Overview
ISO 13803:2014 - Paints and varnishes - Determination of haze on paint films at 20° - defines a standardized test method for measuring haze on coatings. The method is intended for non-textured coatings on plane, opaque substrates and uses a 20° geometry closely related to the 20° gloss measurement in ISO 2813. ISO 13803:2014 is designed to improve differentiation between high-gloss surfaces, for example when assessing dispersion characteristics or subtle surface microstructures that cause milky opalescence.
Key topics and technical requirements
- Principle: Simultaneous measurement of specular reflection and adjacent scattered light using a reflectometric hazemeter to correlate instrument readings with visual haze perception.
- Hazemeter: Composed of a light source, lens, receptor housing, field stop and photoelectric cell. The incident beam axis is specified as α = (20.0 ± 0.1)° to the surface normal.
- Apertures and geometry: Source image and receptor aperture angles and tolerances are defined (see standard table) to ensure consistent measurement area and avoid vignetting. A typical illuminated spot is ~10 mm to average surface irregularities.
- Spectral filtering and calibration: Receptor filtering is specified to match CIE photopic response and CIE illuminant C characteristics; the standard provides a formula-based definition of the required transmittance and a calibration constant for instrument adjustment.
- Measurement standards:
- High gloss standard A: plane black glass (working standard).
- Haze standard B: calibrated ceramic/vitreous enamel or opaque glass standards.
- Zero standard C: very low-gloss plate (e.g., black flock coating).
- Test panels and conditioning: Substrate selection and panel preparation per ISO 1514; conditioning at (23 ± 2) °C and (50 ± 5) % RH for at least 16 hours. Dry film thickness measured per ISO 2808; matched thickness for comparative testing.
- Procedure, calibration and precision: Clauses cover apparatus setup, zero checks, calibration routines, measurement procedures for liquid and powder coatings and precision information including repeatability and reproducibility limits.
Applications and users
ISO 13803:2014 is used by:
- Paint and coatings manufacturers for quality control and product development (formulation, dispersion assessment).
- Industrial and automotive finish specifiers evaluating high-gloss appearance.
- Test laboratories performing standardized haze and gloss characterization.
- Surface finish and furniture manufacturers requiring consistent visual appearance metrics.
Practical uses include differentiating high-gloss finishes, monitoring batch-to-batch consistency, and correlating instrumental haze with perceived milky or opalescent defects.
Related standards
- ISO 2813 - Determination of gloss value at 20°, 60° and 85° (related geometry and gloss reference).
- ISO 1514 - Standard panels for testing (substrates and panel preparation).
- ISO 2808 - Determination of film thickness (dry film thickness measurement).
- ISO 4618 - Definitions for paints and varnishes terminology (haze definition).
Keywords: ISO 13803:2014, haze measurement, hazemeter, 20° geometry, paints and varnishes, high-gloss surfaces, coatings test method, calibration, test panels.
