This test method is considered satisfactory for acceptance testing of commercial shipments of spun yarns by agreement between purchaser and supplier.

5.1.1 In case of a dispute arising from differences in reported test results when using this test method for acceptance testing of commercial shipments, the purchaser and supplier should conduct comparative tests to determine if there is a statistical bias between their laboratories. Competent statistical assistance is recommended for the investigation of bias. As a minimum, the two parties should take a group of test specimens that are as homogenous as possible and that are from a lot of material of the type in question. The test specimens should then be randomly assigned in equal numbers to each laboratory for testing. The average result from the two laboratories should be compared using statistical analysis and a probability level chosen by the two parties before the testing is begun. If a bias is found, either its cause must be found and corrected or the purchaser and the supplier must agree to interpret future test results with consideration to the known bias.

Yarn faults are a factor in determining yarn and fabric quality.

1.1 This test method covers the classifying and counting of faults in spun yarns using capacitance testers.

1.1.1 Protruding fibers or yarn hairiness, or both, are not determined as part of this method.

Note 1—For measuring protruding fibers or hairiness, or both, refer to Guide D5647.

1.2 This test method provides for grading yarns by fault level and type.

1.3 This test method is applicable to all single or plied spun yarns from natural or manufactured fibers or blends of each.

1.4 The values stated in SI units are to be regarded as standard; the values in inch-pound units are provided as information only and are not exact equivalents.

1.5 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.