Celsius << SEHL see uhs, >> scale, is a scale for measuring temperature. It is a part of the metric system of measurement. People in all major countries of the world except the United States use the Celsius scale for everyday temperature measurement. Scientists throughout the world also use this temperature scale.
In the United States, the Fahrenheit scale is generally used for everyday purposes. But the Celsius scale is gradually coming into greater use. Bank thermometers and radio and television weather reports often give temperatures in both Fahrenheit and Celsius degrees.
On the Celsius scale, 0° is the freezing point of water, and 100° is the boiling point. The scale is divided into 100 equal parts between these fixed points. The Celsius scale is sometimes called the centigrade scale, because this word means “divided into 100 parts.” Other important temperatures on the Celsius scale include 37° (body temperature) and 20° (room temperature). Temperatures below the freezing point of water have a negative sign in front of them.
Sometimes it is necessary to compare a Celsius temperature to a Fahrenheit temperature. To change a Celsius temperature to a Fahrenheit temperature, multiply the Celsius temperature by 9/5 and then add 32: °F = 9/5 (°C) + 32. To change a Fahrenheit temperature to a Celsius temperature, subtract 32 from the Fahrenheit temperature and then multiply by 5/9: °C = 5/9 (°F – 32).
Another way to compare Celsius and Fahrenheit temperatures is to sketch two liquid-in-glass thermometers in vertical side-by-side positions. Label the scale on one C and the scale on the other F. Draw a single horizontal line across the lower parts of the sketches and mark 0 on the Celsius scale and 32 on the Fahrenheit scale. Because 5 Celsius degrees are equal to 9 Fahrenheit degrees, you may mark 41 °F (32 + 9) equal to 5 °C (0 + 5), 50 °F (32 + 18) equal to 10 °C (0 + 10), and so on. Interestingly, as you mark the scale below 0 °C and 32 °F, you will see that –40 °F is equal to –40 °C.
The Celsius scale was originally developed in 1742 by the Swedish astronomer Anders Celsius. It was later changed and improved. The ninth General Conference of Weights and Measures officially named the scale the Celsius scale in 1948.
