IEC 60068-3-5:2018

Overview

IEC 60068-3-5:2018 - "Environmental testing - Part 3-5: Supporting documentation and guidance - Confirmation of the performance of temperature chambers" provides a uniform, reproducible method to confirm that temperature test chambers meet the requirements of climatic test procedures (IEC 60068-2 series) and other standards. This second edition (2018, bilingual 2019-05 release) replaces the 2001 edition and clarifies the confirmation procedures used for regular chamber performance monitoring and verification.

Key topics and technical requirements

The standard defines how to measure and report chamber performance without specimens. Key technical topics include:

• Test area environment: guidance to perform confirmations under standard atmospheric conditions (see IEC 60068-1), avoiding direct solar radiation, EMI, vibration and ensuring chambers are levelled and suitably located.
• Temperature measurement system: requirements for sensor type, metrological confirmation and measurement practice (references include IEC 60584-1, IEC 60751, ISO 10012).
• Working space definition and sizing: practical dimensions and minimum clearances (Table 1):
  • Small: up to 1 000 L - X (min.) 50 mm
  • Medium: 1 000 to 2 000 L - X (min.) 100 mm
  • Large: > 2 000 L - X (min.) 150 mm
• Sensor installation and locations: specified locations and minimum number of air temperature sensors for chambers ≤ 2 000 L and for larger chambers.
• Measurement methods and performance metrics:
  • Achieved temperature and temperature stabilization
  • Temperature fluctuation (short-term spread at a point after stabilization)
  • Temperature gradient and temperature variation in space (differences across the working space)
  • Temperature rate of change (°K/min for transitions)
  • Temperature extremes
• Standard temperature sequences, evaluation criteria and acceptance limits for confirmation tests.
• Reporting: the standard lists required contents for a chamber performance test report to support traceability, reproducibility and audit.

Practical applications

IEC 60068-3-5 is used to:

• Verify and document chamber temperature stability, uniformity and ramp rates before running climatic tests on specimens.
• Support routine performance monitoring, preventive maintenance and troubleshooting of temperature chambers.
• Provide documented evidence for laboratory accreditation, quality control and supplier/customer acceptance of test facilities.
• Inform calibration and uncertainty assessments (see IEC 60068-3-11 for uncertainty calculation) and measurements with loaded chambers (IEC 60068-3-7).

Who should use this standard

• Environmental test laboratory managers and technicians
• Calibration and metrology engineers
• QA/quality managers responsible for test infrastructure
• Test equipment manufacturers and purchasers
• Compliance and accreditation bodies

Related standards

• IEC 60068-1 (General and guidance)
• IEC 60068-2 (Tests - all parts / climatic procedures)
• IEC 60068-3-6, 3-7, 3-11 (supporting documentation and measurement guidance)
• IEC 60584-1, IEC 60751 (temperature sensors)
• ISO 10012-1 / ISO 10012-2 (measurement quality assurance)

Keywords: IEC 60068-3-5, temperature chambers, environmental testing, chamber performance, temperature stability, temperature gradient, temperature fluctuation, climatic test procedures, performance monitoring.