ASTM C611-98(2016) pdf free download.Standard Test Method for Electrical Resistivity of Manufactured Carbon and Graphite Articles at Room Temperature.
ASTM C611-98(2016) covers the determination of the electrical resistivity of manufactured carbon and graphite articles at room temperature.
9.2 The within-lab variability is a combination of both test error and material variability since repetitious measurements were not made on singic specimens within a laboratory. Material variability was, however, minimized by normalizing the results to values averaged from consistent results from five laboratories. This yielded the estimate of a fairly small within- laboratory variability from 0.5 % to 0.75 % which still includes a minor material variability.
9.3 Homogeneity of variance by the sensitive Barlctt’s test was not indicated, most likely, because of the very small within-laboratory variance and sensitivity to non-normality.
9.4 The between-lab variability estimation was made on the measurement of the same specimen between laboratories with the obvious exception of the results from Laboratory A. The results still included some material variability as the resistivity varies to some extent along the length of the specimens.
5. Test Specimen
5.1 The test specimen may be in the form of a strip, rod, bar, or tube.
5.2 In order to determine the resistivity, each specimen shall conform to the following:
5.2.1 The cross-sectional area shall he uniform within
0.75 %. In general. the diameter of circular cross section, or the thickness and width of a strip specimen shall be determined by micrometer measurements. and a sufficient number of measurements shall be made to obtain a mean cross-sectional area to within 0.5 %. The test specimen shall be machined o yield planar and parallel end faces. These faces shall be perpendicular to the specimen length to within 0.001 mm/mm. All surfaces shall have a surface finish visually comparable to 0.8 I.lrn rms. Reasonable care should be exercised to assure that all edges are sharp and without chips or other flaws.
5.2.2 The test specimen shall show no defects observable with normal vision and shall be free of surface deposits.
5.2.3 The minimum ratio of specimen length to maximum cross—sectional dimension (width or diameter) shall he 6 : 1.
ASTM C611-98(2016) pdf download
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