Desain dan Uji Teknis Alat Pengukur Nilai Dielektrik Berdasarkan Metoda Q-Meter

Abstract

Dielectric heating has received a lot of attention recently. Microwave heating, however, has the problem of noticeable hot and cold spots within a food. Radio frequency (RF) has the potential to overcome this problem because of its longer wavelength and greater penetration depth, which would lead to more uniform distribution of the electric field and thus a more uniform temperature distribution. The dielectric properties are the measure of a sample's response to an electromagnetic field, which vary significantly with frequency, temperature, moisture, and salt content. The potential of a medium to respond to dielectric heating can be characterized by its dielectric properties, which can be strong functions of frequency and temperature. This experiment is aimed to design and test the performance of a measurement apparatus for the dielectric properties, using the Q-meter method. The equipment consists of three components, namely the oscillator, resonance component, and VTVM voltmeter, available to generate frequency range of 1.33 - 1.75 MHz. Dielectric properties of wheat, sorghum, and soybean were measure within the frequency range. The results show that dielectric constant of wheat, sorghum and soybean atfrequency of 1.35 MHz, 1.40 MHz and 1.45 MHz were 5.48, 5.21, 4.85, respectively, while the dielectric loss factor at frequency of 1.66 MHz, 1.55 MHz and 1.50 MHz were 2.39, 1.37 and 0.84 respectively.