How to select the arrangement in direct current electric method
Wenner arrangement: highest signal to noise ratio, good vertical resolution, but poor horizontal resolution, multi-channel instrument can be used on only one channel.
Symmetrical quadrupole arrangement (Schlumberger order): Requires AB / 2 is greater than five times MN, signal to noise ratio and resolution and Wenner arrangement is similar to a multi-channel instrument can be used on only one channel, four-pole arrangement AntisymmetricIt can be used for four channels.
Dipole - dipole array: the highest resolution but the worst signal to noise ratio, maintain a high signal to noise ratio is to ensure n <= 8, the arrangement is particularly suitable for multi-channel automatic data collection instrument.
Three-pole arrangement: Under AB> (5 * AM) conditions, the impact of extreme infinity is less than 5%. Resolution than the dipole - dipole slightly inferior but high SNR, Infinity extremely difficult and often result in errors arrangement, the inversion of the image may be asymmetrical.
Diode arrangement: Under AB> (20 * AM) conditions, the impact of extreme infinity is less than 5%. But the relatively poor resolution of the observed signal intensity, two infinity poles are arranged relatively difficult and often introduce errors. MN too susceptible to interference humanities, the impact of natural electric fields and currents in the earth.
Gradient arranged at both ends of the section has a good resolution. Gradient arrays plus the normal dipole - dipole array (n <= 6) to obtain very high resolution over the entire cross-section.
Various hybrid arrangement expected to have all the advantages of being mixed in various arrangements, common combinations are: dipole - dipole + Schlumberger, dipole - dipole + gradient, dipole - dipole + Schlumberger + Wenner.