For several decades, the CMF team has been studying the low magnetic and electric fields, DC to low-frequency in order to reduce, control, and finely analyze the magnetic anomalies. We have studied various devices such as military ships, electric equipments (turbo-alternator, hydrogen fuel cells, electric transformers, electric vehicles), devices embarked in satellites, submarines, planes helicopters... In order to characterize the sources, we develop numeric models and solve original inverse problems. One of our major assets is the ability to validate our theoretical and numerical studies with specific measurement facilities, in-situ, and our expertise in precise electromagnetic measurement. Often, our two complementary approaches, modeling and measurements, allow us to propose innovative technical solutions for improving, and predict the performance.