acetate electrolytes. However in chloride and in bromide solutions, stirring led to an increase in electrode potential. Stirring dependencies were also found for the commercial electrodes studied but in the opposite direction.The copper-arsenic trisulfide electrodes did not respond to cuprous ion per se, or to the Cu ++/Cu + couple. No interference was found from Ca + +, Pb + +, Zn + +, Ni + +, or Mn + +. Ferric ion, when present in a ten fold excess, interferes; Ag + also interferes. Qualitative studies of the electrode activation process indicated that direct oxidation of the surface by cupric ion takes place followed by two or more chemical reactions between cupric ion in solution and this oxidized surface. It is this final surface configuration which is involved in cupric ion sensing. ABSTRACTThe Laplace transform solution of the unsteady state diffusion equation which describes the concentration gradients in a convectionless system has been compared to experimentally obtained values. The experimental values were obtained as multiple beam Fizeau-type fringes from an electrolysis cell which was also a Fabry-Perot interferometer using a laser as the light source. The electrochemical system was Zn/ZnSO4/Zn, at 0.5-0.05M concentration at room temperature at constant currents ranging from 1.0 to 0.i mA cm -2. At the middle ranges of times and current densities quite good agreement is found. In general the calculated and experimental values differed more than the expected experimental error. A "passivated" set of electrodes was used and gave much lower concentration changes for similar current densities than the normal electrodes.* Electrochemical Society Active Member.

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Main text This bilateral SIM key comparison on calibration of gauge blocks by interferometry (SIM.L-K1.2007.1) was carried out between CENAM (México) and INTI (Argentina). Its scope is to support and maintain the claimed Calibration and Measurement Capability (CMC) by the participants, which regularly offer the service of gauge block calibration by optical interferometry. The comparison was held from first half of 2018 to second half of 2019, and involved the measurement of eleven steel gauge blocks-eight in the range of short gauge block and three in the range of long gauge block. The reference values for each nominal length were taken as the arithmetic mean. The results of both participants are in good agreement with the reference values for all the gauge blocks measured. This makes the present comparison exercise valid to provide evidence of the participants' competence. The results also provides evidence to support the CMC claims of the participants in gauge block calibration by optical interferometry and for those service that stems out of this key technique as required by the CIPM Mutual Recognition Arrangement (CIPM MRA). To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCL, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

A comparison of 11 steel gauge blocks (8 short and 3 long) calibrated by absolute interferometry is presented. Thus, the results of the individual measurements of five designates signatories (three from INTI and two from CENAM) were analyzed in order to evaluate the impact of possible correlations and systematic effects in the reproducibility of the measurements. All measurements were carried out in the framework of a bilateral key comparison between CENAM and INTI and following their own calibration procedures. The measurement analysis was performed by using inclusive and exclusive statistics. The agreement between all measurements is satisfactory and no detectable systematic effects were observed. Average offsets were also calculated for each operator verifying that systematic effects did not affect the measurements of the present exercise. Even though the approaches deployed to analyze the results are well-established, this work provides a detailed example of analysis in the field of gauge block metrology. This exercise has also allowed to validate the internal criteria considered by each institute for selecting final results.

Die Lösung der Laplace‐Transformation für die Diffusionsgleichung im Nichtgleichgewichtszustand, die die Konzentrationsgradienten in einem konvektionslosen System beschreibt, wird mit experimentell erhaltenen Werten des Zn/ZnSO4/Zn‐Systems verglichen.