Modified prism methods for measuring the refractive index of solid and liquid substances

Methods for measuring the refractive index of optically transparent dielectric materials are considered. Modified methods based on minimum deviation and constant proposed allow determining triangular prisms with unknown apex angles. In methods, angles light three faces prism measured, material determined from solution a system equations. To implement goniometric is used. That was designed to measure between flat surfaces objects in manual automated modes. Reference samples made N-SF 1 optical glass, hollow filled distilled water studied. The compared measurement error estimated. It shown that modified can be used high-precision measurements cases where unknown, or their associated technical difficulties.