Dirt Estimation Chart
TEMPORARILY UNAVAILABLE. CONSIDER Size Estimation Charts.
TAPPI’s Dirt Charts are manufactured from an original negative produced on DuPont CRR film and estimate the equivalent black area (EBA) of dirt or other colored specks. The charts are processed on a rapid-access processor using Kodak/Fujifilm chemistry. Each chart is produced on photographic paper via a contacting frame with an NuArc light source and NuArc light integrator which controls the specific exposure designated for accuracy and consistency. Charts are exposed to 20 units of light. To ensure the accuracy of the charts, each piece is measured by examining the 2.0 dot with a 100 x magnifier that has a reticle (scale) incremented in 5/10,000mm, on the lens. This opaque chart is to be used with TAPPI Test Methods T213, T437 and T537.
You may also be interested in TAPPI’s Size Estimation Charts. Developed from and based on the TAPPI Dirt Estimation Chart, this transparency is used to measure the size of spots, defects, or inclusions over the range of 0.02 to 5.00 square millimeters in paper and other industrial materials such as textiles or plastics.
You may also be interested in TAPPI's Size Estimation Chart (Transparency) and Calibrated Size Estimation Chart (Transparency).