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- MakaleAçık Erişim2021Scopus SJRQ1Prediction of water-adulteration within honey by air-line de-embedding waveguide measurements
Hasar, Hafize; Hasar, Ugur Cem; Kaya, Yunus; Ozturk, Hamdullah; Izginli, Mucahit; Ozbek, Ibrahim Yucel; Oztas, Taskin; Canbolat, Mustafa Yildirim; Ertugrul, Mehmet
An efficient de-embedding air-line microwave method has been proposed for accurate relative complex permittivity, εr=εr′−iεr′′, measurement of water-adulteration level within honey. It could be effectively applied to eliminate the errors arising from usage of imperfect calibration standards because it bypasses the requirement of these standards. Its accuracy is improved by utilizing the unitary and similarity properties of a passive two-port network, and then is compared with the accuracy of a calibration-dependent method present in the literature by using normalized root-mean-square-error (N-RMSE) values of εr′ and εr′′ of distilled water, in reference to the Debye value. From this comparison, it is observed that N-RMSE values calculated for εr′ (and εr′′) by using this calibration-dependent method and the (improved) proposed method are, respectively, around 0.1955 (0.1002) and 0.1962 (1.1067), indicating a good agreement between them. After validation the proposed de-embedding method using distilled water measurements, tested pure honey was adulterated with distilled water by different percentage values δ ranging from 1% to 10% in 1% increments. It is observed that the maximum distance between extracted εr′ (or εr′′) values of adulterated honey by the applied calibration-dependent method and the proposed method is less than 2%. Afterward, an empirical formula was devised to fit εr′ and εr′′ values from measured εr of water-adulterated honey with various δ levels. It is noted that extracted εr′ is much more better fitted than extracted εr′′, especially for δ≤4. Next, an optimization process is followed to evaluate the frequency for optimum prediction of adulteration levels using the empirical formula based on εr′ or εr′′. It is noticed that optimized δ values using the empirical formula based on εr′ (with an average prediction error of around 0.071 at 4.5 GHz) are superior to optimized δ values using the empirical formula based on εr′′ (with an average prediction error of around 0.085 at 4.2 GHz) for prediction of previously known δ values. Sensitivity and uncertainty analyses were performed to assess and improve the accuracy of the proposed method.
AtıfScopus24WoS23OpenAlex24
İncele - MakaleYalnız künye2014Scopus SJRQ2Simple procedure for robust and accurate complex permittivity measurements of low-loss materials over a broad frequency band
Hasar, U.C.; Barroso, J.J.; Kaya, Y.; Bute, M.; Ertugrul, M.
In this research paper, we propose a simple procedure for accurate, stable and broadband measurements of complex permittivity of low-loss dielectric samples with considerable lengths. We identify and demonstrate by numerical and analytical analyses the main ill-behaved factor that gives rise to inaccurate peaks for measurements of electrical properties of low-loss samples in the well-known Nicolson-Ross-Weir method. Without using this factor in the expressions and combining better features of the methods available in the literature, the proposed procedure allows highly accurate permittivity measurements over a broad band. We have validated the proposed method by permittivity measurements of a low-loss sample by different methods.
AtıfScopus4WoS4OpenAlex3İncele