Dissolved oxygen meter measurement steps
1. Fixing of the dissolved oxygen meter: insert a pipette into the dissolved oxygen bottle under the liquid surface, add 1mL of manganese sulfate solution and 2mL of alkaline potassium iodide solution, cover the bottle stopper, invert and mix for several times. Usually fixed at the sampling site.
2. Open the cork and immediately insert 2.0mL of sulfuric acid into the liquid with a straw. Cover the bottle with a stopper and shake it upside down until all the precipitates are dissolved and place it in a dark place for 5 minutes.
3. Take 100.00mL of the above solution into a 250mL Erlenmeyer flask and titrate with sodium thiosulfate standard solution until the solution turns light yellow, add 1mL of starch solution and continue titrating until the blue color just fades, record the amount of sodium thiosulfate solution.
4. In the calculation formula: M - the concentration of sodium thiosulfate standard solution (mol/L);
V——volume of sodium thiosulfate standard solution consumed by titration (mL).
