echelle grating turi-ye narde-yi (#) Fr.: réseau à échelle A diffraction grating in which the groves are relatively widely spaced and serves to provide high resolution and dispersion. Echelle, from Fr. échelle "ladder," , from O.Fr. eschele, from L. scala "ladder;" → grating. Turi, → grating; nardé, contraction of nardebân "ladder; échelle." |
echelle spectrograph binâbnegâr-e narde-yi (#) Fr.: spectrographe à échelle A spectrograph that uses an echelle grating to disperse the light. → echelle grating; → spectrograph. |