Hierarchy classification:

1. top of the aat hierarchies
2. Objects Facet
3. Components (hierarchy name)
4. components (objects parts)
5. [components by specific context]
6. system components
7. electrical system components
8. electron tubes
9. vacuum tubes
10. cathode ray tubes
11. television camera tubes

Anotations

Scope note:

Small television camera tubes of a particular kind, in which the image is formed on a transparent electrode coated with photoconductive material, the video signal being obtained from the variation in the current flowing to or from this as it is scanned by a beam of (usually low-speed) electrons.