The determination of the tuft length of pile yarn floor covering is useful in quality and cost control during the manufacture of pile yarn floor covering. Both appearance and performance can be affected by changes in this characteristic.

In case there are disputable differences between reported test results for two or more laboratories, comparative tests should be performed to determine if there is a statistical bias between them, using competent statistical assistance. At a minimum, test samples should be used that are as homogeneous as possible, that are drawn from the material from which disputable test results were obtained, and that are assigned randomly in equal numbers to each laboratory for testing. The test results from the two laboratories should be compared using a statistical test for unpaired data, at a probability level chosen prior to the testing series. If a bias is found, either its cause must be found and corrected, or future test results must be adjusted in consideration of the known bias.

1.1 This test method covers the measurement of tuft length and pile yarn length of uncoated pile floor coverings.

1.2 Usually the tuft elements measured as directed in this test method will each be bound at only one binding site, but this test method also may be used for tuft elements bound at more than one binding site, provided that every tuft element measured is bound at the same number of binding sites.

1.3 The values stated in SI units are to be regarded as standard. The values stated in inch-pound units are provided as information only and are not exact equivalents. In case of referee decisions, the SI units shall prevail.

This practice 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 practice to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.