Abstract: 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 of the substrate and arranged to receive the diffracted spectral components. The template has formed thereon at least three spatial filters, each for selectively transmitting diffracted spectral components in accordance with respective ones of the desired color-matching functions such as the CIE x(.lambda.), y(.lambda.), z(.lambda.) or r(.lambda.), g(.lambda.), b(.lambda.) color-matching functions. The diffraction grating and the template may be mounted on opposite sides of the substrate, or they may be mounted in a laterally spaced-apart relationship on the same side of the substrate, in which case the opposite side of the substrate is coated with a reflective material. Detectors are arranged adjacent and behind each spatial filter to detect the spectral components transmitted by the respective filters, and the entire assembly is mounted in a light-tight housing which houses the aperture and the assembly in the desired spaced-apart relationship.

US.Class: 356/328; 356/405; 250/226

IPC: G01J 003/18; G01J 003/50