Quartz crystal pressure sensor

A quartz crystal gas pressure sensor senses a range of pressures within a gaseous environment, such as from 0.1 millibar to 1 bar. The sensor includes a quartz crystal connected to manifest a piezoelectric effect upon excitation by an alternating electric field and communicating with the gaseous environment, an oscillator circuit connected to the quartz crystal for generating the alternating electric field and including a feedback circuit for providing a signal for self-excitation at the resonant frequency of the crystal as well as indication of vibrational amplitude of the crystal as a function of gas pressure within the gaseous environment, and an indicator circuit connected to the feedback circuit for converting the electrical signal into an indication of the gas pressure sensed within the gaseous environment. A gas pressure measuring method is also described.