细纤维过滤介质的气流阻力（本文定义为特定速度下的压降）是一个重要特性，因为任何制造的过滤装置的流动阻力都将在很大程度上取决于所用介质的阻力。同样重要的是，过滤效率和过滤能力在很大程度上取决于控制流动阻力的介质的相同性质。对于纤维介质，这些特性包括纤维直径、介质密度、厚度、粘合剂有效性（在一定程度上控制气流作用力下的有效厚度和密度）以及纤维取向和包装均匀性。 因此，当与制造过程中其他变量的适当控制结合使用时，流动阻力的测量和控制可显著帮助确保产生一致且可重复的过滤特性。由于这些原因，过滤介质的规范通常规定了标称流动阻力和允许公差。由于此类规范是介质制造和销售以及成品过滤器设计和生产的基础，因此测试方法和设备必须标准化并准确校准。标准化是必要的，因为测试的几个变量必须任意选择； 其中包括背网或支架的类型、封边方法，以及样品形状（圆形或方形）和尺寸（影响边缘处理）的相关影响。对精确校准的需求是显而易见的，但必须认识到，只要通过使用转移标准对所有测试仪进行相同的校准，就可能不需要对绝对标准进行校准。然而，为了获得该方法及其结果的普遍接受，需要可追溯至绝对标准的校准。引文:研讨会论文，佐治亚州亚特兰大，1978年

The resistance to air flow (defined for this paper as the pressure drop at a specified velocity) of fine fiber filter media is an important property since the flow resistance of any fabricated filter device will depend heavily on the resistance of the media used. Equally important is the fact that filtration efficiency and capacity depend in large part upon the same properties of the media that control the flow resistance. For fibrous media, these properties include the fiber diameter, media density, thickness, binder effectiveness (which to some extent controls the effective thickness and density under the forces of an air stream) as well as the fiber orientation and pack uniformity. Thus when used in conjunction with suitable control of other variables in the manufacturing process, the measurement and control of flow resistance can significantly aid in insuring that consistent and reproducible filtration properties will result. For these reasons specifications for filter media usually state the· nominal flow resistance along with allowable tolerances.Since such specifications serve as a basis for the manufacture and sale of the media and the design and production of tne finished filter, it is imperative that test methods and equipment be standardized and accurately calibrated. Standardization is necessary since several variables of the test must be chosen arbitrarily; These include the type of backing screen or support, the method of edge sealing, and the related effects of sample shape (round or square) and the size (as it affects the edge treatment). The need for accurate calibration is obvious, though it must be recognized that calibration to an absolute standard may not be necessary as long as all testers are calibrated the same by the use of transfer standards. Calibration traceable to absolute standards is desirable however in order to gain universal acceptance of the method and its results.