EN 2591-515:2005

Overview

EN 2591-515:2005 - “Aerospace series - Elements of electrical and optical connection - Test methods - Part 515: Hydrolytic stability” defines a laboratory test method to determine the relative rate and amount of water absorption by plastic and composite materials used in aerospace electrical and optical connection elements. Derived from ASTM D570‑98 and intended for use together with EN 2591-100, this standard supports material selection, qualification and quality control where hydrolytic stability and moisture uptake affect connector performance.

Key topics and requirements

• Scope: Measures water uptake and any water‑soluble material loss for plastics/composites used in connector components.
• Specimen preparation: Prepared per product technical specification; dried in an oven for 24 h at (50 ± 3) °C, cooled in a desiccator and weighed to 0,001 g resolution.
• Test methods: Three methods are provided depending on product requirements:
  • Method A (long‑term immersion) - Immersion in distilled water at (23 ± 1) °C; weight checks at 24 h, 1 week, then every two weeks until saturation (when three consecutive two‑week increases average less than 1% of total increase or 5 mg, whichever is greater).
  • Method B (2‑hour boiling) - Immersion in boiling distilled water for (120 ± 4) min, then cooled and weighed.
  • Method C (30‑minute boiling) - Same as B but for (30 ± 1) min, for high‑absorption materials or thin specimens.
• Reconditioning: After immersion the specimen is re‑dried using the original drying time/temperature, cooled and reweighed to assess water‑soluble matter loss.
• Calculations:
  • Increase in weight, % = (Wet weight − Dry weight) / Dry weight × 100
  • Soluble matter lost, % = (Dry weight − Reconditioned weight) / Dry weight × 100
• Requirements: The total percentage of water absorbed (increase + soluble loss where applicable) must meet values specified in the applicable product standard.
• Final checks: Visual examination per EN 2591‑101 may be required.

Applications and users

• Practical for aerospace engineers, materials scientists, connector manufacturers, test laboratories and quality assurance teams who evaluate connector housings, insulators and composite parts for moisture susceptibility.
• Used during product qualification, supplier acceptance testing, failure investigation and material selection to ensure reliability of electrical and optical connections in humid or wet environments.
• Relevant for risk mitigation where moisture uptake can affect dimensional stability, dielectric properties or mechanical integrity.

Related standards

• EN 2591-100 (General test methods)
• EN 2591-101 (Visual examination)
• ASTM D570‑98 (origin of method)

Keywords: EN 2591-515, hydrolytic stability, water absorption test, aerospace connectors, plastic and composite testing, ASTM D570.