1. Research on aluminum-based eutectic fixed-point cells in portable dry-body thermostat.
- Author
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Zhang, Tingting, Lu, Xiaofeng, Zhao, Yikun, Li, Ting, and Sun, Jianping
- Subjects
EUTECTIC alloys ,COPPER ,THERMOSTAT ,THERMOCOUPLES ,THERMOMETERS - Abstract
Aluminum-based eutectic alloys exhibit melting and freezing plateaus analogous to the metal–carbon eutectic fixed point. To economically investigate the behavior of the eutectic cells, a special graphite crucible with stainless-steel enclosure was designed. The plateau temperature of eutectic alloys with precise ratios of Al combined with 70% silver (Ag), 33%copper (Cu), or 95%zinc (Zn) was assessed similar to high-temperature fixed points. Melting and freezing curves for Al(660.323 °C), Al–Ag(568 °C), Al–Cu(548 °C), and Al–Zn(381 °C) cells, when heated in a portable dry-body thermostat, were determined using a standard type-S thermocouple. Results indicated a noticeable discrepancy between the melting and freezing temperatures due to the thermal conduction; the thermocouple immersion in the thermostat was not sufficiently deep. By extrapolating the furnace temperature offset to 0 °C, the discrepancies were reduced to 77, 150, 141, and 80 mK for Al, Al–Ag, Al–Cu, and Al–Zn cells, respectively. This research suggests that the Al-based eutectic fixed point holds potential for calibrating resistors, thermocouples, and radiation thermometers in future applications. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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