基于T-F变换的多点流体温度测量系统

Fluid multi-point temperature measurement system based on T-F transform

针对一般测温方法在进行流体多点温度测量时存在系统复杂,准确度和速度难以兼顾的问题,提出了一种基于温度-频率(T-F)变换的测量系统。该系统使用PIC18F6722单片机控制MOS管开关阵列,使多个测点的热敏电阻分别与TLC555构成振荡电路,将测点的温度变化转化为振荡频率的变化,使用8253计数芯片对TLC555的输出信号进行测量并产生中断,单片机读取8253计数值反演为测点温度。实验表明,测点数目增多不会增加测量系统的复杂程度,通过设置8253的计数初值,可以在不改变硬件的情况下灵活选择测量的准确度和速度,满足了流体多点精确快速测温的需求。同时该系统具备简洁实用,成本低的优点。

Aiming at the common method existed the complicated system,and also a problem about balance of accuracy and speed in the process of fluid multi-point temperature measurement,introduced a multi-point measurement system based on temperature-frequency transform.This system used the PIC18F6722 MCU to control the switch array of the MOS tube,which made thermistors at many measuring points constituted the oscillating circuit with TLC555,the temperature change of measuring points turned to be a change of oscillation frequency.And it applied the 8253 counter chip to measure the output signal from TLC555 and emerged interruption.The MCU fetched the count value of 8253 and changed to be the temperature at measure points.The practical use shows that the increasing of measuring point numbers doesn’t increase the complexity of the measurement system.With setting up the initial count value of 8253,it can neatly configure the accuracy and speed of measurement without changing hardware,which can satisfy the quick and accurate temperature measurement of the fluid multi-point.Also,the system is very useful and convenient,but costs low.