摘要
大地电磁法(MT)是地球深部探测的有效物探手段之一,也是当今地球物理工作者的研究热点。要实现MT探测,用于野外观测的仪器系统是基础,要求观测系统具有高可靠、高精度、多台同步、轻便等特点。通过集成嵌入式计算机、DTCXO、24位ADC、锂电池组等部件研制了采集主机,动态范围达119 d B(fs=2 400 Hz),功耗约1 600 m W,并配备了轻便的低噪声感应式磁传感器、低漂移电场传感器以及用于野外仪器自检的自检盒,在提高了仪器可靠性的同时也提高了野外数据采集质量和野外施工效率。多次室内及野外试验验证了本观测系统的可靠性、低功耗、轻便性及易用性,可满足陆地MT勘探施工的要求。
The magnetotelluric method( MT) is an effective means to detect the interior of the Earth. It is one of the research hotspots among geophysicists. The field observation system is the foundation of MT exploration. This method requires an observation system with some good characteristics,such as high reliability,high precision,multi-receiver synchronization and lightweight. The receiver integrates embedded computer,DTCXO,24 Bits ADC,lithium batteries and other components. The typical dynamic range is 119 d B@( fs= 2 400 Hz),and the power consumption is about 1 600 m W. The receiver is equipped with low-noise,lightweight inductive magnetic sensors,electric field sensors,and self-test box,thus ensuring the reliability of the instrument. It has improved the quality of field data acquisition,and the equipment is more portable. Several indoor and field tests have verified the reliability of the receiver. The performance and portability could meet the requirements of land MT exploration.