The solution of the laborator freeze dryer can not be lowered

1. Check the connection between the vacuum pump and the main unit, and the clamp is properly clamped;

2. Check if the lower plane of the plexiglass cover is clean and there is no damage;

3. Check if the O-ring is clean and placed correctly.

4. Check if the vacuum pump works normally and observe whether the pump oil is clean;

5. Check if the vacuum valve is tightened;