Question

Why does the mercury doesn't fall in clinical thermometer .com?

Answer 1

If we observe the structure of clinical thermometer, we can see that there is a kink/bend in it near the bulb. This kink prevents the mercury level from falling and keeps it stable. That is why we can see the reading by taking the thermometer outside of our mouth whereas in laboratory thermometer, it doesn't have kink. So if you take it from water, the mercury level will fall down and doesnt give correct measure.

But you should not use clinical thermometer for measuring objects other than our body's temperature