Embodiments described herein generally relate to methods and apparatuses for ensuring the integrity of probe card assemblies and verifying that probe cards are ready for testing. In one embodiment, an apparatus includes a stage that allows stable and precise movement of a sensor. The stage includes a first support, a second support, and a sensor carrier. A plurality of lifting devices is coupled to the second support and the sensor carrier, providing a more stable and precise movement for the sensor carrier. Methods for identifying objects other than the probes disposed on a surface of a probe card and to determine whether the probe card is ready for use are disclosed.