ASTM G5-14 pdf free download.Standard Reference Test Method for Making Potentiodynamic Anodic Polarization Measurements.
ASTM G5-14 covers an experimental procedure for checking experimental technique and instrumentation. If followed, this test method will provide repeatable potentiodynamic anodic polarization measurements that will reproduce data determined by others at other times and in other laboratories provided all laboratories are testing reference samples from the same lot of Type 430 stainless steel.
7. Precision and Bias5
7.1 The precision of the procedure provided in this reference test method has been determined by an interlaboratory test program. This program initially had eight laboratories participating, but three laboratories were eventually excluded because of problems with their procedures and results. Of the remaining live laboratories, one laboratory did not achieve sut1iciently reproducible results at the -0.450 and 0.000 V potentials during one run, so that the results from this run results were also excluded. The interlaboratory program was designed to have each participating laboratory run four replicate tests with the standard Type 430 stainless steel specimens. The current density results at the following potentials were chosen as critical points for evaluation: -0.450, -0.100. 0.000. 0.400 and 1.300 V versus the SCE electrode. The current densities were converted to base 10 logarithm values, and the Practice E691 procedure was used to evaluate the data at these potentials.
7.2 Repeatability refers to the agreement that occurs when identical specimens are run sequentially with the same operator using the same procedure and equipment. In this case, two values are reported to characterize the repeatability, the repeatability standard deviation, r, and the repeatability, r. which is
2.8Sr. Reproducibility refers to the agreement that occurs when several laboratories run the procedure using identical specimens with the same procedure. Two values are reported to characterize the reproducibility, the reproducibility standard
at each potential and their antilogarithrnic values are given in Table 2.
7.3 There is no bias in the current densities determined by this reference test method because the potentiodynamic current densities measured at the critical potentials in this method are determined only in terms of this test method.