The 1250E Frequency Response Analyzer (FRA) delivers accurate measurement of gain and phase. The device under test is stimulated by a sinewave and the response analyzed at various points in the system. These responses are then correlated with the stimulus to determine the amplitude and phase relative to the generator. The ratio of the two measured signals can then be used to provide the system transfer function.
This process rejects all harmonics and, by increasing the integration time to further reject noise and interference, even signals which are buried in noise can be measured accurately.