Amusingly, a loadcell is in fact a very precise measurement of how far something has travelled in response to a load. More specifically, a resistor changes val

Amusingly, a loadcell is in fact a very precise measurement of how far something has travelled in response to a load. More specifically, a resistor changes value very slightly as it is compressed or expanded. If you laminate a resistor to a strip of metal, you can use that change in resistance to measure the deflection, and then derive the force that drove that deflection. In principal you can get the same information with a lever attached to the same strip connected to a potentiometer; indeed, lever scales based on amplifying the deflection like that used to be universally used. Source: I was a loadcell technician in a previous life.