Electrostatic capacitive pressure sensor and pressure detection method using the capacitive pressure sensor

A fluid pressure detection method using an electrostatic capacitive pressure sensor comprising a fixed electrode and a movable electrode which is arranged opposite to the fixed electrode and deflects in accordance with a pressure of a fluid, a reference chamber provided between the electrodes, and a measurement chamber filled with the fluid for causing deflection of the movable electrode, the electrostatic capacitive pressure sensor configured to measure the pressure of the fluid by directly converting an amount of change in a capacitance between both electrodes which changes in accordance with a movable displacement of the movable electrode to an electric signal,

• the method comprising:
• filling the measurement chamber with a pressure detection fluid;
• sequentially applying a first potential and a second potential to the movable electrode;
• generating a first output signal corresponding to the first potential and a second output signal corresponding to the second potential;
• generating a difference signal between the first output signal and the second output signal;
• and
• detecting a pressure of the pressure detection fluid based on the difference signal.