Fahrenheit and Celsius Scales
Temperature
 Laurel Cook |
Air temperature is measured by a mercury thermometer, which uses the principle of contraction and expansion. When the temperature rises, the mercury expands and rises in the thermometer tube. Cold weather makes the mercury contract and fall.
The Fahrenheit scale is used in the U.S. On this scale, 32° is the freezing point of water, 212° the boiling point.
The center of the sun is thought to be 40 million degrees Celsius.
The Celsius, or centigrade, scale is used by the World Meteorological Organization and most countries in the world. On this scale, 0° is freezing, 100° is boiling.
Fahrenheit and Celsius (Centigrade) Scales
| °Celsius | °Fahrenheit | °Celsius | °Fahrenheit |
|---|---|---|---|
| –250 | –418 | 30 | 86 |
| –200 | –328 | 35 | 95 |
| –150 | –238 | 40 | 104 |
| –100 | –148 | 45 | 113 |
| –50 | –58 | 50 | 122 |
| –40 | –40 | 55 | 131 |
| –30 | –22 | 60 | 140 |
| –20 | –4 | 65 | 149 |
| –10 | 14 | 70 | 158 |
| 0 | 32 | 75 | 167 |
| 5 | 41 | 80 | 176 |
| 10 | 50 | 85 | 185 |
| 15 | 59 | 90 | 194 |
| 20 | 68 | 95 | 203 |
| 25 | 77 | 100 | 212 |
Zero on the Fahrenheit scale represents the temperature produced by the mixing of equal weights of snow and common salt.
| °Fahrenheit | °Celsius | |
|---|---|---|
| Boiling point of water | 212° | 100° |
| Freezing point of water | 32° | 0° |
| Absolute zero | –459.6° | –273.1° |
Absolute zero is believed to be the lowest possible temperature, the point at which all molecular motion would cease.
To convert Fahrenheit to Celsius (Centigrade), subtract 32 and multiply by 5/9.
To convert Celsius (Centigrade) to Fahrenheit, multiply by 9/5 and add 32.
