Dirt Estimation Chart
These opaque Charts were developed to estimate the equivalent black area (EBA) of dirt or other colored specks. This opaque chart is to be used with TAPPI/ANSI Test Methods T213, T437 and T537.
TAPPI Dirt Charts are manufactured from an original negative produced on photographic paper by an ISO/IEC 17025:2017 accredited calibration laboratory and an ISO 9001:2015 accredited facility.
You may also be interested in TAPPI's Size Estimation Chart (Transparency) and Calibrated Size Estimation Chart (Transparency).
Developed from and based on the TAPPI Dirt Estimation Chart, the Size Estimation Chart is a transparency used to measure the size of spots, defects, or inclusions in paper and other industrial materials such as textiles or plastics.