请问红外reflectance和absorbance的区别，以及如何转化，十分感谢！？Reflectance与Reflectance factor：Reflectance/transmittance is the ratio of the reflected/transmitted radiant flux to the incident flux (measured in watts). Similarly to the phenomena one distinguishes between regular and diffuse reflectance/transmittance. The usual symbol is the Greek letter ρ forreflectance and τ for transmittance.? ???Reflectance factor is a quantity that has to be distinguished from reflectance. It is defined as the ratio of the radiant flux reflected in the direction delimited by a given cone (see Figure3 - 9), to the reflected radiant flux reflected in the same directions by a perfect reflecting diffuser identically irradiated. Its usual symbol is R.? ???The angular distribution of the irradiation and the cone of observation have to be defined to be able to compare results taken with different instruments. The reflectance factor will approximate the reflectance as the observation cone approaches 2π sr (steradian). On theother hand for regularly reflecting surfaces that are irradiated by a beam of small solid angle,the reflectance factor may be much larger than 1 if the cone includes the mirror image of the source.? ?? ?If the cone delimiting the reflected radiant flux in the definition of the reflectance factor is negligibly small we get the radiance factor, where the reflected radiance of the surface is compared to the radiance of the equally irradiated perfect reflecting diffuser. It is usual to usethe symbol β to describe the radiance factor.Above are the most important quantities used in describing the colorimetric characteristics of materials, for further details please consult the Glossary or the relevant CIE publications，查看更多
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