Operation process of perchloric acid fume hood

The operation process of the perchloric acid fume hood is as follows: a pre-check is required before using the system, which includes the following contents:

1) The water tank should be filled with alkaline water (a solution with a 50% concentration of NaOH), and tested with pH reagent, with the pH value recorded.

2) Check whether all valves in the circulating water system are in the open state. If any valve in the pump’s circulating system is in the closed state, the circulating pump must not be started

3) Whether an experiment involving perchloric acid is to be conducted in the fume hood, the fume hood must have a rated exhaust air volume (with an average surface wind speed between 0.5-0.8 m/s, which needs to be detected using a handheld wind speed meter)

4) Press the water pump start button, and at this point, the circulating water will be evenly distributed behind the deflector in the form of water droplets.

System operation process after the experiment is completed

1) The perchloric acid experiment in the fume hood has been completed

2) Shut down the water pump and conduct a test using pH test strips, recording the pH value as a reference for the preparation of the next experiment. (When the pH value is below 6, the buffer solution needs to be replaced)

3) Close the valve on the water system

4) Turn off the exhaust fan of the fume hood