Australia's Science Forum

A question for all you clever fixers of broken lab equipment......

I have a "Maximum / Minimum" thermometer. On the maximum side, the little blue steel bar has mercury both above and below it. Is there a simple way to fix this or is it a "toss out"?

cheers

Ian

Maybe a magnet?

Hi Ian
Had this happen to me a couple of weeks ago when I sent it down to the canteen to see if it was as hot as they thought. It was (over 50 C) and the mercury went up over the ble rod. I just flicked it down like you do with the old mercury clinical thermometers. My other life as a student nurse made me think of it. Worked perfectly for me hope it does the same for you .
Diana

Yeah, I tried the "Flick". That fixed where the column of mercury had broken into little Mercury Blobs, and I tried with a strong Neo Dynium magnet but to no avail. I even tried placing the whole thing into a beaker of hot water. The mercury just flowed past the rod and the rod stayed at 10 degrees while the mercury went up to 50.

Any more suggestions?

Cheers
Ian

I would place Magnet at top to hold bar above Hg while warming bulb with Hair dryier
See if that works

Finally got it fixed. Used a combination of everything!

I chilled it in the freezer to get the mercury down as far as I could, then used a magnet to coax the rod up while I warmed it in warm water .Eventually, I ended up heating it until the rod and some of the mercury had entered the little bulb at the top, then cooled it so that the mercury went down and the rod stayed in the bulb. Used the magnet to get the rod back into the tube. Eventually I ended up with the rod on the right side of the mercury, but the mercury column was broken, so I flicked it until the mercury came together again. Voila! All fixed!

Now, I wonder what the price of a new one would be compared to the price of my time spent fixing it?

I get paid so little, we probably still came out in front!

Happy Easter everybody!

Cheers
Ian