排灌机械工程学报2013，Vol.31Issue(8)：713-718,6.DOI:10.3969/j.issn.1674-8530.2013.08.012
塿土介电特性与水分检测频率及温度影响
Dielectric properties of Lou soil and moisture content detection affected by frequency and temperature
摘要
Abstract
To determine reasonable detecting frequency for developing soil's moisture sensor based on dielectric properties and to reduce influence of temperature on permittivities,Lou soil in Guanzhong Plain,Shaanxi Province,was used to study the influence of frequency (10-4 500 MHz),moisture content (9％-25％) and temperature (5-50 ℃) on relative dielectric constant and dielectric loss factor by network analyzer and coaxial-line probe technology.The reasons why permittivities changed with these factors were analyzed,and the frequency-,moisture content-and temperature-dependent penetration depth was determined.The results show that with the increasing of frequency from 10 MHz to 4 500 MHz,the relative dielectric constant decreases,while the dielectric loss factor changes from increasing to decreasing then to increasing.Both dielectric constant and loss factor increase with increasing moisture content and temperature over the detected ranges.The penetration depth decreases with increasing frequency,moisture content and temperature.Frequency,moisture content and temperature are major factors which influence dielectric permittivities and penetration depth of soil.Thestudy indicates that the reasonable frequencies for detecting moisture content of soil based on dielectric properties are over the frequency range from 50 MHz to 100 MHz.关键词
土壤/介电特性/穿透深度/温度/含水率Key words
soil/dielectric properties/penetration depth/temperature/moisture content分类
农业科技引用本文复制引用
郭文川,张鹏,宋克鑫,韩文霆,许景辉..塿土介电特性与水分检测频率及温度影响[J].排灌机械工程学报,2013,31(8):713-718,6.基金项目
"十二五"国家科技支撑计划项目(2011BAD29B08) （2011BAD29B08）
教育部、国家外国专家局"111"计划项目(B12007) （B12007）
