Overview
ISO 18314-1:2015 - Analytical colorimetry - Part 1: Practical colour measurement specifies a standardized method to determine the colour coordinates of paint films. It applies to paint films that appear uniformly one colour (monochromatic) and that form an opaque system over a non‑transparent substrate. The standard excludes luminescent, transparent, translucent, retroreflective and metallic paint films.
Keywords: ISO 18314-1, analytical colorimetry, practical colour measurement, paint film colour measurement, colourimetric method.
Key Topics and Requirements
- Scope and sample types: Intended for opaque, uniformly coloured paint films. Transparent/translucent, metallic and retroreflective coatings are outside scope.
- Sample preparation: Follow ISO 15528 (sampling), ISO 1513 (sample prep) and ISO 1514 (test panels). Film thickness for semi‑covering films should be determined per ISO 2808.
- Measurement conditions:
- Illuminant: D65 (standard daylight) - other illuminants for metamerism tests.
- Observer: 10°.
- Colour space: CIELAB or DIN 99; use CIEDE2000 or DIN 99 for small ΔE corrections.
- Temperature: maintain sample at (23 ± 2) °C for reversible thermochromic paints.
- Instrument calibration:
- Use manufacturer‑supplied white and black standards traceable to national standards.
- Calibrate in the same environmental conditions as the measurement; repeat white calibration during long runs or when environment varies.
- Keep standards protected from light, dust and damage; replace damaged standards.
- Apparatus:
- Prefer spectrophotometers with spectral coverage 400–700 nm, spectral step and bandwidth ≤ 20 nm (preferably 5–10 nm).
- Trichromatic colorimeters may be used where metamerism detection is not required.
- Measurement geometry:
- Choice affects results - common geometries include di:8° (captures total first‑surface reflection) and 45°:0° (measures 0° reflected component). Select geometry based on surface gloss, texture and the objective (visual correlation vs. pigment analysis).
- Repeatability and sampling: Use flat, scratch‑free, dust‑free specimens; take multiple readings and exclude outliers. Use the largest practical instrument aperture for better precision.
Applications - Who Uses This Standard
- Coatings and paint manufacturers for production and QC
- Color laboratories and quality assurance teams
- Automotive, industrial and architectural coatings R&D
- Suppliers of pigments and colorants for performance verification
ISO 18314-1 supports consistent, traceable colour measurement workflows for colour matching, batch control and specification compliance.
Related Standards
Keywords reiterated: paint film colour measurement, ISO 18314-1, color measurement, spectrophotometer, CIELAB, D65, coatings quality control.
