Temperature Compensation of the MEMS-Based Electrochemical Seismic Sensors

Abstract

Electrochemical seismic sensors that employ liquid as their inertial masses have the advantages of high performances in the low-frequency domain and a large working inclination. However, the surrounding temperature changes have serious impacts on the sensitivities of the sensors, which makes them unable to work as expected. This paper studied the temperature characteristics of electrochemical seismic sensors based on MEMS (micro–electro–mechanical systems), and analyzed the influences of the temperature effects on the open-loop and closed-loop amplitude-frequency curves. Most importantly, the temperature compensation circuits based on thermistors were developed, which effectively adjusted pole frequencies and sensitivity coefficients, and finally realized the real-time temperature compensation for both open-loop and closed-loop measurements for the first time. The results showed that in the temperature range of −10 °C ~ +40 °C, and with the 3 dB bandwidth range of 0.01 Hz ~ 40 Hz, the change of the maximum sensitivity was reduced from about 25 dB before temperature compensation to less than 2 dB after temperature compensation.

A micromachined electrochemical angular accelerometer with highly integrated sensitive microelectrodes

“…Among them, the 3 dB bandwidth of the three structures was quantified as 0.01–0.05 Hz, 0.01–0.1 Hz and 0.01–0.2 Hz, respectively. Since structure 3 with 100 μm for via spacing and 60 μm for via size demonstrated the largest bandwidth and the highest high-frequency sensitivities, it was chosen as the micromachined angular accelerometer with circuit compensations (a pole compensation circuit 20 and a feedback circuit 19 ), where the sensitivity and 3 dB bandwidth were quantified as 80 V/(rad/s 2 ) and 0.01–18 Hz, respectively.…”

Frequency Response of a Six-Electrode MET Sensor at Extremely Low Temperatures

“…The problem of providing stable, temperature-independent characteristics is currently solved by using electronic circuits whose gain depends on temperature and frequency [17][18][19],…”

“…The problem of providing stable, temperature-independent characteristics is currently solved by using electronic circuits whose gain depends on temperature and frequency [17][18][19], thus compensating for the temperature changes in the properties of the working fluid. Additional stabilization of the characteristics is provided by using a force negative feedback [20][21][22].…”