ISO 24340:2006

Overview

ISO 24340:2006 specifies a laboratory method for determining the thickness of layers in resilient floor coverings using direct optical measurement. The standard defines sampling, specimen preparation, instrumentation, measurement procedure, calculation and reporting requirements to ensure consistent, repeatable layer-thickness results for sheet and tile products.

Key topics and technical requirements

• Principle: thickness measured directly by optical means (microscope or video microscope).
• Apparatus:
  • Microscope/video microscope with magnification of at least 40× and a micrometric scale or adjustable screen lines.
  • Two accuracy classes: eyepiece scale readable to 0.01 mm, or for thin layers an eyepiece readable to 0.0025 mm (for thicknesses below 0.05 mm).
  • Stage micrometer for calibration, lamp/light source, specimen holder, sharp blade and straightedge.
• Sampling & specimens:
  • Sheet coverings: five specimens (10 mm × 25 mm) evenly distributed across the width.
  • Tiles: one specimen (10 mm × 25 mm) from each of five separate tiles from the pack.
• Conditioning: specimens conditioned a minimum of 24 h at (23 ± 2) °C and (50 ± 5) % RH; test in same environment.
• Test procedure:
  • Cut specimens face down on a suitable board to ensure a clean edge.
  • Mount with the cut surface perpendicular to the optical axis.
  • Calibrate eyepiece against stage micrometer and record calibration factor.
  • Focus so both layer edges are sharp; take three readings per specimen at least 10 mm apart.
• Reporting & results:
  • Calculate mean thickness per layer; report to nearest 0.01 mm or 0.0025 mm depending on instrument.
  • Test report must identify samples, previous history, deviations, mean/min/max readings, and a statement of conformity with ISO 24340:2006.

Applications and who uses it

ISO 24340:2006 is used for quality control, product specification, compliance testing and material research by:

• Flooring manufacturers verifying layer structure and wear-layer thickness.
• Independent testing laboratories performing standardized optical thickness measurements.
• Specifiers, procurement officers and inspectors checking product conformity to stated construction.
• R&D teams assessing multilayer constructions and comparative product performance.

Keywords: ISO 24340:2006, resilient floor coverings, thickness of layers, optical measurement, microscope, wear layer thickness, sampling, conditioning, test procedure.

Related standards

• EN 429 - Resilient floor coverings - Determination of the thickness of layers.
• ASTM F410 - Standard test method for wear layer thickness of resilient floor coverings by optical measurement.