With the trend in power electronics to use new materials like SiC or GaN new test challenges like higher current and voltage slew rates as well as isolated gate drives and wideband current measurements occur. But how to overcome these and choose the right measurement equipment? This presentation will discuss current and new approaches to isolate your measurement equipment and in addition will give you a deeper view how to know how much isolation of the measurement equipment is really needed? Also how beneficial is the usage of an optical isolated probe for high-side measurements as well as current shunt measurements.