E009 - Cross Talk
All multi-axis loadcells suffer from mechanical coupling between the mutually perpendicular sensing axes. If axis X is loaded, a small effect is witnessed on both the outputs of the Y axis and the Z axis. This effect is called cross talk and is normally expressed as a percentage of the rated load for the axis. Cross talk errors are often relatively high compared to other loadcell performance errors so assessing the effect of cross talk on the uncertainty of a measurement is very important. Suprisingly many suppliers of multi-axis loadcells do not give a cross talk specification in their data-sheets for multi-axis loadcells so this assessment can be difficult. All of our loadcells do have a cross talk specification and we can supply the cross talk values at all the calibration points of a specific loadcell if you are using software to reduce the measurement errors. Our engineering department will be happy to discuss your requirements for additional calibration information.
The F307 3 Axis Engineering Application Sheet gives additional information on obtaining the best results with a specific 3 axis loadcell.
Our multi-axis loadcell calibrations are carried out with a single axis calibration rig and then the overall performance is verified using a three axis verification rig. Measurements made on our multi-axis verification rig have uncertainties slightly higher than our normal calibration rigs. The axis verification is important as 3 axis vectorial forces that can create changes in loadcell structures resulting in cross talk uncertainty not seen by using a single axis calibration force.