FORCE SENSORS

Since the measurement signal generated by a quartz sensor will decay over time, long-term, static force measurements aren’t feasible. However, shorter-term, or “quasi-static”, measurements are possible within certain deadlines, depending upon the sensor and signal conditioning used.

Due to this limitation, it’s not practical to use quartz force sensors in weighing applications where a strain gauge type load cell is best suited.

How does force sensor work

The force sensors are major equipment whose underlying material is often a force-sensing resistor. Generally, the working rule of force sensors is that they answer the applied load and weight then transform them into a quantifiable output.

Use Force Sensor:

The Force sensor terminal resistance decreases when pressure is applied on the surface of the sensor. therefore the force sensor is essentially a rheostat whose terminal resistance depends on surface pressure. With higher pressure, the terminal resistance is going to be low and for low, resistance is going to be high. For convenience, we convert this Resistance into voltage.

In this resistive network, we’ve two resistances. One is constant resistance (R1) and the other is variable resistance (RV1). Vo is that the voltage at the midpoint of the potential divider circuit and is additionally the output voltage. Vo is additionally the voltage across the variable resistance (RV1). So when the resistance value of RV1 is modified the output voltage Vo also changes. So we’ll have resistance change in voltage change with the potential divider circuit.

Here R1 here may be a constant resistance and FORCE SENSOR acts as a variable resistance. Vo being output voltage and also the voltage across the FORCE SENSOR.

Here,

Vo = VCC (Rx/ (R1+Rx)).
Rx – FORCE SENSOR resistance

Now, when there’s no pressure applied on FORCE SENSOR the terminal resistance is going to be very high. This resistance also appears within the potential divider circuit. therefore the total voltage VCC appears across the sensor. thereupon Vo is going to be high because it is that the voltage across the sensor.

When the pressure is applied on the surface of the sensor the terminal resistance decreases considerably. With this decrease, the drop across the sensor within the potential divider circuit also decreases. So Vo also goes down. If pressure further increased the Vo further decreases.

FEATURES AND BENEFITS:

  • Actuation Force as low as 0.1N and sensitivity range to 10N.
  • Easily customizable to a wide range of sizes.
  • Highly Repeatable Force Reading.
  • As low as 2% of initial reading with repeatable actuation system.
  • Cost-effective.
  • Ultra-thin; 0.35mm.
  • 7. Robust; up to 10M actuations.
  • Simple and easy to integrate.

APPLICATIONS:

  • Robotics.
  • Drop Testing
  • Crash Testing
  • Fatigue Testing
  • Medical Devices.
  • Detect pressure.
  • Press Monitoring
  • Fracture Testing
  • Find center of force.
  • Detect liquid blockage.
  • Detect motion or position.
  • Detect and qualify press.