Spectrophotometer light source

Spectroscopic evaluation of the catalysts. The UV-Vis spectra of the Jacobsen Co-salen catalysts were collected in the transmission mode on a CARY-3E UV-Vis spectrophotometer by dissolving the catalysts in epichlorohydria The Co K-edge (7709 eV) X-ray absorption near edge stracture, XANES, of Jacobsen s Co-salen catalyst was collected during the HKR reaction at beamline XIO-C at National Synchrotron Light Source (NSLS), Brookhaven National Lab, Upton, NY. 

A light source used frequently for ultraviolet absorption studies is the deuterium lamp. If an instrument is meant strictly for ultraviolet work, then the deuterium lamp is the only light source present and the instrument is called a UV spectrophotometer. Often, both a tungsten filament lamp and a deuterium lamp are present and are individually selectable. Also, instead of having two independently selectable... 

How is the wavelength called for in a procedure isolated from the many wavelengths present in the light from the light source in a spectrophotometer ... 

The ultraviolet (UV) absorption HPLC detector is basically a UV spectrophotometer that measures a flowing solution rather than a static solution. It has a light source, a wavelength selector, and a phototube like an ordinary spectrophotometer. The cuvette is a flow cell, through which the column effluent flows. As the mobile phase elutes, the chromatogram traces a line at zero absorbance, but when a mixture... 

Absorption spectra are usually registered by instruments known as spectrophotometers. Figure 1.5(a) shows a schematic diagram with the main elements of the simplest spectrophotometer (a single-beam spectrophotometer). Basically, it consists of the following elements (i) a light source (usually a deuterium lamp for the UV spectral... 

Figure 5.15 A control chart showing a sudden change, a "stair-step" change. This could result from a system component that was replaced, such as a light source in a spectrophotometer, or a recalibration of a component, such as a viscometer tube.

The intensity of radiation coming from the light source varies over the entire UV-Vis range. Most UV-Vis spectrophotometers have dual light sources. A... 

Photometric emission measurements are carried out using either atomic absorption spectrophotometers without the light source, or flame photometers. The latter are... 

For the purposes of chemical oceanography, spectrophotometry is limited to wavelengths from the UV to near-IR (250 to 1500 nanometers). The various forms of spectrophotometer differ primarily in combinations of light sources, dispersive elements, and detectors. 

The spectrophotometer is used to measure absorbance experimentally. This instrument produces light of a preselected wavelength, directs it through the sample (usually dissolved in a solvent and placed in a cuvette), and measures the intensity of light transmitted by the sample. The major components are shown in Figure 5.5. These consist of a light source, a monochromator (including various filters, slits, and mirrors), a sample chamber, a detector, and a meter or recorder. All of these components are usually under the control of a computer. 

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