Comparison Between Melting and Freezing Points of Indium and Zinc

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Comparison Between Melting and Freezing Points of Indium and Zinc (107.01 KB)

In the interest of improving convenience and plateau duration, the use of melting points instead of freezing points for temperature fixed points in temperature calibration is considered. The question is whether adequately low uncertainties can be achieved with melting plateaus. Experimental research was carried out to compare the melting and freezing points of indium and zinc by using the inter-comparison method with standard platinum resistance thermometers (SPRTs). The influence of the furnace maintenance temperature on the performance of melting plateaus of indium and zinc was investigated and discussed. Differences in results between the melting points and the freezing points are shown. Uncertainty budget analysis of the melting points is presented. The experimental results show that because of the small differences between the freezing points and melting points using the optimal methods of realization, it is possible to replace the freezing point with the melting point in the calibration of SPRTs in secondary-level laboratories.