FBS-3A型反馈式宽频带地震计电流标定方法研究

随着时间的推移和环境条件的缓慢变化，地震计各部件的性能参数会有所改变，及时了解这种变化并加以控制和调整，有助于提高地震计输出结果的可信度．所以，一台地震计无论在交付使用前，还是在使用过程中，都需要进行标定．目前，比较常用的标定方法有方波电流标定和正弦电流标定．本文从系统分析的角度出发，在分析得到地震计传递函数的基础上，将方波电流标定和正弦电流标定过程进行理论抽象，进而在复频域对两种电流标定过程进行仿真推导；并在此基础上，讨论了方波电流标定输出曲线与地震计固有参数之间以及正弦电流标定的稳态输出与标定电流之间的关系，并且论述了两组特定频率正弦电流的标定输出之间的关系．最后，作为理论分析在实践中的具体应用，给出了两种电流标定过程在实际工作中的应用方法．本文旨在阐明两种常用的电流标定方法的物理意义，对地震计的调试及应用有积极的参考作用．

STUDY ON THE CALIBRATION OF FEEDBACK BROADBAND SEISMOMETER FBS-3A WITH CURRENT SIGNAL

With the time passing by and the environment changing, the characteristics of the components in a seismometer may change a little to some extent. To realize this kind of change and take steps to control or adjust it is helpful to improve the reliability of the sensor′s output. Therefore, every seismometer must be calibrated, either before leaving factory or in use. Up to now, there are two kinds of calibrations used frequently with current signals, namely using square-wave signal and sine-wave signal. From the point of view of systematic analysis, after getting the transfer function of the seismometer and simplifying the process of calibration with current signal, research has been done, in complex frequency domain, to the process of calibration with simulation method. On the basis of this, the relationship between the output figure of square-wave calibration and the intrinsic parameters of a sensor is discussed in this paper. The relationship between the steady output of sine-wave calibration and the calibration current, as well as the relationship of the calibration outputs caused by two sine waves with specific frequencies is presented. As the result of the theoretical analysis, two applications of the calibration with current signal are provided. The aim of this paper is to clarify the meanings of these two commonly used calibration methods, which would be fairly positive and helpful to the adjustment and the practical application of the seismometers.