physics notes

1. Thermometers must be calibrated before they can be used to measure temperatures.

2. The calibration of an instrument refers to the process of marking-up a scale on the instrument to be used as measurement.

3. To produce a scale on a thermometer, two fixed points must be determined first. Then the two points must be the temperatures which can easily and correctly reproduced in any part of the world.

4.On the Celsius scale, the two fixed points are the ice point (0°C) and the steam/boiling point (100°C).

5. The ice point (0°C), or lower fixed point is the melting temperature of pure ice at standard atmospheric pressure (760 mm Hg).

6. The steam point (100°C), or upper fixed point is the temperature of steam at standard atmospheric pressure (760 mm Hg).