Application of Matteucci Voltage Pulses of Amorphous Wires in Sensing Both Direction and Magnitude of Twist

Abstract

In this work the effect of torsion on the Matteucci voltage pulses in amorphous wires has been studied. It has been shown that: Amplitude of the pulses decreases to zero at a twist angle that depends on the chemical composition of the wire. From zero torsion, the amplitude of the Matteucci voltage increases when the wires are twisted counter-clockwise. However, when the wires are twisted clockwise, the amplitude of the Matteucci voltage pulses decreases up to a minimum point (zero) before, finally, starting to increase. This is a clear distinction (in behaviour) between clockwise and counter-clockwise torsion, which can be employed to determine the direction of initial twist. Also, the low torsion region of the torsion-Matteucci voltage characteristic shows a clear possibility of employing the stress sensitive Matteucci voltage to determine the magnitude of torsion. The Matteucci voltage is quite sensitive to the torsion. It is thus expected to provide high sensitivity for measurement of torsion in the “low and very low torsion region”. It has also been established that when the positioning of the amorphous wire in the magnetizing coil is reversed (wire ends are interchanged), the torsion-Matteucci voltage characteristic obtained is virtually a mirror image of the previous direction. For instance, if the zero amplitude Matteucci voltage was being obtained at a twist angle of 45° clockwise, it will now be obtained at an angle of the same magnitude, but for a counter-clockwise twist. The physics of this latter phenomenon too would be of interest to researchers of physics of magnetism. J. agric. Sci. technol. Vol.5(1) 2003: 116-129