Liu Xikai, Ma Dong, Chen Liang, Liu Xiangdong
MOE Key Laboratory of Fundamental Physical Quantities Measurement & Hubei Key Laboratory of Gravitation and Quantum Physics, School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China.
Sensors (Basel). 2018 Feb 8;18(2):517. doi: 10.3390/s18020517.
Tuning the stiffness balance is crucial to full-band common-mode rejection for a superconducting gravity gradiometer (SGG). A reliable method to do so has been proposed and experimentally tested. In the tuning scheme, the frequency response functions of the displacement of individual test mass upon common-mode accelerations were measured and thus determined a characteristic frequency for each test mass. A reduced difference in characteristic frequencies between the two test masses was utilized as the criterion for an effective tuning. Since the measurement of the characteristic frequencies does not depend on the scale factors of displacement detection, stiffness tuning can be done independently. We have tested this new method on a single-component SGG and obtained a reduction of two orders of magnitude in stiffness mismatch.
调整刚度平衡对于超导重力梯度仪（SGG）的全频段共模抑制至关重要。已提出一种可靠的方法并进行了实验测试。在调谐方案中，测量了单个测试质量块在共模加速度作用下位移的频率响应函数，从而确定了每个测试质量块的特征频率。利用两个测试质量块之间特征频率的减小差异作为有效调谐的标准。由于特征频率的测量不依赖于位移检测的比例因子，因此刚度调谐可以独立进行。我们在单分量SGG上测试了这种新方法，刚度失配降低了两个数量级。
