Abstract: Disclosed is a unique probe and amplifier circuit for use with a digital height gauge or other measuring device. Fundamentally, the invention utilizes a probe tip operatively connected to the primary and secondary windings of an LVDT; the core of the LVDT being fixedly positioned between the windings. Deflection of the probe in either direction along the axis of the core results in an output signal from the LVDT, the amplitude of the signal being indicative of the magnitude of the deflection. The signal is translated into a varying DC level, the value of the DC level being linearly related to the deflection of the probe. The DC voltage is applied to an operational amplifier having selective feedback networks associated therewith which prescribe the gain of the amplifier and hence its subsequent effect upon a calibrated meter connected to the output thereof. The meter provides visual readings indicative of the deflection of the probe.