A thermometer is a temperature proxy, usually with a fixed number of parameters. When a nearly ideal gas or a similarly simple system is not available, the determination of a temperature scale is difficult, and has been subject to debate. Entropy uniqueness, due to Clausius, provides a fundamental theoretical criterion to answer this question. By measuring the heat flow d Q around a grid in p – V space, with M elemental areas, one can test a proposed temperature scale T n by computing ##IMG## [http://ej.iop.org/images/0143-0807/41/5/055101/ejpab9b3dieqn1.gif] {$\sum {\left[\oint \left(\mathrm{d}Q/{T}_{n}\right)\right]}^{2}$} , the rms deviation, from the desired value of zero. This approach also can be used to determine which of a group of n thermometers has the most accurate temperature scale T n . As background we discuss Clausius’s development of the mathematics and the c...

中文翻译：

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熵的唯一性决定温度

温度计是温度的代理，通常具有固定数量的参数。当没有接近理想的气体或类似的简单系统时，温度标度的确定将很困难，并且已经引起了争论。由于克劳修斯的缘故，熵的唯一性为回答这个问题提供了基本的理论标准。通过测量p – V空间中具有M个元素区域的网格周围的热流d Q，可以通过计算## IMG ## [http://ej.iop.org/images/ 0143-0807 / 41/5/055101 / ejpab9b3dieqn1.gif] {$ \ sum {\ left [\ oint \ left（\ mathrm {d} Q / {T} _ {n} \ right）\ right]}} ^ { 2} $}，即均方根与期望值零的偏差。该方法还可用于确定n个温度计中的哪一个具有最精确的温度标度T n。