NF EN 12543-4 : 1999

      Foreword
      Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Test method
5 Measurement and determination of the focal spot size
Annex A (informative) Data analysis

Defines checking of focal spot dimensions higher than 0,5 mm of X-ray systems up to 500 kV tube voltage, by means of radiographs of sharp edges. Resolution and image quality of X-ray images are dependent on the features of the focal spot. Imaging qualities are based on two dimensional intensity distribution in the object plane. The edge procedure is particularly useful for focal spot checking under field conditions so as to find changes of the focal spot. It is unable to be used for complete measurement of the focal spot, for these measurements the method in accordance with annex A is applicable.