- a) Pressurize the Dewar by warm helium gas upto 8psi and sit for 2-3hrs and relief through SVN(A/B) or SVV(A/B) to HR3
- b) Repeat step (a) several times
- c) Check the Dewar is holding pressure. If it's increasing there is still liquid: proceed steps (a) and (b)
- d) Close the needle valves at the neck of the Dewar (connecting to the level sensors)
- e) Set the Dewar Alarm pressure to -30 psi on the Dewar settings page (this is to avoid the LQ(A/B) going to the alarm mode).
- f) Pump and purge the Dewar several times
- g) Then pressurize the Dewar upto 8psi
- h) Open the needle valves
- i) Consider one by one of each tube (at a time) connecting to the level meter (2 copper and 2 plastic) and disconnect each to relieve the gas for a few seconds while the Dewar pressure is at 8psi (if that's too much we can probably try at a lower Dewar pressure)
- j) Connect all the tubes and leave the needle valves open
- k) Start cooldown
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