oscilloscope

noun

1. An electronic measuring instrument that creates a visible two-dimensional graph, on a screen, of one or more continuously varying voltages or currents.

   “If two waveforms have no phase no phase or frequency relationship, there is seldom reason to observe both waveforms simultaneously. However, these oscilloscopes do permit the simultaneous viewing of two such unrelated waveforms, using alternate triggering. […] If the fuse blows, the “ON” indicator will not light and the oscilloscope will not operate.”