This document compares two measurement methods for the determination of extended turbine maps. One method is to minimize heat flows and thus to maintain the assumption of adiabatic processes even in low speed ranges of turbines. The results obtained were compared with those of the Ostfalia eATL method. Here, is slowed down electrically by an electric motor. The direct comparison of the measurement results shows considerable differences in the turbine efficiency. Furthermore, the graphical comparison illustrates clear advantages of the eATL concept for the evaluation, which result from the width and the position of the generated measurement points.