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Measurement of magnetic fields using the voltage generated by a vibrating wire

A vibrating wire may be used as an instrument with a variety of applications, one of which is the measurement of magnetic fields. Often, the magnetic fields are determined by measuring the amplitude of the wire vibration under the action of a Lorentz force. Though generally adequate, this approach may be inconvenient in certain circumstances. One of these occurs when it is necessary to measure the amplitude of high-frequency vibration, as the amplitude is expected to decrease linearly with frequency, and thus becomes harder to measure. Another example may be found in situations where the sensor must operate over a wide range of vibration frequencies. In this case the sensor will be unresponsive to specific frequencies of wire vibration, which are determined by the placement of the sensor. This means that for the instrument to be robust, the sensor must be precisely mobile, or multiple sensors must be used. Here a technique which may be used to supplement the displacement sensor is described. This technique makes use of the voltage generated by the motion of the wire in the magnetic field under measurement. It is predicted that the technique may be more suitable for measurements requiring high frequency vibration, and is sensitive to all frequencies of vibration. Measurements of a magnetic field obtained using this technique are compared to those found using only a displacement sensor, and the benefits and drawbacks of the technique are discussed.