Operating matters and principles of BOD meter

Precautions for BOD measuring instrument operation:

1. The inner filling fluid should be replaced in time after about a week of continuous use.

2. Keep the connection of each connection in good condition, otherwise, the instrument will not work normally (no endpoint, etc.).

3. The platinum electrode plate should be kept bright. If it is used for long-term use with silver chloride and other compounds, you can use 1+3 nitric acid to soak in the digestion cup and wash it with distilled water. If the electrode is not used for a long time, it can be placed in a clean digestion cup without any liquid.

The measurement principle of BOD analyzer:

The water sample containing saturated dissolved oxygen enters the measuring tank and contacts the biosensor. When there is no biodegradable organic matter in the water sample when the diffusion rate (mass) of dissolved oxygen to the oxygen electrode reaches a constant, a constant Current. When there are biodegradable organic matter in the water sample, the organic matter is assimilated by the microorganisms in the biofilm, and the cell respiration of the microorganisms is also enhanced, which consumes a part of the dissolved oxygen and reduces the dissolved oxygen that diffuses on the surface of the oxygen electrode. When the diffusion rate (mass) of dissolved oxygen in the water sample to the electrode reaches a constant value again, a constant current is generated. Because the difference between the two constant currents has a quantitative relationship with the concentration of biodegradable organic matter in the water sample, Therefore, after the current signal is amplified and analyzed by the microcomputer, the BOD detection result is directly displayed.