A template-type calorimeter comprising a light-transparent substrate having a diffraction grating on a surface thereof, the diffraction grating being operative to diffract light incident thereon from a spaced-apart aperture into its constituent spectral components. A template is provided on a surface...http://www.google.fr/patents/US5900932?utm_source=gb-gplus-shareBrevet US5900932 - Tristimulus template-type colorimeter
