Xiangqing Huang1, Zhongguang Deng1, Yafei Xie1, Zhu Li2, Ji Fan1,3
and Liangcheng Tu1,2,3,*
1 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; hxq160@hust.edu.cn (X.H.); dzg_109@hust.edu.cn (Z.D.);
xieyaphe@hust.edu.cn (Y.X.); fanji@hust.edu.cn (J.F.)
2 School of Physics and Astronomy, Sun Yat-sen University, Guangzhou 510275, China; lizhu@sysu.edu.cn
3 Institute of Geophysics, Huazhong University of Science and Technology, Wuhan 430074, China
* Correspondence: tlc@hust.edu.cn; Tel.: +86-027-87558394; Fax: +86-027-87542391
Received: 26 September 2017; Accepted: 25 October 2017; Published: 27 October 2017
Abstract: A new and simple method to adjust the scale factor of a magnetic force feedback
accelerometer is presented, which could be used in developing a rotating accelerometer gravity
gradient instrument (GGI). Adjusting and matching the acceleration-to-current transfer function of
the four accelerometers automatically is one of the basic and necessary technologies for rejecting
the common mode accelerations in the development of GGI. In order to adjust the scale factor of
the magnetic force rebalance accelerometer, an external current is injected and combined with the
normal feedback current; they are then applied together to the torque coil of the magnetic actuator.
The injected current could be varied proportionally according to the external adjustment needs,
and the change in the acceleration-to-current transfer function then realized dynamically. The new
adjustment method has the advantages of no extra assembly and ease of operation. Changes in
the scale factors range from 33% smaller to 100% larger are verified experimentally by adjusting
the different external coefficients. The static noise of the used accelerometer is compared under
conditions with and without the injecting current, and the experimental results find no change at the
current noise level, which further confirms the validity of the presented method.
Sensors 2017, 17, 2471; doi:10.3390/s17112471
