Thermography, << thur MOG ruh fee, >> is a detection technique that converts invisible heat energy into a visible picture. A device called a thermograph is used to produce a thermogram (heat picture). Thermography is used in industry, medicine, and many other fields.
A thermograph looks like a TV camera connected to a TV screen. It “sees” temperature by sensing heat energy, called infrared energy. Infrared energy is radiated naturally by all objects, and hotter objects radiate more than cooler ones. Inside a thermograph, a solid-state detector converts infrared energy into electrical signals. The signals are displayed as pictures on the TV-like screen. The pictures show different temperature ranges by variations of brightness or color. These variations can be analyzed by scientists.
Industrial uses of thermography include detecting overheated parts in electrical distribution systems and energy losses in manufacturing processes. The technique also is used to find leaks in the insulation of homes and other buildings. In addition, thermography provides a means of inspecting blast furnaces. A weak spot in a furnace wall is hotter than the surrounding areas, and so it appears lighter on a thermogram.
In medicine, thermography can reveal arthritis, nerve damage, and blood circulation problems. Physicians also use thermography, along with other tests, to confirm the presence of breast tumors.
Military and police forces and fire fighters use thermography to see in the dark and through smoke. Pollution control experts sometimes use the technique to determine the distribution of thermal (heat) pollution in bodies of water.
