Design and Manufacture of Portable Strong Motion Instrument for Array Observation and Observation/Analysis Manual

本研究的重点是制造便携式强震观测仪器和开发阵列观测方法，以证明在大地震发生后和/或紧急情况下易于移动的观测。在该项目的第一年，我们比较了现有仪器的特点，调查了可能的新仪器规格，并制造了传感器和数据记录仪作为试验。第二年，我们检查了试验，从几个测试中获得了结果，并最终确定了新仪器的规格。采用动圈式加速度计作为传感器，因为它不需要电源。该传感器的主要技术指标是从微动水平直到非常强的微动水平（如科比的情况（150 cm/s））都可以观察到，并且在0.07 Hz至100 Hz范围内具有平坦的响应。该数据记录仪采用24位A/D转换器，动态范围达130 dB，且功耗小。新仪器不含电池的总重量为3 kg。在第三年，我们不仅在日本，而且在美国和希腊考察了现场用于地震和微震阵列观测的新仪器。通过各种实地测试证实，新仪器对于移动的阵列观测非常有用。

This study focused on manufacturing portable strong motion observation instruments and developing array observation methods, certifying a easy mobile observation just after a large earthquake occurrence and/or in case of emergency. In the first year of this project, we compared the features of exiting instruments, surveyed the possible new specifications of instruments and manufactured a sensor and a data logger as a trial. Next year, we examined the trials obtaining the results from several tests and determined finally the specifications for new instruments. A moving-coil type accelerometer was selected as a sensor, because it require no power supply. The principal specifications of the sensor are that it is observable from microtremors level until very strong one like the Kobe cases (150cm/s) and it has a flat response from 0.07Hz to 100Hz. The data logger used 24 bits A/D converter achieved a dynamic ange of 130 dB and it needs less power supply. The total weight of the new instrument without battery is 3 kg. In the third year, we examined the new instruments in the field for array observation of earthquake as well as microtremors, not only in Japan but also in U.S.A.and Greece. It was confirmed through the various field tests that the new instruments were very useful for mobile array observations.