Australia's Science Forum

G'day all,
can any of my colleagues help with ideas for reuniting disjointed columns in spirit thermometers??
~Robyn

//EDITED by adam. Reason: make topic subject more descriptive.

Hi Robyn,

No, I can't solve your current problem, however, I can suggest a way of not letting this happen again.

We had this happening frequently until someone told me to store the thermometers vertically, not horizontally. Since doing this we have not had a single problem. I stand the thermometers up in gas jars. If they seem a bit unstable, pour in about 2cm of sand to weight the base.

All the best,

another Robyn

Hi Robyn
I have restored many thermometers by very gently heating it over a candle :eg a tea light type, watching the rising column very carefully untill the the segments rejoin. The main problem is not to over pressurise the alcohol column - when it rises to the top there usually is enough of an 'empty well' area to pool a small portion of the alcohol enabling the reconnection. If this area at the top is too small or the thermometer is over heated it shatters and gives a bit of a fright. I tend to have a go and if it works OK if not ****
Please note - this cannot be done to min max thermometers personal experience
.regards juliem

Hi Robyn
I have restored many thermometers by very gently heating it over a candle :eg a tea light type, watching the rising column very carefully untill the the segments rejoin. The main problem is not to over pressurise the alcohol column - when it rises to the top there usually is enough of an 'empty well' area to pool a small portion of the alcohol enabling the reconnection. If this area at the top is too small or the thermometer is over heated it shatters and gives a bit of a fright. I tend to have a go and if it works OK if not ****
Please note - this cannot be done to min max thermometers personal experience
.regards juliem

I put the thermometers in oil and gradually heat until the spirit either joins together or goes into the bulb at the top of the thermometer. Then I quickly remove it from the oil and put into ice with salt. The spirit column usually joins up . Sometimes it takes more than one try .Hope you have sucess . You can use ordinary cookikng oil in a beaker.

Hi Robyn
I have an incubator oven that I can set on 120[sup]0[/sup]C. I stand the thermometers in beakers in the oven and leave them until the spirit fills the well at the top, keeping an eye on them all the while so they don't overheat. Then I remove them and let them cool while still vertical.
I have restored many thermometers this way.

Hi Colleagues,

There are a numerous number of ways to re-set the liquid level in thermometers as we can see from all of the posts already.

If I could offer some more ideas it certainly adds to the repertoire of methods, which are certainly worth keeping to one side.

Submersing the thermometer in liquid Nitrogen is a good method as the sub zero temperatures allow the liquid to pool inside the bulb hence being ready for immediate use. The only problem with this method is the availability of Liquid Nitrogen at the times it is really needed.

Another method would include the vigorous shaking of the thermometer to force the liquid back down the capillary into the bulb. This method is somewhat daunting though as it requires some time and some elbow grease.

Hope this is informative and useful.

Robb.......

Hi Robyn,

I used the oil method just last Friday and it worked extremely well.

I will now store them vertically and see if this makes a difference as the other Robyn pointed out.

Regards

Wayne

WELL I am inpressed. I have tried various methods to fix these things with little or no result. Tried dry ice with metho added once.
Just did the oil heating method and recovered 12 out of 14. the other two broke one from the heat and one from the cold. (I thought that protective eye wear may be a good idea?) I don't think it would have worked anyway on these two as the spirit was right up in the very top. But for a 30 miniute job I am very happy. Barb

Yes, eye wear is a must

Hi everyone
Some of you have gone to a lot of bother to solve the thermometer problem. I think my way is the ants pants
Just wave the thermometer backwards and forwards slowly through the flame of a bunsen burner(have safety glasses on of course)until all the alcohol joins up.Watch the movement fairly closely though, as it can rise quickly.Just before the alcohol reaches the top take it away before it actually joins as the retained heat will do it.Takes no time at all!!!

Hi All!!
I saved 17 of 19 thermometers using the hot oil method - brilliant. Thanks for the tip.
Regards
Elizabeth.

Thanks to all for their valuable suggestions as to how to repair broken columns in spirit thermometers.
Other than heating the thermometer in hot oil, we found that bouncing the thermometer onto a folded newspaper to shake the spirit down as far as possible, then heating, worked best in 99% of cases.

I have a few red alcohol thermometers that have got gaps in the red line. I've tried shaking them like my mum used to do with thermometers when we were kids and that didn't work. I've tried heating them but the whole thing moves up so it doesn't get rid of the gaps. Is there a way of getting rid of the gaps? I thought about trying to heat them to above 110c but I'm worried about breaking them.

I'm not sure if the way I do it is right or not but it seems to work.
I carefully kind of wave the bottom of the thermometer back and forward through the heat of a bunsen until the alcohol meets again, then quickly take it out of the heat. You just have to keep an eye on it as it heats up.
I've done lots and haven't had any breakages.

I heat carefully in a bunsen too. Usually works.

Shaking them down like medical thermometers does not work as you say. It can be the cause of the break in column. To fix them, and I usually wait till I have about 5 or 6, I sort of lie them on the hotplate and turn it on full. I support the tops of them with a towel on top of a box, so the tops are above the bottoms. The towel stops them slipping across the surface of the hotplate. As the column rises with the heat, the usually smaller bit of alcohol gets into the bubble of air at the top of the thermometer and keeps sort of displacing the bit of air at the top. Keep on heating till the column gets right to the top and the last bit of air is displaced. As soon as the column is rejoined completely remove from the hotplate and let cool on the bench.
Over many years I have occassionally burst a few, only because I have gone off to do other things. It really should be done without distraction. It is a bit like putting milk on to boil on a stove, it will boil over as soon as you walk away.
By all means wear safety glasses; although I don't as I wear glasses anyway.

Thanks everyone. I'll give it a go when i have some quiet time!

I have now merged these posts, do hope it helps a little.

Hot oil method works well just need to be vigilant!