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An Upgraded Transverse Electromagnetic Parallel Plates for Dielectric Measurement S. K. Yee; R. Padu; C. K. Sia; X. T. I. Ngu; S. H. Dahlan; M. A. Azlan
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 15, No 3: September 2017
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12928/telkomnika.v15i3.7213

A new version of transverse electromagnetic parallel plates with irregular plates’ width and plate separation has been developed for dielectric measurement. The separations between the plates are supported by four rectangular Teflon block and 1 mm of groove is proposed at the center of the upper plate to maintain the measurement repeatability. The groove enables the samples which are slightly higher than 2 cm to be fitted well between the plates without introducing extra force to the plates. Theperformance of both parallel plates has been compared in the frequency range from 100 MHz to 1.1 GHz. It is found that the upgraded parallel plate offers better return loss and insertion loss above 500 MHz compared to the previous parallel plate. It is reported from this work that the return loss of the parallel plate must be lower than -15 dB in order to achieve accurate dielectric constant. However, the insertion loss of the parallel plates does not influence the real permeability significantly. The upgraded TEM parallel plateproduces a consistent reading with a standard deviation of less than 0.05 above frequency 200 MHz. The dielectric measurement of Polypropylene (PP) has proven the capability of this upgraded TEM parallelplate.

Prediction of ammonia concentration in water based on microwave spectroscopy S. K. Yee; S. C. J. Lim; Z. H. Liew; M. Z. N. Shaylinda; N. T. J. Ong
Bulletin of Electrical Engineering and Informatics Vol 8, No 3: September 2019
Publisher : Institute of Advanced Engineering and Science

Ammonia is a common pollutant in water as the result of runoff in agricultural areas where it is applied as fertilizer. It must be monitored regulary for safety purpose. The current testing technique does not allow on-site measurement as the equipment are bulky, the measurement process is time-consuming and tedious with additional mixing reagents. In this study, the presence of ammonia in distilled water is estimated from open-ended coaxial probe in the range of 200 MHz to 14000 MHz. Experimental results were obtained from two set of samples with seven different ammonia concentration each. The measurements are repeated thrice hence producing forty-two data sets with 550 points. Both curve fitting and multiple regression analysis were considered to perform valid ammonia concentration projection. Validation based on 5-fold and 10-fold cross validation suggested the feasibility of the technique as it presents root mean square error (RMSE) which is less than 0.02 in the ammonia prediction. Detection method based on open-ended probe would be convenient, simple and accurate method for in-situ determination of ammonia concentration.

Prediction of ammonia concentration in water based on microwave spectroscopy S. K. Yee; S. C. J. Lim; Z. H. Liew; M. Z. N. Shaylinda; N. T. J. Ong
Bulletin of Electrical Engineering and Informatics Vol 8, No 3: September 2019
Publisher : Institute of Advanced Engineering and Science

Ammonia is a common pollutant in water as the result of runoff in agricultural areas where it is applied as fertilizer. It must be monitored regulary for safety purpose. The current testing technique does not allow on-site measurement as the equipment are bulky, the measurement process is time-consuming and tedious with additional mixing reagents. In this study, the presence of ammonia in distilled water is estimated from open-ended coaxial probe in the range of 200 MHz to 14000 MHz. Experimental results were obtained from two set of samples with seven different ammonia concentration each. The measurements are repeated thrice hence producing forty-two data sets with 550 points. Both curve fitting and multiple regression analysis were considered to perform valid ammonia concentration projection. Validation based on 5-fold and 10-fold cross validation suggested the feasibility of the technique as it presents root mean square error (RMSE) which is less than 0.02 in the ammonia prediction. Detection method based on open-ended probe would be convenient, simple and accurate method for in-situ determination of ammonia concentration.

Prediction of ammonia concentration in water based on microwave spectroscopy S. K. Yee; S. C. J. Lim; Z. H. Liew; M. Z. N. Shaylinda; N. T. J. Ong
Bulletin of Electrical Engineering and Informatics Vol 8, No 3: September 2019
Publisher : Institute of Advanced Engineering and Science

Ammonia is a common pollutant in water as the result of runoff in agricultural areas where it is applied as fertilizer. It must be monitored regulary for safety purpose. The current testing technique does not allow on-site measurement as the equipment are bulky, the measurement process is time-consuming and tedious with additional mixing reagents. In this study, the presence of ammonia in distilled water is estimated from open-ended coaxial probe in the range of 200 MHz to 14000 MHz. Experimental results were obtained from two set of samples with seven different ammonia concentration each. The measurements are repeated thrice hence producing forty-two data sets with 550 points. Both curve fitting and multiple regression analysis were considered to perform valid ammonia concentration projection. Validation based on 5-fold and 10-fold cross validation suggested the feasibility of the technique as it presents root mean square error (RMSE) which is less than 0.02 in the ammonia prediction. Detection method based on open-ended probe would be convenient, simple and accurate method for in-situ determination of ammonia concentration.

Review on water quality monitoring technologies Josephine Ong Ning Ting; S. K. Yee
Indonesian Journal of Electrical Engineering and Computer Science Vol 18, No 3: June 2020
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v18.i3.pp1416-1423

Water quality monitoring is always the prior element to ensure the drinking water is safe to be consumed. A lot of researches have been carried out over the past decades to design and develop a robust and cost-effective water monitoring system. The conventional water monitoring techniques were based on laboratory instruments which is time-consuming and laborious. Furthermore, it is not suitable when the water sampling point is far from the commercial laboratory centres. These limitations were then been solved by the developments of portable testing kits and microwave technique. The microwave techniques such as spectroscopy techniques and microwave sensor approach have improved the water quality monitoring experience which is convenient without sacrificing the measurement accuracy and sensitivity. Its portability enables the on-site measurement at rural areas and thus reduce the transportation and manpower cost. This paper intends to review the water contaminant detection techniques which include standardized drinking water parameter testing and microwave-based in terms of physical, chemical and microbiological parameters. Furthermore, this review also emphasizes the current trend of the water quality testing method in microwave technique. At the end of this paper, a significant advantages and drawbacks of the techniques are summarized, and recommendations are provided for future development in the water quality monitoring.

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