简要介绍了朗缪尔探针测量仪的系统构成和工作原理,给出了信号发生及采集处理系统的电路设计.通过选用精密低噪声的仪用放大器并组合适当大小、适宜材料的电阻和电容构建模拟链路,以及贯穿于整个模拟链路的滤波电路设计,保证了低噪声采集电路的实现.采用高边检流和浮地方法,解决了单探针测量接地误差问题.设计有8×7个不同的电流采样量程,电压电流信号同步采样,可实现10nA～50 mA动态微弱信号的精确测量.%The system structure and working principle of the automatic Langmuir probe measuring instrument are introduced briefly. The circuit design of signal generating, acquisition and processing system is described. Through precision low noise instrument amplifier, appropriate resistance and capacitance, etc., the analog circuit is built. Besides, filter circuit design through the whole analog circuit ensures the realization of the low noise data acquisition system. Ground error on single probe measurement is solved by high-side current sense and floating ground methods. With 8×7 current sampling range switching, simultaneous sampling of voltage and current signals, the precise measurement of dynamic weak signal from 10 nA to 50 mA is achieved
展开▼
