A digital depth gauge is provided for measuring a depth of a hole in an object. Inone embodiment the gauge includes: a user interface with a display and at leastone actuator； a reader shaft with a distal end and a proximal end connected to theuser interface； a probe that extends from the distal end of the reader shaft andwhich includes a tip configured to locate a distal surface of the hole； a sleevemember with a distal end configured to abut a proximal surface of the hole, thesleeve member being coupled with the reader shaft for relative translationaland rotational movement； and a sensor interposed between the reader shaft andthe sleeve member for measuring relative translational movement between thereader shaft and the sleeve member, hi some embodiments,- the gauge may includea means for aligning elements of the sensor.
