About Heat

In physics and thermodynamics, heat is the process of energy transfer from one body or system to another due to a difference in temperature. Energy transfer by heat can occur between objects by radiation, conduction and convection. Temperature is used as a measure of the intemal energy.

A calorimeter is a device used for measuring the heat of chemical reactions or physical changes as well as heat capacity. The word calorimeter is derived from the Latin word calor, meaning heat. A simple calorimeter just consists ofa thermometer attached to a metal container full of water suspended above a combustion chamber.

A hypsometer is an instrument for measuring altitude by the relationship between atmospheric pressure and the boiling point of a liquid.

A thermopile converts thermal energy into electrical energy. It is composed of thermocouples connected usually in series. Thermopiles do not measure the absolute temperature, but generate an output voltage proportional to a local temperature difference or temperature gradient. Thermopiles are the key component of the infrared thermometers that are widely used by medical professionals to measure body temperature via the ear. The output of a thermopile is usually in the range of tens or hundreds of millivolts.