Diana WymanSeptember 19, 2022 AATCC Newsletter

The scales used by textile testing labs are carefully designed and checked for consistency, but they can change with time, exposure, and handling. Follow the guidelines below to ensure repeatable evaluations using AATCC scales. Most scales should be replaced annually, but some can last longer, especially with regular verification.

Gray Scales

AATCC EP1 Gray Scale for Color Change and AATCC EP2, Gray Scale for Staining include a table specifying the color difference for each chip pair and an Appendix describing how to verify the difference.

Color difference for each pair of chips may be measured quarterly on a spectrophotometer with sphere geometry. Use a small area view (approximately 10-mm diameter) and specular component included. Be careful to position the scale so that only the desired chip is in the viewing area for each measurement. If ΔECIELAB is within the stated tolerance for all pairs, the gray scale is still suitable for use.

If you do not have access to a spectrophotometer or choose not to measure your scales every three months, replace each gray scale within one year of its initial use. For your convenience, there is a line on the scale to record the date of initial use. Of course, if there is visible damage to any of the chips or the mask, the scale should be replaced immediately.

Other recommendations for use and care are also listed on the scales and in the evaluation procedures.

  • Store scale in sleeve when not in use.
  • Do not place mask inside folded scale.
  • Inspect frequently for fingerprints and any other marks.
  • Replace annually or measure quarterly and replace as needed.

Replace Your Gray Scales Now (Annually)
AATCC Gray Scale for Color Change: Item #28359B

AATCC Gray Scale for Staining: Item #28360B

AATCC 9-Step Chromatic Transference Scale

Guidelines for the Chromatic Transference Scale are similar to those for the Gray Scales. AATCC EP8 states, “The cleanliness and physical condition of the Scale is extremely important in obtaining consistent results.”

  • Inspect frequently for fingerprints and any other marks.
  • Inspect for physical damage to the chips (e.g., chipped edges, loose or buckled chips).
  • Replace or measure at least annually on a spectrophotometer.

Spectrophotometer measurements can be particularly challenging on the chromatic scale because of the small chip size. The measurement area should not include any open area or adjacent chip. The viewing port diameter must be smaller than 10 mm. Annual measurements are compared to those measured upon receipt. With the large number of chips and very small measurement area, it is generally more practical to simply replace the scale at least once per year.

Replace Your Chromatic Scale Now (Annually)
AATCC 9-step Chromatic Transference Scale: Item #28347A

Stain Release Scales

Stain scales for AATCC TM175, Stain Resistance: Pile Floor Coverings and AATCC TM130, Soil Release: Oily Stain Release Method should be replaced annually—more often if they are visibly soiled or damaged. To avoid premature color change, it is best to store both scales in a dark place between uses.

  • Inspect frequently for fingerprints and any other marks.
  • Store away from light.
  • Replace annually.

Replace Your Stain Scales Now (Annually)
AATCC Red 40 Stain Scale (for carpet): Item #19129A

Stain Release Scale: Item #68379A

3D Appearance Replicas

The scales for appearance (wrinkle recovery, fabric smoothness, crease) evaluation are made up of three-dimension plastic replicas cast from fabric. While these are more durable than the printed scales, they still require careful handling and regular replacement.

  • Wipe with a damp cloth and allow to dry
  • Inspect frequently for marks, cracks, or other damage
  • Store replicas carefully in box slots.
  • Replace every three years.

Replace Your Appearance Scales Now (Every 3 Years)
AATCC 3D Smoothness Appearance Replicas: Item #68353A
AATCC 3D Crease Replicas: Item #68720A
AATCC 3D Wrinkle Recovery Replicas: Item #68390A

Photographic Scales

Several AATCC test methods use photographic scales for evaluation. Some of these scales are mounted on rigid cards, while others are simply a sheet of paper.

  • Inspect frequently for marks, tears, scratches, or other damage
  • Replace every three years.

Replace Your Photographic Scales Now (Every 3 Years)
AATCC Photographic Spray Test Evaluation Scale: Item #78387A

AATCC Photographic Seam Smoothness Scales: Item #68373A
AATCC Photographic Flock Scale: Item #68356A
AATCC Photographic Filter Residue Scale: Item #58335A
AATCC Photographic Dye Dusting Scale: Item #58725A

About the Author

Diana Wyman is Executive Vice President of AATCC. She is passionate about textile testing and standards. Feel free to reach out with your own enthusiasm or frustrations around standards.

Versions of this article were published in November 2018 and October 2021 editions of AATCC News. To subscribe to this free, emailed newsletter, visit www.aatcc.org/subscribe.

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