ASTM C609-23 PDF

Full title and description

ASTM C609-23 — Standard Test Method for Measurement of Light Reflectance Value and Small Color Differences Between Pieces of Ceramic Tile. This test method specifies instrument-based procedures (spectrophotometric) used to determine Light Reflectance Value (LRV) and to quantify small color differences between pieces of glazed or unglazed ceramic tile for product specification, quality control, and code compliance.

Abstract

This standard provides procedures for measuring the Light Reflectance Value (LRV) of ceramic tile and for determining visually small color differences between solid-colored tile specimens. It defines measurement geometry and instrument requirements, specifies use of appropriate illuminants (incandescent, fluorescent and daylight) to detect metamerism, and gives guidance on averaging measurements for non-uniform or textured surfaces. Results are expressed numerically (LRV and color-difference metrics) suitable for product specification and compliance reporting.

General information

• Status: Current / Active
• Publication date: October 16, 2023 (edition designation C609-23)
• Publisher: ASTM International
• ICS / categories: 91.100.25 (Terracotta building products; ceramic tile)
• Edition / version: C609-23 (2023)
• Number of pages: 5

Scope

This test method covers measurement of Light Reflectance Value (LRV) and the instrumental determination of visually small color differences between pieces of glazed or unglazed ceramic tile using any spectrophotometer that meets the standard's requirements. LRV can be measured for solid-colored and for multicolored or textured tiles (with averaged readings); however, small color-difference determinations apply only to solid-color tiles. The procedure requires evaluation under multiple illuminants to detect metamerism and specifies reporting conventions for observer and illuminant conditions.

Key topics and requirements

• Definition and calculation of Light Reflectance Value (LRV) for ceramic tile.
• Instrumental requirements and acceptable spectrophotometer geometries (specular-included and specular-excluded options and disclosure).
• Use of multiple illuminants (incandescent, fluorescent and daylight) for color-difference assessment to identify metamerism.
• Procedures for averaging measurements on multicolored, speckled or textured surfaces to obtain representative LRV.
• Expression of color difference using established color-difference metrics (CIELAB ΔE or equivalent as specified) and direction of difference.
• Reproducibility and precision expectations for solid-colored tiles and limitations for textured/multicolored products.
• Requirements for reporting observer, illuminant, measurement geometry, and any specimen preparation or conditioning.
• Practical guidance for calculating LRV of mixed-material surface installations (weighted average calculation).

Typical use and users

Used by ceramic-tile manufacturers, independent testing laboratories, quality control technicians, architects, interior designers, specification writers, building code officials, and procurement professionals to: certify and specify tile color and reflectance (LRV) for accessibility or energy-related requirements, verify color matching and acceptability between production lots, and support retail/product-acceptance testing.

Related standards

Typically referenced alongside other color and appearance standards, including ASTM D2244 (calculation of color differences), ASTM E259 (ref. transfer standards for reflectance), ASTM E284 (terminology of appearance), ASTM C242 (terminology of ceramic whitewares), and related instrument/appearance standards and vendor practices. Users should consult the standard's normative references for the exact list.

Keywords

light reflectance value, LRV, color difference, ΔE, ceramic tile, spectrophotometer, metamerism, specular-included, specular-excluded, illuminant, color measurement, tile specification

FAQ

Q: What is this standard?

A: ASTM C609-23 is a test method that defines how to measure Light Reflectance Value (LRV) and small instrumental color differences between pieces of ceramic tile using a spectrophotometer and specified measurement procedures.

Q: What does it cover?

A: It covers measurement procedures, instrument and reporting requirements, use of multiple illuminants to detect metamerism, averaging procedures for non-uniform tiles, and calculation/reporting of LRV and small color differences for solid-colored tile specimens.

Q: Who typically uses it?

A: Tile manufacturers, QA/QC labs, testing laboratories, architects, specifiers, and building code or procurement authorities use this standard to verify color consistency, specify LRV for design or code compliance, and perform acceptance testing.

Q: Is it current or superseded?

A: The current edition is ASTM C609-23 (approved in 2023). Users should confirm they are using the 2023 edition when specifying or testing (publication/approval date: October 16, 2023).

Q: Is it part of a series?

A: It is part of the ASTM C standards for ceramic whitewares and related products under Committee C21 (subcommittee C21.06 on ceramic tile) and is commonly used together with other ASTM and appearance/colour standards referenced in the document.

Q: What are the key keywords?

A: Key keywords include: light reflectance value (LRV), color difference, ΔE, ceramic tile, spectrophotometer, metamerism, specular component, illuminant, color measurement, and tile specification.