1. Pre freezing requirements
The sample must be completely frozen into ice (it is recommended to pre freeze with liquid nitrogen or a refrigerator below -40 ℃), as residual liquid can cause gasification spray or contamination of the cold trap.
2. Cold trap temperature control
Before starting, it is necessary to ensure that the temperature of the cold trap drops below -30 ℃ (biological samples are recommended to be below -40 ℃), and regularly clean the condensed water.
3. Vacuum operation specifications
Check the sealing before vacuuming (the contact surface between the organic glass cover and the rubber ring needs to be cleaned).
The vacuum degree should be maintained at 0.1-0.3mbar. When closing, isolate the cold trap before stopping the pump to avoid oil return.
4. Anti sample splash design
When using splash proof balls, it is recommended to seal the filter paper roll and insert it into the inner tube to avoid stuffing cotton (which may affect the sublimation speed or contaminate the sample).
5. Equipment maintenance
Replace the vacuum pump oil every 200 hours and regularly check the sealing of the refrigeration system.
Long term shutdown requires emptying the cold trap to prevent freezing and damage to components.
6. Security protection
Wear insulated gloves when operating low-temperature components to avoid frostbite; The ambient temperature should be below 28 ℃ and the continuous operation should not exceed 48 hours.