NTC数字测温

NTC Digital Measuring of Temperature

本文介绍了一种测温范围0°～100℃,测量误差<0.2℃/100℃,分辨率0.1℃的半导体热敏电阻数字式测温仪。详细阐述了系统的工作原理及转换特性,对测量系统的灵敏度、线性度及分辨率都作了定量的分析和讨论。本系统采用将NTC阻值变化直接变换成频率的变化,在传统的串并联电阻改善线性基础上,对NTC增加三点校正的硬件校正电路;测试数据送入单片机处理,同时,对处理的结果又实现了软件校正;测试结果数字显示。

The paper presents a kind of semiconductor thermistov Digit Tempevature Instrumentation,thoot the range fiading is 0℃～100℃ and the resolving powevis 0.1℃. In this system, not only the variations of NTC resistance is directly turned into the variations of frequency, but also the hardwave correction civcuit of three point correction is added to it on the basis of traditonal series—parallel connection resistance, ItS measured data is processsed in MCS—51 series 8031 Single Chip Microcomputer. And it is corrected by sofwave, too. The result of temper—ature is got by digit display. In addition, the system's working tenet and ite change—over characteristic and its resolving power are all discussed in quantitative analysis. In the overall system, the intermediate links are in the minority and the evvor is small and the reliability is high and the interfer—ence—resisting property is strong. In a word, it is a high precision Digit Tem—perature Instrumentation.