| 摘要 |
PURPOSE:To suppress the change in the BOD component in a standard solution and the generation of slime in a pipeline, in a BOD measuring method using a diaphragm type oxygen electrode and a microorganism electrode comprising a microorganism membrane, by adjusting the pH of the org. substance-containing standard solution to a predetermined value. CONSTITUTION:A measuring cell 5 is attached to the lower parts of a diaphragm type oxygen electrode 3 and a microorganism electrode 2 comprising a microorganism membrane. A buffer solution B, a specimen S, standard solutions C1-C3, a washing solution N and air are supplied to the measuring cell 5 according to a process preset by a control circuit 8 such as a microcomputer and the BOD value of the specimen S is calculated on the basis of the output current of the microorganism electrode 2. Each of the standard solution is an aqueous solution of a glucose-glutamic acid mixture and the pH thereof is adjusted to about 2-3. By using these standard solutions, the change in the BOD component in each standard solution is eliminated even in long-time continuous measurement and the generation of slime in the standard solution within a pipeline is suppressed and BOD can be measured continuously. |
