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Balloon in a bag - measuring pressure
(12-25-2021, 06:49 PM)solid Wrote: An experiment with better control:

I tried experiment of Eric and I got 2 peaks and then more...

Put a smartphone inside a balloon, blow up it and pop with a needle.. Pressure just dropped to the initial value.. As expected.

Hmm... my phone is too big. But I guess you used the same equipment as in the CpCv-article? (jar and bottle connected)

If you did, may I ask if you used a standard off the shelf supermarket balloon (see attachment)? I mean, my peak is just ~2 hPa higher than the room pressure, but your balloon seems to hold a pressure 7.5 hPa higher than the pressure in the room?

The second peak is probably me holding the bag in a tight grip. I can easily get 20 hPa peaks just from squeezing an empty bag with a phone inside (see attachment), so the second "pop peak" is probably me reacting to the "pop".

I will try again with less excess air in the bag, maybe I'll then get closer to the true value of the pressure inside the balloon when I pop it (which is 7.5 hPa?).

Best regards.


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RE: Balloon in a bag - measuring pressure - by Erik Josefsson - 12-26-2021, 04:18 AM

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