Mercury vapor bulbs

Mercuiy is the primary liquid metal that degrades aluminum. Liquid mercuiy does not wet an aluminum oxide surface, but if the natural oxide film in penetrated aluminum dissolves in the mercury to form an amalgam starting a very rapid reaction. The dissolved aluminum oxidizes immediately in the presence of moisture and more aluminum dissolves. This reaction is assisted by the presence of halides. The mercury penetration tends to proceed along grain boundaries, and if tensile stresses are present in the metal, drastic splitting and the exposure of further film free metal occurs. Mercury can plate out of aqueous solutions to produce this effect. A mercuiy content of greater than 0.01 ppm is cause for concern. Detection of even lesser amounts of mercury may indicate a problem, since mercury tends to evaporate and low levels are difficult to analyze. Common sources of mercuiy are broken thermometers and mercury vapor bulbs, or mercury manometers that have been over-pressurized. 

Figures 1 and 2 show examples of the elongation properties of UV curable inkjet ink. These inks were drawndown with a 6 Meyer rod on PVC and cured using a standard mercury vapor bulb at a dose of 700 mJ/cm. The samples were then thermoformed. The digital inkjet ink showed excellent elongation with no cracking. This is useful for many applications, such as fleet graphics for vehicles.

Cold traps must be used if mercury is used in your system (such as manometers, diffusion pumps, bubblers, or McLeod gauges) and if your mechanical pump has cast aluminum parts. Mercury will amalgamate with aluminum and destroy a pump. Even if your mechanical pump does not have aluminum parts, the mercury may form a reservoir in the bottom of the mechanical pump, which may cause a noticeable decrease in pumping speed and effectiveness. Aside from a cold trap between the McLeod gauge and the system, place a film of low vapor pressure oil in the McLeod gauge storage bulb. This oil will limit the amount of mercury vapor entering the system that makes its way to the mechanical pump. In addition, an oil layer should be placed on the mercury surface in bubblers and other mercury-filled components. 

The lamp is mounted securely at its ends and connected to a source of direct current preferably 220 volts or 500 volts through suitable resistances and a switch. The switch is closed and a small Bunsen flame is played on the capillary between A and B. The mercury vaporizes and the arc strikes and is localized between the two bulbs. As soon as the lamp starts, water is turned on so that it flows down around the lamp in a large stream. The cold water keeps the cement intact and preserves the lamp. The energy is so intense that without water-cooling the quartz would be melted immediately. Hard water may be used provided that it passes over the lamp so rapidly that there is not time to heat up the water and deposit lime. The mounting of the lamp may be varied for different purposes. The lamp may be placed in front of a quartz window in a copper tank which is partially drained until the lamp is started. After starting, the tank is allowed to fill to an outlet near the top thus covering the lamp. 

A simple distilling apparatus that can be nsed for this experiment is shown in Fig. 4. The mercury thermometer bulb (or any other thermometer sensor) should be about level with the side arm to the condenser so that the temperature of coexisting vapor and Uqnid is measured. Except when samples of distillate are being taken for analysis, an adeqnate receiving flask should be placed at the lower end of the condenser. 

Lamp bulbs are typically 0.75 m to 1.5 m in length and 15-20 mm in diameter. Mercury vapor is sealed inside this bulb. To produce the radiation, electric current, which generates an electric arc, is passed through the bulb. In actual use in the treatment of water and wastewater, the lamps are either suspended over the liquid to be disinfected or immersed in it. When immersed, the lamps are encased in quartz tube to prevent the cooling effect of the liquid on the lamps. The right-hand side portion of Figure 17.13 shows an ultraviolet lamp assembly the left-hand side shows an actual installation located below floor level. 

Metallic mercury is used in a variety of household products and industrial items, including thermostats, fluorescent light bulbs, barometers, glass thermometers, and some blood pressure devices. The mercury in these devices is contained in glass or metal, and generally does not pose a risk unless the item is damaged or broken, and mercury vapors are released. Spills of metallic mercury from broken thermometers or damaged electrical switches in the home may result in exposure to mercury vapors in indoor air. You must be careful when you handle and dispose of all items in the home that contain metallic mercury. 

Fluorescent light bulbs contain a mixture of mercury vapor and a noble gas such Objective 15... 

A typical fluorescent light bulb contains argon gas and mercury vapor. 

Catalysts for transesterification of vinyl acetate as well as addition to triple bonds Thermometers and leveling bulbs Mercury vapor and fluorescent lamps Electrical switches... 

Bimetallic strip thermometers are preferred for monitoring oven temperatures. Mercury thermometers should not be mounted through holes in the tops of ovens so that the bulb hangs into the oven. Should a mercury thermometer be broken in an oven of any type, the oven should be closed and turned off immediately, and it should remain closed until cool. All mercury should be removed from the cold oven with the use of appropriate cleaning equipment and procedures (see Chapter 5, section 5.C. 11.8) in order to avoid mercury exposure. After removal of all visible mercury, the heated oven should be monitored in a fume hood until the mercury vapor concentration drops below the threshold limit value (TLV). 

You may not realize it, but fluorescent light bulbs generally contain small amounts of mercury. Because mercury vapor can be toxic, breathing the gas released when a fluorescent bulb breaks can be dangerous. It also means that used fluorescent... 

The light intensity per watt for sodium vapor lamps far exceeds that of fluorescent lamps, high-pressure mercury vapor lamps, tungsten halogen lamps, and incandescent bulbs. 

Fig. 1. Mercury lamps for Raman spectrograph. A) Bulb used to condense mercury vapors B) indentation in the lamp which is necessary to keep the liquid level in the arc part of the lamp at a point where the lamp remains lit C) a second condensation bulb D) glass legs of the lamp which contain mercury used to connect to the tungsten electrodes.

An overhead mercury vapor or fluorescent light has burned out. A scissors lift is used to gain access to the bulb(s). New bulbs do not solve the problem therefore, the ballast must need... 

C05-0021.A 2.96-g sample of a compound of mercury and chlorine is vaporized in a 1.000-L bulb at 307 °C, and the final pressure is found to be 394 torr. What are the molar mass and chemical formula of the compound ... 

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