Answer: The detection effect will be improved if the soil is dry or the metal is buried for a long time. The older the metal is buried, the deeper the detection depth. Because metal will gradually oxidize when buried underground for a long time, the metal rust will spread to the surroundings and react with the surrounding soil, generating a strong magnetic field, increasing the area of the metal and increasing the intensity of the signal. The longer the time, the greater the signal strength, and the deeper the detection depth will be!