A load cell is also known as a transducer, made for the purposes of converting force into an output which is measurable. Strain gage base types are mostly used in measuring equipment, even though there are many others in existence too. Scales that used mechanical levers were around before strain lever scales became used. Anything from tablets to railroad scales can be measured on mechanical scales. Accuracy is guaranteed, provided that the scales are maintained properly and calibrated in the right way.

 

For this transducer to operate, the mechanical lever will detect the force or a weight. Alternatively, a balancing mechanism can be used. In earlier times, pre-strain gauge force sensors had pneumatic and hydraulic designs. An English physicist developed a bridge circuit which could measure electrical resistances way back in 1843.

 

This bridge circuit is suitable for measuring any resistance changes that happen in strain gages. While the first wire strain gage was used in nineteen forty it has only become useful in recent times since modern technology made this economically and technologically viable. Strain gauges have since then been used in stand-alone cells and mechanical scale components.

 

In modern times strain gauge types are mainly used in the weighing industry with the only exception being in specific laboratories where there is a need for precision mechanical balances. Where special hygiene and safety issues are important a pneumatic load cell is used. Since they do not need power supply hydraulic types are used in remote areas.

 

The accuracy of these devices are within 0.03 percent to 0.25 percent at full-scale. The devices are ideal for almost every industrial application. Forced balance principal is the method in which the pneumatic versions work.

 

Multiple dampener chambers are used in these devices and this gives much more accuracy than the hydraulic load cell. Certain designs use the first dampener chamber in the place of a tare weight chamber. Another type is pheumatic versions are generally used for measuring small weights in the cases where safety and cleanliness is important.

Article submited by Jeff Crooley, the views and opinions expressed in this article may not reflect the views of eilersen.com