2.1 Certified Reference Material (CRM) - CRM is a stable, pure (99 + mol % purity) hydrocarbon or other stable petroleum product with a method-specific flash point established by a method-specific interlaboratory study following Practice D 6300 (formerly known as ASTM RR:D02-1007 guidelines) or ISO Guide 34 and 35.

2.1.1 Typical values of the flash point corrected for barometric pressure for some reference materials and their typical limits are given in Table A2.1 (see Note A2.2). Suppliers of CRM's will provide certificates stating the method-specific flash point for each material of the current production batch. Calculation of the limits for these other CRM's can be determined from the reproducibility value of this test method, reduced by interlaboratory effect and then multiplied by 0.7 (see Research Report RR:S15–1007).

NOTE 2.1 - Supporting data for the interlaboratory study to generate the flash point in Table A2.1 can be found in research report RR:S15-1010.

NOTE 2.2 - Materials, purities, flash point values and limits stated in Table A2.1 were developed in an ASTM interlaboratory program (see RR:S15-1010) to determine suitability of use for verification fluids in flash point test methods. Other materials, purities, flash point values and limits can be suitable when produced according to the practices of Practice D 6300 (formerly known as ASTM RR:D02-1007 guidelines) or ISO Guides 34 and 35. Certificates of performance of such materials should be consulted before use, as the flash point value will vary dependent on the composition of each CRM batch.

NOTE 2.3 - p-Xylene obtained from any reputable chemical supplier may be used as calibrating fluid as long as it meets the specifications detailed in A2.1.1.

2.2 Secondary Working Standard (SWS) - SWS is a stable, pure (99 + mol % purity) hydrocarbon, or other petroleum product with composition known to remain appreciably stable.

2.2.1 Establish the mean flash point and the statistical control limits (3s) for the SWS using standard statistical techniques. See Practice D 6299.