Rancang Bangun Alat dan Pengukuran Nilai Dielektrik pada Kisaran Frekuensi Radio

Abstract

Dielectric properties indicate the ability of a system to stare, tmmit and reflect electromagnetic wave energy. Recently, the utikatitm of the propetties in agrcutture field tends to incmase. For example, d&ct& of bhgical material is based on the product's ability to aibsorib mdhth and convert it into heat. In addition, lower energy applicafiun of the p p d y can be utilized for non-destmctive measurement of water content. For a a fnvad application, memeasment of the pmperj. and the jdbnchg kfom is indispensm. The objectives of this experiment were to design an hstmment fw measurhg dielectric properties in radio frequency range and to detefmh the di&cW properties of whiie pepper. The instmmenf was desr'gned based on W e r method, which consists of oscillator, LRC ckcuit, and capadfame meter. At the LRC circuit, with Lx3.543 pH, the designed instrument can be useti within a frequency range of 8 MHz to 22 MHz, whem the peak resonance capsdtance was ranged from 21,72 pF to 177.49 pF. Application of the insbvment in measuring the dielectric properties of white pepper showed that the value was fluctuated at frequencies less than 12 MHz. Acconlingly, it was condconcluded that the insbvment is applicaMe for measuring dielectric ptvpettks of bhbghl mahwhk at hquency range of 14 to 22 MHz. It was aiso found that dielectric pnpM& of white pepper were higher at higher moisture content.