射线底片黑度控制的研究  

Study on Blackness Control of Radiographic Film

作　　者：王金友 WANG Jinyou(Fujian Fuqing Nuclear Power Co.,Ltd.,Fuzhou,Fujian Province,350318 China)

机构地区：[1]福建福清核电有限公司,福建福州350318

出　　处：《科技创新导报》2021年第13期71-73,共3页Science and Technology Innovation Herald

摘　　要：缺陷能否通过射线透照而被检出,取决于若干个环节。首先,必须使缺陷在底片上留下足以识别的影像,其次,底片上的影像应在适当的条件下得以充分显示,以利于评片人员观察与识别。这就要求底片有较为合适的对比度范围,根据胶片的特征曲线,胶片的梯度随黑度的增加而增大,然而,黑度过大将造成透过光强不足,导致人眼观察识别能力下降,所以标准既规定了底片黑度的下限值,又规定了底片黑度的上限值。Whether a defect can be detected by radiographic examination depends on several links.First,it is necessary to leave an image on the negative film that can be recognized.Secondly,the image on the negative film should be fully displayed under appropriate conditions to facilitate the observation and recognition of film reviewers.This requires the film to have a more suitable contrast range.According to the characteristic curve of film,the gradient of film increases with the increase of blackness.However,excessive blackness will result in insufficient transmitted light intensity,which will lead to the decline of human eye's observation and recognition ability.Therefore,the standard not only stipulates the lower limit value of film blackness,but also stipulates the upper limit value of film blackness.

关 键 词：底片黑度 曝光量 曝光尺 曝光曲线 暗室处理 

分 类 号：TG441[金属学及工艺—焊接]