A self-centring device designed for mass comparators

By means of a symmetric kinematic pair consisting of arc-shaped guide rails and rollers, a self-centring device was designed to achieve self-centring of high-class, large-mass weights during calibration. Achieving self-centring can reduce the influence of the load offset error on the mass comparator accuracy. Experiments were performed to verify the effectiveness of the self-centring device by comparing measurements gathered with and without use of the device. The results showed that the self-centring device reduced the load offset error of the mass comparator and improved the calibration accuracy.