论文部分内容阅读
植物电位是由生物体发出的不稳定的微弱电信号,其幅值变化有时只有10~20μV[1,2],信号采集过程中,其有效信息很容易被噪声所淹没。根据植物电位的高内阻源特性,在硬件采集系统中,设计了植物信号仪器放大器,该仪器以INA114和OP27组成屏蔽驱动一级放大电路,以TLC2654和OP27构造稳零和二级放大电路;采用UFA42组成硬件陷波电路抑制信号中的50Hz工模干扰,应用小波降噪技术对信号进行降噪处理。以4周大的黄瓜幼苗为实验对象,试验表明,该植物电位采集系统可有效地记录植物微弱的电信号,植物动作电位的波动周期为0.01~0.02s,可监测的幅值最低可达15μV。
The plant potential is an unstable weak electric signal emitted by the organism, and its amplitude varies only sometimes from 10 to 20 μV [1, 2]. During the signal acquisition, the effective information is easily submerged by the noise. According to the characteristics of high internal resistance of plant potential, a plant signal instrumentation amplifier was designed in hardware acquisition system. The instrument consisted of a shield driven first stage amplifier with INA114 and OP27, and a stable zero and second stage amplifier with TLC2654 and OP27. UFA42 hardware trap circuit is used to suppress 50Hz mode interference in the signal, and the signal is denoised using wavelet denoising technology. Four weeks old cucumber seedlings were used as experimental subjects. The experiment showed that the plant potential acquisition system can effectively record plant weak electrical signals. The fluctuating period of plant action potential is 0.01 ~ 0.02s, and the minimum monitored amplitude is 15μV .