PENENTUAN KARAKTERISTIK STATIK SISTEM PENGUKURAN MEDAN MAGNETIK DENGAN SENSOR FLUXGATE

Abstract

The objectives of this research was to determine the static characteristics of the magnetic field measurement system. This research can be categorized into experimental laboratory type. Measurement system consists of an excitation, fluxgate magnetic sensor, analog signal processing circuits, ADC, microcontroller, and display. Data collection techniques that used in this research were direct measurement and undirect measurement. The variables that measured directly were the electric current, output voltage, and magnetic field, while the variables that measured undirectly were slope of a straight line and initial value of a quantity. The data were analyzed by using the graph method and the errors analysis. The results of data analysis indicated that: 1). Magnetic field that generated by an coil with electric current is directly proportional to electric current that given to coil with sensitivity is 1.957 mT / mA, 2). The output voltage of fluxgate sensor is not linear both electric current and magnetic field. The linear range of sensor output voltage for electric current from -10 mA until 10 mA, and for magnetic field from -20 mT until 20 mT, 3). Magnetic field that measured by the measurement system using fluxgate sensor is directly proportional to the magnetic field with the slope is  0.9704 and the initial magnetic field at zero is 0.0061, and 4). The accuracy of the measurement system is high with range variation from 0.925 to 1.000 and average accuracy value is 0.968. Precision of measurement system is also high with range variation from 0.95 until 1.00 and average precision value is 0.99.

Keywords: fluxgate sensor, magnetic field, transfer function, sensitivity, accuracy,    precision