Power analyzers and B-H analyzers are used to measure losses in magnetic materials. Along with higher frequencies and lower losses, the use of high-density mounting and fast-switching power devices has made measurement more difficult. This section describes methods for measuring losses and the sensing issues involved in determining losses from the switching waveforms of circuits driven by GaN/SiC devices (Advanced Polytechnic Centre (Chiba, Japan), Power electronics measurement know-how course).