In this example the actual non linearity is about 0 031 using mv v values and 0 032 when using calculated values which is well below the specification.
Load cell calibration mv v.
This load cell sensitivity rating is specified on a load cell data sheet often in the 1 mv v 3 mv v range.
Span sensitivity mv v this is the full span output per supply volt characteristic for the load cell wheatstone bridge.
This equates to 50 mv per volt or has a 50 1 ratio.
If a load cell has a 5 volt dc vdc excitation voltage and a 0 250 mv output the resultant ratio is 250mv 5vdc.
If the load cell s sensitivity is 3 mv v and the excitation voltage provided by the converter is 10 volts then the divider will be 30 millivolts or 0 03 volts.
Most quality load cells will come with a factory load cell calibration sheet which specifies the actual sensitivity rating for that individual load cell.
The difference voltage proportional to the load then appears on the signal outputs.
The millivolt output of a non amplified load cell is linearly proportional to the excitation voltage.
So a 2 96 mv v load cell will provide 29 6 millivolt signal at full load when excited with 10 volts.
Figure 3 above is an example of a morehouse calibration shear web load cell with a non linearity specification of better than 0 05 of full scale.
The cell output is rated in millivolts per volt mv v of the difference voltage at full rated mechanical load.
This load cell sensitivity value can be used to convert the load cell s output.