Evaluation and routine testing in medical imaging departments - constancy tests - method for radiographic cassettes and film changers and film - screen contact and relative sensitivity of the screen - cassette assembly 医疗成像科评估和常规试验.第2部分:稳定性试验.第2节:屏蔽暗盒组件的x射线暗盒换片器胶片屏蔽触点和相关灵敏度方法