Cathode Ray Tube (CRT)
A cathode ray tube is the heart of the CRO. The below fig
shows the various parts of CRT.
1. Glass Envelope: It is conical highly evacuated glass
housing maintains vacuum inside and supports the various electrodes. The inner
walls of CRT between neck and screen are usually coated with the conducting
material called aquadag. This coating is electrically connected to the
accelerating anode so that electrons which accidently strike the walls are
returned to the anode. This prevents the walls of the tube from charging to a
high negative potential.
Pic 1. Cathode Ray Tube