ISO 7383-3:2026 PDF

This document specifies two evaluation methods for ozone content (total ozone, including ozone contained in ultrafine bubbles (UFBs) or microbubbles (MBs) and dissolved ozone) in UFB dispersions in water, namely, iodometric titration and UV photometry. Iodometric titration is applicable as a well-established, high accuracy chemical procedure, particularly suitable for single-point determinations. The direct measurement range of this technique is typically 0,01 mg/l to 50 mg/l. Ultraviolet (UV) photometry is applicable for rapid or continuous measurement and real-time monitoring. Its typical measurement range is from 0,075 mg/l to 200 mg/l, depending on instrument specification. This document is applicable to industrial processes that require precise ozone dosing and control when MB or UFB systems are used. NOTE This document does not involve the specific effects of ozone UFB dispersion applications. High concentrations of dissolved oxygen (DO), commonly found in water containing oxygen UFBs, can interfere with iodometric titration and lead to overestimation of ozone content. When extremely high ozone levels are expected, water containing oxygen UFBs can be used as the blank control.