Degradation in the time

As it happens in all the tubes electron-beams, also in the CRT the efficiency of electron emission from part of the cathode, in the time stretches to diminish progressively, with consequent minor brightness of the images on the screen. In the oscilloscopes, the consequence is one smaller brightness of the trace. Cause of the degradation, is the alteration of the oxide layer deposited on the surface of the cathode and the formation on the surface of small letters lumps, true and own slags, consequence of innumerevoli the ignitions and extinctions, whose presence constitutes one screen to the flow of electrons generated. In the years in which tube CRT it was of universal use, data the elevated cost for its substitution, existed in commerce particular apparatuses calls to you "regenerative", which allowed to carry out a momentary cleaning of slags deposited on the cathode. The method consisted in applying one sufficiently high tension, between the pin connected to the connected cathode and the pin to the first grill near to it. The eventual voltaico arc that was formed, destroyed consisting slags more giving for short new time life to the tube.