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Goniometric methods of measuring the refractive index of optically transparent materials based on the refraction of light by a triangular prism are studied. A modified minimum deviation method and 3 modified constant deviation methods are examined which make it possible to determine the refractive indices of triangular prisms with unknown refracting angles. According to the modified prism methods the deflection angles of the light by the prism are measured with a goniometer, while the refractive index of the material and the refraction angles of the prism are determined by solving systems of equations. Thus, there is no need for preliminary measurement of the prism angles, which would require special autocollimation goniometers. In addition, in the modified prism methods, light reflected from the faces of the prism is not used, which makes it possible to extend the spectral range of a measurement of the refractive index to the infrared and ultraviolet ranges. The errors in measurements of the refractive index by these methods are compared for the example of a prism with a refractive index of 1.5 and a refraction angle of 60°. It is shown that the modified minimum deviation method has the smallest error among all the prism methods, so it can be recommended for high-precision measurements of the refractive index in those cases where the refractive angles of the prism are unknown or it is technically difficult to measure them. The modified methods examined here can be used for measuring the refractive index of triangular prisms made of optically transparent materials, as well as of liquids poured into hollow prisms with plane-parallel transparent windows. Practical implementation of methods of this type should be useful in the optical, chemical, and food industries for monitoring the composition and properties of optically transparent materials. [ABSTRACT FROM AUTHOR]

In order to improve the accuracy of the dynamic goniometer, the influence of its bearing unit on the measurement error has been studied. The spectral characteristics of the random error of two dynamic goniometers with similar optical angle sensors and different bearings (air and angular contact ball bearings) have been studied. It is shown that the use of a ball bearing in the goniometer leads to nonstationarity of the random error of angular measurements. Using wavelet analysis and the Allan variation, the random error of the dynamic goniometer has been analyzed, the sources of nonstationarity have been identified, and its potential accuracy has been determined. It has been established that the use of an air bearing allows increasing the accuracy of a dynamic goniometer and bringing its value closer to the accuracy of a static goniometer, in which the influence of the bearing unit is minimized. The results obtained are of interest to users and developers of dynamic goniometers. [ABSTRACT FROM AUTHOR]

A method of studying the error of a laser dynamic goniometer by a cross-calibration method with the use of a created calculation algorithm is proposed. The algorithm is based on the method of sequential rotations of a polygon relative to a ring laser from the goniometer structure. The results of the application of the specified calculated algorithm to estimate the error of a laser dynamic goniometer are presented. The dominant source of error of this goniometer is defined: the nonuniformity of the angle scale of the ring laser, which is caused by the slope of the scale to the angle of rotation of the spindle of the goniometer. Adjustment corrections are computed and introduced into the calculation algorithm, which made it possible to reduce the systematic error of the goniometer to 0.03″. [ABSTRACT FROM AUTHOR]

The geometric diagram of a bench for determining the instrument errors of high-precision two-dimensional optoelectronic goniometers is considered. These errors are found by measuring the angles between known spatially fixed reference directions and comparing the values obtained to the sizes of these angles measured by means of autocollimators oriented to a special caliber (calibrating prism) that fixes the point of intersection of the geometric axes of the controlled goniometer. The caliber standard is in the form of a multifaceted prism with reflective surfaces the normals to which form the required geometric diagram in space. [ABSTRACT FROM AUTHOR]

A simplified cross-calibration procedure used in laser dynamic goniometry is examined, in which the angular displacement increment of the studied angle sensor exceeds its resolution. The obtained method error for M uniform angular increments of the angle sensor is determined by the overall amplitude of the Mth harmonic and its aliquot harmonics of the goniometer systematic error. It is demonstrated experimentally that when the angular displacement increment of an angle sensor is less than 120°, the method error does not exceed 0.01′′. [ABSTRACT FROM AUTHOR]

A complex of interrelated problems, the solution of which will make it possible to increase the precision of measurements based on the use of an extremal counting interpolation digital photoelectric measurement system, is considered. Examples of an implementation of such a measurement system are presented. [ABSTRACT FROM AUTHOR]

The structural diagram of dynamic goniometers intended for determining the parameters of digital angledata transmitters is presented and the process of calibration of the goniometers is described. It is shown that elimination of the unsteadiness of the random error by means of filtration of the upper frequencies makes it possible to determine corrections to the results of measurements and to reduce by 150% the total error of dynamic goniometers constructed with the use of ball bearings. [ABSTRACT FROM AUTHOR]

The effect of the manufacturing quality of the optical components on the standard uncertainty in measuring the refractive index by the goniometer method is investigated. The results obtained are used to compile a budget of the uncertainty of the State Primary Standard of the unit of refractive index. [ABSTRACT FROM AUTHOR]

Abstract  The noise generated by a dynamic laser goniometer is considered and a method of reducing the random error of the device based on compensation of the generalized shift of the zero of a ring laser and suppression of the noise of the dynamic laser goniometer is proposed. Results of experimental studies are presented. [ABSTRACT FROM AUTHOR]

Abstract  Measurement algorithms are compared for laser dynamic goniometry. When one uses an algorithm for balancing out the generalized zero shift, there is a reduction in the effects of instability in the rotational velocity of the ring laser as regards the systematic and random components of the measurement error with a laser dynamic goniometer. [ABSTRACT FROM AUTHOR]