ASTM D3244-20

4.1.1 This practice can be used to ensure that such properties are correctly stated on labels or in other descriptions of the product.

4.1.2 This practice can be implemented in those cases where a supplier uses an in-house or a commercial testing laboratory to sample and test a product prior to releasing the product to a shipper (intermediate receiver) and the ultimate receiver also uses an in-house or commercial testing laboratory to sample and test the product upon arrival at the destination. The 4.2 This practice can assist in the determination of tolerances from specification limits which will ensure that the true value of a property is sufficiently close to the specification value with a mutually agreed probability so that the product is acceptable to the receiver. Such tolerances are bounded by an 4.3 Application of this practice requires the 4.3.1 This agreement should include a decision as to whether the ATV is to be determined by the absolute or rounding-off method of Practice E29, as therein defined.

4.5.1 Site precision (R′) as defined in Practice D6299 for the appropriate test method(s) from each lab, as substantiated by control charts meeting the requirement of D6299 from in-house quality control programs, for property typical of the product in dispute, should have a TPI > 1.2 for methods with Precision Ratio <4 and TPI > 2.4 for methods with Precision Ratio ≥4 (see Practice D6792 for TPI explanation).

4.5.2 Each lab shall be able to demonstrate, by way of results from interlaboratory exchange programs, a lack of a systemic bias relative to exchange averages for the appropriate test method(s) as per methodology outlined in Guide D7372.

4.5.3 In the event that the site precision of laboratories from two parties are statistically different as confirmed by the F-test (see Annex A4), then, for the purpose of establishing the ATV, each laboratory's test result shall be inversely weighted in accordance with laboratory's demonstrated variance.