pressure sensing

Pressure sensing is a technique in which pressures applied to a surface are converted into an electrical signal. There are relatively simple but highly sensitive methods for this, which are based on the frequency change ofoscillating circuits.

In this method, pressure is applied to an electrode of a capacitor by a resonant circuit. The pressure causes the capacitor to change its capacitance. This results in a change in the frequency of the oscillating circuit. If the resonant circuit is the frequency-determining component of an oscillator, the change in capacitance is accompanied by a change in frequency. As the capacitance increases with pressure, the oscillator frequency decreases.

The output of the pressure sensor is an analogvoltage that is converted to a digital signal in an AD converter. Corresponding pressure sensing systems can be used for calibrated measurement of pressures, forces, weights and accelerations.