UNIPULSE load cells adopt the strain gauge type.

When our customer selects a load cell, they sometimes ask: "Strain gauge or piezoelectric— Which type of load cells should we choose?"

This time, we will explain the differences of load cells between the strain gauge type and the piezoelectric type.

The strain gauge type uses elastic properties of metals. The right-side figure below is a representative graph that shows the process of metal growth in terms of the relationship between force and elongation.

As you can see in the graph, the strain is directly proportional to the stress in the elastic range. This is the range that can be used as a load sensor.

Advantages and Disadvantages of Strain Gauge Type Load cell?

Advantages: 

• Even if the same amount of load is continuously applied, there is hardly any fluctuation. (i.g. Excellent creep properties)

Disadvantages:

• At a momentary load measurement such as an impact force, it has less responsiveness than the piezoelectric type.

The piezoelectric type uses a piezoelectric element, which generates an electric charge when force is applied.

The piezoelectric element outputs larger voltage when receiving compression force, and less voltage when receiving tensile force.

Advantages and Disadvantages of Piezoelectric Type Load cell?

Advantages:

• As the rigidity can be improved, less deflection amount and high responsiveness are possible.

Disadvantages:

• Even with constant load, the output fluctuates over time. (i.e. Poor creep properties)

The piezoelectric type is ideal for the applications that measure dynamic force at a fast rate such as an impact force and such. However, due to poor creep properties, it is not suitable for static measurement such as continuously applying a constant load. Moreover, as the output fluctuates over time, it is unsuited for a continuous test, or an accurate measurement for hysteresis property of a damper, a spring and such.

Meanwhile, due to excellent creep properties, the strain gauge type is ideal for both static and dynamic load measurements, such as weight measurements, press force measurements and more.

UNIPULSE offers many line-up of load cells that are "compact" and "with high rigidity & high responsiveness".

SCB is a "hardly breakable" load cell unique to UNIPULSE.

This strain gauge type sensor has achieved phenomenal rigidity and high responsiveness.

With a wide line-up and high safe overload, it is ideal for not only press load measurements but also impact & destructive tests.

• Line-up from 100 N to 200 kN
• High responsiveness with the natural frequency of 40kHz at maximum
• Hard to break due to the safe overload of 500%

If you cannot decide to select a load cell, do not hesitate to ask us.