Temperature Units

Temperature is a measure of average heat of the thing. Average heat is the degree of hotness or coldness of that object.

For example the temperature of human body, temperature of boiled water, etc.

The common notions of temperature is hot and cold. If we hold ice, we sense cold; it means the ice has lower temperature with our body.

From physic concept, temperature is the measure of the average kinetic energy of the molecules. Each time molecule moves there will a kinetic energy. Hot means molecules move faster so the kinetic energy is increasing. Cold means molecules move slower so the kinetic energy is decreasing.

Temperature unit is a unit of measurement of temperature. The basic unit of SI (International Standard) is Kelvin (K). Kelvin unit is referenced the absence of thermal energy or absolute zero. Absolute zero is defined as Zero degree Kelvin (0K). 0K means it has no thermal energy at all.

There are many other temperature units like Fahrenheit, Celsius, and Reamur. Fahrenheit commonly used for temperature measurement in US. Celsius is used almost in every countries except US.

Celsius temperature scale is used for practically all purposes almost in every countries throughout the world. This scale was devised by the Swedish astronomer Anders Celsius

Celsius related to the temperature of water. Zero Degree Celsius (0 °C) corresponds to the temperature of water freezes. 100 °C corresponds to boiling point of water at sea level under normal atmospheric pressure.

Based on International Standard, Celsius is defined by these two points:

• The triple point of water is defined as 0.01 oC.
• One degree Celsius equals the change of temperature with one degree on the ideal gas-scale.

0 K (Absolute zero) is defined as being precisely as -273.15 °C. The temperature value of the triple point of water is defined as being precisely 0.01 °C. It means:
-273.15 °C = 0 K
0 °C = 273.15 K

Although Celsius has been replaced this scale in most countries. Some countries still use this scale. Fahrenheit is widely used in US and Belize. This scale is devised by Daniel Fahrenheit.

The zero point is determined by placing the thermometer in brine (a mixture of ice, water, and ammonium chloride, a salt). At standard atmospheric pressure, the freezing point of water is 32 °F and the boiling point 212 °F.

The absolute zero (0 K) is -459.67 °F

Celcius:

[°C] = ([°F] - 32) × 5/9
[°C] = [K] - 273.15

Fahreinheit:

[°F] = [°C] × 9/5 + 32
[°F] = [K] × 9/5 - 459.67

Kelvin:

[K] = [°C] + 273.15
[K] = ([°F] + 459.67) × 5/9