Mercury electron tubes

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... 

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. 

Hulbrnt and Crew observed what seemed to be the same spectnun in the first striation of a discharge tube at 1 mm. of mercury. Bramley has found that at 1 mm. pressure the electrons in the striation nearest the cathode have velocities of about 10 or 15 volts and Horton and Davies give 12.6 volts as the lowest value of the electron velocities necessary to give this spectrum and find that a slight increase in voltage causes the blue... 

G. Bourdon Gauges. As an alternative to mercury manometers there is a variety of gauges based on mechanical or electrical pressure transducers. This section presents a description of purely mechanical gauges which still find use in this electronic age.4 The metal Bourdon gauge (Fig. 7.5) is fashioned around a semicircular thin-walled metal tube with mechanical linkage to a pointer. Fused-quartz spiral gauges are also available. In this case, a thin spiral is sensitive to a pressure differential, and the deflection is balanced with air pressure in the surrounding envelope. The air pressure is then measured with a manometer. 

First, you must document whether the manometer of the device (electronic or aneroid) registers pressure accurately. Connect the device to be tested to the reference device (mercury, aneroid, or electronic) with a Y tube, as shown in Figure I. 

The Y tube transmits pressure equally to the reference device and the device to be tested. Using the bulb connected to the Y pressure is increased to 300 mmHg and then lowered by 10 mmHg. Recording the pressure on each device validates the accuracy of the aneroid or electronic device, Any device that differs by more than 3 mmHg from the mercury or reference standard is considered to be out of calibration and should be removed from service. 

To test the electronic device connect the pressure sensing input to the Y tube to the Mercury primary standard. Raise and lower pressure in system with the bulb. 

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