(1)Turn on the cooling water switch (there are two, one for cooling and one for circulation).

(2)Check the vacuum pump and open the water tap to allow a moderate flow of water.

(3)Attach the round-bottom flask, holding it with your hand and not letting go.

(4)Turn on the vacuum pump switch.

(5)Close the vent hole. (At this point, you can slowly release your grip on the round-bottom flask.)

(6)Turn on the rotary switch and adjust the rotation speed, ensuring it does not exceed "3" on the scale.

(7)(Pressure) Hold the handle and slowly lower the round-bottom flask until it is about half immersed in water.

(8)Adjust the solvent temperature to the appropriate level; no heating is required for ether and dichloromethane, while other solvents should be heated to about 20°C below their boiling points.

(9)After concentration is complete, reverse the steps and turn off the apparatus.