Nernst. glower

H2 and D2 lamp tungsten lamp Xe arc lamp Nernst glower globar... 

Nernst glower Nernst glowers Nernst-Planck equation Nerol [106-25-2]... 

The main sources of infrared radiation used in spectrophotometers are (1) a nichrome wire wound on a ceramic support, (2) the Nernst glower, which is a filament containing zirconium, thorium and cerium oxides held together by a binder, (3) the Globar, a bonded silicon carbide rod. These are heated electrically to temperatures within the range 1200- 2000 °C when they will glow and produce the infrared radiation approximating to that of a black body. 

IR spectrometers have the same components as UY/visible, except the materials need to be specially selected for their transmission properties in the IR (e.g., NaCl prisms for the monochromators). The radiation source is simply an inert substance heated to about 1500 °C (e.g., the Nernst glower, which uses a cylinder composed of rare earth oxides). Detection is usually by a thermal detector, such as a simple thermocouple, or some similar device. Two-beam system instruments often work on the null principle, in which the power of the reference beam is mechanically attenuated by the gradual insertion of a wedge-shaped absorber inserted into the beam, until it matches the power in the sample beam. In a simple ( flatbed ) system with a chart recorder, the movement of the mechanical attenuator is directly linked to the chart recorder. The output spectrum is essentially a record of the degree of... 

The amount of radiation used is also important. A Nernst glower is used in ordinary infrared spectroscopy. This light source emits a relatively low amount of radiation, and no destruction of the analyzed material occurs. However, Raman infrared spectroscopy employs a radiation source of much greater energy. This radiation is sufficiently energetic to cause bond disruption and some destruction of the analyzed material. 

Nernst glower Oxides of zirconium, thorium, and yttrium 1500 Mid-IR 10,000-500 cm Poor emission at high wavenumbers, brittle, preheating required... 

Infrared radiation is usually detected by means of a bolometer or a thermocouple. Since emission spectra are often too weak to be detected, we are here primarily interested in absorption spectra. These are obtained by interposing the substance between the prism and a source of infrared emission, such as a Nernst glower or any other suitable incandescent solid body at temperatures of 1000 to 1500°C. Several discussions on this subject are available. ... 

A Nernst glower is a cylinder of zirconium and yttrium oxides that emits IR radiation when heated to a high temperature by an electric current. Electrically heated spirals of nichrome wire also serve as Inexpensive IR sources. 

The infrared light source generates wideband radiation by heating solid materials to incandescence using electric power. There are two commonly used IR sources the Nernst glower, which is composed of mainly oxides of rare-earth elements and the Globar, which is... 

The Nernst glower is one of the oldest sensors and is used to measure the composition of automotive exhaust. 

Fe(C0)4 and presumably dihydrogen are formed upon u.v. irradiation of H2Fe(CO)4 in argon matrices. Upon exposure to Nernst glower radiation the reverse process [oxidative addition of hydrogen to Fe(CO)4] takes place. Oxidative addition in low-temperature matrices has also been observed upon irradiation (A < 360 nm) of Fe atoms in methane, the species MeFeH being identified by its i.r. spectrum. ... 

The excitation source was a filtered Nernst glower. At the power levels... 

The Wien displacement law for blackbody radiators states that the product of temperature in kelvin and the wavelength of maximum emission is a constant k k - T - Calculate the wavelength of maximum emission for a Globar infrared source operated at 18(X) K. Use the data In Figure 6-22 for the Nernst glower for the evaluation of the constant. 

FIGURE 16-16 Spectral distribution of energy from a Nernst glower operated at approximately 200 K. 

Figure 16-16 shows the spectral output of a Nernst glower operated at approximately 2200 K. Note that the overall curve shape is similar to that of a black-body. The small peaks and depressions are a function of the chemical composition of the device. 

A source with somewhat lower intensity hut with longer life than the Globar or Nernst glower is a lightly wound spiral of nichrome wire heated to about 1100 K by an electrical current. A rhodium wire healer sealed in a ceramic cylinder has simil.ir properties, although it is more expensive. Nichrome wire stturees ire less... 

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