ISO 24218-1:2023 ファインバブル技術 — ファインバブルのキャラクタリゼーション — Part 1: レーザー回折法によるサイズと濃度指標の評価 | ページ 2

Foreword

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This document was prepared by Technical Committee ISO/TC 281, Fine bubble technology.

A list of all parts in the ISO 24218 series can be found on the ISO website.

Introduction

Fine bubble technology has seen growth in its application to markets such as cleaning, water treatment, agriculture, aquaculture and biomedical fields. Now the methods to evaluate the characteristics of fine bubbles such as the size and concentration indices become necessary to clarify the performances of fine bubble generating systems used for various applications.

The shape of the size distribution of fine bubble dispersions (FBD) can be bimodal or multimodal, and this distribution can extend broadly from ultrafine bubble (UFB) range to microbubble (MB) range.

To evaluate the relationship between the characteristics of fine bubbles and their effects, it should be considered that the respective modes of multimodal size distribution can have their independent contributions to the total performance of fine bubbles.

The laser diffraction method can evaluate multimodal size distributions from the range of UFB (<1 μm) to that of MB (on the micron scale).

Due to the nature of number-based size distribution, any examination of a sample on a number basis which mixes populations of ultrafine and micro bubbles is unduly weighted to the fraction of smaller size bubbles (ultrafine bubbles). The important fraction of larger size bubbles (micro bubbles) can therefore be lost. At the viewing of size distribution data, the confirmation of its dimension (number basis or volume basis) is necessary. Moreover, the suitability of approach about the dimension of size distribution should be taken into consideration in terms of what it can do to the size distribution and what is the most appropriate approach for the application under evaluation.

This document is intended to specify the evaluation of fine bubbles size and concentration indices by combined use of number-based size analysis and volume-based size analysis by laser diffraction method. Both bimodal and multimodal samples are appropriate. It is applicable to fine bubbles with and without shell over a size range which includes UFB and MB dispersions and any combination thereof.

1 Scope

This document specifies the evaluation of fine bubbles size and concentration indices applied to the combined use of number-based size analysis and volume-based size analysis by the laser diffraction method. The methodology described is appropriate to both bimodal and multimodal samples over a broad size range (from tens of nanometers to tens of micrometers) and applies to ultrafine bubble and microbubble dispersions (MBD) and mixtures thereof.

2 Normative references

The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 20480-1 and the following apply.

ISO and IEC maintain terminology databases for use in standardization at the following addresses:

Bibliography