Abstract: Variable-temperature probe system is a key component in the desktop nuclear magnetic resonance analytic instrument. Semiconductor frigorific flake has been widely used as the frigorific element in various applications because of the advantages it possesses including small volume, low power loss and being easy to control. In this work, semiconductor frigorific modules were used as key components to develop a variabletemperature probe system, with which the sample temperature could be varied from -20 ℃ to 60 ℃. The performance of the probe system was tested on an NMI20-Analyst desktop nuclear magnetic resonance analytic instrument with 3.5% CuSO₄ solution as the sample. It was shown that, compared to the conventional variable-temperature probe system, the probe system developed has a relatively simple structure and high performance to cost ratio. The potential improvements for the variable-temperature probe system were also discussed.

Key words: NMR, variable-temperature probe system, nuclear magnetic resonance analytic instrument, semiconductor frigorific flake, Peltier effect