| Title | A resonant pressure sensor based on a squeezed film of gas |
| Publication Type | Journal Article |
| Year of Publication | 1993 |
| Authors | Andrews, M.K., Turner G.C., Harris P.D., and Harris I.M. |
| Journal | Sensors and Actuators: A. Physical |
| Volume | 36 |
| Issue | 3 |
| Pagination | 219 - 226 |
| Date Published | 1993 |
| ISSN | 09244247 (ISSN) |
| Keywords | Cavity resonators, Gas dynamics, Gas spring constant, Gases, Instruments, Oscillators (mechanical), Pressure effects, PRESSURE MEASUREMENT, Pressure transducers, Resonate pressure sensors, Resonators, Squeeze film effect, Squeezed gas films |
| Abstract | A new resonating sensor for gas pressure is described. The device measures the resonance frequency of a silicon microstructure that contains a thin film of gas trapped in the structure by the squeeze-film effect. The gas is confined in the structure during an oscillation cycle only by its viscosity. It exerts a measurable influence on the resonance frequency at a pressure of 10-2 mbar, and provides the dominant spring force at pressures near one atmosphere, where the short-term stability of the sensor is of the order 1/30 mbar. We present data showing that the resonance frequency is species independent, which implies that the compressions are isothermal. Damping, however, depends on the gas viscosity, and the measurement of the oscillator Q value allows species to be identified. In the device, the oscillating diaphragm is not under a pressure load so that long-term creep is not a consideration. Further, at higher pressures, the device directly measures the spring constant of a defined volume of gas with only a small contribution from the silicon spring constant. It therefore has potential as a long-term reference of pressure. © 1993. |
| URL | http://www.scopus.com/inward/record.url?eid=2-s2.0-0027593470&partnerID=40&md5=6d599ec80aaf02791846f453923e6a70 |
| DOI | 10.1016/0924-4247(93)80196-N |
