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G'day; there is no metal that gives off more UV than any other at a given temperature. The UV radiation comes from the temperature of any highly heated object no matter what it is so long as it (the object) doesn't change because of heat.. At room temperature no UV is radiated; UV is negligible at temperatures lower than white heat. UV is considerable and thus dangerous at such high temperatures as the sun, a welding arc, a carbon arc lamp or a bomb. The spectrum of electro magnetic radiation is very wide indeed. Even at 1 degree above absolute zero (-230C) an object still radiates at some very long wavelengths indeed. Infra red is easily detected at 35C. All mammals radiate infra red. An electric soldering iron radiates infra red strongly and at 500C human nerves detect it very easily at well over a foot distant. At 650C the object is only just detectable by the human eye in an otherwise totally dark room, as a very dark, dull red. At 1150C - molten steel - you see it glowing as white hot. As soon as you get to around 1000C invisible Ultra Violet enters the equation. At 2000C the object is so hot as to be positively dazzling and it is just below that temperature that platinum melts. So hot that you can't look at it and must have dark glasses to view it. But most glasses are fairly transparent to some wavelengths of UV, and such glasses need a component that blocks UV. Go even hotter and you get some radio radiation. An electric arc will radiate plenty of radio interference. A fluorescent tube light gives off some radio and some ultra violet unless properly designed. (it is an arc too, and is called a plasma) Finally, fission or fusion bombs give off enormous pulses of radiation at a very huge range of wavelengths indeed, from harmless infra red right up to and including x-rays. Which is why a fusion bomb set off in orbit will destroy radio transmitters; it is so powerful. An atomic bomb explosion produces an enormous pulse of electricity which will induce a high electric current in conductors, sufficient to burn them out. So will lightning, of course. So .... at silver soldering temperatures, practically no ultra violet radiation is given off at all. But plenty of infra red is given off, and prolonged exposure to strong infra red, such as from orange hot molten glass will affect eyesight Cheers for now, John Burgess Mapua, Nelson NZ |
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