Samples collapsing and becoming soft?
Common causes: Insufficient pre-freezing, rapid temperature rise, thick samples
Solution approach: Extend pre-freezing time, thin the samples, optimize the temperature rise curve
Slow cooling or failure to cool down?
Common causes: Dust accumulation in the condenser, excessive environmental heat, abnormal refrigerant
Solution approach: Clean the heat dissipation, improve ventilation, contact for maintenance
Excessive frost on the cold trap?
Common causes: High sample moisture content, frequent opening of the door, incomplete defrosting
Solution approach: Control the loading volume, reduce door opening, perform regular defrosting