Overview
ISO 20298-1:2018 - Fine bubble technology - Sampling and sample preparation for measurement - Part 1: Ultrafine bubble dispersion in water specifies standardized procedures for sampling, sample preparation, and record keeping for ultrafine bubble dispersions (UFBD) in water. The standard targets relatively stable ultrafine bubble systems where bubble size and number concentration remain essentially constant during sampling, preparation and measurement. It excludes less-stable fine bubble and microbubble dispersions.
Key topics and requirements
- Scope and applicability: Applies only to stable ultrafine bubble dispersion in water; not for microbubble dispersions.
- Terms and definitions: Defines UFBD, fine bubble dispersion (FBD), microbubble dispersion (MBD), and water diluent (blank/known UF bubble concentration).
- Apparatus and cleaning:
- Required equipment: tank, closed sample container, pipette, motor-driven stirrer (≈50–200 rpm), motor-driven drum roller (≈10–20 rpm).
- Cleaning: rinse tank with water diluent; rinse container, pipette and stirrer with UFBD or water diluent.
- Sampling procedure:
- Static (tank) sampling only - not for flowing samples.
- Use pipette to transfer slowly; flow sample down the inside wall; do not add the last pipette drop (avoid introducing large bubbles).
- Consider aspirating speed influence on UFBD characteristics to estimate measurement uncertainty.
- Sample preparation:
- Establish homogeneity in containers before measurement (Annex A). Avoid over-stirring; stirring >200 rpm can affect number concentration.
- Dilution using water diluent when UFBD concentration exceeds instrument dynamic range. Use calibrated balances or volumetric glassware and homogenize diluted samples (Annex B provides an example dilution and calibration procedure using linear regression to extrapolate original number concentration).
- Records: Must document sample identity and chemistry, sampling site/environment/date/procedure/operator, and sample preparation site/environment/date/procedure/operator.
Applications and users
ISO 20298-1 is practical for laboratories, QC teams, instrument manufacturers, researchers and process engineers working in:
- Fine bubble technology R&D
- Aquaculture, agriculture, cleaning and water treatment applications where ultrafine bubbles improve performance
- Metrology labs validating measurement methods for bubble size, bubble number concentration, and stability
Users benefit from reproducible sampling, minimized artefacts, and traceable records that improve measurement confidence.
Related standards
- ISO 20480-1 - Fine bubble technology - General principles / terminology
- ISO 21255 - Storage and transportation of ultrafine bubble dispersion in water
- ISO 123 - Sampling (referenced for homogenization methods)
- ISO/IEC Guide 98-1 - Uncertainty of measurement
Keywords: ISO 20298-1, ultrafine bubble, fine bubble technology, sampling, sample preparation, UFBD dilution, homogeneity, water diluent, measurement.
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