引言射线照相法是一种重要的无损检测技术,通常采用透射光线对射线底片上的图象进行分析。最近Mar-dix试图对射线底片的对比度予以说明。这也可说是Altman成果的深化,他认为底片上乳剂层的对比度可用测定的黑度值来表达。Smith提出产生对比的原因是由于形成乳胶层的主要物质明胶的硬化或软化,已软化部分吸收的水份要比未软化部分少。Smith提出对比度的产生在于干燥过程中,由低光学密度 Introduction Radiographic methods are an important non-destructive testing technique that uses transmitted light to analyze images on radiographic films. Mar-dix recently attempted to illustrate the contrast of radiographic films. This can also be said to be the result of the deepening of Altman’s work. He believes that the contrast of the emulsion layer on the negative can be expressed in terms of the measured blackness. Smith suggests that the reason for the contrast is that the softened portion absorbs less moisture than the unsized portion because of the hardening or softening of the gelatin, the major material forming the latex layer. Smith proposed the contrast produced by the low optical density during the drying process