There are many different types of load cell available and each one is specialised to a particular job. Therefore it is imperative to ensure that the task needing to be carried out is very well defined so that the correct force measurements can be captured.
Many applications will have only limited amounts of space available for the incorporation of a load cell, and they can also often involve very large amounts of force. In these particular cases miniature, and also subminiature, compression load cells can be used as they are very small. These devices are also very rugged as they are made out of stainless steel. Where accuracy is key there are high performance cells that ensure measurement readings from the device are stable over time.
Other applications will require a type of force measurement that is a lot more sensitive to the minimum and maximum forces along with increments in forces being exerted. For these types of applications, which are typically found in laboratory measurement activities, there are low force sensors, which allow the observer to measure very small forces and also very small changes in force.
More and more processes are becoming automated and also involved robotics. The types of machinery in these processes are often hinged and operate in such a way that both tensile and compressive forces are exerted. Therefore a sensor is required that can measure both type of forces within a single device. Considering that industrial automation, and particularly robotic automation, is often carried out by small pieces of machinery the load cell required must also be relatively small. There is a range of load cells available in miniature and subminiature sizes, which can take tension or compression measurements, thus only requiring a single force measurement element.
For larger applications requiring both tension and compression measurements there are ‘S’ type load cells available. These devices feature an ‘S’ shaped gauge made out of three sections. The junctions of the devices are designed in such a way as to provide the type of force measurement, i.e. tension or compression, and the size of the force being measured. These devices are ideal for larger scale force measurements, such as those found in the weighing of suspended loads or in hoppers.
Commercial processes often need to measure the weight of a system, but there is a requirement for flexibility of the system to be able to measure the force exerted accurately no matter where the load has been placed on the platform. Platform weighing of loads is too time consuming if the load has to be placed in exactly the right place for the sensor to measure accurately. Therefore there are platform load cells, which have been developed to carry out exactly this role. They are able to provide accurate weight readings of a load placed on a platform no matter where that load has been placed on that platform.
From the information provided above, it is clear that the selection of a suitable load cell must be carefully carried out in order to ensure a match between the force types and sizes to be measured and the type of cell that is put in place.