基于锁定放大器相关原理的超导电阻测量系统

Superconductor resistance measurement system based on correlation principle of locked amplifier

针对超导体电阻值微小、信号中通常会夹带大噪声造成的超导电阻信号测量困难的情况,通过对超导电阻特性和传统测量方法的分析研究,提出了一种基于微弱信号检测的超导体电阻测量的新方案。利用高性能DSP芯片TMS320VC5509A,软件实现了超导体电阻的测量,同时利用89C2051单片机配合双积分A/D转换器ICL7135测量超导体的环境温度。实验表明,系统能够有效地检测微弱的超导电阻信号,运行稳定,有良好的测量精度和灵敏度,充分显示出了自身在超导体电阻测量等微弱信号检测方面的优越性。

The problems that the superconductor resistance value is very small and that the signal usually mixes with big noise makes the superconductor resistance measurement difficult. Through analyzing the properties of the superconductor resistance and the traditional measurement methods, a new program of superconductor resistance measurement is proposed based on the weak signal detection. Through software, the superconductor resistance measurement is realized with a high-performance DSP chips TMS320VC5509A. And the ambient temperature of superconductor is measured by single-chip 89C2051 with a double-integrating AID converter ICL7135. The experimental results show that this system can detect weak superconductor resistance signals effectively. It can run stable and has good measurement accuracy and sensitivity, and it has large advantage in the weak signal detection such as superconductor resistance measurement.