This test method specifies a sampling and testing procedure for the measurement of average fiber diameter and variation in diameter of animal fibers as required in Test Method D 2968.

Test Method D 2130 for testing wool and other animal fibers for average fiber diameter is considered satisfactory for acceptance testing of commercial shipments since current estimates of between-laboratory precision are acceptable and the method has been used extensively in the trade for acceptance testing. In cases of disagreement arising from differences in values reported by the purchaser and the seller when using this method for acceptance testing, the statistical bias, if any, between the laboratory of the purchaser and the laboratory of the seller should be determined with each comparison being based on the testing of specimens randomly drawn from one sample of material of the type being evaluated.

1.1 This test method covers a procedure, using the microprojector, for the determination of the average fiber diameter and the fiber diameter variation on wool and other animal fibers, such as mohair, cashmere, alpaca, camel's hair, etc. (Note 1) in their various forms.

1.2 The values stated in inch-pound units are to be regarded as the standard. The metric equivalents of inch-pound units may be approximate.

Note 1—This test method may also be applied to any fibers having a round cross section and accordingly may be used many times for melt-spun man-made fibers such as polyamides, polyesters, and glass; also it may be applied to a limited number of polyacrylics and regenerated cellulose type fibers. The values given in Appendix X1 for density and correction factors, however, apply only to wool and should not be used for other fibers. For suitable values for the density of other fibers, see Table 5 in Test Methods D 629, Quantitative Analysis of Textiles.

Note 2—In subsequent sections of this test method, the term “wool” also signifies mohair or other fibers if the circumstances are applicable.

Note 3—For fineness specifications for wool, wool top, mohair, mohair top, alpaca, and cashmere, refer to Specifications D 3991 and D 3992, Specification D 2252, Test Method D 2816.

1.3 This standard does not purport to address the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.