A centering device and method includes a sensor for sensing the center of a bore preformed in a workpiece, and a remote output unit for outputting the positional signal generated by the sensor. The sensor in held within a spindle of a machine tool and includes a stylus which contacts the inner surface of the bore, a local oscillator and modulator and an RF oscillator and antenna. The stylus oscillates a linear proximity sensor. The proximity sensor outputs a proportional DC voltage which is input to a voltage controlled oscillator (VCO) which outputs a square-wave with a frequency which is a function of the stylus position. The RF oscillator and antenna includes a radio transmitter and antenna and receives the square-wave output of the VCO, converts the square-wave to a modulated RF signal and transmits the modulated RF signal to the remote output unit. The remote output unit includes an RF receiver and demodulator, and a signal processor and output and display. The RF receiver and demodulator includes an antenna for receiving the modulated RF signal and a radio receiver and demodulator which outputs a demodulated square-wave. The signal processor and output display includes a two-stage amplifier which amplifies the demodulated square-wave, a tachometer circuit which converts the frequency of the demodulated square-wave to a voltage for display on an analog meter, and an audio output circuit which outputs an audio signal with a frequency proportional to the frequency of the demodulated square-wave.