ISO Brightness numbers can exceed 100%, but not by too. Therefore, the ISO standard will always yield a higher brightness versus TAPPI for the same paper.
The fluorescence present in a paper sample, which can provide a significant contribution to brightness, will be stimulated more using the ISO standard versus TAPPI. indoor light plus some unfiltered daylight. Because of its lower UV content, it yields the lowest brightness reading. indoor lighting plus some filtered daylight (tinted windows). ¯ TAPPI - original standard, most common. The Impact of Kappa Number Composition on Eucalyptus Kraft Pulp 63 Brazilian Journal of Chemical Engineering. Since the reporting for Bekk smoothness is in units of time (seconds), a surface that measures 500 Bekk seconds is smoother than a surface that measures 200 Bekk seconds. An example of this would be the Bekk method, where a smoother surface requires more time for a given volume of air to leak across the surface. In the title of a test method, the term “smoothness” is used when an increasing number is correlates with a smoother surface measurement. Tappi Versus Iso Brightness Standard Average ratng: 5,8/10 3385votesīy: George Hagerty, Technidyne Corporation Terminology: The terms “smoothness” and “roughness” are generally well understood as far as a dictionary meaning goes however, the use of the terms in test methods is sometimes confusing.
