Electron tubes containing mercury

BLUE GLOW. A type of luminescence emitted by certain metallic oxides, when heated. A blue glow is normally seen in electron tubes containing mercury vapor, arising from the ionization of the molecules in the mercury vapor. 

Cinnabar Electron tubes containing mercury Mercuric salt Mercurous compound Mercury compound, liquid, n.o.s, 6.1 Mercury compound, solid, n.o.s., 6.1 Mercury contained in manufactured articles, 8 Mercury vapour tubes Phenylmercuric compound, n.o.s., 6.1 Quicksilver... 

One application in which concerns about mercury have had litde effect is fluorescent lamps. A fluorescent lamp contains mercury vapor (gas). When the lamp is turned on, an electric current passes through the mercury vapor, causing it to give off invisible radiation. The radiation strikes the inside of the glass tube, whose walls are coated with a phosphor. A phosphor is a material that gives off visible light when stmck by electrons. The tube glows as the radiation strikes the phosphor. 

The instrument consists of an electronic cabinet and a sampling stand. The former contains a digital counter, an oscilloscope screen, upper and lower threshold controls, aperture current and amplification switches, and a zero reset switch. The sampling stand consists of an aperture tube, a mercury manometer, a control stopcock, two electrodes, a vacuum pump, and a 35x microscope for viewing the aperture. 

Donor and acceptor levels are the active centers in most phosphors, as in zinc sulfide [1314-98-3] ZnS, containing an activator such as Cu and various co-activators. Phosphors are coated onto the inside of fluorescent lamps to convert the intense ultraviolet and blue from the mercury emissions into lower energy light to provide a color balance closer to daylight as in Figure 11. Phosphors can also be stimulated directly by electricity as in the Destriau effect in electroluminescent panels and by an electron beam as in the cathodoluminescence used in television and cathode ray display tubes and in (usually blue) vacuum-fluorescence alphanumeric displays. 

In emission spectroscopy the molecule or atom itself serves as the somce of light with discrete frequencies to be analyzed. In some cases, such as Exp. 39, which deals with the emission spectrum of molecular iodine vapor, excitation by a monochromatic or nearly monochromatic laser or mercury lamp is utilized. For other cases, such as the emission from N2 molecules, electron excitation of nitrogen in a discharge tube provides an intense somce whose spectrum is analyzed to extract information about the electronic and vibrational levels. Such low-pressure (p < 10 Torr) line somces are available with many elements, and lamps containing Hg, Ne, Ar, Kr, and Xe are often used for calibration purposes. The Pen-Ray pencil-type lamp is especially convenient for the visible and... 

The sample is enclosed in a glass piezometer and separated from the pressure transmitting fluid by mercury. As the sample volume decreases with increasing pressure the level of the mercury, which is contained in a calibrated glass tube, sinks and thus opens the electric contact to a tungsten tip. By means of a screw spindle the contact of the tungsten tip with the mercury level is made again. The number of revolutions needed for it is a measure for the decrease in volume of the sample and can be measured by an electronic altimeter outside the autoclave. The reproducibility of the density is 0.0003 g cm . ... 

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