Mantis 5000 Especificações descarregar pdf (Página 5)

Figure 2: Collection of scattered light by an integrating sphere. I

= incident light, I

= scattered light.

In order to perform useful measurements on scattering samples, it is necessary to

collect a high proportion of the scattered radiation. The integrating sphere is a highly

efficient collector of scattered radiation. Because of its design, the Diffuse

Reflectance accessory overcomes many of the problems associated with measuring

turbid or scattering samples, which include sloping baseline, poor signal-to-noise ratio

and high background absorbance.

Whilst the DRA should be used when measuring the transmittance of opaque or

diffusing solid samples, the accessory may also be used when measuring turbid

liquids.

Because the cuvette is located so as to be part of the wall of the sphere, a greater

proportion of the scattered radiation transmitted by the sample is collected by the

sphere, as shown in Figure 2 above

With the PTFE reference disk in position, a sample is placed in the cuvette, and light

is passed through the sample.

Factors affecting accuracy or precision

Below are the major factors that may affect the accuracy of measurements when using

the DRA.

Aperture area/total surface area ratio

1 2 3 4 5 6 7 8 9 10 ... 48 49

Sem comentários

Mantis 5000 Especificações Página 5