Question

What type of expansion of mercury is used to calibrate thermometer?

Answer 1

A special kind of mercury-in-glass thermometer, called a maximum thermometer, works by having a constriction in the neck close to the bulb. As the temperature rises, the mercury is pushed up through the constriction by the force of expansion. When the temperature falls, the column of mercury breaks at the constriction.

Answer 2

linear expansion of mercury is used to calibrate thermometer