Industry Reference Materials (IRMs), used for a number of test methods under the jurisdiction of ASTM Committee D11, are prepared according to ASTM D4678, "Preparation, Testing, Acceptance and Documentation for Industry Reference Materials (IRM)". Refer to this for details not covered in this document. Candidate materials that are intended as IRMs are tested and accepted on the basis if (1) homogeneity of the lot and (2) an Accepted Reference Value or AR-value, for the appropriate properties for any IRM. The AR-value is the test value that should be obtained (within specified limits) for the selected one or more properties. AR-values are of two types: Global AR-values, obtained as an average (with specified 3 s limits) from an interlaboratory test program and Local AR-values, obtained as an average (with specified 3 s limits) for the laboratory involved with the preparation and testing.