Effect of the load pad size on the output of the column-type force transducer

Abstract

The size of the load pad had a significant effect on the output of the column-type force transducer. It was important to eliminate the influence when the transducer was loaded in a force transducer build-up system which worked as the primary force transfer standard. A common model of the output about the column-type force transducer affected by the shape of load pad was analysed. Seven load pads with various dimensions were designed and fixed on a 300-kN force transducer to investigate the influence of the dimension on the indication error of the transducer. The results showed that the load pad of the sphere–plane contact design would cause the smallest indication error but the largest contact stress. It was better to use the load pad of the sphere–sphere contact design with the spherical radius ratio of ball to cup equalled to 0.2. The spherical radius of the ball should be small under the permission of material strength. In addition, it was important to enhance the stiffness of the build-up system to eliminate the effect of the load pad size on the indication error of the transducer.