ASTM D 1425 : 1996

1.1 This test method covers the indirect measuring of unevenness of textile strands from tow, top, sliver, roving, and yarn produced from staple fibers and filament yarns by means of continuous runs using capacitance testing equipment.

1.2 The test method provides a value of "short-term unevenness," a single value expressing the complicated strand property that is unevenness.

1.3 The test method is applicable to all yarns, rovings, slivers, and tops, except as indicated below.

1.3.1 Low twist filament yarns should be tested only if additional twist is inserted during testing.

Note 1-In many cases, these low twist yarns tend to flatten to a ribbon while passing through the condenser of the instrument, and the recorded value of unevenness is increased above the true value.

1.3.2 Strands made from fiber blends should be tested only if blending is uniform along the strand.

Note 2-Nonuniform blending may cause a higher reading of unevenness than the true value if the component fibers differ in dielectric constant. The magnitude of the increase of unevenness readings due to nonuniform blending cannot be stated in general terms.

1.4 The values stated in either acceptable metric units or in other units shall be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system must be used independently of the other, without combining values in any way.

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.