便携式玉米叶片含水率无损检测仪的设计与试验  

Design of portable nondestructive tester for water content of maize leaves

作　　者：郭文川[1,2] 杜荣宇 高德顺 程小冬 徐磊 朱新华 GUO Wenchuan;DU Rongyu;GAO Deshun;CHENG Xiaodong;XU Lei;ZHU Xinhua(College of Mechanical and Electronic Engineering,Northwest A&F University,Yangling,Shaanxi 712100,China;Key Laboratory of Agricultural Internet of Things,Ministry of Agriculture and Rural Affairs,Yangling,Shaanxi 712100,China)

机构地区：[1]西北农林科技大学机械与电子工程学院,陕西杨凌712100 [2]农业农村部农业物联网重点实验室,陕西杨凌712100

出　　处：《西北农林科技大学学报（自然科学版）》2023年第5期148-154,共7页Journal of Northwest A&F University(Natural Science Edition)

基　　金：国家公益性行业(农业)专项(201503137);西北农林科技大学试验示范站(基地)科技创新与成果转化项目(TGZX2020-27);国家级大学生创新创业训练计划项目(S202010712143)。

摘　　要：【目的】设计一款便携式玉米叶片含水率检测仪,以实现植物叶片含水率的无损和快速现场检测。【方法】基于玉米叶片中的水分在波长980和1050 nm附近有吸收峰的现象,以峰值波长为980和1050 nm的发光二极管为便携式玉米叶片含水率检测仪的光源。分别以STC12C5A60S2单片机、数字光电传感器TSL2561和有机发光二极管为检测仪的控制器、检测器和显示器,采用C51语言编写检测仪的软件。以‘咸科858’和‘咸科602’两个玉米品种的叶片为对象,分析玉米叶片湿基含水率与波长980和1050 nm处吸光度值的关系,建立预测玉米叶片含水率的模型,将模型导入检测仪并对其性能进行测试。【结果】玉米叶片吸光度随含水率的增大而减小,可用二元一次关系式拟合叶片含水率与吸光度的关系,其相关系数为0.84。同国标规定的干燥法相比,该便携式检测仪对玉米叶片含水率的绝对测量误差为-6.3%~6.0%,平均误差为-0.1%,输出含水率的变异系数平均值为2.03%,每个样品的检测时间约为2 s。【结论】所设计的便携式玉米叶片含水率检测仪操作简单,结果可靠,可为其他植物叶片含水率的无损快速检测提供参考。【Objective】A portable water content tester was designed to realize non-destructive and fast on-site detection of water content of maize leaves.【Method】Since water in maize leaves has absorption peaks around 980 and 1050 nm,two light emitting diodes(LEDs)at the central wavelengths of 980 and 1050 nm were used as light sources to develop the hardware system of the tester.STC12C5A60S2,TSL2561 and organic light-emitting diode were used as the controller,sensor and display of the tester,respectively.C51 language was applied to develop the software.The leaves of two maize cultivars of‘Xianke 858’and‘Xianke 602’were selected to analyze the relationship between water content(wet basis)of maize leaves and absorbance values at 980 and 1050 nm and develop models.After downloading the model to the tester,the measurement precision was tested.【Result】The absorbance of maize leaves decreased with the increase of water content.The relationship between water content and absorbances could be described by binary equation with correlation coefficient of 0.84.Compared with the measurement results using the national standard method,the absolute measurement error of the portable tester was-6.3%to 6.0%with the average of-0.1%and the mean coefficient of variation of output water content was 2.03%.The detection time for each sample was about 2 s.【Conclusion】The designed portable water content tester for water content of maize leaves was convenient to use and reliable on measurement,providing reference for non-destructive and rapid detection of water content of other plant leaves.

关 键 词：玉米 叶片含水率 无损检测 吸光度 检测仪 

分 类 号：S237[农业科学—农业机械化工程]