# Resistive force sensor: some basic questions about its functionality

I want to know what the circular force sensor outputs when it is connected to the breadboard (with resistor). Does it output force measured in grams? When I slightly touch the sensor with a finger, the output value varies around 500-600.

Another question: Do I need to somehow calibrate the output values in order to use them for other measurements?

• It's just a variable resistance. I doubt that it is calibrated at all. – Dave Tweed Mar 2 '16 at 3:08
• 500-600 Ohms? 500-600 Volts? 500-600 llamas? Units are important. – Chris Mueller Mar 2 '16 at 12:54
• Units! units! units! – DLS3141 Mar 2 '16 at 13:32

So, if you are reading 500 Ohms of resistance across the force sensor, then the approximate mass on the sensor (force $\neq$ mass, argh) is 4 kg. In order to get a more accurate measurement though, you will need to calibrate the sensor with a range of known masses since every sensor produced by the company will be slightly different.