Novel nulling/balancing technique for fiber optic magnetic gradiometer

Author

Rempt, R.D.

Author_Institution

Boeing Aerosp., Seattle, WA, USA

Volume

1

Issue

5

fYear

1989

fDate

5/1/1989 12:00:00 AM

Firstpage

105

Lastpage

106

Abstract

A technique for balancing a fiber-optic magnetic gradiometer configured as a Mach-Zehnder interferometer is presented. The method uses different dither frequencies for nulling the DC field experienced by each transducer and a third frequency common to both transducers for detecting the gradient. The method overcomes the hysteresis when each transducer is separately nulled, and the balance is performable in real time. Noise spectra are shown in the near DC and a gradient sensitivity of 0.14 gamma /ft- square root Hz RMS at 0.22 Hz is demonstrated. This is believed to be the most sensitive direct measurement of a magnetic field gradient by a fiber-optic sensor that has been reported.<>

Keywords

fibre optic sensors; light interferometers; magnetometers; 0.22 Hz; DC field; Mach-Zehnder interferometer; balancing; dither frequencies; fiber optic magnetic gradiometer; fiber-optic sensor; gradient sensitivity; hysteresis; noise spectra; nulling; nulling/balancing technique; real time; transducer; Arm; Frequency; Geologic measurements; Magnetic field measurement; Magnetic hysteresis; Magnetic sensors; Magnetic separation; Optical fibers; Solenoids; Transducers;

fLanguage

English

Journal_Title

Photonics Technology Letters, IEEE

Publisher

ieee

ISSN

1041-1135

Type

jour

DOI

10.1109/68.34755

Filename

34755