Design and fabrication of a piezoelectric sensor for weighing in motion

Based on piezoelectric effect of quartz crystal, a piezoelectric sensor with the range of 150 kN has been developed for weighing in motion (WIM).The sensor consists of the sensitive elements and load-carrying beam. In order to decrease the cost and difficulty of processing of the load-carrying beam, separate structure of the load-carrying beam is designed with series bolts. Moreover, the preload on the sensitive elements can be adjust by the bolts, thus the sensitivity of the sensor also can be adjust and calibrated conveniently. The experimental results show the sensitivity of the sensor is about 1.32 PC/N, and the non-compliance of output along the length direction is less than 3.75%. The dynamic test shows the rise time of the step response is less than 0.1 ms that meet the requirement of WIM.