Information Why does the Signal Strength Vary with the Magnetic Field in High Gradient Locations?

If the sensor is in a very large gradient field such as inside a building near some steel objects, then the high gradients (change of field with distance) causes different parts of the internal sensor components to respond to different fields, making the sum signal smaller. This only takes place when the gradients are very large such as several thousand nT per meter and will not be seen under normal survey conditions.