ASTM D6166 Test Method for Color of Naval Stores and Related Products
ASTM D6166 Standard Test Method for Color of Naval Stores and Related Products (Instrumental Determination of Gardner Color)
8. Report
8.1 Report the color in Gardner color units to a tenth of a Gardner unit as given by the instrument or as calculated by the method in the appendix. Note if the material was filtered.
9. Precision and Bias
9.1 Interlaboratory Test Program - An interlaboratory study of the color of three materials was run in 1996. Each of 13 laboratories tested each of the three materials. The design of the experiment, similar to that of Practice E 691 and a within-between analysis of the data are given in ASTM Research Report.
9.2 Test Result - The precision information given below for Gardner color is for the comparison of three test results, each of which is the average of three test determination as follows:
9.2.1 Repeatability Limit, 95 % (within laboratory) = 0.06 Gardner units.
9.2.2 Reproducibility Limit, 95 % (between laboratories) = 0.50 Gardner units.
9.3 These terms (repeatability limit and reproducibility limit) are used as specified in Practice E 177. The respective standard deviations among test results, related to the above numbers by the factor of 2.8, are as follows:
9.3.1 Repeatability standard deviation = 0.02 Gardner units.
9.3.2 Reproducibility standard deviation = 0.18 Gardner units.
9.4 Bias - Since there is no accepted reference material suitable for determining the bias for the procedures in this test method, bias has not been determined.
10. Keywords
10.1 instrumental Gardner color; rosin; tall oil; tall oil fatty acids
