热丝法检测装置研究

Study of Hot-wire Detecting Instrument

提出了一种利用电子开关转换实现的热丝法测温方案，实现了热电偶加热状态和检测状态的转换。该方案采用了线性平方电路，从而大大降低了测量的非线性误差。建立了以8031单片机为核心的信号处理电路，着重对加热控制电路和检测电路的设计作了介绍，并实验验证了该装置的可靠性。

A temperature detect scheme of hot-wire method with electronic switching is given in this paper. The change of heating state and sensing state for thermocouple is completed successfully. The comparator controlling circuit and detecting circuit are analyzed. The inline error decreases with linear alignment circuit. A mesentery system composed of an 8031 single-chip is established. The methods which stabilize the switching voltage are used in order to increase the measurement accuracy. Besides, sample hold circuit and digital display circuit are used in the scheme. The feasibility of the detecting instrument is also proved with experiments.