ISO 9848:2003规定了一种方法，用于确定黑白相机底片的ISO速度和ISO平均梯度，该底片用于第一代源文件缩微胶片，曝光时间通常为钨源。这些原始文件包括任何手写或印刷的字母数字和线条文件，如书籍、期刊、商业信函和工程图纸。ISO 9848:2003中所述的额定值系统仅适用于来自白炽钨光源的消费者。它不包括图像或连续色调复制、计算机输出缩微胶片（COM）、反转处理或直接正片胶片或其他由非钨源（如激光或阴极射线管）曝光的胶片。 通过应用ISO 9848获得的ISO速度和ISO平均梯度值: 2003用于比较胶片/工艺组合和计算曝光量。

ISO 9848:2003 specifies a method for determining the ISO speed and ISO average gradient of black-and-white camera negative photographic films used for first generation microfilming of source documents at exposure times typically found with tungsten sources. These source documents include any handwritten or printed alphanumeric and line documents such as books, periodicals, business correspondence, and engineering drawings. The value-rating system described in this ISO 9848:2003 is only useful to the consumer if his exposure illumination is from an incandescent tungsten source. It is not intended to include pictorial or continuous tone reproduction, computer output microfilm (COM), reversal processed or direct positive films or other films exposed by non-tungsten sources such as laser or cathode ray tube. The ISO speed and ISO average gradient values obtained by applying this ISO 9848:2003 are intended for practical use in comparing film/process combinations and for computing exposures.