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从繁流放电理论可直接导出热阴极电离真空计的特性方程,证明通常的概念即在热计的电子流ie一定时其离子流i+与压强P成正比的关系,只在离子流甚小于电子流时才能成立。在被测气体的压强较高时,离子流和压强之间呈现下列指数关系: i+/ie=1-e(-(K1P-K2P2))(K1及K2为常数),且随着压强的增长而逐步趋于饱和。进一步的推导则得出,当容许测量误差为1%时,热计的线性上限(临界压强)为Pc=0.22/Г,此处Г为热计的灵敏度。这种理论可以容易地解释近年来一些实验工作者例如Nottingham,Schultz,Goto,Hinzpeter等的实验结果。此外我们还使用了特殊设计的“封闭式”电离计作实验,得到的结果和理论预计十分符合。这种电离计本身则可用作10-7~0.6托的宽程量具。The characteristic equation of hot-cathode ionization gauge is derived from the theory of Townsend discharge, with the form i+/ie=1-e(-(k1p-k2p2)) where i+ is the ion current, ie the electron current, p the gauge pressure, and both k1 and k2 are constants. Only at i+?ie, the equation shown above becomes i+/ie=Гp where Г is the sensitivity of gauge and approximately equals k1. The critical pressure, at which linearity between i+ and p breaks down, is Pc=0.22/Г while the permissible error of gauge calibrated is 1%. Plenty of experimental results shown by Nottingham, Schultz, Goto, Hinz-peter etc. can be easily explained. Data taken from a specially designed "drum" gauge give good coincidence with theoretical results. The "drum" gauge itself can be used for a wide range to measure pressures from 10-7 to 0.6 Torr.
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