NMR thermometers are a convenient way to determine the temperature inside the sample of an NMR spectrometer. They rely on signals with strongly temperature-dependent chemical shifts, often of OH groups; 99.8% perdeuterated methanol is an established example which is particularly well suited for modern, high-sensitivity spectrometers, but it is so far calibrated only in the range of 282 to 330 K. In this work, we extend this calibration to the entire liquid range of methanol, 175 to 338 K. Additionally, we use a temperature sensor calibrated traceably to the International Temperature Scale (ITS-90) and accounted for the magnetic field effect on the sensor, yielding a more accurate calibration curve with an uncertainty (2σ) varying between 25 and 190 mK.

中文翻译：

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甲醇-d4核磁共振温度计校准的扩展和改进

NMR 温度计是确定 NMR 光谱仪样品内部温度的便捷方式。它们依赖于具有强烈温度依赖性化学位移的信号，通常是 OH 基团；99.8% 过氘化甲醇是一个成熟的例子，它特别适合现代高灵敏度光谱仪，但迄今为止它仅在 282 到 330 K 的范围内进行校准。在这项工作中，我们将此校准扩展到整个液体范围甲醇，175 至 338 K。此外，我们使用可溯源至国际温标 (ITS-90) 校准的温度传感器，并考虑了传感器上的磁场效应，从而产生更准确的校准曲线，具有不确定性 (2 σ ) 在 25 和 190 mK 之间变化。