An International Round Trial Comparing Certified Tile Calibrations to Standard Wool Top Calibrations for Greasy Wool
Abstract
The results of an international round trial comparing colour calibration using Tiles and a Reference Wool for greasy wool are reported. It is shown that wool colour measuring instruments can be successfully calibrated using a Certified Tile Calibration and Illuminant D65 with the 100 Observer.
Table A: Comparison of 95 % Confidence Limits for a Single Test in One Laboratory Tile Calibration (D65/100)
|
Tile Calibration (D65/100) |
Wool Calibration (D65/100) |
Wool Calibration (C/20) |
Draft Standard* DTM - 56 |
|
X |
2.0 |
2.1 |
2.0 |
2.2 |
|
Y |
2.1 |
2.0 |
1.8 |
2.3 |
|
Z |
2.2 |
2.4 |
2.5 |
3.0 |
|
Y-Z |
0.9 |
1.0 |
1.1 |
1.0 (1.5) |
* Waring Blender Limits. Carding limits for Y-Z only in Brackets.
The trial results indicate that there is no difference in precision when comparing Wool and Tile calibrations with the current requirements of the draft standard. The results suggest the industry can immediately adopt the tile calibration system. Baremes can be provided which relate the new colour values obtained in D65/100 colour space to those obtained in the C/20 colour space.
Citation
"An International Round Trial Comparing Certified Tile Calibrations to Standard Wool Top Calibrations for Greasy Wool", D.W. Crowe and G. R. Shepherd, RWG05, Raw Wool Group, IWTO Florence Meeting, May 1999.