Load cells are transducers that help convert an input mechanical force into the electrical output signal. They are also known as load transducers and load sensors. There are different kinds of these devices and the most common is the strain gage based.

 

These cells are used for industrial weighing. They are used in place of mechanical lever scales which are just not as accurate. They can be used for many different functions, though, from a small pill to a large railroad car. They need to be calibrated and properly maintained on a regular basis. This causes a lot of work and money.

 

These instruments are usually balanced with precision mechanical balances. Making sure they are accurate is highly important. Strain gage based are usually the most accurate and take less maintenance than other types.

 

There are several different types to choose from. There are hydraulic ones that is a force balance device and it measure the weight and change in the pressure of the internal filling fluid. The force that is placed on the loading head is then moved to a piston and that fills the chamber with fluid. As the fluid rises, the pressure changes the controls and the output is reflected. This type of scale is great for large objects and also because it has a sensor it can be used to measure hazardous materials.

 

Pneumatic load cells  work with force and balance. The accuracy is much higher than hydraulic devices. They are usually used to weigh small objects. They are not prone to explosions and does not change with the temperature. It also has no fluids. It can be slow, however.

 

The strain gage load cells use electronic signals and are the most reliable. It has high sensitivity. These can be used with any weight and have lower cost for maintenance.

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