A 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 consists of three main components:
(a) The electron gun
(b) The deflection system
(c) The fluorescent screen
Figure shows the main structure of a C.R.O.
