The Doble M5400 Frequency Response Analyzer is designed to investigate the mechanical integrity of transformers, reactors and other equipment that utilize windings. The M5400 sends a ramping excitation signal into the power apparatus being tested and measures the returning signal. Comparing this response to baseline readings and results from similar units allows you to identify deviations and confirm internal mechanical problems. The M5400 reduces the uncertainty about apparatus condition by providing solid evidence of mechanical integrity or winding movement. Use it to help determine how a transformer is deteriorating, if it can go back in service after a fault or if it has been damaged during transit.