Abstract: Disclosed is a method and apparatus to improve the capabilities of automatic and semi-automatic diode, integrated chip, and wafer probers. Prober contact with the upper surface of the wafer to be tested is accomplished through an electronic logic circuit triggered by electrical contact of the probe as opposed to a mechanical sensor. This improved surface position signal is supplied to additional digital logic circuitry to operate a vertical axis control mechanism which precisely locates the probes relative to the wafers that will be tested. Thus, prober contacts with test wafers are positively and accurately made improving the reliability of the test stage of wafer production.