Australia's Science Forum

Helppppp!!!!!
I have 2 Hoffman Voltameters and both have snapped glass pieces from the top where the taps are.Seems that the students use too much pressure when turning the taps that sometimes are stiff.I have used vaseline on the taps to help with the smoothness of the turning,but this can block the little holes.On both, the breaks have occurred at exactly the same point of the middle glass tube.Maybe it is a fault with the manufacturing as the glass is delicate anyway.Can someone recommend a different brand or type that is sturdier pleaseeeee!!!
Cheers
Mother

Expensive little exercise. If you have any others smeer Silicon grease round either end of taper.
If buying new voltameters, you will find they have teflon taps this solve problem
cheers!

Hello Lee,

Yes, they are very fragile. Expensive little numbers also. Silicon is the go for sure.

Cheers Kath

Dear Mother - Just logged-in after a few hectic days - so just catching up with the latest!!! We had some older type Voltameters and unfortunately the electrodes broke so we purchased a new Voltameter from Q Stores. The electrodes were made in such a way that they filled almost the entire glass cylinder and we have to catch the gas in the top third of the cylinder - not like our old ones were the electrodes were located very low down and we were able to get a good collection of gas. They are made in such a way that it is impossible to adjust them without breaking them, so be aware when making your purchase. Oh yes - go with the silicon. Hope this helps. Cheers. Judy.