Temperature Defined


Temperature measures the intensity of heat to be found in one molecule of a substance. According to molecular theory as it relates to heat, temperature actually shows the speed of motion of molecules being affected by a force upon it.

Molecules are made up of atoms. These atoms have mobility. The speed at which they move is determined to be its temperature. The measurement of heat is actually a multiplication of the thermal energy to be found in one atom by the total number of atoms being affected.

The designation of degree Fahrenheit is a conventional unit of temperature used in the United States. It is a scale based on ideas put forward by a physicist in 1724. The basic unit of measurement is 0F. It is known for setting the temperature of freezing ice at 32ºF and the boiling point of water at 212ºF.

The Kelvin scale is a scale that has as its null point absolute zero. This is the point at which all thermal motion stops. It is a base unit of temperature according to the International System of Units(SI).

The Rankine scale is an absolute scale of thermodynamic temperature. Absolute zero is same on the Rankine scale and the Kelvin scale. It is determined that one Rankine degree is equal to one Fahrenheit degree.

Celsius is also known as the centrigrade scale and is recognised as a unit of measurement by the International System of Units. This unit of measurement is both a measurement of temperature and an expression of a temperature interval or the differences between two temperatures. In this scale, the freezing point of water is set at 0ºC while the boiling point of water is set at 100ºC.


A thermometer is something that measures temperature. To be a thermometer it must have two things. It must have a temperature sensor and a means by which to convert that temperature into a numerical value.

All thermometers are absolute in their readings and are exact in their expression of empirical information. Thermometers are calibrated according to and in compliance with a thermodynamic absolute temperature scale. They are assessed based on their ability to determine the absolute temperature of two different items that are suspended in the same thermodynamic state. Both thermometers must agree on which item has the higher temperature or that the temperatures achieved are the same.

Thermometric Applications


Thermometers are used in a variety of measurement systems for scientific, industrial, technical, electrical, and engineering applications.

Thermometers are used in air conditioners, freezers, heaters, refrigerators, water heaters, nuclear power plants, luminescent products, items that are smaller than a micron, low temperature environments, medical field, food safety, cooking, meteorology, climatology, thermal expansion, and vapor pressure.

Some names of thermometers used are vapor pressure thermometer, Galileo thermometer, liquid crystal thermometer, infrared thermometer, fluorescence thermometer, fiber optical thermometer, electrical resistance thermometer, quartz thermometer, nuclear magnetic resonance thermometer, and a cryometer.