COD rapid detector: the use points of water quality detector

1. The system needs to be shut down. It is necessary to tighten the connection of the Karl Fischer reagent liquid circuit, from the reagent bottle to the metering pump and then to the reaction cell, otherwise, the leakage of the reagent will directly affect the test result. Another problem is its problem. The non-sealing is that the Karl Fischer reagent absorbs moisture in the air during the test, which causes the endpoint of the titration to be delayed.

2. The problem of accurate sampling. When calibrating the Karl Fischer reagent, you need to take in 10mg of water, try to use a 10ul sampler, which is not only accurate and fast but also can prevent the adhesion of water droplets. Similarly, using methanol reagents and ethyl esters have similar problems, so care should be taken to minimize the opening time of the reaction tank after transfer.

3. Magnetic stirring speed adjustment. In the reaction cell, since the titration reagent is applied locally instead of at one place of the electrode, the stirring speed should be fast and will not form turbulence, so the endpoint can be reached. as soon as possible.

4. The multi parameter water quality meter should be far away from the strong magnetic field to prevent the electronic display from jumping and abnormal phenomena during operation. Manual moisture analyzer, because the glass automatic burette needs to be used to measure Karl Fischer reagent and methanol solvent. Due to the equilibrium pressure, the glass burette itself needs to be connected to the outside.

5. When adjusting the titration speed of the burette, it should be adjusted to 1 drop/sec. The rapid acceleration of the titration will produce a large delay error when the endpoint is reached, and the slow titration speed will prolong the test process, resulting in a delay in reaching the endpoint.

6. The titration speed should be set quickly and then slow. The titration speed is fast, the test time is short, and the strain near the endpoint is slow, which improves the measurement accuracy.

7. The system is as close as possible. The manual moisture analyzer requires a U-shaped tube filled with desiccant on the pipette and glass burette. To reduce the interference of air humidity on the test results, in an environment where the relative humidity of the air is greater than 70%, a moisture test should be arranged as much as possible.

8. After the test of the day, be sure to empty the Karl Fischer reagent in the system, and then wash it with methanol. Do not clean the system with water, because it is not volatile, so Karl Fischer reagent will be produced in the next test Resulting in incorrect calibration.