What's “temperature”?

Temperature is a physical quantity that indicates how hot or cold an object is, microscopically speaking it is the intensity of the heat movement of the molecules of an object. Temperature can only be measured indirectly by certain properties of an object that vary with temperature, and the scale used to measure the numerical value of an object's temperature is called a temperature scale.

It specifies the starting point of temperature reading (zero point) and the basic unit of temperature measurement. International units for thermodynamic temperature scale (K). Other temperature scales used internationally are the Fahrenheit scale (°F), the Celsius scale (°C) and the International Practical Temperature Scale (IPTS).

From the molecular kinematics point of view, temperature is a sign of the average kinetic energy of the molecular motion of an object. Temperature is the collective expression of the thermal motion of a large number of molecules and contains statistical significance. For individual molecules, temperature has no meaning. The degree of hotness or coldness measured on one of several arbitrary scales based on an observable phenomenon (e.g., the expansion of a column of mercury).

What is the Kelvin temperature?

The temperature for which absolute zero is used as the starting point for calculation. The temperature obtained by defining the temperature at the triple point of water as exactly 273.16 K, which used to be called the absolute temperature. The Kelvin temperature is often represented by the symbol K. Its unit is the Kelvin, defined as 1/273.16 of the temperature at the triple point of the water. the difference between the Kelvin temperature and the customary Celsius temperature is a constant of 273.15, i.e. = +273.15 (which is the symbol for the Celsius temperature).

For example, with the Celsius temperature expressed in the three-phase point temperature of water is 0.01 ℃, while the Kelvin temperature is expressed as 273.16 K. The difference between the Kelvin temperature and the Celsius temperature is only the calculation of the temperature of the starting point is different, i.e., the zero point is different, and each differs from the other by a constant, which can be converted to each other. The difference between the two can not be confused with the difference between the thermodynamic temperature and the international practical temperature scale temperature, the latter difference between the two is the definition of the difference. The thermodynamic temperature can be expressed as a Kelvin temperature; similarly, the IUPAC temperature can be expressed as a Kelvin temperature. Of course, they can also be expressed as Celsius temperature. So 1°C = 274.15K and 0°C = 273.15K.

What is the Fahrenheit temperature?

Fahrenheit and Centigrade are both units used to measure temperature. Many countries around the world, including China, use Celsius, while the United States and some other English-speaking countries use Fahrenheit and less often Celsius.

It is named after its inventor, Gabriel D. Fahrenheit (1681-1736), and has a freezing point of 32 °F and a boiling point of 211.9532 °F. In 1714 the German Fahrenheit made a glass mercury thermometer with mercury as the temperature-measuring medium, and selected the temperature of a mixture of ammonium chloride and ice water as the temperature of the thermometer. The temperature of the mixture of ammonium chloride and ice water was chosen as the zero degree of the thermometer, and the temperature of the human body was taken as the 100 degree of the thermometer. The mercury thermometer was divided into 100 parts from 0 degree to 100 degrees according to the distance of volume expansion of the mercury, and each part was 1 degree Fahrenheit, which was recorded as “1℉”. The vast majority of countries in the world, including my own, use Celsius; only five countries in the world use Fahrenheit, including the Bahamas, Belize, the British Cayman Islands, Palau, and the United States of America and its other dependent territories (Puerto Rico, Guam, and the United States Virgin Islands).

What is the Celsius temperature?

It was invented by Anders Celsius (1701-1744) and has a freezing point of 0 degrees Celsius and a boiling point of 99.974 degrees Celsius. In 1740 Celsius, a Swede, proposed to specify the temperature of an ice-water mixture as 0 degrees and the boiling temperature of water as 99.974 degrees at standard atmospheric pressure. According to the two fixed temperature points of water to the glass mercury thermometer for indexing. The two points are divided into 100 equal parts, each of which is called 1 degree Celsius. This is recorded as 1°C. The Celsius temperature has been incorporated into the International System of Units. In physics, the Celsius temperature is denoted as t, and the absolute temperature (in kelvins) is denoted as T. The definition of Celsius temperature is t=T-273.15. Degrees Celsius is a specialized name that replaces kelvins when expressing Celsius temperatures, and numerically 1 K = 1 °C.

What is the Reaumur temperature?

Established by Reaumur (1685-1757, France) in 1740. He fixed the freezing point of water at 0° R; and the change of temperature for a change of one thousandth of the volume of alcohol as 1° R. This gives the boiling point of water as 79.9792° R. The temperature of water is the same as that of alcohol.

What is a Rankine Temperature?

The Rankine Temperature scale is a thermometer that starts at absolute zero and goes up to the Fahrenheit scale instead of the Celsius scale like the Kelvin thermometer, which is called the Rankine Temperature.