A magnetometer system to estimate location and size of long, horizontal ferrous rods

Author

Mcfee, John E. ; Ellingson, Robert O. ; Elliott, John ; Das, Yogadhish

Author_Institution

Threat Detection Group, Defence Res. Establ. Suffield, Medicine Hat, Alta., Canada

Volume

45

Issue

1

fYear

1996

fDate

2/1/1996 12:00:00 AM

Firstpage

153

Lastpage

158

Abstract

An experimental instrument is described which explicitly estimates location of ferrous rods parallel to a plane of measurement by analyzing simultaneous magnetic field and position data. The instrument consists of a unit containing a fluxgate magnetometer, position sensor and signal-conditioning circuits, connected to a unit containing a microprocessor, displays and associated electronics. An operator scans the sensor unit over the measurement surface, and the microprocessor estimates location, rod length and diameter. Experiments to estimate the parameters of horizontal typical reinforcing rods under a horizontal plane showed that the axis position could be estimated with an error of less than 0.5 cm, the length with a precision of <5 cm (<3.5%) and the depth with a precision of <0.4 cm at depths of 8 to 18 cm. Estimation of rod diameter was unreliable due to the presence of substantial remanent magnetization

Keywords

computerised instrumentation; diameter measurement; fluxgate magnetometers; length measurement; position measurement; remanence; signal processing; signal processing equipment; 8 to 18 cm; diameter; fluxgate magnetometer; location; long horizontal ferrous rods; microprocessor estimates location; position data; position sensor; reinforcing rods; remanent magnetization; rod length; signal-conditioning circuits; simultaneous magnetic field; size; Displays; Instruments; Length measurement; Magnetic analysis; Magnetic circuits; Magnetic field measurement; Magnetic sensors; Magnetometers; Microprocessors; Position measurement;

fLanguage

English

Journal_Title

Instrumentation and Measurement, IEEE Transactions on

Publisher

ieee

ISSN

0018-9456

Type

jour

DOI

10.1109/19.481328

Filename

481328