基于近红外光谱的活体植物叶片水分检测仪器

Water detection instrument design for living leaves based on near infrared spectroscopy

在近红外光谱区,采用超低功耗单片机MSP430及新型的光频转换芯片TSL230,研制快速无损、可现场测定植物叶片水分含量的透射式检测仪器。仪器整体由信号采集系统、单片机系统及相应的软件支撑、校正模型组成。其信号采集系统采用近红外LED光源,890nm和980nm的窄带干涉滤光片和光频转换芯片。光频转换芯片的使用简化了信号采集电路,减少了噪声的引入。该文介绍了该仪器的硬件设计、软件设计,对紫荆叶片水分含量的建模及预测。预测结果与水分真实值基本一致,二者相关系数为0.900。仪器具有较高的重复性、稳定性和可靠性,与其他水分测量仪相比,该仪器具有体积小、结构简单、重量轻、超低功耗、抗干扰等特点。试验结果表明本仪器可在田间现场对植物叶片水分含量进行快速无损检测。

In near infrared range,using low power consumption MCU MSP430 and light-to-frequency chip TSL230,a transmission water-measuring instrument was designed,which can realize non-destructive and in situ measurement of leaves.The instrument consisted of signal acquisition module,microprocessor system,software and calibration model.The signal acquisition module was made up of NIR LED,890 nm and 980 nm interference filter,light-to-frequency chip.The light-to-frequency chip simplified the signal acquiring circuit and decreased noise disturbance.The design of hardware and software,modeling and prediction of Chinese redbud leaves water were introduced.The predicted results were identical with the real values of leaf water,and the correlation coefficient was 0.900.The main features of the instrument were higher repetitiveness,stability and reliability.Compared with other apparatus,the instrument had advantages such as small volume,simple structure,lightweight,low power consumption and anti-interference.The experiment results indicated that this system was feasible to detect leaf water non—destructively and fast on fieldwork.