It's All in the Details; Textured Geomembrane Example

摘要

Several measurements of the same property of a specific sample by a particular test will not give the same precisernresults. Values from replicates show variability and it can also be observed from comparing tests results derived fromrndifferent laboratories that tests performed on the same material will also vary. These variability's have economicrnconsequences when verifying material quality versus a specification.rnOn the surface, interpretation of test data from geosynthetic testing seems quite straight forward; compare the meanrnvalues shown on a test report to the specification requirements. However, a statistical look at the test data presentsrnsome interesting issues. These statistical issues can be a problem if not understood or a help when understood.rnIt can be seen when viewing a geosynthetic test report that values from replicates vary. Sometimes the variation inrnreplicates is large while in other cases it can be relatively small. This variability can also be observed whenrncomparing tests results derived from different laboratories. Thus, there are variations between replicates andrnbetween different laboratories. It is obvious that several measurements of the same property of a specific sample byrna particular test will not give the same precise results.rnThis leads to the question of what are the true or reliable results. It is a particular problem when comparing test datarnbetween two different laboratories. Is one laboratory correct and the other wrong or are they both either right orrnwrong? The answer to these questions is critical when one laboratory is a manufacturers' laboratory and the other isrnan independent or third party laboratory verifying material quality versus a specification.