5.1 Puncture using a 50?mm flat circular probe is applicable to determine the index strength resistance and deformation of a particular geotextile or geotextile-related products.

5.2 This test method is considered satisfactory for acceptance testing of commercial shipments of geotextiles.

5.3 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 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 that are as homogeneous as possible and that are from a lot of the type in question. The test specimens then should 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 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 in light of the known bias.

5.4 This test method is not applicable to materials that are manufactured in sizes that are too small to be placed into the test apparatus in accordance with the procedures in this test method. Furthermore, it is not appropriate to separate plies of a geosynthetic or geocomposite for use in this test method.