Lamps operating life

High-pressure mercury lamps operate at pressures about 10 atmospheres and essentially two types are used in industrial applications. The point source lamp focuses on a small-diameter spot, thus delivering an intense radiation to that spot. The capillary lamp is used for narrow webs up to approximately 20 cm (8 in.) wide.4 They are capable of producing a wider spectrum than the medium-pressure lamps and operate with higher power (150-2880 W/cm). Their disadvantage is a relatively short operating life, typically hundreds of hours. 

The power levels of radioactive sources presently available are comparable to the output of the most intense discharge lamps available. Ultraviolet sources produce 10 to 100 w. of useful ultraviolet radiation. Kilocurie sources of 2 Mev. activity produce approximately 20 w. The total available power from such a source having a half-life of 10 years is an order of magnitude lower than the total power output available from an ultraviolet lamp operating for 1000 hours, the normal expectancy for lamps of this type. 

EDLs. The intensities of electrodeless discharge lamps are better than those of normal hollow cathode lamps. In addition, the operation life of EDLs is long. However, the problem with these lamps is the long-term instability of the emission signal. 

We wish to test a new type of ceramic tube to the AljOg tube normally used to fabricate high-pressure sodium lamps in order to eompare lamp qualities and life-time operation. Select a method which would produce the desired results and describe how this would be accomplished. Note that the ceramic tube requires both strength and a high melting point. 

Consumables, such as lamps, were estimated at 250 per lamp, with a life expectancy of 1000 hr at full power (30 Hz). Total operating costs of the system were estimated to be 0.85/hr in 1994. The cost of equipment used in a U.S. Department of Energy study was approximately 150,000 (D13776S, p. 33). 

Eximer light sources may require water cooling for optimal operation. Their life times have not yet been determined, but excimer lamps (see Table 1) have been operational for more than 3000 hours with radiant efficiencies of approximately 6%. 

Figure 14.4 is the three-dimensional view of the process. The figure illustrates the relative water head at different stages. Because of flexible design, Ultrox UV/oxidation treatment systems have a number of advantages (1) very few moving parts (2) operation at low pressure (3) minimum maintenance (4) full-time or intermittent operation in either a continuous or batch treatment mode (5) use of efficient, low-temperature, and long-life UV lamps and (6) use of a microprocessor to control and automate the treatment process (Zeff and Barich, 1992). 

The lamps may be operated as continuous wave sources or be modulated or pulsed. EDLs have a poor stability or poor shelf life in some cases, but they have high intensities, produce narrow spectral lines, and are relatively inexpensive. 

Many detectors track the number of hours the lamp is ignited. Although the lamp life may vary, the detector s meter reading can be a helpful guide for troubleshooting. Lamps can sometimes operate for more than 2000 h. To distinguish a lamp problem from air bubbles, one should stop the mobile phase flow. A lamp problem will persist when the flow is stopped, whereas, if the problem is due... 

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