Monotonicity-preserving interproximation of B–H-curves

B–H-curves are used for modelling ferromagnetic materials in connection with electromagnetic field computations. They are needed for the numerical simulation of devices such as transformers or magnetic valves. Starting from real-life measurement data, we present an approximation technique which is based on the use of spline functions and a data-dependent smoothing functional. It preserves physical properties, such as monotonicity, and is robust with respect to noise in the measurements.