A sensor device includes: a first signal generator and a second signal generator which each generate at least one of a signal of a first frequency and a signal of a second frequency; and a calculation part configured to obtain a reference phase difference based on a first reference signal which is obtained by generating the signal of the first frequency from the first signal generator in such a state that the calculation part is connected to the first signal generator, and a second reference signal which is obtained by generating the signal of the second frequency from the second signal generator in such a state that the calculation part is connected to the second signal generator, and calculates a reference voltage corresponding to the reference phase difference based on the first reference signal and the second reference signal in accordance with a heterodyne system.