The extremely low frequency electromagnetic monitoring network apply a German-manufactured magnetotelluric instrument,comprising an ADU-07e main unit and an MFS06e magnetic probe in long-term MT stations.Natural sources in the frequency range of 0.001-1 000 Hz and artificial sources in the range of 0.1-300 Hz of electromagnetic fields are observed.These observations have been continuously conducted for a decade.In recent years,data observed at some stations have shown significant variations,with noticeable differences in the form or values of the raw time series compared to previous data.The resistance of the electric and magnetic channels has also been abnormal,and the cause of the malfunction could not be determined based on previous work experience.In response to these phenomena,internal calibration signals are generated by the ADU-07e's calibration board to check the ADB board and connection board,and the magnetic probe is calibrated to identify faults in the probe itself or in the cables connecting to the magnetic probe.This approach has proven effective in practical applications.This paper outlines the rapid detection methods how to check the ADU-07e system and do a"In Situ"(In Field)calibration of the Metronix Magnetic Field Sensors,as well as the observed fault phenomena.This detection method is also applicable for pre-operational checks of conventional magnetotelluric measurements.
关键词
台站/极低频电磁/主机检查/磁探头标定/故障排查
Key words
station/ELF/check the ADU-07e system/coil calibration/troubleshooting
维普
万方数据