Experiences In Radiographic Unsharpness Determination By Means Of A Knife-edge Object

Abstract

With reference to a mathematical model developed by A.A. Harms and D.R. Wyman References 3 and 4, regarding a knife-edge object as an unsharpness indicator in neutron radiography and with reference to a practical need for such a device, clearly expressed within the International Organization for Standardization, Working Group 4 (ISOITC 135/SC5), a limited investigation program has been initiated within the Petten Neutron Radiography Services (PNRS) to assess the unsharpness parameter of a radiographed knife-edge object under different experimental conditions. First, the optimum shape is established by testing various shapes under different circumstances, secondly, the unsharpness parameter, derived from an optimized design is evaluated. Thereafter, a series of measurements have been performed to test the usefulness of such a device as an instrument for geometric unsharpness. All relevant data and their evaluation are given in this contribution.