IEC 60068-2-30:2005

Overview

IEC 60068-2-30:2005 - Test Db: Damp heat, cyclic (12 h + 12 h cycle) - is an IEC environmental test method that determines the suitability of components, equipment or other articles for use, transport and storage under high-humidity conditions combined with cyclic temperature changes that may produce surface condensation. The procedure defines a 24 h cycle (12 h high-temperature dwell + 12 h low-temperature dwell), chamber performance criteria, stabilization and recovery requirements, and optional severities (upper temperatures and number of cycles).

Key Topics and Requirements

• Test purpose: Verify resistance to damp heat with cyclic temperature changes and condensation on specimen surfaces.
• Stabilization: Specimens must be stabilized at 25 °C ± 3 K before cycles; relative humidity raised to ≥95% RH at 25 °C.
• 24 h cycle: Rise to the specified upper temperature within 3 h ± 30 min; maintain upper temperature for 12 h ± 30 min with 93% RH ± 3%; then lower temperature to 25 °C ± 3 K over 3–6 h and maintain RH conditions for the remainder of the cycle.
• Variants for temperature fall:
  • Variant 1: Requires controlled rate during the first 1.5 h of cooling and RH ≥95% (condensation likely).
  • Variant 2: Allows wider tolerances during temperature fall and RH ≥80% (for specimens less prone to condensation).
• Severities (examples given):
  • Upper temperature 40 °C - cycles: 2, 6, 12, 21, 56
  • Upper temperature 55 °C - cycles: 1, 2, 6
• Chamber performance: Temperature variation in the working space must be small - local differences should not exceed 1 K and short-term fluctuations may need to be within ±0.5 K to maintain RH tolerances. Total temperature tolerances of ±2 K to ±3 K are specified. Chamber water must have resistivity ≥500 Ω·m; condensed water must be drained and not reused.
• Measurements: Initial, intermediate (if specified), recovery and final inspections/tests are required. Recovery period has been extended in this edition.

Applications and Users

• Practical applications: qualification testing for electronic components, assemblies, enclosures, and packaged goods exposed to humid climates or condensation during storage and transport.
• Typical users: environmental test laboratories, quality/qualification engineers, product reliability teams, suppliers in electronics, automotive, aerospace, telecommunications, and defense.
• Notes: Small, low-mass specimens that do not readily condense should consider alternative methods such as IEC 60068-2-38.

Related Standards

• IEC 60068-2-38 - Composite temperature/humidity cyclic test (alternative for low-mass specimens)
• IEC 60068-3-6 - Chamber performance confirmation for temperature/humidity tests
• IEC 60068-1 - General and guidance
• IEC 60068-5-2 - Terms and definitions for test methods

Keywords: IEC 60068-2-30, damp heat cyclic test, environmental testing, condensation, temperature cycle, humidity chamber, test Db, reliability testing.