Development Of Weight Measurement System Based On Bend Sensor And Linear Compression Spring

In this paper, we proposed to develop a weight measurement system by using bend sensors and a linear compression spring. In the proposed system, a bend sensor is mounted vertically to a linear compression spring. The free end of the bend sensor is attached to the top end and the other end having electrical connection is attached to the bottom end of the spring. The bend sensor is a flexible sensor whose resistance varies with the variation in bending radius of the curvature. The weight to be measured is applied on top of the pane placed on the compression spring. With the application of weight, the length of the compression spring will vary and hence this variation will vary the bending radius of the flex sensor. Thus, the variation in bending radius will introduce variation in the resistance of the bend sensor. Using resistance to voltage converter, the variation in resistance is converted to voltage. The signal conditioning circuit is used to process the output of resistance to voltage converter. Further, National Instruments Data Acquisition card NI USB-6001 is used to acquire the signal and transmit it to a personal computer in real time. The Graphical User Interface developed on LabVIEW platform hosted in personal computer displays the measured weight in real time. The advantages of the system are it’s simple in design and low in cost.