The modification of yaw sensor for length standard calibration system

Yaw error measurements using a yaw sensor have been carried out to determine the characteristics of yaw errors and analyze the behaviors of the structural guide. The modification of yaw sensor design is necessary to improve the yaw error measurement. The contactless of a magnetic levitation technique that is supported a load of magnetic bearing. It is more suitable for reduction of yaw measurement error. This paper presents the new design of yaw sensor for the application that would be improved both the measurement error and repeatability. Those are measurement error and repeatability approximately minimized to 36 arcsec and less than 15 arcsec respectively, with the measurement uncertainty is 28.5 arcsec, at the confident level 95%.