Articles

Found 2 Documents
Search

EDDY CURRENT SENSOR BERBASIS FLAT COIL FR4 UNTUK MENENTUKAN KETEBALAN PELAT LOGAM NON MAGNETIK AL Emrinaldi, Tengku; Salomo, Salomo; Hamzah, Yanuar; Iwantono, Iwantono; Umar, Lazuardi
Spektra: Jurnal Fisika dan Aplikasinya Vol 2 No 3 (2017): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 2 Nomor 3, Desember 2017
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (391.066 KB) | DOI: 10.21009/SPEKTRA.023.07

Abstract

Abstrak Sensor arus eddy (eddy current) digunakan untuk pengukuran ketebalan logam khususnya logam non magnetik seperti alumunium.  Penelitian ini telah mengembangkan sensor eddy current berbahan PCB (printed circuit board) jenis FR4 yang memiliki ketebalan lapisan tembaga 35micron. Prototipe yang dihasilkan mempergunakan koil sensor dengan jumlah gulungan (n) 30 lilitan, diameter (Æ) 30mm, lebar dan jarak antar koil, (dkoil) 0,254mm dan tahanan (Rkoil) sebesar 4,26Ω. Respon sensor ketebalan pelat logam terhadap bahan uji dievaluasi dengan memberikan eksitasi frekuensi tunggal 700Khz, 1MHz dan 1.33MHz. Rangkaian ketebalan pelat telah mempergunakan rangkaian pengunci fasa (phase locked loop) dan mampu mengukur variasi ketebalan  mulai 0,2 mm sampai 2 mm, sementara jarak antara sensor dengan logam uji dijaga konstan 2 mm. Hasil pengukuran memberikan respon kurva U(t) dalam hubungan Kata-kata kunci:sensor eddy current, PCB FR4, material non magnetik, ketebalan logam, rangkaian phase locked loop Abstract Eddy current sensor is used to measure the thickness of metals, especially non-magnetic metals such as aluminum. This research has developed eddy current sensor made from PCB (printed circuit board) type FR4 which has 35micron copper layer thickness. The developed prototype uses a designed coil sensor with the number of winding (n) 30 turn, diameter () 30mm, width and distance between coils, (dkoil) 0.254 mm and coil resistance (Rkoil) of 4.26 Ω. The sensor response to the test material was evaluated by giving a single frequency excitation of 700 Khz, 1 MHz and 1.33 MHz. The plate thickness electronics has used a phase locked loop circuit and is capable to measure the thickness variations from 0.2 mm up to 2 mm, while the distance between the sensor coil and the test object was kept constant at 2 mm. The measurement results give the U (t) curve response in the exponential relationship. Keywords: eddy current sensor, PCB FR4, nonmagnetic material, thickness, phase locked loop circuit
ANALOG COMPUTER FOR STUDYING DIATOMIC MOLECULAR SPECTRA IN TERAHERTZ FREQUENCY Malik, Usman; Hamdi, Muhamad; Salomo, Salomo
Spektra: Jurnal Fisika dan Aplikasinya Vol 3 No 2 (2018): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 3 Issue 2, August 2018
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (230.394 KB) | DOI: 10.21009/SPEKTRA.032.06

Abstract

This paper introduces a harmonic oscillator model for rovibronic terahertz spectrum of a model of a rigid diatomic rotor with some control parameters. The model shows a study of rotationally-resolved terahertz band spectra of the vibrational transition in diatomic molecules. THz radiation absorption is used as a closed-form system known as the analog computer dynamics mode. The optical terahertz region spectrum of the diatomic molecule consists of a series of lines. Their separations are not exactly constant. A diatomic molecule is not truly a rigid rotator, because it simultaneously vibrates with a small amplitude. Due to quantized vibrational and rotational energy levels and the selection rules, allowed transitions result in a highly ordered spectrum consisting of a P branch separated by a central gap. Adjacent spectral lines are separated by a spacing of 2B, and since line intensities depend on Boltzmann factor for thermal population and quantum number J, each branch monotonically increases and decreases. As temperature increases, more lines are observed, and line intensities decrease due to the population being spread over more rotational levels. Interactivity research also involves on effects of the fundamental vibrational frequency, rotational constant B and temperature included line width on the observed spectrum.