scope:

This international standard specifies evaluation methods for oxygen content in fine bubble dispersion in water.

Three test methods, optical sensor, electrochemical probe, and iodometric method, are adopted. 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 well-established chemical analysis procedure is advantageous to the situation which instruments to be used in forecited two methods are not available.

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

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

If optical sensor or electrochemical probe methods are used for saline water such as sea or estuarine waters, correction for salinity is essential.

NOTE 1 Chemical analysis methods other than iodometric method can be applied ¹⁾ as an alternative.

NOTE 2 If extremely high oxygen level is expected for a sample to be measured, a measuring method should have a sufficiently wide measuring range.