Abnormal COD
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The cuvettes in the COD online analyzer’s testing chamber tend to scale up, resulting in higher COD analysis values. How can this be resolved?
After each analysis cycle, automatic flushing with purified water is required. You can discuss it with the equipment supplier.
1. Increase the amount of water used for cleaning； 2. Clean regularly ；
The last edit to this post was made by sunshineda_VGMP on 2018-11-23 at 10:26. Code detectors generally use the potassium dichromate redox method; the scaling substances in the cuvette are likely compounds formed over time as a result of the reaction between ammonium ferrous sulfate and reducing substances, which then cause color formation. It is best to clean the cuvettes promptly after each experiment. A cleaning solution prepared by mixing 3 mol/L hydrochloric acid with ethanol in a 1:1 ratio can be used; after cleaning, rinse them several times with pure water before use, or inquire with the equipment manufacturer whether there is a specialized cleaning solution for cuvettes.