critical angle refractometer

critical angle refractometer

[′krid·ə·kəl ¦aŋ·gəl ‚rē‚frak′täm·əd·ər] (optics) A refractometer, such as the Abbe or Pulfrich refractometer, in which the index of refraction of a medium A is measured by observing its critical angle with respect to another medium B with a known index of refraction, or by measuring the critical angle of B with respect to A.