Daily usage standards

Environmental requirements: Place in a well ventilated, dry environment with a temperature of 10-25 ℃, away from heat sources, open flames, and electrical equipment. The ground should be flat and slip resistant.

Operation protection: Operators must wear low-temperature resistant gloves, fully enclosed goggles, long sleeved lab clothes, and anti smashing shoes to avoid direct skin exposure.

Sample access: Single opening time ≤ 30 seconds to reduce liquid nitrogen evaporation; Use a basket to slowly lift and lower the sample, avoiding violent shaking that may cause the sample tube to rupture.

Prohibited behaviors: It is strictly prohibited to seal the can mouth, place flammable materials, use hard objects to remove neck tube frost, or add liquid directly without pre cooling.

Fluid replacement operation specifications

Pre cooling and flow rate control: Before adding liquid, use a small amount of liquid nitrogen to pre cool the tank body and guide pipe, slowly inject along the tank wall, with a flow rate of ≤ 3L/minute to prevent splashing.

Capacity limitation: The filling amount should be controlled at 80% -90% of the total capacity, and gas phase space should be reserved to prevent expansion and overflow; In summer, the filling amount can be appropriately reduced.

Safety monitoring: Weigh and record immediately after adding the liquid, lightly touch the edge of the can mouth to check the sealing, and replace the sealing ring if there is any cold air leakage.

Maintain standards

Regular inspection: Monitor the liquid level with a liquid level gauge or weighing method every week, and replenish the liquid in a timely manner when the liquid level is below 30%; Check the vacuum degree and neck plug elasticity every month.

Cleaning and corrosion prevention: Clean the exterior of the tank with neutral detergent every 3-6 months, and prohibit the use of organic solvents; Rinse the inner container with 37 ℃ warm water and let it dry naturally.

Component maintenance: Regularly test the sensitivity of the safety valve, unclog the interface of the liquid level gauge and apply low-temperature lubricating grease, and check the flexibility of the valve opening and closing.

Emergency response standards

Leakage handling: evacuate personnel and turn on ventilation equipment when there is a small amount of leakage, and let it evaporate naturally; A large amount of leakage requires wearing a self-contained breathing apparatus and using sand to block the liquid to prevent it from flowing into the sewer.

First aid for frostbite: Immediately soak the frostbitten area in 37-40 ℃ warm water after skin contact with liquid nitrogen, remove damp clothing, cover with sterile gauze, and seek medical attention.

Equipment malfunction: If the valve freezes, thaw it with clean warm water or hot nitrogen gas, and do not strike it; When the inner liner leaks, transfer the sample to a spare tank and contact professional personnel for repair.