As a Universal Disturbance Analyzer, the Model 626 may be used for many applications. For example, it monitors, measures, records and prints disturbances. Depending on the particular plug-ins installed, the instrument is capable of monitoring disturbances on single phase or 3-phase AC power lines, AC neutral power lines (with respect to earth ground), and DC lines. The Model 626 may also be used as a sequence of events recorder, recording and printing out any changes of state detected at its inputs. Details of these and other specific functions of this universal instrument are presented in other manuals.