Question

How do upper fixed point calibrate in a thermometer? Explain it.​

Answer 1

Answer

To mark the upper fixed point, the thermometer is placed in a hypsometer containing water as shown in the figure. The bulb of the thermometer should be outside the water. When the mercury level becomes stationary at a temperature of steam, the level is marked, which represents the upper fixed point of the thermometer.

Answer 2

The upper fixed point is that at which the fluid used in the thermometer has maximum volume.

Explanation:

• A thermometer is made up of a glass capillary tube.
• The thermometer is pushed into a wall of a vessel known as hygrometer.
• Boiling water is put into the tube and it is made sure that the bull does not dip into the water.
• The mercury is placed into the thermometer and is allowed to cool.
• After cooling the thermometer is graduated into upper and lower pints by marking fixed upper and fixed lower points.
• The upper fixed point is that at which the fluid used in the thermometer has maximum volume.