i have a glass alcohol(i think) thermometer that ranges from -10 to 150*c.

the red fluid is solid from the bulb at the bottom to about 22*. then there is an empty gap (no red stuff) about 3" from 22* to about 105* where there is another spot of red stuff about 2.5* long.

is my thermometer screwed up?
should i be adding the 2.5* to the first line of red fluid - 22* is really about 24.5*?
is there a way to fix it by pegging the gauge - ends about 1/2" above the 150* mark? - thinking that the fluid would retract as one solid batch???


  1. Yes, it’s screwed up.

  2. (Adding 2.5 degrees) You could do it that way.

  3. Don’t peg the thermometer; it’s very dangerous if you don’t know how. Instead, put it in the freezer. If your freezer runs down to -20C, as it should, all of the liquid will join in the bulb.

thanks for the reply.
put it in the thermometer in the freezer and got it down to about 17 below, but there is about 4" of space between the buld and the bottom of the scale - i did not belioeve it would work because of all the space between the bottom of the scale and the bulb.

seems like it would be easy to drive all the fluid to the top using a heat gun. i’ll just get a feel for bringing it up about 1*/about 30 seconds when i get near the top - sound about right?

I have fixed several thermometers by pegging them. It is nit difficult, but I like to live on the wild side. I recommend using a blast sheild, and do not do it without goggles.

very good idea!
i’m gonna get some gloves and face shield and go to it!

A small piece of dry ice would provide a safer solution to your problem.

The labels on our lab thermometers from Fisher Scientific recommend the freezing approach.

I don’t see how heat would solve the problem. The gap is a bubble of air. Heating would only drive the bubble up. You need cool it enough to get all of the fluid into the bulb so that the bubble can pop.