Overview - ISO 8106:2004 (Glass containers - Capacity by gravimetric method)
ISO 8106:2004 specifies a laboratory gravimetric test method to determine the capacity of glass containers (brimful or specified fill level) and to assess compliance with specification limits. The method calculates volume from the mass of water filling the container adjusted by a volume correction factor (VCF) for water density at the test temperature (reference 20 °C). This standard is used for quality control, acceptance testing and regulatory compliance of bottles, jars and other glass packaging.
Key topics and technical requirements
- Principle: Capacity = mass of water × VCF (ml/g). Measure mass difference between filled and empty container and apply temperature correction.
- Reference temperature: 20 °C; tests typically corrected to this reference using VCF values for water.
- Sampling: Test on a predetermined, representative sample of the consignment.
- Apparatus:
- Calibrated thermometer (graduated ≥ 1 °C)
- Balance with specified accuracy depending on container capacity (e.g., ±0.1 g for up to 10 ml; increasing tolerances for larger volumes)
- Strike plate for brimful determination of wide-mouth containers
- Depth gauge for defined filling level measurements
- Procedure highlights:
- Maintain water and container temperatures within ±1 °C of measured values during the test.
- Keep outer container surfaces dry; fill on a flat horizontal surface.
- For brimful capacity, top up to the rim meniscus (or use strike plate for wide mouths).
- For filling-level capacity, use a depth gauge so the meniscus meets the gauge tip.
- Weigh empty and filled containers to prescribed balance accuracy.
- Expression of results:
- Use the VCF table to convert mass (g) to volume (ml). The standard provides VCFs for distilled water at 16–28 °C and notes that tap water requires an additional density correction.
- Report individual capacities, bulk/average capacity if required, and identify non‑conforming units.
- Test report requirements: reference to ISO 8106, container description, sample size and sampling method, individual capacities, acceptance calculation, date, location, and responsible signature.
Applications and typical users
- Who uses it: glass-container manufacturers, packaging engineers, laboratory technicians, quality control and QA/QC departments, filling equipment manufacturers, beverage and pharmaceutical packaging teams, and regulatory/inspection bodies.
- Practical uses:
- Production acceptance testing and lot verification
- Calibration/validation of filling machines and lines
- Compliance with customer or legal specification limits (e.g., measuring bottles used as measuring containers)
- Product development and dimensional inspection of glass packaging
Related standards
- ISO 7458 (Internal pressure resistance)
- ISO 7459 (Thermal shock resistance)
- ISO 8113 (Resistance to vertical load)
- ISO 7348 (Glass containers - Vocabulary)
- Cites Directive 75/107/EEC for correction to 20 °C
Keywords: ISO 8106:2004, glass containers, gravimetric method, capacity determination, brimful capacity, filling level capacity, VCF, test method, packaging quality control.
