This European standard specifies the measurement of focal spot dimensions of industrial X-ray systems up to and
including 500 kV tube voltage. It describes a method of direct mechanical scanning of focal spots above 0,1 mm with
a highly collimated receiver.
The image quality and the resolution of X-ray images depend highly on the characteristics of the focal spot, in
particular the size and the two-dimensional intensity distribution.
For the characterization of commercial X-ray tube types (i.e. for advertising or trade) the specific maximum values
given in annex A should be preferred.