Significance and Use
This test method specifies sampling and testing procedures for the measurement of average fiber diameter and variation in diameter of animal fibers.
This test method is considered satisfactory for acceptance testing of commercial shipments of wool and other animal fibers in raw and sliver form because current estimates of between-laboratory precision are acceptable. In cases of disagreement arising from differences in values reported by two or more laboratories when using this test method for acceptance testing, the statistical bias, if any, between the laboratories 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. Test Method D2130 shall be used as a referee test method.
This test method may be used for determining compliance with average fiber diameter and diameter variation to assign grades when determining conformance of shipments to material specifications given in Specifications D2252, D3991, and D3992, and Test Method D2816.
The procedures for determining mean fiber diameter and standard deviation of fiber diameter provided in this test method and in IWTO Method 47-98 are in essential agreement.
Scope
1.1 This test method covers a procedure that uses an Optical Fiber Diameter Analyser (OFDA) for the determination of the average fiber diameter and the fiber diameter variation in wool and other animal fibers in their various forms.
Note 1—This test method may also be applied to other fibers having a round cross section such as some polyamides, polyesters, and glass; it may also be applied to a limited number of polyacrylics and regenerated cellulose-type fibers.
Note 2—In subsequent sections of this test method, the term “wool” also signifies other animal fibers where applicable.
Note 3—For fineness specifications of wool, wool top, mohair, mohair top, alpaca, and cashmere, refer to Specifications D3991, D3992, D2252, and Test Method D2816, respectively.
1.2 The OFDA reports average fiber diameter and standard deviation of fiber diameter in micrometer units (μm). The coefficient of variation of fiber diameter is reported as a percentage.
1.3 This standard does not purport to address all of 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.