5.1 Option A procedures of Test Method D3774 for width are considered satisfactory for acceptance testing of commercial shipments because they are used extensively in the trade.

5.1.1 In case of a dispute arising from differences in reported test values when using Test Method D3774 for acceptance testing of commercial shipments, the purchaser and the 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 which are as homogeneous as possible and which 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 results from the two laboratories should be compared using Student's t-test for unpaired data and an acceptable probability level chosen by the two parties before 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 in the light of the known bias.

1.1 This test method covers the measurement of the width of woven or knitted fabrics, usable width, or both. The method is applicable to full rolls, bolts of fabric, and short specimens removed from a roll or bolt. Unless otherwise specified, measurements shall include the selvages when present.

1.2 The method offers two options:

1.2.1 Option A—Full Roll or Bolt.

1.2.2 Option B—Short Specimen Removed from Full Roll or Bolt.

1.3 The values stated in either SI units or U.S. customary units are to be regarded as standard. The U.S. customary units may be approximate.

1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.