I had a company come calibrate my system, now the LVDTs are not displaying correctly, or the rut is visible on the samples, but the display is showing no rutting. Why is this?

Unlike other wheel tracker systems which have LVDTs separate from the arm movement, the SmarTracker system uses an LVDT that is integrated into the arm movement. This means that all the displacement measurements must be made under the wheel, not the LVDT tip. The gage blocks need to be placed under the center of the wheel while the arm is forward at the middle position of the stroke. This ensures a more accurate measurement of the rut because the compliance variables of the arm are included in the calibration. If after calibration the display is showing little or no rut, the LVDTs will need to be recalibrated with the correct procedure.