statistical bias between them, usin

statistical bias between them, using competent statistical assistance. As a minimum, use the samples for such a comparative test that are as homogeneous as possible, drawn from the same lot of material as the samples that resulted in disparate results during initial testing and randomly assigned in equal numbers to each laboratory. The test results from the laboratories involved should be compared using a statistical test for unpaired data, a probability level chosen prior to the testing series. If bias is found, either its cause must be found and corrected, or future test results for that material must be adjusted in consideration of the known bias. 5.1.2 This test method is suitable for use with narrow fabrics when the count across the total width is measured in the narrow direction and extrapolated to the number of yarns per centimeter (inch).6. Apparatus 6.1 Use any suitable device, such as pick glass, rule and pointer, microfilm reader, or projection equipment. The use of optical sensing equipment may be used as agreed upon by the purchaser and supplier. 6.2 Use a scale graduated in mm (1/6-in.) to measure the distance over which thread counts were taken.7. Sampling 7.1 Lot Sample-As a lot sample for acceptance testing,take at random the number of rolls of fabric as directed in an applicable material specification or other agreement between the purchaser and the supplier. Consider rolls of fabric to be the primary sampling units. 7.2 Laboratory Sample- As a laboratory sample, take a full width swatch at least 2 m (2 yd) long from each roll of fabric in the lot sample. Consider each designated place at which end counts and pick counts are made as a test specimen. NOTE 3-For specimens not obtained as directed in Section 7, the results should not be used for acceptance testing of a lot.8. Con ditioning 8.1; Condition specimens as directed in Practice D 1776. 8.2 Fabrics woven from yarns having a relatively low moisture regain in the standard atmosphere for testing textiles,which, is 21士2 0C X70士4 0F) and 65士%relative humidity, and which are not significantly affected by minor variations in different atmospheric conditions, for example,nylons, acrylics, and polyesters, may be tested without preconditioning. Fabrics woven from yarns composed wholly or in part from wool, rayon, cotton, or acetate are more sensitive to atmospheric changes and must be conditioned prior to testing,except by agreement of all parties interested in the test results. 8.3 When full rolls or bolts of fabric cannot be properly conditioned in a reasonable time with available facilities,perform the test without conditioning and report the actual conditions prevailing at the time of the test. Such results may not correspond with the results obtained after testing in the standard atmosphere for testing textiles.