TAPPI has a solution for dirt -- the kind that gets into your products during the manufacturing or shipping process.
TAPPI’s Dirt Chart cards estimate the equivalent black area (EBA) of dirt or other colored specks. The equivalent black area of a dirt speck is defined as the area of a round black spot on the white background of the TAPPI Dirt Estimation Chart that makes the same visual impression as the dirt speck on the material in which it is embedded. Dirt Estimation Charts are manufactured from an original negative on Kodak photographic paper. The paper positive is produced in a NuArc contacting frame with an Olite light source and Olix light integrator. The light integrator precisely controls the exposure. Each piece of photographic paper that is produced during the manufacturing process is evaluated with an X-Rite densitometer for correct exposure.
To ensure the accuracy of the charts, each piece is measured by examining the .20 dot with a 100 x magnifier that has a reticle (scale) incremented in 5/10,000 mm on the lens. This opaque chart can be used with TAPPI Test Methods T 213, T 437, and T 537.
You want to hear more? Check out TAPPI’s size estimation chart (for use with Test Method T 564). Developed from 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.
The TAPPI Calibrated Size Estimation Chart is a great solution for quality control applications where exact dimension specifications are required. Each Calibrated SEC comes with its own data sheet that provides an actual dot measurement area (expressed in squared mm) to correspond with the increments (dots) on the chart.
Dirt Estimation Chart (Opaque)
Temporarily Unavailable, please see Size Estimation Chart
Product Code: 0109DIRT
Size Estimation Chart (Transparency)
Product Code: 0109DIRTT
Calibrated Size Estimation Chart (Transparency)
Product Code: 0109DIRTCAL
New Volume Discounts for TAPPI Chart purchases: