Integrating Sphere Spectrophotometer

In order to compare the Vis-NIR instrument equipped with a difihise reflectance probe to a standard laboratory color instrument (in this case, an X-Rite SP-68 integrating sphere spectrophotometer), off-line measurements were carried out on pressed plaques at room temperature, All color values were calculated using a standard A illuminant and a 10° observer angle. 

To collect scattered transmission and correct for diffuse reflectance, a spectrophotometer with an integrating sphere should be used. This is important if films are not very transparent. 

Recording spectrophotometer with integrating sphere attachment, with ports for sample and standard... 

Spectrophotometer able to scan visible spectrum and equipped with integrating sphere... 

Attach an integrating sphere to a spectrophotometer, turn on the spectrophotometer, and allow it to warm up for 30 min prior to use. 

All ground state diffuse reflectance spectra were recorded using a Phillips PU8800 UV-Visible spectrophotometer equipped with an integrating sphere, interfaced to an Elonex PC-386SX computer. These ground state diffuse reflectance spectra were measured relative to a BaSC>4 white reflectance standard (Eastman Kodak Ltd.). 

Spectroscopy. UV-VIS reflectance spectra of the pulps were recorded directly after irradiation in the wavelength range 250-750 nm on a Perkin-Elmer Lambda 15 spectrophotometer equipped with an integrating sphere. The reflectance values (RM, strictly speaking the reflectivity of an infinitely thick specimen) at 457 and 557 nm were taken from the reflectance curves. Difference spectra were calculated by subtracting the spectrum of the irradiated pulp from the spectrum of the unirradiated one. 

Reflectance spectra are usually measured using a diffuse reflectance accessory with an integrating sphere attached to a spectrophotometer. Spectra are referenced against a reflectance standard, such as smoked MgO, barite or Halon powder. The latter is a commercial fluorocarbon that does not absorb water or suffer radiation damage as does MgO. Each of these standards is virtually free of spectral features in the wavelength range 0.3 to 2.5 pm. 

In vivo light absorption spectra (400-700 nm) were recorded with a Varian-Cary spectrophotometer equipped with an integrating sphere. Samples were taken to an approximate optical density of 0.1. Data were corrected for scattering by subtracting a baseline value as measured at 725 nm. The spectrally averaged, chlorophyll a specific absorption cross section (aph, m2 mg Chi a-1) was calculated as follows ... 

Reflectance was determined with a commercial UV/visible recording spectrophotometer with integrating sphere, using a vitrolite standard calibrated by the National Bureau of Standards. The value at 457 nm was taken arbitrarily as the reflectance. This is similar, but not equivalent to, TAPPI brightness (42),... 

Figure 34.8 Schematic illustration of the spectroscopic analysis of gold nanorods in a mouse using an integral sphere. The anesthetized mouse was placed on a port of an integrating sphere. Monochromatic light from a spectrophotometer was introduced into the abdomen of the mouse through optical fibers.

The BET surface area and pore volume and diameter of the catalysts were obtained by nitrogen adsorption at -196°C after heat pretreatment under vacuum for 4h at 350°C. The XRD patterns were collected with a Bruker D5005 diffractometer (50 kV, 35 mA) between 3 and 80° 20 using CuKa radiation. The UV-Vis DR spectra were recorded at ambient conditions with a Perkin-Elmer Lambda 19 spectrophotometer equipped with an integrating sphere reflectance accessory. The measurements were carried out at wavelengths ranging from 200 to 2000 nm, using MgO as a standard white reference. 

Diffuse Reflectance UV-Vis DR UV-Vis spectra of differently loaded V20s/Si02 samples, calcined in situ in O2 at 600°C, were obtained by a Perkin Elmer Lambda 19 spectrophotometer, equipped with an integrating sphere. 

The total reflectance of an optically thick layer of dyed particles of AgBr can be measured with a spectrophotometer equipped with an integrating sphere. One then interprets the reflectance spectrum with the aid of Kubelka-Munk functions (20), as is commonly done with paints and pigments. 

Unlike the colorimeter s filter system, a spectrophotometer works by measuring the whole spectrum of visible light reflected from a sample, i.e., between 380nm and 700nm. Commonly, measurements are taken, via an integrating sphere and then a diffraction grating (see Fig. 5.2b) with the results being expressed as the... 

F (1) Color Difference Meter Macbeth Spectrophotometer MS-2000 Integrating sphere 0°/d C... 

UV-Vis spectra were recorded on a Perkin Elmer model Lambda 6 spectrophotometer equipped with an integrating sphere. Gas-chromatographic analyses were carried out with a Dani 8521 gas chromatograph equipped with a flame ionization detector and a Carbowax 20 M 5% on Chromosorb W-AW packed column. 

For UV diffuse reflectance measurements CVD powder was placed in a high vacuum tight quartz cell with optical windows made of Suprasil. Thermal activation, as well as adsorption and desorption steps were performed by connecting the cell to a conventional vacuum line that also guarantees pressures less than 10" mbar. The UV spectra were acquired using a Perkin Elmer Lambda 15 spectrophotometer equipped with an integrating sphere. BaS04 powder was used as a reference. 

Figure 4.23 Schematic diagram of an NIR integrating sphere for DR. The sphere is placed in the sample compartment of a Hitachi model U-3410 dispersive UV/VIS/NIR spectrophotometer. The sphere design permits only diffuse reflectance to reach the detector the specular component is reflected out through the same opening the light enters. [Courtesy of Hitachi High Technologies America, Inc.,...

Topography of the samples was investigated with atomic force microscope Solver P47 in semicontact and contact modes. Optical properties were analyzed with the spectrophotometer Hitachi U-3010 (0.2 - 1.1 microns) with integrated sphere and monochromator MDR-3 (0.5 - 1.8 microns) with automatic system of signal registration. Spectra of x-ray diffraction have been recorded with the help of x-ray diffractometer Bruker D8 Advance. 

The geometry of the measurement, incident and refleeted angle of spectrophotometer beams, reference beams and use of integrating spheres are important considerations of these measurements especially when comparing optical properties measured using different configurations or instmments. 

Optical properties of the as-prepared samples were meeisuiEd on a Perkin Elmer Leunbda 1050 UV/VIS/NIR spectrophotometer. Transmittance spectra were collected from 250 to 3300 nm with a spectral resolution of 1 ran. Toted reflectance spectra were collected with a 150 mm Integrating Sphere Reflectance Accessory the samples were measured from 250 to 2500 nm with a spectral resolution of 1 ran. 

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