This document specifies evaluation methods for the oxygen content in fine bubble dispersion in water.

Three test methods which are adopted include the optical sensor, the electrochemical probe and the iodometric method. The first two methods have an advantage in availability of in situ and real-time measurement, and high accessibility to commercially available instruments. The last one, composed of a well-established chemical analysis procedure, is advantageous in the situation where the instruments to be used in the first two methods are unavailable.

The detection limits of the electrochemical and optical sensor methods are stated in the instruction manuals of the instruments, in most cases 0,1 mg/l or 0,2 mg/l. The upper limit depends on the specification of the instrument used. Most instruments allow measurement of a supersaturated sample.

Measurement range of the iodometric method is between 0,2 mg/l and 20 mg/l.

NOTE            Chemical analysis methods other than the iodometric method can be applied^[1] as an alternative.