中文摘要：

设计了一种耐155℃高温的井下测量系统,为了满足多通道信号的测量,其前置放大电路采用分时复用的工作机制,刻度信号与目标信号通过模拟开关分时送至前置放大器.发射电流经取样后得到参考信号,运用数字相敏检波算法计算其幅度和相位,为分时导通的刻度信号和目标信号提供相位基准.通过对模拟通道进行实时的刻度,确保测量结果不随电路的温度漂移而发生变化.实验结果表明,该方法能有效地抑制温漂对测量系统的影响.

英文摘要：

This paper proposes a design of an under well measuring system for high temperature up to 155 ℃.In order to measure multi-channel signals,the pre-amplifiers employ a time-division scheme,calibration signal and sensor signals are sent to the amplifier separately through an analog multiplexer.The reference signal is sampled from transmitter circuit,so as to provide phase reference to both calibration and sensor signals.Amplitudes and phases are calculated in a digital phase sensitive detection algorithm.Due to the real-time calibration of analog channels,the measurement remains stable regardless the temperature drift of circuits in the channels.Experiment result shows that,this method can effectively suppress the impact of temperature drift.