The Tettex 2293 from Swiss firm Haefely Test AG is the result of extensive research and years of experience testing transformers. A simple one-time-connection system, together with the simultaneous winding magnetization method (SWM), drastically reduces measuring time. The SWM guarantees fast and reliable measurements even on large power transformers with delta windings on the low-voltage side, where stable measurements can seldom be reached using traditional winding resistance measurement instruments, the company says. In addition, the new demagnetization function eliminates the magnetic remanence in the core after the application of a DC voltage. A full graphical interface with a 7-inch touch screen guides the operator through the test procedure. The unit visualizes each test cycle and displays the results graphically or in list format. (