Mantis 5000 Dokumentacja Pobierz pdf (Strona 4)

exhibits NIR performance that is superior to traditional coatings

(1)

, whilst maintaining

UV-Vis performance.

Warning

If the DRA is not used in the manner specified by the manufacturer, the protection

provided by the accessory may be impaired.

Theory

Reflection consists of two components: specular and diffuse. Specular reflectance is the

mirror-like reflection off a sample surface. Diffuse reflectance occurs when the surface

reflects light in many different directions, giving the surface a matt finish.

Figure 3: The two components of reflection: specular and diffuse reflection. n represents

the surface normal, an imaginary line at 90° to the sample surface.

Traditionally, the accessory used to measure diffuse reflectance is the integrating sphere.

Applications include characterizing solar materials, color measurement and

characterization, and obtaining reflectance spectra of a painted surface. Integrating

spheres have also proven ideal for measuring the transmission of turbid, translucent or

opaque refractory materials where standard techniques proved inadequate due to loss of

light resulting from the scattering effects of the sample. Samples which distort the beam

of the instrument, such as a lens, can also be studied with the Diffuse Reflectance

accessory.

The DRA is an integrating sphere accessory that replaces the sample compartment of the

spectrophotometer instrument. An integrating sphere is a hollow optical device, either

constructed from or coated internally with a white diffusing material and fitted with the

same detector configuration as the host spectrophotometer. The coatings used in an

1 2 3 4 5 6 7 8 9 ... 87 88

Brak uwag

Mantis 5000 Dokumentacja Strona 4