2000 Fiscal Year Final Research Report Summary
Moisture Content Measurement Setup for Material Using Phase Shifts of Two Microwave Frequencies
| Project/Area Number |
11450138
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
電子デバイス・機器工学
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| Research Institution | Shizuoka University |
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Principal Investigator |
OKAMURA Seichi Shizuoka Univ., Dept.of E.E.Engineering, Professor, 工学部, 教授 (20022014)
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| Project Period (FY) |
1999 – 2000
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| Keywords | moisture content / measurement / microwave / phase / phase shift / density / timber / free space |
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| Research Abstract |
Moisture measurement is very important to many producing process for industrial or agricultural products with high quality. Developing new equipments is expected for on-line moisture measurement. This project is to invent new moisture measurement method used at on-line systems in various fields. It is confirmed that the method using two phase-shifts at two microwave frequencies is powerful to measure moisture content of wood or timber in spite of the changes in the thickness, density and direction of grain of the wood.
This research has been studied using samples of timber and green tea. The leaves of green tea are easy to get various densities by a little compression. The results are followings.
1. The new method using two phase-shifts at 9 and 12 GHz is useful to moisture content measurement of the samples with different thickness, density and direction of grain.
2. The mean and maximum errors in the measurement of six timbers with moisture contents of 2 to 30 % on dry basis are 1.4% and 4.4%, respectively.
3. The mean and maximum errors in the measurement of two green tea samples having the weight of 912g and 1853g and the moisture contents of 6 to 42% on dry basis are 2.2% and 5.4%, respectively.
4. These results are better both in the measurable range and in the measurement errors than another method using amplitude and phase shift of wave at single microwave frequency.
These results let us expect that the method of this study will be actually used for on-line measurement of moisture content of wood after some researches for practical use.
The results of this study are presented in three international papers of IEEE Trans. on Instrumentation and Measurement, J.of Microwave Power and Electromagnetic Energy, and Subsurface Sensing Technologies and Applications, and in two technical reports of the Institute of Electronics, Information and Communication Engineers of Japan. Some parts of results will be presented in a conference held in 2001.
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