| 摘要 |
PURPOSE:To measure BOD accurately by detecting a plurality of dissolved- oxygen concentrations during the period wherein the dissolved-oxygen concentration is stable, using the average value as a steady-state value, and detecting the accurate dissolved-oxygen concentration. CONSTITUTION:The liquid which does not substantially contain organic material is continuously sent into immobilized microorganism. At this time, the steady- state values of dissolved-oxygen concentrations are detected with first and second dissolved oxygen electrodes 13 and 17. Then sample liquid is continuously sent into the immobilized microorganism. At this time, the steady state values of the dissolved-oxygen concentrations are detected by the electrodes 13 and 17. The decreasing amount of the dissolved-oxygen concentration caused by the oxidation of the organic material is obtained. When the steady-state values of the dissolved-oxygen concentrations are detected by the electrodes 13 and 17, a plurality of the dissolved-oxygen concentration are extracted during the period wherein the dissolved-oxygen concentration is stable. The average value of the detected dissolved-oxygen concentrations is made to be the steady-state value. |
