Size Estimation Chart (Transparency)
The TAPPI Size Estimation Chart is a transparent chart 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. Instructions for use of this transparency are outlined in TAPPI Test Method T 564. 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 circular area. A must for quality inspection professionals, these charts serve as quality assurance resources to determine the size of imperfections in the following applications.
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- Measure the size of defects in products
- Inspect third-party packaging
- Determine the size of imperfections in molded plastic products and medical tubing
- Detect embedded specs
- Measurement of visible ink spatter on printed surfaces
- Estimation of the growth rate of bio-colonies
- Detect air inclusions in transparent plastic castings and films
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The Size Estimation Charts are manufactured from an original negative on negative working contact film. The film positive is produced in a NuArc contacting frame with a NuArc light source and built-in light integrator which controls the exposure. Each piece of photographic film that is produced during the manufacturing process is evaluated with an X-Rite transmission densitometer for correct exposure.
To measure the accuracy of the end product, each transparency is measured by looking at the .2 dot with a 100-power magnifier that has a reticle (scale), incremented in 5/10,000’s of a millimeter, on the lens. The dots on the chart are correct within an average 10% or 0.005 square millimeters, whichever is the larger.
Calibrated Size Estimation Charts are ideal for quality assurance processes that require more exact measurement. Each transparent chart has 23 dots that are measured and documented within the specified tolerances. The actual measurements for each dot in square millimeters are exported to a Data Sheet with a unique serial number corresponding to the chart.
Frequently Asked Questions
Questions regarding TAPPI Charts? Contact press@tappi.org.
New Volume Discounts for TAPPI Chart purchases: