systems exposed to environmental extremes during operation or transport.
• Military and Defense: Qualification of devices for performance under combined environmental stresses typical in diverse operational theaters.
• Consumer Electronics: Reliability assessment for devices used in varied climate zones including humid, cold, or high-elevation locations.

This standard equips manufacturers and test houses to replicate realistic environmental stresses, enabling risk mitigation and product lifecycle enhancement.

Related Standards

• IEC 60068-1: General and guidance on environmental testing-essential for understanding principles of temperature stability and environmental test methods.
• IEC 60068-2-78: Details damp heat, steady state tests, complementing humidity aspects covered in IEC 60068-2-39.
• Additional parts of the IEC 60068 series provide specific testing methods for various environmental factors such as vibration, shock, and mechanical stresses, creating a comprehensive testing regime.

By aligning with IEC 60068-2-39:2015 and related standards, organizations can reliably evaluate electrical and electronic products' endurance against combined temperature, humidity, and air pressure challenges-ensuring quality, safety, and customer satisfaction in global markets.