7 temperature scale that you must know

Celsius (symbol °C), also known as centigrade, is a scale and unit of measurement for temperature. It is named after the Swedish astronomer Anders Celsius (1701–1744), who developed a similar temperature scale. The degree Celsius (°C) can refer to a specific temperature on the Celsius scale as well as a unit to indicate a temperature interval, a difference between two temperatures or an uncertainty. The unit was known until 1948 as "centigrade" from the Latin centum translated as 100 and gradus translated as "steps".

From 1743 until 1954, 0 °C was defined as the freezing point of water and 100 °C was defined as the boiling point of water, both at a pressure of one standard atmosphere with mercury being the working material. Although these defining correlations are commonly taught in schools today, by international agreement the unit "degree Celsius" and the Celsius scale are currently defined by two different temperatures: absolute zero, and the triple point of VSMOW (specially purified water). This definition also precisely relates the Celsius scale to the Kelvin scale, which defines the SI base unit of thermodynamic temperature with symbol K. Absolute zero, the lowest temperature possible at which matter reaches minimum entropy, is defined as being precisely 0 K and -273.15 °C. The temperature of the triple point of water is defined as precisely 273.16 K and 0.01 °C.

Fahrenheit (symbol °F) is a temperature scale based on one proposed in 1724 by, and named after, the physicist Daniel Gabriel Fahrenheit (1686–1736).[1] Within this scale, the freezing of water into ice is defined at 32 degrees, while the boiling point of water is defined to be 212 degrees - on Fahrenheit's original scale the freezing point of brine was zero degrees.

The Fahrenheit scale was replaced by the Celsius scale in most countries during the mid to late 20th century, though Canada retains it as a supplementary scale that can be used alongside Celsius. Fahrenheit remains the official scale of the United States, Cayman Islands, Palau and Belize. The Rankine temperature scale was based upon the Fahrenheit temperature scale, with its zero representing absolute zero instead.

On the Fahrenheit scale, the freezing point of water is 32 degrees Fahrenheit (°F) and the boiling point 212 °F (at standard atmospheric pressure). Absolute zero is defined as -273.15 °C or -459.67 °F. The Rankine temperature scale was created to use degree intervals the same size as those of the Fahrenheit scale, such that a temperature difference of one degree Rankine (1 R) is equal to a difference of 1 °F, except that absolute zero is 0 R – the same way that the Kelvin temperature scale matches the Celsius scale, except that absolute zero is 0 K.

The Kelvin is a unit of measurement for temperature. It is one of the seven base units in the International System of Units (SI) and is assigned the unit symbol K.

The Kelvin scale is an absolute, thermodynamic temperature scale using as its null point absolute zero, the temperature at which all thermal motion ceases in the classical description of thermodynamics. The kelvin is defined as the fraction 1/273.16 of the thermodynamic temperature of the triple point of water (exactly 0.01 °C or 32.018 °F). 

Rankine is a thermodynamic (absolute) temperature scale named after the Glasgow University engineer and physicist William John Macquorn Rankine, who proposed it in 1859. (The Kelvin scale was first proposed in 1848).

The symbol for degrees Rankine is °R (or °Ra if necessary to distinguish it from the Rømer and Réaumur scales). Zero on both the Kelvin and Rankine scales is absolute zero, but the Rankine degree is defined as equal to one degree Fahrenheit, rather than the one degree Celsius used by the Kelvin scale. A temperature of -459.67 °F is exactly equal to 0 °R.

The Newton scale is a temperature scale devised by Isaac Newton around 1700. Applying his mind to the problem of heat, he elaborated a first qualitative temperature scale, comprising about twenty reference points ranging from "cold air in winter" to "glowing coals in the kitchen fire". This approach was rather crude and problematic, so Newton quickly became dissatisfied with it. He knew that most substances expand when heated, so he took a container of linseed oil and measured its change of volume against his reference points. He found that the volume of linseed oil grew by 7.25% when heated from the temperature of melting snow to that of boiling water.

After a while, he defined the "zeroth degree of heat" as melting snow and "33 degrees of heat" as boiling water. His scale is thus a precursor of the Celsius scale, being defined by the same temperature references. Indeed it is likely that Celsius knew about the Newton scale when he invented his. Newton called his instrument a "thermometer".

The Réaumur scale (°Ré, °Re, °R), also known as the "octogesimal division", is a temperature scale in which the freezing and boiling points of water are set to 0 and 80 degrees respectively. The scale is named after René Antoine Ferchault de Réaumur, who first proposed something similar in 1730. Réaumur’s thermometer contained diluted alcohol and was constructed on the principle of taking the freezing point of water as 0°, and graduating the tube into degrees each of which was one-thousandth of the volume contained by the bulb and tube up to the zero mark. 

He suggested that the quality of alcohol employed be such that it began boiling at 80 °Ré — that is, when it had expanded in volume by 8%. He chose alcohol instead of mercury on the grounds that it expanded more visibly, but this posed problems: his original thermometers were very bulky, and the low boiling point of alcohol made them unsuitable for many applications. Instrument-makers generally chose different liquids, and then used 80 °Ré to signify the boiling point of water, causing much confusion.

Rømer is a temperature scale named after the Danish astronomer Ole Christensen Rømer, who proposed it in 1701.

In this scale, the zero was initially set using freezing brine. The boiling point of water was defined as 60 degrees. Rømer then saw that the freezing point of pure water was roughly one eighth of the way (about 7.5 degrees) between these two points, so he redefined the lower fixed point to be the freezing point of water at precisely 7.5 degrees. This did not greatly change the scale but made it easier to calibrate by defining it by reference to pure water. Thus the unit of this scale, a Rømer degree, is 100/52.5 = 40/21 of a kelvin (or of a Celsius degree). The symbol is sometimes given as °R, but since that is also sometimes used for the Rankine scale, the other symbol °Rø is to be preferred. The name should not be confused with Réaumur.

There are a few different between the all the scale temperature, here the comparative scale

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http://en.wikipedia.org/wiki/Celcius
http://en.wikipedia.org/wiki/Fahrenheit
http://en.wikipedia.org/wiki/Kelvin
http://en.wikipedia.org/wiki/Rankine_scale
http://en.wikipedia.org/wiki/Newton_scale
http://en.wikipedia.org/wiki/Réaumur_scale
http://en.wikipedia.org/wiki/Rømer_scale
http://en.wikipedia.org/wiki/Temperature_conversion_formulas