Temperature Measurement and Thermometer Scales Part 2

Other temperatures have been developed that point out the temperature by measurement of the extremely little electric current generated in a thermocouple. These thermometers are frequently used in the measurement of far above the ground temperature above the range of a glass steam thermometer. These instruments are called pyrometers. 

The Fahrenheit scale is so fixed that it divides the temperatures dissimilarity between the freezing temperature of water and the boiling temperature of water into 180 equal divisions and sets the freezing temperature of water at 32 divisions higher than the 0 on the scale. Therefore, water freezes (ice melts) at 32 F. and water boils at 212 F. (180 F. + 32 F.) assuming normal atmospheric pressures. 

The centigrade level has coarser divisions than the Fahrenheit level and the zero (0) of this level is set at the melting temperature of ice. The boiling point of ware is fixed 100 divisions higher than that point at 100 C. assuming normal atmospheric pressure. In the German language, the word for centigrade is Celsius. Some English talking countries as well as use the word Celsius. 

You may wonder why the melting temperature of ice and the boiling temperature of water were taken as values these conditions were selected because water has very constant freezing and boiling point temperature, and water is a general substance.