Sensitivity & Searching DepthThe concepts of sensitivity and searching depth are overlapped but there are some differences.Generally, sensitivity is defined based on the target of a US quarter coin. When flatting the coin and moving it horizontally at a regulated height above the center of the coil at a certain speed, for example if moving the coin at the height of 7" and then the metal detector reacts, the sensitivity of the metal detector is regarded as 7".The biggest searching depth targets big metal. Usually we test the searching depth with an iron or aluminium board of 1.5' in diameter and 1-2 cm thickness. The height of the metal detector above the board is defined as the maximum searching depth when the metal detector reacts.*The indicator of our products usually provides sensitivity but not the maximum searching depth.