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Liquid Nitrogen Tank Operation and Maintenance

Locator Jr. Plus Specifications:

  • Liquid N2 capacity: 71 L
  • Liquid N2 evaporation rate: 0.85 L/day


  1. The tank uses a vacuum to ensure temperature control and care must be taken to prevent premature vacuum loss.

  2. Do not tamper with or remove the vacuum port (covered by a black plastic cap on the side of the vessel).

  3. When inserting or removing racks, be careful not to come into contact with the neck tube area of the vessel. Remove them slowly in a vertical manner. Scratches on the neck tube area can cause premature vacuum failure.

  4. Do not use the tank for transport. Use an intermediate liquid N2 vessel to transport liquid N2 from the dock to the tank. Cracks in the floor and bumping into objects can disrupt the vacuum.

Adding liquid N2 to a warm vessel:

  1. Add only a small amount of liquid N2 (5-10 liters) to the new or warm vessel. Liquid N2 is available on the first floor on the dock.

  2. Allow this small amount of liquid N2 to sit in the covered vessel for at least 2 hr. to allow the vessel to equilibrate to the temperature change.

  3. Add an additional 15 liters of liquid N2 to the vessel and allow the vessel to sit for 48 hr. Monitor the liquid N2 consumption with a wooden yardstick (never a hollow tube or plastic dipstick).

  4. Fill the vessel with liquid N2 no higher than the top of the racks (approximately 12 inches with racks inserted).

  5. Insert and remove racks slowly. Allow the liquid N2 to run out of boxes and off racks before completely removing from the Locator.


  1. Monitor the level of liquid N2 in the tank every 1-2 days to anticipate subtle changes in consumption and prevent problems before they arise. Keep a record of the liquid N2 levels using the Liquid N2 Tank Level Log.

  2. No vacuum will last forever, so have the vessel tested by the manufacturer (Thermo Fisher) or a qualified cry-vessel service technician every 7-10 years.