On the Air Buoyancy Effect in MEMS-Based Gravity Sensors for High Resolution Gravity Measurements
| Autor: | Qian Wang, Lujia Yang, Chun Zhao, Wang Qiu, Fangjing Hu, Ji'ao Tian, Xiaochao Xu, Yanyan Fang, Liang-Cheng Tu |
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| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | IEEE Sensors Journal. 21:22480-22488 |
| ISSN: | 2379-9153 1530-437X |
| DOI: | 10.1109/jsen.2021.3106667 |
| Popis: | 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 $\mu$ 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 $\mu {\mathrm {Gal}}/\sqrt{\rm Hz}$ @1 Hz, as well as an excellent stability, with an Allan deviation of 3 $\mu$ 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. |
| Databáze: | OpenAIRE |
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