The measured size of a focal spot, a function of its actual size and the angulation of the anode surface. ... See: focal spot. ... (05 Mar 2000) ... 
Type: Term Pronunciation: fō′kăl spot sīz Definitions: 1. The measured size of a focal spot of an x-ray tube, a function of the actual size of the cathode and the angulation of the anode surface. See: focal spot