Since tear resistance may be affected to a large degree by mechanical fibering of the membrane under stress, as well as by stress distribution, strain rate, and size of specimen, the results obtained in a tear resistance test can only be regarded as a measure of the resistance under the conditions of that particular test and not necessarily as having any direct relation to service value. This test method measures the force required to tear a reinforced geomembrane along a reasonably defined course such as that the tear propagates across the width of the specimen. The values may vary between types of reinforcement used within a geomembrane.

The tongue tear method is useful for estimating the relative tear resistance of different reinforcing textiles or different directions in the same reinforcing textiles.

Disputes-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 difference between their laboratories.