Here we still use the experimental results of the water tank model to discuss the distribution law of electric anomalies of near-field source devices on plate-shaped bodies. Among them, a copper plate is used to simulate a low-resistance polarizing plate, and a dyed graphite plate is used to simulate a high-resistance polarizing plate.
Figure 2-2-33 Water tank model experimental results of near-field source device polarization anomalies on the main section of the upright copper plate
(1) Experimental results on the upright copper plate
Figure 2-2-33 shows the etas profile curves of the three near-field source devices on the main section of the upright copper plate and the etas profile contours of the quadrupole device. It can be seen from the figure that the abnormal change patterns of the cross-sections of the three devices and the distribution characteristics of the cross-section abnormalities of the quadrupole device are the same as the above-mentioned sphere. But at this time, the optimal pole distance of the two-pole device is AM≈H0 (the depth of the center of the copper plate); the pole distance of the three-pole device is close to saturation AM≈2H0; the pole distance of the four-pole device is close to saturation is AM≈3H0.
(2) Experimental results on the inclined copper plate
Figure 2-2-34 shows the eta profile curves and quadrupole of three near-field source devices on the main section of the inclined copper plate eta section contour of the device. It can be seen from the figure that at this time, the etas profile curves of the three devices all appear asymmetrical, and the abnormal values ??generally increase. For the two poles, the anomaly decreases slowly in the tilt direction, and the right peak anomaly is small; for the three poles, the asymmetry is more obvious, and the maximum value is displaced in the tilt direction; for the four poles, the abnormal value in the tilt direction is The abnormality in the direction decreases slowly, but the abnormal value of the right peak is large, so the right side of the "eight" shape on the cross-sectional view is consistent with the tendency of the copper plate.
Figure 2-2-34 The water tank model experimental results of electrostatic anomalies in the near-field source device on the main section of the inclined copper plate. The scale and burial depth of the copper plate are the same as before.
Figure 2-2-35 The water tank model experimental results of electrostatic anomalies in the near-field source device on the main section of the horizontal copper plate. The scale and burial depth of the copper plate are the same as before.
In addition, in the case of tilted copper plates, the optimal pole pitch of the two-pole device AM≈1.2H0; the nearly saturated pole pitch of the three-pole device AN≈2.5H0; the nearly saturated pole pitch of the four-pole device AB ≈3.5H0.
(3) Experimental results on the horizontal copper plate
Figure 2-2-35 shows the ηs profile curves and quadrupole of the three near-field source devices on the main section of the horizontal copper plate eta section contour of the device. It can be seen from the figure that the outliers of the three devices at this time are further increased compared to the upright and inclined copper plates, and the ηs profile curves of the two-pole and four-pole devices and the eta section contours of the four-pole device are symmetrical again. . Its abnormal characteristics and changes with polar distance are the same as those of the sphere and the upright copper plate, so they will not be described again.
In addition, in the case of a horizontal copper plate, the optimal pole distance of the two-pole device is AM≈2H0, the three-pole device is close to the saturated pole distance AN≈3H0, and the four-pole device is close to the saturated pole distance AB≈ 4H0.
(4) Experimental results on inclined dip-dyed graphite plates
For dip-dyed graphite plates that are high-resistance polarized plates, compared with low-resistance polarized copper plates, the experimental results show that , although the outliers generally decrease, it still has the characteristics that the upright plate has the smallest anomaly, the horizontal plate has the largest anomaly, and the inclined plate is in the middle. In addition, the abnormal characteristics change with the polar distance. Except for the inclined plate, the results for other occurrences are basically the same. Therefore, below we only discuss the experimental results of the quadrupole device on the tilted dissipated graphite plate.
Figure 2-2-36 The experimental results of the water tank model of the near-field source quadrupole device on the main section of the inclined dispersion-dyed graphite plate
It can be seen from the experimental results in Figure 2-2-36 It can be seen that under the current conditions, the ηs profile curve has a bimodal anomaly, and the peak value in the anti-tilt direction is larger than the peak value in the tilt direction. Therefore, on the cross-section contour map, the tendency of the high-value abnormal axis on the surface is opposite to the tendency of the disseminated graphite plate. We know that for inclined low-resistance polarized copper plates (see Figure 2-2-34), their directions are consistent. Therefore, when judging the tendency of polarized bodies based on abnormal asymmetry, attention should be paid to the resistivity data.