Multiple cable insulating sheath monitor - employs X=rays of varying intensity to change probe video signal contrast range

摘要

A cable with multiple layers of insulation is irradiated with x-rays and a video signal is generated by probing with an electron beam to derive a preresentation of the cable. By rpesentting threshold values, a signal is derived which gives information about the position and thinkness of the insulation layers. The investigation starts with a relatively low anode voltage which gives a low radiation intensity, and is increased to higher values as the scan traverses the layers. In this way the video signal develops a greater contrast to the individual layers.