Load Cell Vs Force Sensor

Load Cell Vs. Force Sensor

This free whitepaper from Machine Design explains the specific differences between these two common force-sensing technologies.

Engineers in many industries need reliable ways to measure compressive force, either during product development, or as an embedded component in a product or device. Load cells and force sensitive resistors are common force sensor technologies, but how do they compare?

A load cell is a type of force sensor that, when connected to appropriate electronics, return a signal proportional to the mechanical force applied to the system. They can be hydraulic, pneumatic, or, most commonly, based on strain gauges. 

Typical Load CellTypical Load Cell

Advantages of a Typical Load Cell

  • Very accurate (<0.1% of full scale)
  • Readily available
  • Calibrated by manufacturer

Disadvantages of a Typical Load Cell

  • Bulky in size and rigid construction
  • Costly signal conditioning electronics
  • Not a good solution for OEM/Design-in applications

There are other types of force sensors available, such as force sensitive resistors (AKA, piezoresistive force sensors, or touch sensors) which measure force differently. A force sensitive resistor measures a compressive force directly instead of correlating the strain of a beam to force applied. The force applied to the sensor compresses two layers of a flexible, printed, piezoresistive ink together. This compression results in a proportional change in electrical signal, which like the signal of a load cell, can be calibrated to engineering force units.

Force Sensor ConstructionForce Sensor Construction

Advantages of a Force Sensitive Resistor

  • Very thin (0.2mm) and flexible construction allows for unobtrusive measurement
  • Readily available
  • Inexpensive signal conditioning electronics
  • Great solution for OEM/Design-in applications
  • Customizable
  • Ideal for innovative product design - thin, light weight, low power requirements

Disadvantages of Piezoresistive Force Sensor

  • Less accurate (±5% full scale) than typical load cell
  • Calibrated by user

Does your product or application require force sensors?

Whether you are looking for an embedded sensor for an OEM application, or you need a force sensor for test and measurement purposes, there are a number of factors to consider in choosing the right technology. Our free whitepaper details the differences between the key technologies on the market..

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