SSJ数字式地震事件记录器

本文介绍了一种用于地震观测的三分向数字式地震事件记录器。采用半导体存储器延迟信号,短时间平均器与长时间平均器对输入信号积分。用事件比较器比较两个输出,当超过给定的阈值时,事件比较器输出电压使自动离合机构工作,同时启动数字磁带机。采样频率有80Hz和40Hz两档,相应的信号延迟时间分别为5.12s和10.24s。观测结果表明,适当选择触发阈值,可将虚警率降低。这种记录器体积小,功耗低,适用于单台观测。

SSJ DIGITAL SEISMIC RECORDER WITH A TRIGGER

In this paper, a three-component digital seismic recorder designed for seismic observatories is described. A semiconductor memory is used as a delay unit. Short-term averager and long-term averager integrate the input signals. Their outputs are compared by an event comparator. When its output exceds a given threshold value, the event comparator will give a voltage output which enables automatic clutch to work and the digital tape recorder is started. The sampling rate may be set to 80 Hz and 40 Hz, corresponding to a signal delay time of 5.12 sec and 10.24 sec, resprectively. The observation result shows that the false alarm rate will be reduced if the triggering threshold is suitable.This recorder has a small size and its power consumption is low. It is suitable to a single seismic observatory.