Blendl C, Goergens K
Fachbereich Photoingenieurwesen, Fachhochschule Köln.
Aktuelle Radiol. 1998 Nov;8(6):288-92.
The German standard series DIN 6868 does not include a separate requirement for deviations in the sensitivity of different emulsion numbers or, respectively, the relative contribution of the film to sensitivity S of a screen film system (SFS) whose sensitivity is determined according to DIN 6867-1 [1]. The inclusion and interpretation of these contributions in the test body exposure according to DIN 6868-3 [2] has not proved to be of value since an unambiguous error recognition is only possible with considerable experimental experience (additional exposure of a sensitometer strip and interpretation of the resulting consequences). The investigations reported here demonstrate that the correlation of sensitometric parameters obtained from sensitometer strips generated with sensiometer exposure and X-ray exposure is so large that differences in sensitivity of different emulsion numbers of a screenfilm larger than delta log H > or = 0.015 or delta H > or = 4% can be surely detected on exact observance of the experimental limiting conditions. Thus, the statements by the manufacturers in "ZVEI information Nr. 7 of the X-ray Regulation" [3] with regard to the claimed scattering width of screenfilms can be tested and evaluated at least tendencially when the systemic fluctuations and measurement uncertainties, see in particular DIN 6868-55 Appendix E of Sept. 1996 (4), are correctly taken into consideration. In general a deviation in the sensitivity exceeding the manufacturers claimed maximal scattering range of delta log H = 0.06, i.e. delta H = 15% can be detected with certainty.
德国标准系列DIN 6868并未针对不同乳剂编号的感光度偏差,或者分别针对胶片对屏-片系统(SFS)感光度S的相对贡献提出单独要求,该系统的感光度是根据DIN 6867-1 [1]确定的。根据DIN 6868-3 [2],在测试体曝光中纳入并解释这些贡献并未被证明有价值,因为只有具备丰富的实验经验(对感光计条带进行额外曝光并解释其结果)才能明确识别误差。此处报告的研究表明,由感光计曝光和X射线曝光产生的感光计条带所获得的感光测定参数之间的相关性非常大,以至于在严格遵守实验限制条件的情况下,可以肯定地检测到屏-片不同乳剂编号之间的感光度差异,即ΔlogH≥0.015或ΔH≥4%。因此,当正确考虑系统波动和测量不确定性(特别是参见1996年9月DIN 6868-55附录E (4))时,至少可以大致测试和评估制造商在“X射线法规的ZVEI信息第7号”[3]中关于所声称的屏-片散射宽度的声明。一般来说,可以确定地检测到感光度偏差超过制造商所声称的最大散射范围ΔlogH = 0.06,即ΔH = 15%。