Sample Setup: Reflected Color
欧美激情小说Color measurement involves determining the reflection spectrum of a sample and applying it to a standard illuminant. The amount of light energy the sample reflects is manipulated and reduced to tristimulus values X, Y and Z. These values correspond to the physiological response of the three types of color receptors in the human eye. X, Y and Z values are combined into uniform colorspace values such as L*, a* and b*.
A USB4000 with a 25 m Slit and Grating #2 (350-1000 nm) works well for color analysis. For those using an integrating sphere as the sampling optic, we recommend an L4 Detector Collection Lens to improve sensitivity.
When taking reflective-color measurements, your data depends on sampling geometry. The R400-7-VIS-NIR Reflection Probe provides illumination and detection from the same direction. If you use the probe at a 45? it measures diffuse reflection. If you use the probe at a 90? it measures specular reflection. The distance from the probe to the surface determines the sample size. An alternative is the ISP-REF Integrating Sphere, which provides 180?illumination and detection from flat surfaces for measuring specular and diffuse reflection.
Reflectivity is measured against a reference standard such as the WS-1 Diffuse Reflectance Standard. SpectraSuite Spectroscopy Operating Software calculates a variety of colorspace values from the reflection spectra.