ASTM D572-99 pdf free.Standard Test Method for Rubber-Deterioration by Heat and Oxygen.
Determine the tensile strength and ultimate elongationor the stress – strain properties of the specimens，aged fordifferent intervals, as the intervals terminate,disregarding thefact that more specimens may still be aging.In determining thephysical properties after aging, consider as the final values themedian of results from three specimens except that under thefollowing conditions expose and test two additional specimensand use the median of the values for the five specimens:If one or more values do not meet the specifiedrequirements when testing for compliance with specifications,or，If referee tests are being made. After completion ofthe tests, examine the broken specimens visually and manuallyand note their condition.This precision and bias section has been prepared inaccordance with Practice D 4483. Refer to this practice forterminology and other statistical calculation details.A Type 2 (interlaboratory) precision was evaluated in1974.Both repeatability and reproducibility are short term, aperiod of a few days separates replicate test results.A test resultis expressed on the basis of a median value, as specified by TestMethods D 412 obtained on 3 determinations or measurementsof the property or parameter in question.Six different materials were used in the interlaboratoryprogram, and were tested in 3 laboratories on 2 different days.These precision results were obtained for a variety of com-pounds prepared in accordance with Method D 15 prior to itsremoval from the Annual Book of ASTM Standards. Please seethe Annex of Test Method D 573 for more details on this work.14.4 The results of the precision calculations for repeatability and reproducibility for both percent tensile strength changeand percent elongation change are given in Table 1, inascending order of material average or level， for each of thematerials evaluated.
The precision of this test method may be expressed inthe format of the following statements that use an appropriatevalue of r,R, ( r),or (R),that is，that value to be used indecisions about test results (obtained with the test method).The appropriate value is that value of r or R associated with amean level in the precision tables closest to the mean levelunder consideration at any given time, for any given material inroutine testing operations.ASTM D572 pdf download.