Overview - EN ISO 17502:2013 (Leather - Determination of surface reflectance)
EN ISO 17502:2013 defines a standardized test method to measure the diffuse surface reflectance of leather across visible and near‑infrared wavelengths. The method identifies if a leather can be classified as solar reflective by measuring reflectance at 900 nm. It applies to all leather types, with particular relevance for coloured and finished leathers.
Key topics and technical requirements
- Scope and purpose: Measure reflectance properties (400–1 100 nm) to assess solar‑reflective behaviour and user comfort under solar exposure.
- Solar‑reflective criterion: Leather is classified as solar reflective when diffuse reflectance at 900 nm ≥ 55%.
- Apparatus:
- Spectrophotometer with an Ulbricht integrating sphere (suitable geometry specified) and appropriate light source/detector for visible to near‑IR.
- White diffuse reflectance standard (>98% reflectance from 250 nm to 1 500 nm) for calibration.
- Optional fibre‑optic links and software to record spectra (400–1 100 nm).
- Specimen: Dry leather sample approximately 300 mm × 200 mm.
- Procedure:
- Calibrate instrument so white = 100% and black = 0% across 400–1 100 nm.
- Measure diffuse reflectance with the integrating sphere placed flat on the tested surface; record % reflectance at 900 nm (nearest 1%).
- Take at least three measurements at different locations and report the average; note if variation >10%.
- Precision (informative): At the 55% level, repeatability ≈ ±2% (single lab) and reproducibility between labs ≈ ±4% (95% confidence).
- Test report must include: reference to ISO 17502, leather type and surface tested, % reflectance at 900 nm and solar‑reflective classification, deviations, and test date.
Practical applications
- Product development and R&D: evaluate coatings, dyes, and treatments that affect near‑IR reflectance.
- Quality control and supplier verification: ensure consistency for automotive, motorcycle, upholstery and footwear leathers where surface temperature and comfort matter.
- Marketing and compliance: substantiate claims for “solar reflective” leather by standardized measurement.
- Research on thermal comfort and material selection for outdoor or vehicle interiors.
Who should use this standard
- Leather manufacturers and finishers
- Material testing laboratories and certification bodies
- Automotive and footwear specifiers, designers, and R&D teams
- Procurement and quality assurance professionals verifying supplier claims
Related standards
EN ISO 17502 should be used alongside other leather test methods and spectrophotometry best practices when specifying optical or thermal performance. For procurement and compliance, reference this standard when requiring validated solar‑reflective performance.
