What reasons can cause the residual oxygen level to not meet the standard during the maintenance of vacuum deaerator?

If the heating temperature of the deoxygenated water is 3-5 ℃ higher than the corresponding saturation temperature under operating vacuum, the residual oxygen content should be qualified. If a lower residual oxygen level is required, the deoxygenated water temperature can be slightly increased until the vacuum degree of the deaerator begins to decrease. If the residual oxygen level still does not meet the requirements, the main reasons may be:

1. The vacuum degree inside the degassing tower is not high, as mentioned earlier.

2. The sampling operation is too slow, and oxygen enters the sampling bottle.

3. The preparation of laboratory drugs is inaccurate or outdated.