THE RATING OF THE X-RAY TUBE

In general, rating is concerned with the maximum rate at which radiation can be obtained from an X-ray tube and for how long it can be continued at this rate. This chapter explains, though not in very great detail, the physical basis of the rating charts and indicate briefly how they should be used. There are two features from which the restrictions arise, electrical, and thermal (or heating), and both are taken into account in the rating chart. The maximum rating values are fixed by the detailed design of the voltage generator unit and, apart from needing to make sure at the time of the initial purchase of the X-ray unit that they are adequate for the envisaged usage. It is rare in most day-to-day work to need to consider anything other than the single, isolated exposure rating limitation.