Inventors:
Roman C. Gutierrez - Glendale CA
Christopher B. Stell - Valencia CA
Tony K. Tang - Glendale CA
Vatche Vorperian - Irvine CA
Jaroslava Wilcox - Los Angeles CA
Kirill Shcheglov - Pasadena CA
William J. Kaiser - Los Angeles CA
Assignee:
The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC
International Classification:
G01L 1100
Abstract:
A pressure sensor has a high degree of accuracy over a wide range of pressures. Using a pressure sensor relying upon resonant oscillations to determine pressure, a driving circuit drives such a pressure sensor at resonance and tracks resonant frequency and amplitude shifts with changes in pressure. Pressure changes affect the Q-factor of the resonating portion of the pressure sensor. Such Q-factor changes are detected by the driving/sensing circuit which in turn tracks the changes in resonant frequency to maintain the pressure sensor at resonance. Changes in the Q-factor are reflected in changes of amplitude of the resonating pressure sensor. In response, upon sensing the changes in the amplitude, the driving circuit changes the force or strength of the electrostatic driving signal to maintain the resonator at constant amplitude. The amplitude of the driving signals become a direct measure of the changes in pressure as the operating characteristics of the resonator give rise to a linear response curve for the amplitude of the driving signal. Pressure change resolution is on the order of 10. sup.