便携式叶绿素含光电检测仪设计.doc

便携式叶绿素含量光电检测仪设计* 郭 鑫 张 立 北京林业大学理学院, 北京 100083 摘 要：本文介绍了一个基于单片机的便携式叶绿素含量检测仪。该检测仪根据光电无损快速检测叶绿素原理设计, 通过比对650 nm和940 nm两束光波透过叶片的强度变化定量描述叶绿素相对含量。仪器硬件设计采用模块化设计思想, 每个模块完成相对独立的功能, 包括有测量模块、实时时钟模块、温湿度检测模块等。软件系统采用C语言设计, 实现SPAD测量、数据存储和分析、与PC通信等功能。此外, 本文研究了该仪器分别与植物分析光谱仪和分光光度计的比对实验, 实验表明仪器测量值与其他方法的测量结果具有显著的一致性。叶绿素检测仪创新的采用光电检测方法, 在不破坏叶片的前提下测量叶绿素含量, 而且记录环境温湿度。仪器采用常见芯片, 成本较低, 同时具有中文界面, 便于在我国科研教学、农林工作中推广。 关键词：单片机；光电检测；叶绿素；便携式 中图分类号：TN206　　　文献标识码：A　　　国家标准学科分类代码：460.4035 Design of portable chlorophyll photoelectric detection instrument Guo Xin Zhang Li College of Science, Beijing Forestry University, Beijing 100083, China Abstract: This paper presents a portable chlorophyll detector based on Micro Controller Unit MCU . The detector adopts the non-destructive fast chlorophyll detecting theory and makes the quantitative description of the chlorophyll content by comparing the change in strength of the two light beams at 650 nm and 940 nm respectively. The hardware of the device is designed in modules and each one has an independent function, including SPAD measurement, real-time display, temperature and humidity detection and so on. The software system is designed in C language, realizing corresponding functions according to the hardware modules. In addition, this paper introduces two experiments, that are comparison of the instrument with plant spectral analysis instrument and spectrophotometer. In short, this device does no damage to the leaf during the whole process using the new photoelectric way. Also the instrument can detect the temperature and humidity of environment. The instrument adopts common chips on the market with a relatively cheap price, displays in Chinese, which makes it easy to spread in China. Keywords: MCU; photoelectric detect; chlorophyll; portable 1 引 言 叶绿素含量是衡量植物光合作用与生长状况的一项重要指标, 叶绿素含量检测技术的研究在农业生产、林业研究等方面有着至关重要的意义[1-2]。传统的叶绿素含量检测方法都是先提取叶绿素, 再用分光光度法[3-4]测定其含量。这种方法具有耗时长、对叶片有破坏性、不便于野外测量、不便于连续测量等诸多缺点。目前, 以日本SPAD502[5]为代表的便携式叶绿素检测仪已经在某些场合取代了传统的检测方法, 得到