Patent ID: 7283221

Claim:
An improved refractometer cell constructed of a transparent material of refractive index n g and comprising A. a first exterior surface ( 9 ) and a second exterior surface ( 14 ), said first and second exterior surfaces ( 9 , 14 ) permitting a light beam ( 1 ) to pass therethrough so as to enter and exit, respectively, the refractometer cell, and B. a pair of fluid-containing chambers ( 4 , 6 ) through which said light beam passes, said chambers ( 4 , 6 ) 1) each forming a cavity which contains at least two plane, non-parallel surfaces ( 10 , 11 and 12 , 13 ); 2) are separated by a transparent window therebetween; 3) contain fluids of refractive index n 1 and n 2 respectively, and; 4) are characterized in that said chambers comprise entrance and exit beam-passing plane surfaces ( 10 , 11 , 12 , 13 ), at least one of which has no other internal beam-passing surface parallel thereto.