NAPM IT2.51 : 0已作废
PHOTOGRAPHY - SOURCE DOCUMENT MICROFILMS DETERMINATION OF ISO SPEED AND ISO AVERAGE GRADIENT
出版：National Association of Photographic Manufacturers, Inc.
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基本信息
标准编号： NAPM IT2.51 : 0
标准类别：Standard
出版单位：National Association of Photographic Manufacturers, Inc.
标准页数：0
标准简介
Determines the ISO average gradient and speed of black-and-white camera negative photographic films that are used in the first generation microfilming of source documents, that are exposed and typically found with tungsten sources.
本标准替代的旧标准
