重金属污染场探测装置抗噪性能与灵敏度比较

Comparison of anti-noise performance and sensitivity in heavy metal pollution field

为比较对称四极与三极电测深装置在重金属污染场探测过程中的抗噪性能与灵敏度,基于电场理论推导两探测装置信号强度关系与灵敏度方程。建立层状重金属污染场地二维模型,正演模拟视电阻率和视极化率变化规律,分别在无噪声、平均值5mV的扰动电压、5%随机噪声工况下,反演模拟两种探测装置视电阻率和视极化率误差。建立均匀大地介质和二层水平均匀介质模型,利用Comsol软件对两探测装置进行灵敏度仿真分析。研究结果表明:相同极距与隔离系数布极方式下,对称四极装置信号强度是三极装置的2倍;对称四极装置纵向灵敏度对称平行分布,纵向分辨率高,三极装置灵敏度横向包络大,横向分辨率高,且探测深度大于对称四极装置。

To compare Schlumberger array and Pole-Dipole array in heavy metal pollution in the process of detecting anti-noise performance and sensitivity,the relations between the two arrays signal intensity and sensitivity equation was deduced based on electric field theory.The two-dimensional model of layered heavy metal pollution field was established by IP forward simulation.Inversion numerical simulations were done in the absence of noise,average 5 mV voltage disturbance and 5%random noise working conditions.Respectively,sensitivity simulation was carried out for uniform earth medium model and two-layer horizontal uniform medium model based on Comsol.The research results show that the signal intensity of Schlumberger array is twice that of Pole-Dipole.The longitudinal sensitivity of Schlumberger array is symmetrical and parallel arranged with high longitudinal resolution.The sensitivity of the Pole-Dipole array has a large lateral envelope with lateral resolution and the detection depth is higher.