Traceability enhancement in angle measurements

Abstract

Traceability of angle measurements is based mainly on the standard of the plane angle prism (polygon) calibrated at appropriate accuracy. Nevertheless, the standard (etalon) of flat angle - polygon has many restrictions for the transfer of angle unit - radian (rad) and other units of angle. It depends on number of angles formed by the flat sides of the polygon. Here is proposed a possibility to create the standard of the plane angle equal to it rad using the circular scale with the rotation axis of very high accuracy and two opposite placed precision reading instruments with appropriate alignment. Proposed method permits an implementation of PI rad as primary standard angle and enables to assure a traceability of flat angle measurements at laboratory environment. Short information about the multipurpose angle measurement test bench developed is presented.