Thermometer

[Girishkumar]

Why there is a small kink in the glass tube of Clinical Thermometer?

[Gef]

So that the mercury does not flow back into the bulb while you are taking the reading. A clinical thermometer is shaken before use to get the mercury back into the bulb. Other themometers are read in situ, ie with the bulb immersed say in water. This is not possible when a clinical thermometer is under your arm, in your mouth etc.