Belt Scale Design Considerations

Belt scales are frequently used in the mining industry because of the ability to handle large tonnages without interrupting the material flow, fitting easily into all types of bulk handling systems and being relatively inexpensive. Although manufacturers claim weighing accuracies better than Y2%, many operators experience, in practice, much larger errors and they have become apprehensive about the use of belt scales. However, in spite of these disappointing instances, a belt scale is one of the most valuable tools for process and inventory control. Since it is a measuring device, care should be given to the design and installation of belt scales. The basic components of a belt scale are: (1) conveyor belt, (2) scale suspension, (3) sensing device, (4) integrating and recording. The first component of this system is of great importance to the overall accuracy and has been thoroughly discussed in earlier papers. This paper will review primarily the various scale hardware designs currently available, and will be confined to the last three components of the system.