IEC 60068-2-2:2025

Overview - IEC 60068-2-2:2025 (Test B: Dry heat)

IEC 60068-2-2:2025 is the sixth edition of the international standard that defines dry heat environmental tests for evaluating the performance of components, equipment and other articles at elevated temperatures. It applies to both non-heat-dissipating and heat-dissipating specimens, and covers testing of energized and non-energized items in packed (transport/storage) or unpacked (in-use) conditions. This edition (2025) replaces the 2007 edition and constitutes a technical revision.

Key technical topics and requirements

• Test types (Bb, Bd, Be):
  • Test Bb - dry heat for non-heat-dissipating specimens (operating or non-operating).
  • Test Bd - heat-dissipating specimens energized after initial temperature stabilization.
  • Test Be - heat-dissipating specimens energized throughout the test.
• Temperature conditioning and exposure: Preferred values and exposure durations are specified; the standard addresses conditioning temperature, exposure time, and temperature tolerances (revised in this edition).
• Air velocity in test chamber: Procedures to ascertain high or low air velocity, including options when chamber air-flow adjustment is impractical.
• Nomogram procedure: Reintroduction of a nomogram to correct conditioning temperature for high air velocity situations (relevant to Tests Bd and Be).
• Temperature monitoring and measuring points: Clarified requirements for measuring points around, on or in specimens, and guidance on temperature stability.
• Test setup and procedures: Guidance on mounting, preconditioning, conditioning, intermediate and final measurements, thermal radiation and specimen cooling/heating where applicable.
• Documentation: Revised standardized requirements for the relevant specification and test report, plus inclusion of advantages/disadvantages of available procedures.

Practical applications and who uses this standard

• Design and reliability engineers assessing electronics and electromechanical equipment for high-temperature environments.
• Test laboratories performing environmental qualification for product development, shipping/ storage simulation and certification.
• Manufacturers of consumer electronics, industrial control equipment, automotive and aerospace subsystems that must demonstrate thermal endurance.
• Quality assurance and certification bodies that reference IEC tests in acceptance criteria and compliance reports.

Practical outcomes include validated operating/storage temperature capability, informed design changes for cooling/ventilation, and documented test reports for regulatory or contractual compliance.

Related standards (applicable)

• IEC 60068-1 - Environmental testing - General and guidance (normative reference).
• IEC 60068-2-1 - Test A (Cold) - complementary for cold-temperature testing.
• Other parts of the IEC 60068 series covering environmental testing methods and classifications.

Keywords: IEC 60068-2-2, dry heat test, environmental testing, high temperature testing, heat-dissipating specimens, nomogram, air velocity, test Bd, test Be, test Bb.