Thermopile
Encyclopedia
A thermopile is an electronic device that converts thermal energy
into electrical energy. It is composed of several thermocouple
s connected usually in series or, less commonly, in parallel.
Thermopiles do not respond to absolute temperature
, but generate an output voltage
proportional to a local temperature difference or temperature gradient.
Thermopiles are used to provide an output in response to temperature as part of a temperature measuring device, such as the infrared thermometer
s widely used by medical professionals to measure body temperature. They are also used widely in heat flux sensor
s (such as the Moll thermopile and Eppley pyrheliometer
) and gas burner safety controls. The output of a thermopile is usually in the range of tens or hundreds of millivolts. As well as increasing the signal level, the device may be used to provide spatial temperature averaging.
Thermopiles are also used to generate electrical energy from, for instance, heat from electrical components.
Thermal energy
Thermal energy is the part of the total internal energy of a thermodynamic system or sample of matter that results in the system's temperature....
into electrical energy. It is composed of several thermocouple
Thermocouple
A thermocouple is a device consisting of two different conductors that produce a voltage proportional to a temperature difference between either end of the pair of conductors. Thermocouples are a widely used type of temperature sensor for measurement and control and can also be used to convert a...
s connected usually in series or, less commonly, in parallel.
Thermopiles do not respond to absolute temperature
Temperature
Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...
, but generate an output voltage
Voltage
Voltage, otherwise known as electrical potential difference or electric tension is the difference in electric potential between two points — or the difference in electric potential energy per unit charge between two points...
proportional to a local temperature difference or temperature gradient.
Thermopiles are used to provide an output in response to temperature as part of a temperature measuring device, such as the infrared thermometer
Infrared thermometer
Infrared thermometers infer temperature using a portion of the thermal radiation sometimes called blackbody radiation emitted by the object of measurement. They are sometimes called laser thermometers if a laser is used to help aim the thermometer, or non-contact thermometers to describe the...
s widely used by medical professionals to measure body temperature. They are also used widely in heat flux sensor
Heat flux sensor
A heat flux sensor is a transducer that generates an electrical signal proportional to the total heat rate applied to the surface of the sensor. The measured heat rate is divided by the surface area of the sensor to determine the heat flux....
s (such as the Moll thermopile and Eppley pyrheliometer
Pyrheliometer
A pyrheliometer is an instrument for direct measurement of solar irradiance. Sunlight enters the instrument through awindow and is directed onto a thermopile which converts heat to an electrical signal that can be recorded. The signal voltage is converted via a formula to measure watts per square...
) and gas burner safety controls. The output of a thermopile is usually in the range of tens or hundreds of millivolts. As well as increasing the signal level, the device may be used to provide spatial temperature averaging.
Thermopiles are also used to generate electrical energy from, for instance, heat from electrical components.
See also
- Peltier Effect
- Thermoelectric EffectThermoelectric effectThe thermoelectric effect is the direct conversion of temperature differences to electric voltage and vice-versa. A thermoelectric device creates a voltage when there is a different temperature on each side. Conversely, when a voltage is applied to it, it creates a temperature difference...
- Radioisotope Thermoelectric GeneratorRadioisotope thermoelectric generatorA radioisotope thermoelectric generator is an electrical generator that obtains its power from radioactive decay. In such a device, the heat released by the decay of a suitable radioactive material is converted into electricity by the Seebeck effect using an array of thermocouples.RTGs can be...
- Horizon Sensor