#$%^&*AU2017101011A420170831.pdf#####An earthquake precursor strain gauge consisted of a unit of high-pass filtering and elimination of air pressure, specializing in: it can be used to record abnormal structural strain changes within 30 days before a large earthquake and the anomalous tectonic strain changes occurred about 20 days before the earthquake. An earthquake precursor strain gauge, recorded 30 days earthquake anomaly signal before the earthquake. Through the high-pass filtering between 120s and 7680s in the cycle, the solid tidal effects were filtered and the linear regression was used to eliminate the influence of air pressure. Abnormal strain signals recorded 20 days before 28 large earthquakes were found, which highlights the dominant frequency of the abnormal signal. After the wavelet analysis, the abnormal signal can be decomposed into 6 cycles, 2-4min, 4-8min, 8-16min, 16-32min, 32-64min, 64-128min, respectively. The main frequency of the abnormal signal is 4- 8min, and disappears after 32min.
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