A transducer that can convert force into an electrical output is a load cell. There are a lot of different types of this technology and of those, the most often used is called a strain gage based cell. These are predominantly used in applications for weighing.

 

Before the strain gage, there were mechanical scales. The earliest use of an early version of this type of technology was first used in 1843. Since then, many improvements have been made to technology and the technology is now technically and economically more efficient.

 

The cell coverts the load that acts upon it into an electrical signal (analog). The many types are distinguished by the signal that is generated and or how they can detect weight. Some other types are compression, tension, shear and bending. Most of this technologies uses is completely dependent upon what needs to be measured and in what way. When trying to keep costs down, there are clearly advantages in using one method, or type of cell over another. Determining the right type to use will depend on a number of different factors. Each of the different types has both an advantage and disadvantage. Namely, pneumatics have the higher tendency of being problematic.

 

A hydraulic load cell is a balancing device. They measure changes in pressure of the fluid inside. As force is increased, pressure of the fluid rises.

 

Pneumatic cells work about the same as a hydraulic. Instead, these do not use fluids. They are fairly slow and need nitrogen or air being regulated.

 

A strain-gage load cell turns the load into an electrical signal. These are the most commonly used. They are continually being improved upon and are cheaper to use and maintain. Strain-gage is overall the easier to maintain and to improve upon. The other types have great advantages, but if cost is a concern then a strain-gage would be the clear choice.

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