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In industrial automation, weighing is the calculation of the mass of a given product, raw material, component or vehicle.
When speaking of weighing systems, reference is often made to load cells, i.e., electronic transducers that measure the force applied on an object by means of an electrical signal that varies as the deformation that the force in question produces on the transducer changes. So it is in electronic weighing systems and in the measurement of mechanical compressive and tensile forces in the logistics, transportation, building construction, laboratory, robotics, scale manufacturers, and food industries that load cells find their main applications.

Load cells are transducers that convert compressive, tensile, torsional, pressure or rotational forces into an electrical signal.
They are used for measuring force and weight (from micrograms to tons). They usually generate an analog signal as an output that is amplified through special acquisition boards.

• Design features: single point, tension/compression, cantilevered
• Applications: industrial electronic weighing systems, mechanical strain measurements, weighing of trucks, rail cars, ships, cranes, hoppers and tanks, batching of food products.
• Models: analog, digital, miniature, specialty for automotive, robotics, metrology, hazardous areas.

LVDT (Linear Variable Differential Transformer)

Load cell based on inductive displacement transducers. The force applied to the platform compresses the spring and moves the moving crew of the LVDT. The latter provides an output proportional to the displacement and thus to the force. They are suitable for precision measurements.

Strain gauge bridge

The load cell includes four strain gauges placed along the ring of the
cell. The applied force causes an elongation of strain gauges R2 and R4 and a compression of strain gauges R1 and R3. This bridge configuration is such that it gives the maximum voltage change as a result of load application, while the unbalance due to temperature change is minimal. Can be used in stationary measurements.

Piezoelectric crystal

Applying a force to the surface of a piezoelectric crystal generates a charge buildup proportional to the force. The surfaces of the piezoelectric material behave like the faces of a capacitor. Piezoelectric load cells possess a high response rate, however, because of the leakage current the voltage supplied by the charge amplifier tends to decrease. This makes them suitable for vibration measurements.