How accurate are magnetic loss measurements?

Massimo Pasquale, Enzo Ferrara, Nicoleta Banu, Fausto Fiorillo, Luciano Rocchino, Michal Ulvr, Franziska Weickert, Korbinian Pfnuer, Joachim Luedke, Katja Hoffmann, Stuart Harmon, Daniel Brunt, Adam Wilson