IEC 60068-2-5:2018

Overview

IEC 60068-2-5:2018 is an international standard for simulated solar radiation testing and guidance for weathering of equipment and components at the surface of the Earth. This third edition (2018) retains the thermal-effect procedure (Test Sa) and adds a dedicated weathering procedure (Test Sb). The standard defines how to reproduce the spectral irradiance of solar radiation in laboratory conditions and how to combine radiation with temperature, humidity and wetting to evaluate product performance and durability.

Key topics and technical requirements

• Scope and purpose
  • Methods to assess effects of daylight or daylight filtered through glass on equipment/components.
  • Applicable to products and materials used at ground level (outdoor or sun-exposed indoor applications).
• Test methods
  • Test Sa - Thermal effect test: focuses on heating and thermal stresses caused by simulated solar irradiance. Includes three Sa procedures (Sa1, Sa2, Sa3) covering different irradiation/dark cycles and continuous irradiation.
  • Test Sb - Weathering test: addresses photo-degradation and combined environmental effects (radiation with humidity, wetting and temperature cycles).
• Radiation characteristics
  • Simulation of spectral irradiance representative of solar radiation at ground level; guidance on acceptable spectral matching and uniformity.
  • Laboratory radiation sources and filters (e.g., xenon-arc lamps with daylight/window-glass filters) are discussed.
• Test apparatus and instrumentation
  • Requirements for test chambers, mounting, irradiance measurement, spectral measurement, temperature control and black-panel thermometry.
  • Consideration of contaminants (ozone/other gases) and surface contamination.
• Test program documentation
  • Initial and final measurements, test duration and exposure cycles, and information to be provided in test specifications and test reports.
• Informative annexes
  • Standard solar spectral data, recommended radiation sources, typical weathering apparatus and measurement instrumentation.

Practical applications

• Evaluate long-term durability of coatings, plastics, polymers, and outdoor enclosures exposed to sunlight.
• Assess electronic equipment and housings for thermal stress under solar loading.
• Simulate window-filtered sunlight for building materials, glazing and indoor‑exposed products.
• Useful for product development, accelerated life testing, material selection, and failure analysis.

Who should use this standard

• Environmental test laboratories and test-house engineers
• Product designers and R&D teams for outdoor/solar-exposed equipment
• Material scientists and coatings formulators
• Certification bodies and quality assurance teams

Related standards

• IEC 60068-1 (General environmental testing) - referenced normative guidance
• National and industry weathering standards (e.g., ASTM/CIE spectra) - informative comparisons in annexes

Keywords: IEC 60068-2-5, simulated solar radiation, solar radiation testing, weathering test, Test Sa, Test Sb, environmental testing, spectral irradiance, xenon-arc, accelerated weathering.