Sub-micro-g resolution test of accelerometers based on tilt dynamic modulation in gravity field

Abstract

Abstract Strategic-grade accelerometers play a pivotal role in various application fields and fundamental research. As the performance of accelerometers are improving rapidly, the requirements for test method have been raised. However, due to the influence of environmental noise, the test facility for accelerometers, especially when the resolution reaches sub-μg level, remains a challenge. To address this limitation, this study introduces a resolution test facility based on tilt modulation in gravity field, driven by piezoelectric ceramic stacks. The input acceleration ranges from 30ng to 10 μg, and the frequency is adjustable from 0.01 Hz to 20 Hz. Since the input acceleration oscillates at certain frequency, modulation & demodulation technology enables us to extract ultra weak signal out of relatively noisy background. With this facility, we test the resolution of commercial strong motion accelerograph, quartz flexure accelerometers, and homemade accelerometer based on levitated optomechanics, proving the reliability of this method. Our advancement in test method lay solid foundation for strategic-grade accelerometers, not only provides a minimal resolution test solution in the ng to μg range, but also provides a possible scheme of evaluating dynamic response characteristic with an ultra-low acceleration input in a considerable frequency range.