High-accuracy device for measuring the twist angle

Abstract

This paper describes a high-accuracy optoelectronic device for measuring the twist angle, based on an autocollimation method and using a reflector in the form of a unit of right-angle prisms. The device makes it possible to measure the relative twist angle of objects in the range ±2.5° when there is a distance of 2.5–3.5 m between the reflector and the optoelectronic unit of the device. The rms deviation of the measured angle from the true value in this case does not exceed 2′′ in the range ±2.5°, and it does not exceed 1′′ in the range ±10′. A specially shaped mark is used in the device that makes it possible to measure the auxiliary angle between the direction of the edge of the prism reflector and a plane perpendicular to the optical axis of the device. The installation can be used to transfer the azimuthal direction vector.