提高NTC热敏电阻器测量响应速度的方法

为了满足温度测量场合对响应速度的要求,利用电阻电容(RC)一阶系统的阶跃响应特性,设计了一种测量时间与阻值成正比的高精度测量电路,提出了一种快速充放电的方法,消除测量方法的无效等待时间.基于该思想,利用STM32单片机I/O开漏与推挽方式的输出控制,完成自由与快速充放电过程,利用负温度系数(NTC)热敏电阻,实现了高精度温度的测量.稳定性测试实验表明:测量系统在恒温为25℃时,连续测试10h,NTC热敏电阻的阻值相对波动0.006％,具有较高的稳定性.温度响应实验表明:测量系统符合典型的一阶阶跃响应特点,响应时间较常规的RC温度测量电路明显变短,响应速度得到了提高.基本满足一般测温场合对响应速度的要求.

Method for improving response speed of NTC thermistor measurement

In order to meet requirement of response speed in temperature measurement occasions,use slep response characteristics of resistance capacitance first-order system,design high precision measurement circuit whose measurement time is proportional to the resistance,and put forward a method for fast charging and discharging,eliminate invalid waiting time of measuring method.Based on this idea,respectively use STM32 microcontroller unit(MCU) I/O open drain and push-pull output control,complete free and fast charging and discharging process,use negative temperature coefficient thermistor (NTC),realize high precision temperature measurement.Stability test results show that the measurement system in constant temperature of 25 ℃,continuous measurement of 10 h,relative volatility 0.006 ％ NTC thermistor resistance,with higher stability.Temperature response experiments show that the measurement system accords with the typical first-order step response,the response time is shorter than that of the conventional RC temperature measurement circuit,and the response speed is improved.Basically meet the requirements of response speed in general temperature measurement occasion.