Review of AC Loss Measuring Methods for HTS Tape and Unit

AC loss measuring methods of high-temperature superconducting (HTS) tapes and units, generally consisting of electronic, magnetic, and calorimetric techniques, have matured and made great contributions to ac characteristics of HTS materials, research, and development of HTS applications. This paper briefly introduces and summarizes the principles of ac loss measurement techniques, focusing particularly on electric and calorimetric method for measuring ac losses of HTS tapes. A novel developed calorimetric method for measuring ac loss based on optical fiber Bragg grating (FBG) was introduced a little bit in detail. After comparing the sensitivities of various measuring methods, ac loss measuring methods available for HTS tapes and units are suggested.