In the process of seawater distillation, the concentration of dissolved oxygen (DO) in feed seawater is reduced to about 10μg/lin order to prevent the plant from the corrosion of metallic materials. An electrochemical DO meter (model 6400) made by Electronic Instruments Ltd. is an on-line analyser of gas transfer type for measuring trace amounts of DO in μg/lunit, but this instrument was developed for pure water such as boiler feed water. The DO meter is equiped with the mechanism of zero point and 25μg/lchecks and the accuracy of the measurement is ±10%.
Previously, the authors had reported an apparatus for the preparation of water containing trace amounts of DO. This study was done with DO meter combined to the new preparating apparatus that was developed for this purpose. Measuring conditions were varied to investigate the influence on the measurement in a range of 0-60μg/lin pure water and seawater.
The measured values were proportional to the calculated ones, but measured values using seawater