PROTOTYPE OF SENSOR TO MEASURE EXPANSION BASED ON FLUXGATE MAGNETOMETER

• Main Author: WAHYUDI (NIM 20207086), ISMU
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/12269
• Institution: Institut Teknologi Bandung

It has been developed a sensor of expansion based on fluxgate magnetometer as an instrument to measure expansion of metal, whereas the element sensor consists of one secondary coil (pick-up coil) and two primary coils (excitation coil). Primary coil was made from symmetrical girded at two ferromagnetic cores, while secondary coil girded at both cores. The change of excitation magnetic field generated by the expansion of metal will generate the difference of magnetic field in secondary, and resulted the changing of magnetic field. The change of magnetic field will induce secondary coil, so that will cause inducing of voltage signal. By signal processor circuit, the signal will be strengthened, overcome at phase detector, deferented, integrated, and then was strengthened again at final brace. After went through rectifier, signal was processed by digital to analogue of converter then was displayed in LCD by using microcontroller AT89S52. Based on result of analysis data, it was obtained that sensor expansion was able to be used in measuring maximum length range expansion of 3,675 mm, with sensitivity of 250 mV/mm. Absolute error from measurement using this instrument was 0,027 mm, while its relative error was equal to 0,676%.