Some wonderful demonstrations using an inexpensive pressure pump

Available for about €20 from

I’m thinking of getting about 8 to act as a class set, and a few more for presents to nephews and nieces.

The ‘Presssure and Sound’ demo can be done with mobile phones as I suggest – the sound level does drop noticealbly in the classroom, but not enough to be picked up by the camcorder.

I presume it would also go down well on Open Day.

Limitless potential.
Eoghan in Second Year suggested using coke to see if it goes flat – I won’t tell you the answer but it’s worth checking out. In hindsight we should have tried to guess what we would have observed.

Then we wondered if the pH would change.

Then we wondered if the level of Carbon Dioxide in the chamber would increase noticealby, even as we pumped out the air. I need to see if we can use a datalogger to see how the  concentration of the gas changes in real time on a laptop.

Then I mentioned that we need to buy lots of marshmallows to see which work the best.

Then Robyn said that she cooks marshmallows at home, so now she has promised to bring in the ingredients and we will try to cook them in school and see if we can make giant ones!

All for €20 plus the price of few marshmallows, balloons and shaving foam.



  1. Hi Noel,
    I’ve wanted to get my hands on one of those containers + pump for a couple of years. However whenever I tried to order one online (nobody seems to supply them in Ireland) I always got a reply saying something like ‘certain materials can’t be delivered overseas…’ – never knew exactly what that meant. I managed to get the pump+valve, but not the container.
    Thanks for the tip the demos look great..

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