Abstract
In this paper, the air buoyancy effect on Micro-Electro-MechanicalSystem (MEMS)-based gravity sensors for high-resolution gravity measurements is investigated. The MEMS gravimeter is operated in an atmospheric environment without any vacuum chamber; thus significantly simplifying the design, implementation and maintenance, and reducing the cost of the instrument. It is experimentally observed that the measured acceleration signal shows a clear correlation with the air buoyancy, and consequently the air pressure. A detailed theoretical model of the air buoyant force acting on the MEMS gravity sensor is proposed, giving a gravity-air pressure coefficient of 501.5 μ Gal/hPa for the silicon springmass system. After removing the error introduced by the air buoyant force, the MEMS gravity sensor exhibits an ultra-low self-noise floor of 1 μ Gal/ Hz@1 Hz, as well as an excellent stability, with an Allan deviation of 3 μ Gal (40 s integration time). The sensor is capable of measuring the Earth tides in a 16-day span. This discovery identified one major error source in high-resolution MEMS gravity sensors operating in atmosphere, which could potentially be useful for the development of future MEMS-based gravimeters.
| Original language | English |
|---|---|
| Pages (from-to) | 22480-22488 |
| Number of pages | 9 |
| Journal | IEEE Sensors Journal |
| Volume | 21 |
| Issue number | 20 |
| DOIs | |
| Publication status | Published - 23 Aug 2021 |
Bibliographical note
Funding Information:This work was supported by the National Key Research and Development Program of China under Grant 2018YFC0603301. An earlier version of this paper has been accepted for presentation at the Transducers 2021 Conference and will be published in its proceedings [DOI: 10.1109/Transducers50396.2021.9495620].
Publisher Copyright:
© 2001-2012 IEEE.
Keywords
- air buoyancy
- gravity sensor
- high resolution
- high-stability
- MEMS devices