【摘要】 针对航天器上常用的热敏电阻半桥测量电路，文章研究了负温度系数热敏电阻的分压-温度(U-t)曲线拐点，并发现在拐点附近有较宽的线性区间，且不同上拉电阻取值时对U-t曲线线性区间宽度有影响，上拉电阻越小，U-t曲线的线性区间越宽，线性区越向高温区移动。通过理论推导给出了最优上拉电阻公式，应用在某航天器0～20℃范围测量中，线性拟合后的残差小于0.1℃。同时研究比较了常用热敏电阻全测量范围内的一次线性拟合和三次多项式拟合，三次多项式拟合残差小于1℃的温度范围为-36～+68℃,基本涵盖全温度范围，温度跨度是同样残差条件下的一次线性拟合跨度的2倍。更多还原

【Abstract】 Regarding the commonly used half-bridge thermistors measurement circuit on spacecraft, the inflexion point of the thermistors’ voltage-temperature(U-t) curve with negative temperature coefficient is studied in this paper, and it is found that there is a good linearity near the inflexion point, the width of U-t curve linear interval is affected by different values of pull-up resistance. The smaller the pull-up resistance, the wider the linear interval of U-t curve, and the linear region moves towards the high temperature region. The optimal pull-up resistance formula is derived theoretically, and applied to a certain spacecraft measurement in the range of 0～20℃. The residual error after linear fitting is less than 0.1℃. At the same time, the first-order linear fitting and the cubic polynomial fitting in the whole measuring range of thermistor are studied and compared. The temperature range of the cubic polynomial fitting is-36～+68℃ when the residual error is less than 1℃, which basically covers the entire temperature range. The temperature span is twice that of first-order linear fitting under the same residual condition.更多还原