Principles and nomenclature for the quantification of light

This chapter does not deal with any practical aspects of light measurement, only with theoretical concepts. The following concepts are explained: energy fluence, energy fluence rate, photon fluence, photon fluence rate, radiance and mol, as well as the following superfluous or obsolete terms and synonyms: actinic flux, space irradiance, scalar irradiance, spherical irradiance, vectorial irradiance, and einstein. The chapter furthermore deals with spectral weighting of radiation and some psychophysical concepts, such as illuminance, lumen, lux, etc