PRECISION ACCELEROMETERS WITH MU-G RESOLUTION

A highly miniaturized accelerometer for micro- gravity measurements in spacecraft has been developed. It is based on a capacitive micromechanical silicon chip and an associated CMOS measurement integrated circuit. The accelerometer has been modeled in order to select and to optimize the system. The technology for the electromechanical chip, based on a glass-silicon sandwich structure has been developed. The final accelerometer developed, with an analog output signal of 5 V/g and a working range of ± 0.1 g, has a resolution of less than 1 μg at 1 Hz. Transverse sensitivities are below 0.4%. The temperature coefficients of offset and sensitivity are typically 30 μg/°C and 150 ppm/ °C respectively. Bandwidth is d.c. to 100 Hz. The hybrid technique accelerometer package has a size of 33 mm × 15 mm × 5 mm. © 1990.