subject: Bolometer: A Simple Device But Really Useful [print this page] Bolometer: A Simple Device But Really Useful
By the end of nineteenth century physics had advanced a lot and as you can see the advancement has not stopped it will grow and new kinds of inventions are still in the offing. One such invention of the nineteenth century is the bolometer. It was first made by Samuel Pierpont Langley an American astronomer and since then many improvements have been made to make it a more efficient tool.
This device helps us as mentioned earlier in measuring the energy of a vast range electromagnetic radiation that falls on any surface of the body. It is made up of some simple components the main being a set of two thin sheets of metal, an absorbing element, which is supplied with constant heat to raise its temperature. The heat can be done by connecting them to a heat sink which can heat the metal sheets continuously. At one point of time the temperature of the sheets of metal will be above the supplying heat sink. This temperature rise can be measured using a device like a thermometer.
Initially the sheets were made of metal but now a modified bolometer has the sheets made of superconductor substances that are absorptive in nature. The device thus made works even at very low temperatures called the cryogenic temperatures. At this temperature greater sensitivity is seen to occur. This way it can be used to measure wavelengths of the sub-millimeter range. In astronomy it is found to be the most sensitive and most useful to measure the energy for these wavelengths.
For different wavelengths other than this range other devices are used for better results and the use of bolometer has become obsolete. It is seen that at very low temperatures that are close to absolute zero the most sensitivity is observed when using this device. A cooling device that can cool the object to these temperatures is generally used for this purpose.
Bolometer has other uses too like it is used for searching for dark matter. It shows comparatively high efficiency in energy resolution and sensitivity. Thus it is also known as a thermal detector. Also in particle physics it is termed as particle detector. The sensitivity to a range of frequency of radiation they find various uses.
The bolometer is named after its inventor and known as Langley bolometer. This invention has led to the discovery and invention of many entities in physics. A modification of this device the microbolometer is used in a thermal camera. The principle of this equipment is used to create images. Thus it finds use in several ways that are useful to mankind.
