Vacuum pump for demo

[murphey]

I'm teaching an intro to aviation course - again - to middle school kids this summer (we start in a week). This time I really want to demonstrate atmosphere ideas such as boiling water at room temp. I have the bell jar & stand but need a vacuum pump. Anyone know if the $16 from Harbor Freight will work, or do I need a better one? Any suggestions where else I could find one?

tanks

 

[Capt. Geoffrey Thorpe]

I would assume it will work if you have a good compressed air source - these things are pretty simple. I would expect it to be noisy, and I have no idea how fast it will pull a vacuum.

In the instructions it says it takes two minutes "before reaching full power" which would suggest a pretty low flow rate on the vacuum side. You might need to suck down an air tank ahead of time to get things to happen in a timely manner (and that will take a long time)