sbreheny - 9-2-2014 at 20:02
Hi all,
Is anyone familiar with Thermo Scientific dry LN2 shippers, specifically the CMD Series, model 8039? These are dewars which have an absorbent material
in them so the LN2 cannot spill or slosh around - but it still releases N2 gas slowly at near 77K so it keeps whatever you put inside - usually
biological samples - at close to LN2 temperature.
I recently bought one on eBay and it was supposedly in near-new condition. It does appear to be in very fine condition BUT when you gently tilt it
from side to side, with the canister and top removed, you can hear something rolling around inside, almost like a ball bearing. Is this normal? I
asked the seller and he said that he is not sure if it did that before shipment and he doesn't have any others to test. I think he is willing to take
it back but since it was a good deal price-wise, I don't want to return it if it is actually in good condition.
Thanks,
Sean
Aconite - 22-2-2014 at 12:38
I've not worked with CMD dewars before, but my experience with other dry shippers is that they shouldn't have any 'floating' parts. If you have a
temptale, It might be a good idea to charge the dewar and monitor the temp over several days (depending on the model rating for hold time) to ensure
it is entirely functional. Alternatively, just weigh it immediately post charge and each day after to determine if it's functioning properly. The
loose part may be of no consequence. However, if it's easy to exchange out, I'd get a new one.