应用于激光闪光法测量热扩散率装置的微弱信号放大调理技术研究

Research on Weak Signal Amplification and Processing Technology Applied to Laser Flash Method for Measuring Thermal Diffusivity

针对激光闪光法热扩散率测量装置中光伏型探测器输出信号微弱、易受干扰的问题,设计了微弱信号放大调理电路。应用输入保护环技术增强抗干扰能力,精选电子元器件提高测量准确度,应用开尔文开关技术实现自动切换功能避免导通电阻的干扰。经实验证明,本文研制的微弱信号放大调理电路具有较好的重复性、较小的波动度和长期稳定性,为激光闪光法热扩散率测量装置的应用提供了重要技术保障。

Aiming at the weak output signal of photovoltaic detector in the laser flash thermal diffusivity measurement device,a weak signal amplification and conditioning circuit is designed.The input protection ring technology is used to enhance the anti-interference ability,and the electronic components are selected to improve the measurement accuracy.The Kelvin switch technology is used to realize the automatic switching function to eliminate the interference of the resistance.The experimental results show that the circuit has good repeatability,small fluctuation and long-term stability,which provides an important technical guarantee for the application of laser flash thermal diffusivity measurement device.