Tungsten lamp, standard

Compared to the tungsten lamp, luminescence standards are quite simple to use. The polynomial and associated mathematical manipulations are usually implemented automatically in the spectrometer software (21). The user need only acquire a spectrum of the standard under the same conditions as the sample of interest, usually once per session. After the spectrum [Sl(Au)]... 

In preparative-scale (10 M 1-naphthol) experiments, an Ace-Hanovia 450-W medium-pressure mercury arc was used with a Pyrex filter sleeve and a magnetically stirred Ace water-cooled reaction vessel. In experiments involving rose bengal as a sensitizer, tungsten lamp illumination was used. Ultraviolet spectral changes were measured with a Perkin-Elmer model 552A spectrophotometer. For GC-MS analysis, a Hewlett-Packard 5985A instrument was used with a fused silica capillary column coated with a bonded nonpolar polymethyl silane phase introduced directly into the electron Impact ionization source. Compounds were tentatively identified by comparison to published spectra and confirmed where possible with authentic standard materials. 

Studied cell characteristics Polycrystalline photoelectrode, Pt counter electrode, Aredox of Fe +/Fe + = 0.77 V vs SHE, standard hydrogen electrode illumination 40-50 mW cm by a tungsten lamp, initial current during discharge =... 

Record the spectrum of a broadband intensity standard. Although white light sources such as halogen or tungsten lamps can be employed, the illumination geometry does not mimic that of the Raman collection well as it does not act as a point source. Thus the use of fluorescent standards (where they exist) such as those provided by the American NIST is recommended, although there are sometimes point to point variations in the signal found from these standards. 

Instrument calibration standards - physical sources such as line and tungsten lamp emissions, known instrument independent luminescence standards, and so forth... 

Fig. 11. Energy distributions of CIE standard illuminant A, a tungsten incandescent lamp a cool white fluorescent lamp E and CIE standard illuminant...

Clearly, standardized light sources are desirable for color matching, particularly in view of the phenomenon of illuminant metamerism described below. Over the years CIE has defined several standard illuminants, some of which can be closely approximated by practical sources. In 1931 there was Source A, defined as a tungsten filament incandescent lamp at a color temperature of 2854 K. Sources B and C used filtering of A to simulate noon sunlight and north sky daylight, respectively. Subsequently a series of D illuminants was estabUshed to better represent natural daylight. Of these the most important is Illuminant E). ... 

Sample cells were fabricated from tungsten. Additional crucibles composed of a Pt-40 w/o Rh-8 w/o W alloy were also used in experiments on the PuPt phase. Each tungsten cell was vacuum outgassed at 1800 for 1 h before an experiment. The cell temperature was determined during the measurements by sighting with a pyrometer (Pyrometer Instrument Co.) onto a blackbody hole in each cell base. The pyrometer and sight glasses were calibrated with an NBS standard lamp. 

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