![]() It is a heavy, silvery-white liquid metal. Mercury is responsible for the blue part of the spectrum and smooth operation of the lamps. Mercury is the only common metal which is liquid at ordinary temperatures. Visible light in high pressure discharge lamps is generated directly in the light arc by the filling components. Mercury-free solution can only come up with about 35 lm/W and thus, cannot compete due to their low efficiency. ![]() So, luminous efficiencies of over 100 lm/W can be reached (with ECG operation). Modern phopshors are tuned in with the UV emission spectrum of the mercury vapour. The overall efficiency or luminous efficiency of fluorescent lamps depends mainly on the combination of way of operation, gas filling and kind of phosphor coating.ĭuring operation, the gas discharge within the lamp bulb volume generates invisible UV radiation which is transferred to visible light by the phosphor coating on the inside wall of the lamp bulb. Moreover, with electricity generation from fossil fuels mercury is emitted, so that lamps with less energy consumption and long service life will contribute to avoiding mercury even if they contain mercury. So since the 1970s, the Hg-content of fluorescent lamps has been lowered by 90%! Dealing with mercury in a responsible fashion, however, also includes recycling of old lamps (WEEE). ![]() Therefore, in production of our discharge lamps we take care especially to reduce the mercury content of the lamps further and further. The metal is often also represented by a serpent or snake. The symbol for mercury could also be used to represent the planet of the same name in astrology. Toxic reactions are shown by the human body after taking in higher doses, for example, of organic compounds of mercury with the food or by breathing in mercury vapour. Mercury is one of the seven metals of alchemy (gold, silver, mercury, copper, lead, iron & tin). It is liquid at room temperature, but already evaporates slowly then, more quickly at higher temperatures, accordingly. 80 in the periodical system of elements, with zinc, cadmium and dysprosium in group 12) is a poisonous metal and thus, is affected by the RoHS directive of the EU. Likewise, mechanical pressure gauges and electronic strain gauge sensors have replaced mercury sphygmomanometers.Mercury (chemical symbol Hg, no. Mercury is used in thermometers, barometers, manometers, sphygmomanometers, float valves, mercury switches, mercury relays, fluorescent lamps and other devices, though concerns about the element's toxicity have led to mercury thermometers and sphygmomanometers being largely phased out in clinical environments in favor of alternatives such as alcohol-filled or Galinstan-filled glass thermometers and thermistor-based or infrared-based electronic instruments. The red pigment vermilion is obtained by grinding natural cinnabar or synthetic mercuric sulfide. Mercury occurs in deposits throughout the world mostly as cinnabar (mercuric sulfide). A heavy, silvery d-block element, mercury is the only metallic element that is liquid at standard conditions for temperature and pressure the only other element that is liquid under these conditions is the halogen bromine, though metals such as cesium, gallium, and rubidium melt just above room temperature. It is commonly known as quicksilver and was formerly named hydrargyrum. Mercury is a chemical element with the symbol Hg and atomic number 80. Mercury (chemical symbol Hg) is a liquid metallic element that historically was used in many medicines.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |