体应变仪大地震时两次自动调零数据的处理

How to processing the twice auto-zero data of volumetric strain instruments when earthquake happens

仪器在较大波动幅度的影响下产生自动调零(电磁阀门开启),与地震信息混在一起,难以直接使用原始数据。合理消除自动调零带来的影响,还原真实情况,成为台站必须解决的问题。采用确定校正值的方法,力图还原为连续记录,结果发现:处理后的资料可以和另外一台没有调零动作的体积应变仪器的原始资料相符合。

An 8.0 earthquake occurred 14：28 on May 12, 2008 in Wenchuan,Sichuan, 1 392.0 km away from Xuzhou Seismic Station. Two volumetric strain instruments in Xuzhou Seismic Station recorded the seismic wave and the coseismic step of this earthquake at 14：34. At the same time, one of these two instruments arose automatic zero under the influence of the large fluctuation （solenoid valve opens） , and it becomes very hard to use the original data when the automatic zero information and the earthquake information mixed. We have to solve the problem whether and how to reasonably eliminate the impact of auto-zero, truely restore the original situation. We adopted the scientific method of determining the correction value, trying to restore a continuous record, this method has been initially verified： the processed data and the original data produced by another volumetric strain instruments without automatic zero were consistent.