Theoretical and Practical Comparison of Open-Loop and Closed-Loop Hysteresis Measurement Systems for Permanent Magnets
It is established that measuring the BH curve of permanent magnets with open-loop and closed-loop measurement system yields the same results for the key parameters of a hysteresis trace: Br; HcB, HcJ and BHmax. Beyond these four key parameters, there exists small differences between the two measurement systems. This presentation will focus on these differences from the theoretical point as well as highlight some practical cases.
From the theoretical point, it is recognized that small differences can be observed near the knee point. Our efforts show that this can be accounted for using simple numerical techniques. But the proof is in the pudding, and in our continuous efforts to demonstrate that both systems yield the same results together with our customers and partners, we have gathered numerous data of which we will present some cases.