5042 x 3361 px | 42,7 x 28,5 cm | 16,8 x 11,2 inches | 300dpi
Aufnahmedatum:
2002
Weitere Informationen:
Thermal radiation is electromagnetic radiation emitted from the surface of an object which is due to the object's temperature. Infrared radiation from a common household radiator or electric heater is an example of thermal radiation, as is the light emitted by a glowing incandescent light bulb. Thermal radiation is generated when heat from the movement of charged particles within atoms is converted to electromagnetic radiation. If the object is a black body, the radiation is termed black-body radiation. The emitted wave frequency of the thermal radiation is a probability distribution depending only on temperature, and for a genuine black body is given by Planck’s law of radiation. Wien's law gives the most likely frequency of the emitted radiation, and the Stefan–Boltzmann law gives the heat intensity. Nichrome is a brand name for a nickel-chromium resistance wire, a non-magnetic alloy of nickel and chromium. A common alloy is 80% nickel and 20% chromium, but there are many others to accommodate various applications. It is silvery-grey in colour, is corrosion resistant, and has a high melting point of about 1400 °C. Due to its relatively high resistivity and resistance to oxidation at high temperatures, it is widely used in heating elements, such as in hair dryers, electric ovens and toasters. Typically, Nichrome is wound in wire coils to a certain electrical resistance, and current passed through to produce heat. Nichrome is used in the explosives and fireworks industry as a bridgewire in reliable electric ignition system, such as electric matches and model rocket igniters. Nichrome wire is commonly used in ceramics as an internal support structure to help some elements of clay sculptures hold their shape while they are still soft. Nichrome wire is used because of its ability to withstand the high temperatures that occur when a clay work is fired in a kiln.
