In sandy or combined soils, the bottom is resistive instead of conductive, so the readings tend to be more responsible. In moist or clay soils, having said that, the bottom is much more conductive, so the radar pulse cannot penetrate deeply. Lessen frequencies can penetrate better than bigger frequencies, but https://ewr1.vultrobjects.com/blissdrive/Bess-Utility-Solutions-Hayward/Underground-Utility-Locating-Services-Near-Me.html