土壤温度和容重对频率反射土壤水分传感器测量精度的影响

为探究土壤温度和容重对FDR(频率反射)含水率测量结果的综合影响规律,以陕西杨凌地区的塿土为研究对象,以基于 FDR 技术的电流型 DSW-T2型土壤温湿度传感器为测量仪器,研究了土壤的含水率(3.82%~21.43%)、容重(0.91~1.30 g/cm3)和温度(2.5~50℃)对传感器输出信号的影响;建立了传感器的输出电流与土壤含水率、容重和温度的综合测量数学模型,实验分析了模型在预测含水率方面的可行性.结果表明,传感器的输出电流随土壤含水率、温度和容重的增大而增大,可用三元二次方程表示输出电流与土壤含水率、温度和容重之间的关系;在0.05的显著水平上,含水率、温度和容积密度均对模型有显...

Full description

Saved in:
Bibliographic Details
Published in农业工程学报 Vol. 29; no. 10; pp. 136 - 143
Main Author 郭文川 宋克鑫 张鹏 韩文霆
Format Journal Article
LanguageChinese
Published 西北农林科技大学机械与电子工程学院,杨凌 712100%西北农林科技大学水土保持研究所,杨凌 712100%西北农林科技大学中国旱区节水农业研究院,杨凌 712100 2013
Subjects
Online AccessGet full text
ISSN1002-6819
DOI10.3969/j.issn.1002-6819.2013.10.019

Cover

More Information
Summary:为探究土壤温度和容重对FDR(频率反射)含水率测量结果的综合影响规律,以陕西杨凌地区的塿土为研究对象,以基于 FDR 技术的电流型 DSW-T2型土壤温湿度传感器为测量仪器,研究了土壤的含水率(3.82%~21.43%)、容重(0.91~1.30 g/cm3)和温度(2.5~50℃)对传感器输出信号的影响;建立了传感器的输出电流与土壤含水率、容重和温度的综合测量数学模型,实验分析了模型在预测含水率方面的可行性.结果表明,传感器的输出电流随土壤含水率、温度和容重的增大而增大,可用三元二次方程表示输出电流与土壤含水率、温度和容重之间的关系;在0.05的显著水平上,含水率、温度和容积密度均对模型有显著影响.基于模型的计算输出电流与实际输出电流的绝对误差范围是-1.167~1.216 mA,计算含水率与实际含水率的绝对误差范围是-2.638%~2.812%.本研究对于开发具有温度和容积密度补偿功能的新型FDR土壤含水率传感器的综合测量模型有指导作用.
Bibliography:soils;moisture content;temperature;frequency domain reflectometry;volume density
Moisture content of soil is helpful for water-saving irrigation. Soil moisture sensors using frequency domain reflectometry (FDR) are more and more popular in market. Soil temperature is a major factor affecting moisture measurement precision. So it has been widely considered in developing FDR soil moisture sensor. However, volume density, which is also a major factor influencing measurement precision of soil moisture, has been considered hardly. To investigate the comprehensive influence of temperature and volume density on moisture content by FDR moisture sensor, Lou soil in Yangling region, Shaanxi Province, were used as samples , and DSW-T2 soil temperature and moisture sensor (current output type) using FDR technology, was used as instrument to study the influence of moisture content at seven levels (3.82%, 7.58%, 9.29%, 11.65%, 14.87%, 18.61%and 21.43% in wet basis), volume density at five levels (0.91g/cm3 , 1.00g/cm3 , 1.0
ISSN:1002-6819
DOI:10.3969/j.issn.1002-6819.2013.10.019