A weigh module is a weighing device that consists of a load cell and the mounting hardware needed to attach the load cell to a platform, conveyor, tank, hopper, vessel or any object that is to become a scale. Typically, three or four weigh modules are used to fully support the full weight of the object. This effectively converts the object into a scale. A weigh module system must be able to (1) provide accurate weight data and (2) support the object safely.
There are two basic types of weigh modules: compression and tension.
Compression Weigh Modules
Compression weigh modules are suitable for most weighing applications. These modules can be attached directly to the floor, piers, or structural beams. The tank or other object is mounted on top of the weigh modules. A typical compression weigh module is shown in Figure 1-1. It consists of a load cell, a top plate (which receives the load), a load pin (which transfers the load from the top plate to the load cell), and a base plate (which is bolted to the floor or other support surface). A hold-down bolt may be used to prevent the vessel from tipping. Three weigh modules in a triangular pattern is the minimum number required to fully support a scale; 4 weigh modules in a square or rectangular pattern is also common.
Tension Weigh Modules
Tension weigh modules are used to create scales from tanks, hoppers or other objects that must be suspended from above, for example, from a building’s superstructure or upper floor. A typical tension weigh module is shown in Figure 1-2. It uses an S-shaped load cell that has threaded holes on both ends. A spherical rod-end bearing is screwed into each end and a clevis arrangement connects via threaded rods to the structure above and to the tank below. Typically three or more weigh modules are used to fully support the scale.
To learn more, download the Weigh Module Systems Handbook: