Noranda Inc.

Michel Hamelin

Frank Kitzinger

Vladimir M Labuc

Patrick Andrieux

David Sprott

A magnetic testing device for obtaining a damaged index of an elongated magnetically-permeable object in real time includes a permanent magnet assembly with spaced-apart poles, a tubular pole piece adapted to surround the object, Hall effect devices placed in the magnetic flux path, a leakage flux sensor installed between the pole pieces, and a real time signal processing unit. The signal processing unit provides local fault (LF) signals generated by the leakage flux sensor, and loss of metallic area (LMA) signals generated by the Hall effect devices. The standard deviations of the LF signals are summed, the root-mean-square of the LF signals is summed, the absolute values of the LF signals are integrated, and the LMA signal is multiplied by a coefficient which is dependent on the object construction. The damage index is then determined using the thus-calculated values. Preferably, when a wire rope is passed through the monitoring device, the damage index is given to the user in a hand-held display means. Preferably, no interpretation is required by the user.

Wire rope damage index monitoring device

A magnetic testing device for detecting loss of metallic area and internal and external defects in elongated magnetically-permeable objects includes a permanent magnet assembly having poles adapted to be spaced apart in the longitudinal direction of an elongated object for inducing a longitudinal magnetic flux in a section of the object between the poles of the magnet assembly, the magnet assembly being strong enough to magnetically saturate the section of the object. A tubular pole piece is arranged to surround the object adjacent each pole of the permanent magnetic assembly for directing the magnetic flux into the object at one pole and out of the object at the other pole. Hall effect devices are placed in the path of the magnetic flux for sensing the reduction of the flux passing through the elongated object due to any reduction of cross-sectional area of the elongated object between the pole pieces caused by loss of metallic area in the elongated object. A leakage flux sensor is installed between the pole pieces for detecting an external and internal defects in the objects. Circuitry is provided for increasing the linear resolution of the metallic area measurement of the object, whereby signals obtained correspond more closely to the variations in the metallic area of the elongated object. Preferably, the circuitry combines the local fault (LF) signal with the loss of metallic area (LMA) signal to benefit from both the high linear resolution of the LF signal and the long range stability of the LMA signal to improve the resolution of the LMA signal.

Apparatus for increasing linear resolution of electromagnetic wire rope

A borehole deviation monitor comprises a probe body adapted to be lowered in a borehole and including two inclinometers mounted in an orthogonal configuration to provide simultaneous X and Y axis inclination signals indicating the dip angle of the borehole with respect to the vertical and two triaxial magnetometers to provide reference signals indicating the azimuth angle of the borehole. The magnetometers are separated by a predetermined distance along the axis of the probe. A cable takeup winch mechanism is provided to lower the probe body into the borehole by predetermined increments equal to the distance between the two magnetometers. A control and data storage station is connected to the two inclinometers and magnetometers for reading and storing the data collected at each incremental distance and for correcting the azimuth reading given by the top magnetometer by substracting any difference in readings between the two magnetometers at the previous position of the probe.

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St-Lazare, Canada

Michel Hamelin