DISSOLVE OXYGEN MEASUREMENT
DISSOLVE OXYGEN MEASUREMENT Different methods are used for measurement of the amount of dissolve oxygen present in a liquid. It measure the dissolve oxygen in mg/L, partial pressure or a % of saturation or ppb. There are three techniques for DO measurement 1) Colorimetric method 2) Titration 3) Sensor and meter · Colorimetric method: It is very simple method mainly used for determination of DO in water sample. Based on the reagent used, this method is divided in two types. a) Indigo carmine method: In this method, reduced indigo carmine dye added into the sample that react with the presence of dissolve oxygen and undergo color changes (blue color), and change in color is directly proportional to DO. This color change compare with color comparator and determine the DO. LOD of this method is 0 to 50 ppm. b) Rhodazine D method: This method is used to determine the dissolve oxygen in very low concentration in ppb. In this method,