What is meant by cathode ray oscilloscope? Cathode Ray Oscilloscope or Cathode Ray Oscilloscope PdfA cathode ray oscilloscope (C.R.O.) is an instrument that converts electrical signals to a visual display. The main structure of the C.R.O. is a highly evacuated cathode ray tube (C.R.T.) which emits an electron beam known as cathode ray beam. The cathode ray tube … [Read more...] about Cathode Ray Oscilloscope Construction and Working