This model demonstrates the relationship between the different temperature scales. Four thermometers representing Celsius, Kelvin, Fahrenheit and energy scales are on display. The thermometers' temperature may be changed in the input windows. Note that as you alter the temperature on one of the thermometers, the temperatures on the other thermometers change as well (the mercury column rises or drops). You may also change the temperature by moving the thermometer slides with the mouse.
Celsius scale is the most commonly used temperature scale of all. Water freezing and boiling points under standard conditions are adopted as its reference points. Water freezes at 0 degrees Celsius, and it boils at 100 degrees Celsius. The Celsius scale is used in astronomy, e.g., when comparing the temperatures of planets and planetary satellites. Kelvin and Celsius temperature scales relate to each other in accordance with a simple ratio
T = t + 273 Ê.
The scale factor of Kelvin and Celsius units is the same. A change by 1 degree Celsius and a change of 1 Kelvin refer to an equal change in temperature.
Fahrenheit scale is mainly used in the English-speaking countries. Triple saline water point and the temperature of a healthy human body are the Fahrenheit scale's main points of reference. The zero point on the Fahrenheit scale is attainable by mixing equal parts of water, ice, and salt. The temperature of a healthy human body is 98.6 degrees Fahrenheit.
The energy scale is similar to the Kelvin scale, but its core units are known as Joules, or millielectron-volts.