Dual-Pin Impedance Probe for Crop Quality Estimation Using the RF Return Loss Method

This paper presents a significant advancement in the RF return loss method for crop quality characterization by introducing a dual-pin probe, designed to address the limitations of traditional coaxial probes. The dual-pin probe enhances the measurement process by providing a larger probe-to-sample contact area, which improves accuracy and repeatability, particularly for inhomogeneous crop samples such as cassava. In this study, return loss measurements were correlated with dry matter content determined through the oven-drying method. The results revealed a strong correlation, with a linear regression analysis at 27 MHz yielding an <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$R^{2}$</tex> value of 0.8214. This indicates that the dual-pin probe significantly enhances the reliability of nondestructive dry matter content estimation. The proposed method offers substantial advantages for the rapid and precise assessment of food quality, making it a valuable tool for applications in the agricultural and food processing industries.