The invention relates to the technical field of
capacitance displacement sensor calibration, and particularly provides a
differential capacitance displacement sensor scale factor test method and
system based on a torsional
pendulum, a detection pole plate is suspended through a suspension wire to form the torsional
pendulum, and the rotation angle of the detection pole plate is measured through a high-precision optical measurement instrument; after excitation
voltage is applied to the excitation pole plate,
induced voltage is generated on the detection pole plate and interacts with the induction pole plate to generate electrostatic
negative stiffness, so that the resonant frequency of the torsional
pendulum is reduced, the
induced voltage generated on the detection pole plate is calculated through the change of the resonant frequency, and then a scale factor is obtained. The induction
voltage of the detection pole plate is indirectly tested in a non-
contact mode, then the scale factor is obtained, actual measurement of the scale factor of the
differential capacitance displacement sensor is achieved, errors generated by using
simulation or theoretical calculation results are avoided, interference introduced by existing direct measurement of the induction
voltage is also avoided, and the measurement accuracy of the
differential capacitance displacement sensor is improved. And the
measurement precision of the scale factor is effectively improved.