EN 2155-9:1989

Overview

EN 2155-9:1989 is a CEN (European) aerospace series standard titled "Test method for transparent materials for aircraft glazing - Part 9: Determination of haze." It specifies a laboratory method for measuring the haze of planar sections of transparent plastics used in aircraft glazing. The procedure uses a hazemeter based on an integrating sphere to quantify light scattering expressed as haze percentage. Note: this method is not recommended for haze values greater than 30% as measured by this technique.

Key Topics

• Scope and applicability: Designed specifically for planar sections of transparent plastics commonly used in cockpit canopies, cabin windows and other aircraft glazing components.
• Measurement principle: Uses an integrating-sphere hazemeter to separate and quantify forward-scattered light (haze) from transmitted light.
• Specimen requirements: Addresses testing of planar samples (thickness and preparation considerations implied by scope); intended for materials representative of glazing elements.
• Instrumentation and calibration: Defines the use of an integrating-sphere-type hazemeter and associated calibration/verification procedures (instrument requirements and calibration routines are specified by the standard).
• Reporting: Requires reporting of haze values (percentage), test conditions and any relevant sample preparation details to ensure reproducibility.
• Limitations: Explicitly cautions against using this method for materials yielding haze above 30% by this method.

Applications

EN 2155-9 is especially useful for:

• Aerospace manufacturers assessing optical clarity and scattering properties of cockpit and cabin glazing materials.
• Materials suppliers and compounders validating product quality during development and production.
• Quality control and acceptance testing in production lines for transparent plastic components.
• Test and certification laboratories performing comparative optical property testing to support certification or procurement.
• Design and safety engineers evaluating visual performance, glare and visibility implications of glazing materials.

Practical benefits include standardized haze measurement, improved material selection for visibility and safety, and consistent test data for procurement and certification.

Related Standards

• Part of the EN 2155 aerospace test series addressing transparent materials for aircraft glazing.
• Comparable haze and optical scattering test methods exist in international standards bodies (ISO, ASTM); users often cross-reference equivalent haze methods for broader acceptance and comparative testing.

Keywords: EN 2155-9, haze determination, integrating sphere, hazemeter, aircraft glazing, transparent plastics testing, aerospace materials testing, CEN standard.