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82 SMT007 MAGAZINE I FEBRUARY 2019 comparison is permissible insofar as all EDX spectra were recorded under the same measur- ing conditions (high voltage, the running time of the analysis, the aperture setting, and the sample distance to the detector) [2–6] . Test Evaluation Storage Atmosphere As expected, the highest O² peaks, and thus the highest surface oxidation, could be mea- sured on the samples stored under air. When comparing the samples stored in N² and dry air, it is noticeable that the lowest O² peaks and surface oxidation occur during dry storage. The results of this long-term test prove that dry storage can be classified as very suitable for long-term storage due to its optimal oxidation protection [2–6] . Dry storage is preferable to ni- trogen storage not only in terms of quality but also in terms of energy consumption [7] . Influence of Temperature on Ageing Rate In addition to corrosion, the components age through diffusion processes at metallic bound- ary layers. Each temperature increase leads to an increase in the ageing rate due to an in- crease in the reaction rate. A rule of thumb pre- dicts a doubling to quadrupling of the ageing rate with a temperature increase of 10°K. The physical and chemical processes are described in more detail with the Arrhenius equation. For this reason, it is recommended to reduce the storage temperature as much as possible during long-term storage. However, there are also negative effects such as whisker forma- Figure 1. Ag sample. Figure 2: AgCu28. Figure 3: AgCu50. Figure 4: Copper.