王克栋,王一鸣,冯 磊,杨卫中.基于相位检测原理的土壤水分时域反射测量技术[J].农业机械学报,2010,41(1):. Wang Kedong,Wang Yiming,Feng Lei,Yang Weizhong.Measurement of Soil Moisture Based on Phase Detecting Principle[J].Transactions of the Chinese Society for Agricultural Machinery,2010,41(1):.
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摘要点击次数: 3422 全文下载次数: 1947
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基于相位检测原理的土壤水分时域反射测量技术 [下载全文] |
Measurement of Soil Moisture Based on Phase Detecting Principle [Download Pdf][in English] |
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DOI:10.3969/j.issn.1000-1298.2010.1.014 |
中文关键词: 土壤含水量 介电常数 时域反射 相位检测 |
基金项目:国家“863”高技术研究发展计划资助项目(2006AA10Z264) |
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中文摘要:针对土壤水分测量
的特点,提出了用高频正弦波代替脉冲信号作为测试信号,利用相位检测原理测量信号传播
时间,从而测量土壤含水量的方法。设计了由高频信号发生器、相位检测器、微处理器和土
壤水分探头等组成的P〖CD*2〗TDR原理样机。试验表明,该样机测量信号传播时间的精度可
达到10ps,在砂土、壤土和粘壤土中的土壤含水量测量结果与称重法对比差值不超过00
3。 |
Wang Kedong Wang Yiming Feng Lei Yang Weizhong |
College of Computer and Information Engineering, Beijing Technology and Business University, Beijing 100048, China
2College of Information and Electrical Engineering, China Agricultural Univers
ity, Beijing 100083, China;College of Information and Electrical Engineering, China Agricultural Univers
ity, Beijing 100083, China;College of Information and Electrical Engineering, China Agricultural Univers
ity, Beijing 100083, China;College of Information and Electrical Engineering, China Agricultural Univers
ity, Beijing 100083, China |
Key Words:Soil moisture, Dielectric constant, TDR, Phase detecting |
Abstract:The basic principle of time domain reflectometry used for soil moisture measurem
ent is introduced, and the disadvantages of currently available TDR instruments
are discussed as well as their advantages. A new TDR system, called P〖CD*2〗TDR
, composed of a high frequency signal generator, a phase detector, a microproce
ssor and a soil moisture probe is developed. Single frequency sinusoidal voltag
e signal is adopted as test signal, and the travel time of the test signal along
with probe embedded in moist soil is measured by a phase detector instead of hi
gh speed sampling oscilloscope, from which the soil water content will be estim
ated. It has high accuracy and resolution in travel time measurement. Calibratio
n experiments are conducted in sand, loam soil and clayey loam soil samples with
the volumetric water contents varied from zero to saturation. The experimental
res
ults show that the measuring deviation is less than 003 between P〖
CD*2〗TDR and gravimetric sampling method. |
Transactions of the Chinese Society for Agriculture Machinery (CSAM), in charged of China Association for Science and Technology (CAST), sponsored by CSAM and Chinese Academy of Agricultural Mechanization Science(CAAMS), started publication in 1957. It is the earliest interdisciplinary journal in Chinese which combines agricultural and engineering. It always closely grasps the development direction of agriculture engineering disciplines and the published papers represent the highest academic level of agriculture engineering in China. Currently, nearly 8,000 papers have been already published. There are around 3,000 papers contributed to the journal each year, but only around 600 of them will be accepted. Transactions of CSAM focuses on a wide range of agricultural machinery, irrigation, electronics, robotics, agro-products engineering, biological energy, agricultural structures and environment and more. Subjects in Transactions of the CSAM have been embodied by many internationally well-known index systems, such as: EI Compendex, CA, CSA, etc.
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