The image formed by the CCD can then be reproduced in visible light. These cameras typically contain charge-coupled device (CCD) imaging chips that are sensitive to IR light. Night vision cameras use a more sophisticated version of a bolometer. If a warm body comes into this instrument's field of view, the heat causes a detectable change in the voltage across the thermistor. This can be detected by electronic sensors, such as those used in night vision goggles and infrared cameras.Ī simple example of such a sensor is the bolometer, which consists of a telescope with a temperature-sensitive resistor, or thermistor, at its focal point, according to the University of California, Berkeley (UCB). All objects on Earth emit IR radiation in the form of heat. One of the most useful applications of the IR spectrum is in sensing and detection. The receiver converts the light pulses to electrical signals that instruct a microprocessor to carry out the programmed command.
TV remote controls that rely on infrared radiation shoot out pulses of IR energy from a light-emitting diode (LED) to an IR receiver in the TV, according to How Stuff Works. Infrared lasers can be used for point-to-point communications over distances of a few hundred meters or yards. Incandescent bulbs convert only about 10 percent of their electrical energy input into visible light energy, while the other 90 percent is converted to infrared radiation, according to the Environmental Protection Agency. Household appliances such as heat lamps and toasters use IR radiation to transmit heat, as do industrial heaters such as those used for drying and curing materials. The sun gives off half of its total energy as IR, and much of the star's visible light is absorbed and re-emitted as IR, according to the University of Tennessee. Everything with a temperature above around 5 degrees Kelvin (minus 450 degrees Fahrenheit or minus 268 degrees Celsius) emits IR radiation. IR radiation is one of the three ways heat is transferred from one place to another, the other two being convection and conduction.