An apparatus includes a portion that moves along a guided path and a displacement gauge that outputs readings based on the portion's position on the guided path. The apparatus additionally includes an intermediate limit switch that is activated in response to the portion being moved to an intermediate position on the guided path. The apparatus also includes a processing device configured to calibrate the apparatus based on a first reading corresponding to a first position on the guided path and a second reading corresponding to a second position on the guided path. The processing device verifies the calibration based on a third reading corresponding to the intermediate position.