min max thermometer

[fred]

Mercury has split and vigourous shaking is not effective. Any other solutions ?

[Andy Burns]

Are the floating min/max pins magnetic?

try a few hot/cold cycles

[tabbypurr]

+1 fwiw

NT

[Andrew Gabriel]

Sounds like an Astrology problem... ;-)

Can you get it cold enough to pull all the mercury into the bulb, like maybe in your freezer?

[Andy Burns]

Might help to cool the bulb only, rather that the whole thermometer?

[alan_m]

Freezer spray?

Probably much cheaper elsewhere. Also used for freezing water in plumbing pipes etc.

[Robin]

I found string tied to the end plus lots of room to swing it a quick method that had some effect.

[invalid]

When mine did that I heated it up until most the mercury went into the expansion bulb. Then it cooled with the mercury unbroken.

You have to be sure that none of the liquid passes the mercury.

[The Natural Philosopher]

I missed the OP but if its a thermomter with the little thingies that stay there to indicate max or min, maybe a really powerful magnet can reset them and pull the mercury back

[Tim+]

What liquid?

Tim

[Andrew Gabriel]

Air duster cans used upside down also work (I buy in bulk from Costco), and also butane lighter refill cans (used outside, away from ignition sources). Never measured what temp they go down to though.

[Robin]

The liquid (eg alcohol) in the bulb that pushes the mercury round the glass into the vacuum as the temperature rises. The mercury is just an indicator.

[Tim+]

Cheers. Not owned a min/max thermometer before.

Tim

[Brian Gaff]

It has a small leak somewhere. Brian

[Robin]

It's hard to see how they work if the ends are shrouded leaving what looks like 2 thermometers side by side. I remember a school A-level problem to explain by inspection how such a thing worked. IIRC I got there in the end; but that I thought the universe would be a better place if there were a liquid that looked like mercury but contracted as it got hotter.

[The Natural Philosopher]

No, it isn't

[Robin]

Are you suggesting that it's not a "Six's thermometer"?

Or are you taking the point that the length of the mercury will also change with temperature? (IIRC by about 1 mm for a temperature change of 50 degrees C in a typical small model.)

[fred]

Ill try the string !

[fred]

Over night in the freezer and all morning om a hot radiator/ Mercury stil has bubbles in it and I'm only seeing one tell tale

Cheap Chinese (£5) so what could I expect ? Thought it worth a punt

[Andrew]

hang on tight or do it outdoors, or you'll be collecting mercury blobs from all over.