Strainsert has updated their application note on Bi-Axial Load Pins.
Download a PDF version of the Bi-Axial Load Pin Application Note
Bi-Axial Load Pins are designed for applications that measure a radially applied force (Pr) where the load direction is unknown and/or changing in direction. This is facilitated by the installation of 2 perpendicular strain gage bridges (Px and Py), instrumentation, and geometric calculations.
One common use for a Bi-Axial Load Pin is at the hub of a sheave (or pulley) system, which is used to measure line tension. A Bi-Axial Load Pin installation has one end of the line at a fixed angle as a reference while the other end will vary in angle.
Other applications include rotating joints, mooring lines, hinge pins, loader buckets, aircraft landing gear and hydraulic actuators.
Also included in the application note is information on the Crosstalk correction. Crosstalk error is observed when a radial force (Pr) is applied at varying angles and the sensor output magnitude does not fit the expected circular pattern. Instead, there are higher-than-expected readings at angles between the primary X and Y axes. This error is primarily caused by internal strain gage transverse sensitivity, which is due to physical design and construction constraints. Ideally, the ratio of transverse-to-axial sensitivity is negligible, however, this is not always the case in practice. Crosstalk error is unique and variable to each individual sensor Therefore, crosstalk errors may be marginal and crosstalk corrections may not always be required.