Today’s modern industrial scales are extremely accurate and very dependable. In fact, thanks to digitals technology you have a wide range of options when it comes to choosing the right kind of scales. But what makes these scales so accurate and reliable? It has to do with technology like the compression and tension load cell. Let’s take a closer look at load cells and check out their history, to make you a better informed buyer.
In the Beginning
Lever type scales were the norm for many years. They worked with springs and dials and when properly maintained and calibrated they delivered reasonable accuracy. These scales worked by either balancing weights or force placed upon the lever mechanism.
The modern compression and tension load cell operates by sensing force, but this is nothing new. In fact, both pneumatic and hydraulic designs have been around since the mid 19th Century. Yet, it was not until many decades later that modern strain gauges came into being.
Strain Gauge Load Cells
When you apply force to something stationary, both stress and strain develop. Stress is the internal force while strain is displacement that happens. In 1856, Lord Kelvin subjected metal to strain and noticed it changed electrical resistance. Yet, it wasn’t until 1938, before the idea of using load cells (capable of measuring the resistance caused by the force placed upon them) was developed. The more force, the greater the resistance and the higher the reading.
How Tension Load Cells Work
The modern tension load cell works like the old fashion strain gauge mechanisms. The weight is suspended and the resistance applied by the weight is measured. The difference in strain is measured by the resistance change within the cells and it creates a digital signal registered by the control unit. This makes it possible to have the weighing mechanism far away from the readout.