Determination of Moisture Content in Oil Palm Fruits Using a Five-Port Reflectometer

Sensors

Lee Kim Yee³  Zulkifly Abbas¹  Mohamad Ashry Jusoh¹  You Kok Yeow² 

[1] Department of Physics, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia; E-Mail:;Radio Communication Engineering Department (RaCED), Faculty of Electrical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia; E-Mail:;Department of Electrical and Electronic Engineering, Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, 53300 Setapak, Kuala Lumpur, Malaysia; E-Mail:

关键词: five-port reflectometer;    coaxial sensor;    monopole sensor;    graphical programming;    moisture;    data acquisition;   

DOI  :  10.3390/s110404073

来源: mdpi

【 摘 要 】

This paper presents the development of a PC-based microwave five-port reflectometer for the determination of moisture content in oil palm fruits. The reflectometer was designed to measure both the magnitude and phase of the reflection coefficient of any passive microwave device. The stand-alone reflectometer consists of a PC, a microwave source, diode detectors and an analog to digital converter. All the measurement and data acquisition were done using Agilent VEE graphical programming software. The relectometer can be used with any reflection based microwave sensor. In this work, the application of the reflectometer as a useful instrument to determine the moisture content in oil palm fruits using monopole and coaxial sensors was demonstrated. Calibration equations between reflection coefficients and moisture content have been established for both sensors. The equation based on phase measurement of monopole sensor was found to be accurate within 5% in predicting moisture content in the fruits when compared to the conventional oven drying method.

【 授权许可】

CC BY   
© 2011 by the authors; licensee MDPI, Basel, Switzerland.