5:15 PM - 6:45 PM
[MTT38-P04] Performance Evalution of the New MEMS Microbarometer
Keywords:MEMS barometric pressure sensor, Infrasound, Microbaroms, Microbarometer
Introduction
By measuring infrasound, which is sound waves with frequencies lower than human audible frequency (approximately 20 Hz to 20 KHz), large-scale fluctuations such as earthquakes and volcanic eruptions that lead to natural disasters can be detected. A well-known barometer that can measure this infrasound is the quartz crystal barometer. This barometer is high-performance with a resolution of parts-per-billion and an accuracy of ±0.08 hPa (±0.008% FS). However, it has the disadvantage of being expensive. Conversely, popular barometers are inexpensive but lack sampling speed and resolution. To improve the accuracy of infrasound observations, it is important to deploy infrasound sensors (microbarometers) over a wide area. For this purpose, a low-cost and high-performance microbarometer is needed.
Design of the new MEMS microbarometer
The MEMS barometric sensor in the new MEMS microbarometer we designed is a capacitive barometric sensor, which is a low-cost, compact, and low power consumption device. However, it lacks the signal-to-noise ratio required to measure infrasound on its own. To solve this problem, oversampling and Infinite Impulse Response (IIR) filter were used to remove noise from the air pressure value output from the MEMS barometric sensor. In addition, multiple (n) MEMS barometric sensors were placed in a housing and averaged to reduce the noise level to 1/√n.
Observation and Results
To evaluate the performance of the new MEMS microbarometer, we observed wave-induced microbaroms phenomena at the Yokohama Research Laboratory of the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) and at Mitomi Giken Co., Ltd. As a result, microbaroms could be observed multiple times. In addition, the PDS graph was comparable to that of a quartz crystal barometer, which was simultaneously observing, and captured microbaroms with a period of 0.2 Hz. The amplitude of the microbaroms was about ±100 mPa, which indicates that the noise level of the new MEMS microbarometer is about 10 mPa. In this presentation, we will report the evaluation results of the temperature characteristics, humidity characteristics, and stability of the new MEMS microbarometer, as well as the observation results.
By measuring infrasound, which is sound waves with frequencies lower than human audible frequency (approximately 20 Hz to 20 KHz), large-scale fluctuations such as earthquakes and volcanic eruptions that lead to natural disasters can be detected. A well-known barometer that can measure this infrasound is the quartz crystal barometer. This barometer is high-performance with a resolution of parts-per-billion and an accuracy of ±0.08 hPa (±0.008% FS). However, it has the disadvantage of being expensive. Conversely, popular barometers are inexpensive but lack sampling speed and resolution. To improve the accuracy of infrasound observations, it is important to deploy infrasound sensors (microbarometers) over a wide area. For this purpose, a low-cost and high-performance microbarometer is needed.
Design of the new MEMS microbarometer
The MEMS barometric sensor in the new MEMS microbarometer we designed is a capacitive barometric sensor, which is a low-cost, compact, and low power consumption device. However, it lacks the signal-to-noise ratio required to measure infrasound on its own. To solve this problem, oversampling and Infinite Impulse Response (IIR) filter were used to remove noise from the air pressure value output from the MEMS barometric sensor. In addition, multiple (n) MEMS barometric sensors were placed in a housing and averaged to reduce the noise level to 1/√n.
Observation and Results
To evaluate the performance of the new MEMS microbarometer, we observed wave-induced microbaroms phenomena at the Yokohama Research Laboratory of the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) and at Mitomi Giken Co., Ltd. As a result, microbaroms could be observed multiple times. In addition, the PDS graph was comparable to that of a quartz crystal barometer, which was simultaneously observing, and captured microbaroms with a period of 0.2 Hz. The amplitude of the microbaroms was about ±100 mPa, which indicates that the noise level of the new MEMS microbarometer is about 10 mPa. In this presentation, we will report the evaluation results of the temperature characteristics, humidity characteristics, and stability of the new MEMS microbarometer, as well as the observation results.