Overview
CEN ISO/TR 22007-5:2014 (ISO/TR 22007-5:2011) documents the results of an interlaboratory comparison for measuring thermal conductivity and thermal diffusivity of two poly(methyl methacrylate) (PMMA) materials. The Technical Report compiles measurement data from multiple laboratories using transient, modulated and steady‑state methods described in ISO 22007 parts 1–4 and other established techniques. Its purpose is to inform the development and application of ISO 22007 test methods and to highlight practical measurement issues, uncertainty and repeatability for polymer thermal-property testing.
Key topics and technical requirements
- Materials tested: two PMMA grades (cast and extruded) supplied as sheets (≈2 mm and ≈3 mm) and pellets (extrusion grade).
- Measurement methods covered:
- Transient plane heat source (Hot Disk)
- Temperature wave analysis (modulated methods)
- Laser flash method
- Transient line source (probe) and guarded heat flow meter (steady‑state)
- Specimen preparation: guidance on thickness, cutting/stacking, surface coatings (e.g., graphite or sputtered layers for laser flash) and method‑dependent specimen dimensions.
- Data analysis & calculations: procedures to derive λ (thermal conductivity), α (thermal diffusivity) and volumetric heat capacity (ρCp) from measured data.
- Uncertainty and repeatability: expanded uncertainties calculated per the Guide to the Expression of Uncertainty in Measurement (GUM); results typically within ±10% of the mean for both λ and α.
- Key measurement issues identified:
- Adequate specimen thickness for each method
- Sample anisotropy and its influence on apparent bulk vs. directional properties
- Sensitivity of calculated values to specific heat capacity and density inputs
Applications and who uses this standard
- Thermal characterization labs validating or comparing methods for polymers.
- Materials scientists and R&D teams evaluating PMMA thermal performance for optical, electronic or thermal management applications.
- Polymer manufacturers and quality control teams using standardized methods to report thermal properties.
- Standards developers and accreditation bodies using interlaboratory data to refine test protocols and uncertainty statements.
Practical uses include material selection, thermal modeling, component design and compliance testing where accurate polymer thermal properties are required.
Related standards
- ISO 22007-1: General principles (series lead)
- ISO 22007-2: Hot Disk (transient plane heat source)
- ISO 22007-3: Temperature wave analysis
- ISO 22007-4: Laser flash method
- ISO 472: Plastics - Vocabulary
- ASTM D5930 (line source probe) and ASTM E1530 (guarded heat flow meter)
- GUM: Guide to the Expression of Uncertainty in Measurement
Keywords: thermal conductivity, thermal diffusivity, PMMA, ISO 22007-5, interlaboratory testing, Hot Disk, laser flash, temperature wave analysis, heat flow meter, uncertainty, repeatability.