Scales and balances are used to measure static or dynamic loads for a wide range of industrial applications. They are used to weigh small packages, the contents of hoppers, and extremely heavy loads that are hauled by trucks or trains. Performance specifications for scales and balances include measurement type, rated load, and accuracy. There are three basic measurement types: compression, shear, and tension. Compression squeezes contents along the same axis. Shear is compression along the offset axes. Tension weigh modules are used to convert a suspended tank or hopper into a scale. To provide reliable measurements, mounting hardware is used to ensure that only the vertical load is measured. Rated load is the maximum load that scales and balances can handle without sustaining permanent damage. Accuracy is the limit tolerance or average deviation between the actual output and the theoretical output.