This document specifies the evaluation method for the size index of microbubbles in microbubble dispersion. It is only applicable to microbubbles with or without shell in water within the range from 1 µm to 100 µm. It describes the sampling methods from the point generating or dispersing microbubbles in the retention container to the detecting point of the measuring instruments.Cross References:ISO/TS 21749:2005ISO 26824:2013ISO/IEC Guide 98-1:2009ISO 20298-1:2018ISO 4287:1997ISO 13320:2020ISO 20480-2ISO 13322-2ISO 20480-1ISO 21501-3All current amendments available at time of purchase are included with the purchase of this document.