By definition, a load cell is a form of transducers. Transducers are devices which are used to convert energy from one form into another. A wide range of energies is possible such as sound, heat, mechanical and electromagnetic. Load cells, in particular, are used to convert a force into a form of electrical signal.
There is a wide range of varieties for this device which include double and single ended shear beams, canister, bending beam and a load pin. Likewise, they have many different uses which include but are not limited to measuring force, using as portable forms of a weighing scale, feedback control, and on-board weighing.
They are used widely within the industry, with such applications being with use on wind farms and factory assembly lines.
This makes the device a necessary and useful application of technology in modern society. The way in which one of these devices manages to transduce Emenergy is interesting as it is a complicated process which takes place. This process will happen in two different stages.
Firstly, a mechanical arrangement is made and then the strain gauge will be deformed by the force that is being sensed. A pressure gauge will measure whatever deformation that happens in the form of an electric signal. This happens because a strain will change any electrical resistance of the wire.
These cells are made from four strain gauges, which are normally in a kind of configuration termed the Wheatstone Bridge configuration. There are other forms of them which are also available and include half bridges or two strain gauges, and the quarter bridge.
Before it can be used, however, it requires amplifying by using a device called the instrumentation amplifier. This is because the typical signal output is only a few millivolts. These kinds of load cell are the most common type which is used, but there are of course other types out there.
Ones which are employed in geomechanical applications are known as vibrating wire load cells, and a different kind which is used for dynamic force measurement is known as a piezoelectric load cell. When cell changes take place, a cell will be subject to a kind of ‘ringing.’ The primary reason is that they have a behavior to act somewhat like springs.
To measure them, they need to deform. A finitely stiff one will behave not unlike a spring. This way it can produce vibrations at the natural frequency. Oscillating data patterns can be result out of this ringing. It is, however, possible to suppress the ringing a little. These devices can be extremely useful and used in a wide range of different applications.