Historical
TAPPI T 564 sp-16
Transparent chart for the estimation of defect size
2.1 The transparent chart developed for this method is to be used to estimate the size (area) of spots, defects, and/or other inclusions over the range of 0.02 to 5.00 mm2.
2.2 The chart can be used in a large number of applications where there is a need to estimate a size (area) by way of a direct comparison to a known area disk or rectangle. Applications may include, but are not limited to, the measurement of visible ink spatter on printed surfaces, the estimation of the growth rate of bio-colonies, air inclusions in transparent plastic castings and films, etc.
2.3 The chart must not be used to estimate the equivalent black area (EBA) of dirt or other colored specks. Dirt measurements by the EBA method should be performed in accordance with TAPPI T 437 “Dirt in Paper and Paperboard,” TAPPI T 213 “Dirt in Pulp,” or TAPPI T 563 “Equivalent Black Area (EBA) and Count of Visible Dirt in Pulp, Paper, and Paperboard by Image Analysis.” Do not use this chart for T 437, T 213, or T 563.
Technical Association of the Pulp and Paper Industry [tappi]