The process of averaging reduces the noise level proportionally to the square root of the number of averagings, strictly this is only true if the noise has a flat frequency spectrum (white noise) and a Gaussian-amplitude distribution. When the process of signal averaging does not smooth the noise Histogram and make it close to a Gaussian distribution, it means that the noise is not random. The most probable case is interference with signal from the supply line at multiples of 50 or 60Hz. In such a case it is recommended to try to remove the source of this interference as the process of averaging will not necessarily remove it. However the effect can be minimised by ensuring that the time to acquire one transient is not an exact multiple or an integer fraction of the periodic time of the mains supply (20ms for 50Hz). The total time of the measurement is given on the Acquisition folder. The progress of the process of averaging is visualised on the Progress bar at the bottom of the main form. After the measurement is completed the data are automatically stored in the current data path with the default name “data_tmp.iso", provided this action is enabled on the Customise form.
One can automates the process of transient averaging using the measurement Scripts. The Script is simply a configuration file which contains all information about the measurement parameters and conditions. These scripts can be organised in lists, and such a list can be executed. The Script utility can be accessed only from the Measurement menu, and becomes enabled only when the hardware is successfully initialised. The process of preparing and running scripts is described in details in one of the following chapters.