Oscilloscope: Oscilloscopes and used for detailed monitoring of AC and DC electric signals in measurement systems. Whereas digital multimeters display the numerical value of a voltage or current signal, an oscilloscope displays signals as waveform on a screen with high accuracy and precision. Dials or buttons on the equipment's front panel allow the modification of the amplitude and time scales of the signal being displayed. Typical oscilloscopes have two to four channels for signal monitoring. Signals are accessed via probes or clamps connected to oscilloscope channels.