CRT

CRT technology was the first to be developed of the three discussed here. While it has some drawbacks, such as size, weight, and power consumption, in some applications it is still superior to the other technologies. In instruments, CRT display technology was first used in oscilloscopes, and it continues to be the best choice of display technologies for displaying information rapidly with a high graphic waveform content requiring high visibility. In a CRT, an electron beam is guided over a phosphor screen inside a vacuum tube; when the electron beam is turned on, it illuminates the luminescent material it touches. The luminescence persists only for a short period of time, so it must be refreshed continuously by passing the electron beam over the screen again and again.