免维护超低噪声固体不极化电极的研制与性能测试

Development and performance tests of maintenance-free ultra-low noise solid nonpolarizing electrodes

针对传统不极化电极极差稳定性差、低频噪声大、寿命短、需要定期维护等缺点,研制出免维护超低噪声固体Pb-PbCl_(2)不极化电极。室内测试结果表明:所研制的电极极差在一个月内漂移小于0.06 mV,只有法国进口PMS9000电极的5%;温度系数小于20μV/℃,不到PMS9000电极的1/5;在100 m电极距条件下,相对于天然感应电场的信噪比为40 dB@10^(3) s、20 dB@10^(4) s和10 dB@10^(5) s。野外对比测试表明:利用新研制的固体不极化电极可以明显提高对地电场信号的采集精度,显著提升大地电磁死频带和低频段数据质量。

To overcome the shortcomings of traditional nonpolarizing electrodes,such as the poor stability of potential difference,high low-frequency noise,short life,and requiring regular maintenance,the authors researched and developed maintenance-free ultra-low noise Pb-PbCl_(2) nonpolarizing electrodes after over a decade of development and constant tests.Lab test results show that the new nonpolarizing electrodes have a potential difference drift within one month of less than±0.06 mV and a temperature coefficient of less than 20μV/℃,which are 5%and less than one-fifth of those of the PMS9000 electrodes exported from France,respectively;under the ideal condition of the distance between two adjacent electrodes of 100 m,the signal-to-noise ratios relative to the natural induced electric field are 40dB@10^(3)s,20dB@10^(4)s,and 10dB@10^(5)s.The field comparative tests show that the newly developed solid nonpolarizing electrodes can significantly improve the acquisition accuracy of geoelectric field signals and the data quality of dead and low magnetotelluric frequency bands.