Abstract：The zinc freezing point is the defining fixed-point of the International Temperature Scale of 1990 (ITS-90). Also, it is an important reference point for calibrating standard platinum resistance thermometers (SPRT). In order to improve the level of realization of the zinc freezing point, the zinc fixed point cell with metal shell was used to study the influence of different inducing methods on the zinc freezing plateaus and supercoolings. The Overall Maximum Estimate（OME）method was adopted to determine the impurity concentration. The reliability of the cell was evaluated using the changes of the impurity concentrations and the differences between the melting plateaus and freezing plateaus. The results showed that the different inducing methods can obtain good zinc freezing plateaus. For the inducing rods of different materials, the appropriate inducing times should be selected. In addition, when the furnace temperature was controlled at 418.5℃, the supercoolings of high-purity zinc in the cell were approximately 25mK, and the inducing methods had no effect on the supercoolings.
2024, Vol. 45 
