Force Sensing Resistor (FSR)

These Force Sensing Resistors (FSRs) from Sensitronics (founded by the inventor of FSRs) are the perfect way to add touch or pressure measurement to your project.  The FSRs uses two metallic plates and a proprietary conductive pad which, when compressed, increases in conductivity.

Sensitronics FSRs differ from others on the market as they minimize sensor "drift"; when a dead weight is placed on the FSR, the voltage reading can drift, and this is not desired.  Sensitronics FSRs have very little drift with their patent-pending technology.

They come in two sizes:

• 0.5" Diameter (12.7mm), and
• 1" Diameter (25.4mm).

and come in two types of construction: 

• Shunt-mode, where the electrical current flows along one side of the pad, and
• Thru-mode, where the electrical current flows on both sides of the pad.

Thru-mode construction is slightly more sensitive than Shunt-mode construction.

Each FSR come with a 2 pin 0.1" female header attached, making them great for breadboards and prototyping without needing solder.  They also come with a 3M peel-and-stick adhesive backing for easy installation into your project.

Note:  Please ensure you do not pass more than 5mA across the FSR.  FSRs are sensitive to temperature, and this can damage the sensor's pad.  You can limit this by using a resistor in series (eg. use at minimum a 1kR pull-up resistor when supplying 5V to the sensor).

 

Documentation: 

• Guide (Theory and Circuit Application)

• Shunt-mode - 0.5" 
  • Presssure-to-Resistance Chart
  • Sensor Construction

• Shunt-mode - 1" 
  • Pressure-to-Resistance Chart
  • Sensor Construction

• Thru-mode - 0.5" 
  • Pressure-to-Resistance Chart
  • Sensor Construction

• Thru-mode - 1" 
  • Pressure-to-Resistance Chart
  • Sensor Construction