Problem(s) Encountered:

Both at the beginning and end of the night, after I filled the

dewar, I was initially unable to disconnect the fill tube from the OSMOS

dewar. In both cases, I finger tightened the nut but didn''t make

it terribly tight, and at the end of the night, before I opened

the valve on the storage dewar, I made sure I could loosen it again.

But both times after the fill I had to use pliers to loosen

the nut, even though I can usually disconnect the fill tube

easily with just my hands. It also seems like the metal part of

the fill tube is off centered from the metal connector to the

rubber tube (if that makes any sense), which might be affecting

how things screw together, but I couldn''t re-center it.

Solutions:

This is a symptom of high humidity. More moisture in the air causes ice on the connection. If you fill early enough simply let it thaw for a while longer than usual.