Calibrating the Load Cell
When you get your load cell connected, you’ll want to calibrate it. You can use this simple formula to convert the measured mv/V output from the load cell to the measured force:
Expected Force or Weight = K ⋅ (Measured mV/V - Offset)
Where K is gain value that will change depending on what unit of force or weight you want to measure. Since the offset varies between individual load cells, it’s necessary to measure it for each sensor. Record the output of the load cell at rest on a flat surface with no force on it. The mv/V output measured by the Phidget Bridge is the offset.
Once you’ve found the offset, measure something with a known weight and solve the equation for K. You can also calibrate the load cell at multiple known weights and use these points to model a linear function. For more information on calibration, you can read our past blog post.
We’ve just covered the basics of connecting load cells to the Phidget Bridge, but if you’re interested to learn more about load cells then read the load cell primer or 1046 user guide.