Infrared light, wavelengths

In the gas correlation techniques, gas-filled cells mounted on a rotating disk cross the analyzing infrared beam in turn. One correlation cell is filled with a gas that will not absorb infrared light, such as nitrogen (N2). The other cell (or cells) are filled with a high concentration of the gas to be measured. The wavelength range is selected at the absorption band of the gas to be measured by an optical band-pass filter. 

Electric eye door openers use photoconductors that respond to infrared light with a wavelength (d) of 1.5 pm. Which is suitable for photoconductors operating at this wavelength, germanium Eg — 64 kJ/mol) or silicon Eg = 105 kJ/mol) ... 

C02-IR detection systems for example contain a light source emitting infrared light ideally at wavelengths around 4.2 pm (often a simple light bulb), an absorption path (the so called cuvette), a spectral filter and a detector (thermopile). The filter is normally integrated into the detector housing. 

Miniaturized chemical analysis systems have been developed for most macroscopic counterparts (Dittrich et al. 2006). The availability of optical fibers, light sources, and detectors in the visible UV and near-infrared (NIR) wavelengths makes it possible to integrate spectroscopic measurements in microreactors (Lobbecke et al. 2005). Fourier transform infrared spectroscopy (FTIR) is an efficient, broadly applicable... 

The spectrum of melanin has minimal optical absorbances at wavelengths greater than about 750 nm, suggesting that it does not protect us against the heat from the sun (i.e. infrared light). 

A phosphor emits a weak light at 400 nm when illuminated with infrared light of wavelength 1 /rm. (a) Make an energy diagram to explain this luminescence. 

Infrared light is divided into three zones the near-infrared, the mid-infrared, and the far-infrared, as shown in Table 12.2. The wavelength of the near-infrared is below 2.5 pm, that of the mid-infrared ranges from 2.5 pm to 25 pm, and that of the far-infrared is above 25 pm. Infrared emission between 3 pm and 30 pm is caused by vibrational modes of the molecules, while that above 30 pm is caused by rotational modes. 

The cause of global warming from man-made atmospheric gases also stems from the same factor of atmospheric persistence, as well as their ability to absorb infrared light radiating from Earth to space. Thermal radiation from a radiant body has a distribution of wavelengths, with the maximum value given by Wien s law ... 

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