Integration Sphere

ASTM. (1988). Standard Test Method for Solar Ahsorptance, Reflectance, and Transmittance of Materials Using Integrating Spheres. Philadelphia Author. 

The nature and the distribution of different types of Fe species in calcined (C) and steamed (S) samples were investigated by means of UV-vis spectroscopy. UV-vis spectra of Fe species were monitored on UV-vis spectrometer GBS CINTRA 303 equipped with a diffuse reflectance attachment with an integrating sphere coated with BaS04 and BaS04 as a reference. The absorption intensity was expressed using the Schuster-Kubelka-Munk equation. 

Fig. 1 Schematic diagram of the integrating sphere portion of a diffuse reflectance spectrometer, illustrating the key elements of the optical train. Although the detecto has been placed in the plane of the sample and reference materials, in common practice it would be mounted orthogonal to the plane created by the intersection of the optica beams.

The optoelectrical characteristics of the display have been measured using an integrating sphere and a calibrated photodetector connected to a radiometer [30]. First, the total luminous flux from the AM-PLED was measured for different /data. Then, the AM-PLED luminance was calculated from the measured display luminous flux. For a Lambertian emitter, the luminance (L) can be calculated from the measured luminous flux (<1>) by using the following equation ... 

Y. Hong and J. Kanicki, Integrating sphere CCD-based measurement method for organic light-emitting devices, Rev. Sci. Instrum., 74, 3572-3575, 2003. 

In the middle of the 1970s, Technicon Instruments had Dickey-John produce a filter instrument for them, named the InfraAlyzer. The first, numbered 2.5, featured dust proof optics and internal temperature control. This improved stability and ruggedness made it practical for consumers to operate. Technicon also introduced the gold plated integrating sphere. 

Absolute determinations of quantum yield are possible using integrating spheres, by calorimetry and by other methods, but they are difficult and uncommon. 

Figure 8.11. Diffuse reflectance absorption spectra of a strongly fluorescent sample (1,6-diphenylhexatriene adsorbed on porous alumina) (a) conventional measurement w ith monochromatic irradiation and detection via an integrating sphere (b) measurement in a fluorimeter with two monochromators. Reaction spectra during Irons - cis photoisomerization are also given (adapted from Ref. 26).

In this section the ideal case of vanishing reabsorption, Ke = 0, is discussed, where Fb + Ff= Ftot- A large area of the sample should be irradiated close to /to = 2/3, what is a very convenient geometry in most spectrometers, or diffusely via an integrating sphere, what is less convenient but guarantees homogeneous density of irradiation. Under these conditions Eqs. (8.27) and (8.28) are sufficiently accurate for quantitative evaluation. 

Hitzenberger, R., U. Dusek, and A. Berner, Black Carbon Measurements Using an Integrating Sphere, J. Geophys. Res., 101, 19601-19606 (1996). 

In the diffuse reflectance technique (Fig. 14.2d), light scattered by a thick layer of particles is directed by the integrating sphere to a detector. Absorption... 

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. 

Fig. 7.4 Total transmission spectrum (measured with an integrating sphere) of a CD Agl fihn on glass.

When light is directed onto a sample it may either be transmitted or reflected. Hence, one can obtain the spectra by either transmission or reflection. Since some of the light is absorbed and the remainder is reflected, study of the diffuse reflected light can be used to measure the amount absorbed. However, the low efficiency of this diffuse reflectance process makes it extremely difficult to measure 120) and it was speculated that infrared diffuse reflection measurements would be futile 120). Initially, an integrating sphere was used to capture all of the reflected light121) but more recently improved diffuse reflectance cells have been designed which allow the measurement of diffuse reflectance spectra using FT-IR instrumentation 122). 

The energy of the laser pulse is measured using an integrating sphere and a (GeGaAs) photodiode, integrated by a boxcar. To ensure that mass spectra and laser energies are recorded in pairs, a home built amplitude to time converter is used to write the energy as a time delay at the end of each mass spectrum. 

UV-VIS-NIR diffuse reflectance (DR) spectra were measured using a Perkin-Elmer UV-VIS-NIR spectrometer Lambda 19 equipped with a diffuse reflectance attachment with an integrating sphere coated by BaS04. Spectra of sample in 5 mm thick silica cell were recorded in a differential mode with the parent zeolite treated at the same conditions as a reference. For details see Ref. [5], The absorption intensity was calculated from the Schuster-Kubelka-Munk equation F(R ,) = (l-R< )2/2Roo, where R is the diffuse reflectance from a semi-infinite layer and F(R00) is proportional to the absorption coefficient. 

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