Osram lamps

The chlorination of the chloroformate, obtained by the method given on p. 102, was carried out like that of methyl formate, in lead-lined or enamelled vessels. The lids of these vessels were also enamelled and carried eight Osram lamps protected by glass bells. The chlorine was introduced through eight pipes. 

I, 000 c.p. Osram lamp. By this method a much higher yield of bromobenzyl cyanide is obtained. ... 

Vapor discharge lamps produce emission by passing an electric current through a vapor composed at least partly of the element of interest. Such lamps are produced by Osram in Germany and Philips in Holland. Osram lamps exist for the elements mercury, thallium, zinc, cadmium, and the alkalis. 

Osram lamps for mercury cannot be used in atomic absorption, because they contain vapor at so high a pressure that the emission line is almost completely self-absorbed, and the sensitivity is very small. It is also generally agreed that hollow-cathode lamps for thallium, zinc, and cadmium are superior to the discharge lamps. 

Osram lamps require special mounts, and a special power supply capable of delivering a I-ampere current at a starting voltage of about 300 volts and a running voltage of about 50 volts. Furthermore, even in double-beam equipment, they require a wait of about ten minutes for warm-up, while the time in single-beam instruments is in excess of a half hour. 

Gaseous discharge lamps which contain internal electrodes also can serve as sources for atomic absorption. They are variously called arc lamps, spectral lamps, vapor lamps, and by the name of the manufacturer, such as Osram lamps and Philips lamps. Gaseous discharge lamps contain an inert gas at low pressure and a metal or metal salt. They are especially suited to metals of relatively high vapor pressure, such as the alkali metals and some other metals such as mercury, cadmium, and lead. 

Philips and Osram spectral discharge lamps have been used as spectral sources for analytical atomic fluorescence. These lamps have internal electrodes and produce intense spectral lines. The spectral lines, however, are subject to line reversal and the lamps are available only for a limited number of elements. Use of Philips and/or Osram lamps require careful control of input energy to produce maximum intensity without line reversal. Under these conditions they have produced satisfactory atomic fluorescence signals for some elements, including cadmium, mercury, zinc, and thallium. 

The manufacturer of OSRAM lamps specifies the average lifetime 600 hours forthe mentioned type. This... 

A soln. of methyl 2-methoxy-5-phenylfuran-3-carboxylate in methanol irradiated with a halogen-Superphot 650 W Osram lamp in the presence of a little methylene blue under O,-bubbling at —40 for 2 h - product. Y 100%. F.e.s. M.L. Graziano et al., J. Chem. Soc. Perkin Trans. I 1988, 1699-704. 

Figure 10.7 Escherichia coli survival on Ag-TiON sputtered on polyester for different Ag deposition times on TiON layers. The light source is an Osram lamp L18W/827 (4 mW/cm, 400—700 nm). Reactive gas flow composition Ar 90% N2 5% 02 5% and total P = 0.5 Pa. Rtimi Sami Baghriche, Oualid Sanjines, Rosendo Pulgarin, Cesar Ben-Simon, Michael Lavanchy, Jean-Claude et al. TiON and TiON-Ag sputtered textile showing antibacterial activity induced by simulated-solar-light. J Photochem Photobiol A 2013 256 52-63.

Fig. 14 Radiation characteristics of a high pressure Hg lamp (Osram HBO 100 continuous line) and of a xenon lamp (PEK 75 broken line) [4]. The intensity /is represented logarithmically in relative units.

Fig. 44 Apparatus for irradiation with UV light. — 1 excitation apparatus (Heraeus, Hanau OSRAM StE 501), 2 UV lamp (TNN 15-31001721), 3 housing, 4 TEC plate.

Fifteen -blockers have also been activated photochemically with the same radiation unit (Heraeus, Hanau Osram STE 501 UV lamp TNN 15-3200/721)[23]. Their detection limits, the working range and associated standard deviation of the method are listed in Table 1 below. The blue fluorescence of the chromatogram zones (Xg 5 = 313 nm, > 390 nm) was measured after dipping the chromatogram in liquid paraffin - n-hexane (1 + 2). Figure 18 illustrates the separation of seven P-blockers. 

For comparison the output power of a high-pressure mercury lamp (Osram HBO 200) also is listed. The reader has to consider, however, that the mercury lamp radiates this power into the unit solid angle (= 60°) distributed over the spectral range from 2000 to 6000.A, whereas the laser intensity is concentrated at a single wavelength and collimated in a beam with a very small divergence between 10 and 10" sterad. 

Mackey and Pollack (76) have designed an electronic chopper for use with spectral lamps such as the moderately priced Osram series. Figure 17 shows a schematic diagram of the chopper system. Six type-6CD6GA tubes... 

Mackey and Pollack investigated the switch-off characteristics of a large number of lamps. Typical values ranged from 10.5 /xsec for a Beckman hydrogen arc to 600/xsec for an Osram mercury lamp. As the authors point out, some of the lamps with the greater deionization times may well be of value in cases of long decays. 

Neon light (two 15-W lamps) (Osram, Germany) for photopolymerisation of the PP2A/PVA-AWP mixture on the screen-printed graphite working electrode. 

Figure 2 Spectral irradiance of a pair of cool white fluorescent lamps (OSRAM, model L18W/20, 60-cm long, 20 W) measured at 9-cm distance.

Fig. 23 Spectral changes upon irradiation of 31a. Top in dichloromethane, (a) before irradiation, (b) after 1 min irradiation with an Osram HWLS 500 W lamp. Bottom in dichloromethane at pH 4-5, irradiation with a daylight lamp after reduction to hydroquinone 34a.

Photochemical reactors are commercially available or can be custom-built. They consist of an oval mirror-type wall of ca. 30 cm maximum radius equipped with two Hanovia 450-W or Philips HPT 400-W high-pressure mercury lamps inserted into a water refrigerated Pyrex flask, or equipped with a 300-W Osram sunlamp vessel (Pyrex flask). 

Fig. 2. Spectral changes during the photolysis of 2.68 x 10 M (pro-phoslCu lCOalCu prophos) in acetonitrile at room temperature under argon at 0 (a), 15 and 40 min (b) irradiation times with /lirr=313 nm (Osram HBO 200 W/2 lamp), 1-cm cell.

Methyl 3-Hydroperoxy-2-methylene-4-phenylpentanoate A solution of 2.04 g (10.0 mmol) of methyl 2-methyl-4-phenyl-2-pentenoate4 [98 2 mixture of (E)- and (Z)-isomers] and ca. 10 mg (0.01 mmol) of tetraphenylporphin (TPP) in 150 mL ofCHCl3 is irradiated in an immersion reactor44 with an Osram Violax NAV-TS 250-W sodium lamp at 0°C while continuously passing a stream of dry oxygen through the reaction mixture. After 18 h, the solvent is evaporated at 0 C/15 Torr and the residual oil is purified by column chromatography [silica gel, petroleum ether (30 75" Cj/EtOAc 1 1] to afford a colorless oil yield 1.93 g (82%). 

Figure 3 Spectral power distributions of the two cool white lamps available overlaid with detector response curve. Source. Courtesy of Dr. R. Levin, Osram Sylvania.

The manufacture of these substances was carried out by the formate method or the chloroformate method, as mentioned on p. 99. The method of chlorination in each of these is similar and requires a suitable source of light. Many experiments on this subject have indicated that the Osram watt arc lamp and the mercury vapour lamp are suitable light sources, and the... 

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