The apparatus incorporates aeration-oxidation (Vacuum aspiration) method, in which a stream of air is passed through an acidified wine sample carrying released SO₂ through a condenser into a hydrogen peroxide trapping solution containing acid/base indicator. Precision of the analysis is dependent largely upon thorough consistent aeration and subsequent efficient trapping in the H₂O₂ solution.

The improved apparatus replaces the inefficient and imprecise Pasteur pipet sparging and impinger tubes with precise glass frits to assure thorough sparging the binding of SO. In addition, the use of glass frits results in an apparatus much less sensitive to small changes in the aspiration rate.