Overview
ISO 18753:2017 describes a standardized liquid pycnometry method to determine the absolute particle density of fine ceramic powders and small sintered parts. The standard specifies sample preparation, suitable immersion liquids, required apparatus, a degassing procedure (vacuum or ultrasonic), calculation steps, repeatability criteria and reporting requirements. It is intended for laboratories performing density measurements on advanced/technical ceramics using a pycnometer (liquid medium). Note: other pycnometry methods (e.g. helium/gas pycnometer) also exist.
Key topics and technical requirements
- Scope: Absolute density of ceramic powders or small parts using liquid pycnometry (ISO 18753:2017).
- Sampling & preparation: Representative sampling per ISO 8213; particle size must fit pycnometer neck; thorough drying (≈110 °C air bath or reduced pressure if heat-sensitive) and cooling in a desiccator.
- Immersion liquids: Distilled water, xylene, ethanol (≈95 %), or 1‑butanol - selected to avoid reaction or dissolution and to wet the sample. Absolute liquid density at measurement temperature must be determined (ISO 758); distilled water reference data provided for 15–30 °C.
- Apparatus: Gay‑Lussac glass pycnometer (25 or 50 ml per ISO 3507) or equivalent, vacuum container with observation, vacuum pump (≈666.5 Pa / 5 mmHg or better), vacuum gauge, balance with 0.1 mg sensitivity, thermometer ±0.1 °C, ultrasonic bath alternative.
- Degassing: Reduce pressure to ≤13.33 kPa (100 mmHg) or use ultrasonic bath (optionally with surfactant) until no bubbles are released - essential to ensure full wetting and accurate results.
- Measurement & calculation: Record a series of masses (empty pycnometer, with sample, with sample + liquid after degassing, with liquid only, reweigh empty). Compute particle density using the measured mass differences and immersion liquid density; report four significant digits.
- Quality control: Run duplicate tests - if results differ by >0.03 g/cm3, repeat measurements.
- Reporting: Test report per ISO/IEC 17025 including sample description, pycnometer type, immersion liquid, pre-treatment, temperature and final density.
Applications and users
ISO 18753:2017 is applied in:
- Materials characterization labs and QA/QC for advanced ceramics and technical ceramic powders
- Ceramic powder manufacturers and suppliers verifying batch density
- Sintered part manufacturers and testing facilities assessing closed-porosity effects
- Research institutions developing new ceramic materials
Practical benefits include reproducible, traceable absolute density values for process control, materials selection and comparative R&D.
Related standards
Keywords: ISO 18753:2017, liquid pycnometry, pycnometer, absolute density, fine ceramics, ceramic powders, helium pycnometer, density measurement.