Cosor portable oscilloscope, c 1952.

An oscilloscope displays electrical waveforms. Although the waveshape of voltages was able to be viewed during the 19th century, it was not until the progres in electronics during World War II that the oscilloscope (as it was by then generally known) became what it is today. A cathode ray oscilloscope such as this Corror portable one consists of a display tube and asociated power supply, an amplifier and a time base supplying a sawtooth linear sweep to the horizontal plates.