Abstract: A system for decoding a signal of a rotating portion of a machine. The system includes a sensor configured to output N signals based on signals received from the rotating portion, and a processor configured to derive a value from a plurality of differences between sampled data obtained from the N signals.

Abstract: A capacitance probe measures and tracks frequency and amplitude changes of a component during a high cycle fatigue portion of a life test. The probe includes an internal oscillator, an adjustable receiver circuit, a product detector, and a pair of gain amplifiers. The oscillator generates a single controlled frequency output. The receiver circuit receives the frequency and creates a DC voltage shift that nulls the capacitance bridge. The product detector detects an amplitude modulated product of the oscillator and rejects undesirable frequencies. The gain amplifiers detect a DC voltage shift and permit the capacitance effect to be easily nulled.