LN2 Loss Calculator

[cold.nut]

hey guys

i am trying to calculate my LN2 loss. i am working on gathering data as to how much LN2 i am losing per week/day. my initial dewar weight was 28lbs.. full dewar weighed 78lbs.. i used 10lbs. of LN2 at a school chemistry laboratory, however i am going to start calculating data from today until mid next week. i am going to gather the weight of the dewar each day.

what i need some help with is the calculations though.. the mass of LN2 is 0.807g/mL. i tried to figure some basic calculations tonight, but i couldn't figure it out . weird for a chemistry student..

help is appreciated!

cold.nut

 

[Bobnova]

It totally depends on your dewar and it's vacuum's condition.
There is no way to calculate it.

 

[MattNo5ss]

Just gather the weight each day, like you said, then calculate how many lbs a liter of LN2 weighs. That will give you how many L you lose per day.

EDIT: You would have to do this a a "per dewar" basis, as Bobnova said, it all depends on the dewar.

 

[cold.nut]

Just gather the weight each day, like you said, then calculate how many lbs a liter of LN2 weighs. That will give you how many L you lose per day.

EDIT: You would have to do this a a "per dewar" basis, as Bobnova said, it all depends on the dewar.

perfect, i way over thought that !

78lbs full dewar - 28lbs empty dewar = 50lbs net weight of LN2

50lbs LN2/ 30L = 1.67lbs LN2/ L

therefor i currently have 68lbs total dewar - 28lbs empty dewar= 40lbs net LN2

40lbs LN2/ 1.67lbs LN2/ L = ~24L LN2

thank you Matt & Bob!

 

[xsuperbgx]

I would think that keeping your reward at a constant temperature would effect your results also.