Abstract: Measuring distance along a wire rope, by steps that include moving the wire rope across a sensor head; counting rotations of a rotary encoder driven by the moving wire rope; detecting a first distance marker crossing the sensor head at a first position of the wire rope; detecting a second distance marker crossing the sensor head at a second position of the wire rope; and establishing calibration parameters for producing a calibrated distance measurement corresponding to any output of the rotary encoder, based at least on correlating a known distance between the first and second distance markers to a counted number of pulses of the rotary encoder between the first and second positions of the wire rope.

Abstract: A magnetic inspection device and method for nondestructive testing of wire ropes and the like utilizes a leakage flux generator moveable relative to a wire rope to be inspected for inducing in sections of the wire rope magnetic flux at a saturation level. A leakage flux detector moves with the leakage flux generator, and cooperates with the leakage flux generator for detecting leakage flux at the outer surface of the wire rope saturated by the generator. The detector provides a high fidelity signal representative of the loss of metallic cross section at individual locations along the wire rope. A signal processor receiving the high fidelity signal representative of the loss of metallic cross section from the detector extracts a wire rope roughness component from the high fidelity signal.

Abstract: Measuring distance along a wire rope, by steps that include moving the wire rope across a sensor head; counting rotations of a rotary encoder driven by the moving wire rope; detecting a first distance marker crossing the sensor head at a first position of the wire rope; detecting a second distance marker crossing the sensor head at a second position of the wire rope; and establishing calibration parameters for producing a calibrated distance measurement corresponding to any output of the rotary encoder, based at least on correlating a known distance between the first and second distance markers to a counted number of pulses of the rotary encoder between the first and second positions of the wire rope.

Abstract: A magnetic inspection device and method for nondestructive testing of wire ropes and the like utilizes a leakage flux generator moveable relative to a wire rope to be inspected for inducing in sections of the wire rope magnetic flux at a saturation level. A leakage flux detector moves with the leakage flux generator, and cooperates with the leakage flux generator for detecting leakage flux at the outer surface of the wire rope saturated by the generator. The detector provides a high fidelity signal representative of the loss of metallic cross section at individual locations along the wire rope. A signal processor receiving the high fidelity signal representative of the loss of metallic cross section from the detector extracts a wire rope roughness component from the high fidelity signal.

Abstract: A magnetic inspection device for nondestructively inspecting elongated objects, such as wire cables, pipes, and the like, for loss of metallic cross-section due to abrasion, corrosion, and external and internal discontinuities, having a magnet for inducing in sections of the object between the stations, magnetic flux at the saturation level. A magnetic flux detector having magnetic sensors positioned between the poles and laterally of the elongated object utilizes shields and flux decompressors to render the flux detector more sensitive to leakage flux caused by discontinuities in the objects.

Abstract: A magnetic inspection device for nondestructively inspecting elongated objects, such as wire cables, pipes, and the like, for loss of metallic cross-section due to abrasion, corrosion, and external and internal discontinuities, having a magnet for inducing in sections of the object between the stations, magnetic flux at the saturation level. A magnetic flux detector having magnetic sensors positioned between the poles and laterally of the elongated object utilizes shields and flux decompressors to render the flux detector more sensitive to leakage flux caused by discontinuities in the objects.

Abstract: An eddy current sensor assembly of a magnetic inspection device is for nondestructive detection of structural faults in an elongated magnetically permeable object, such as a pipe. The sensor assembly has an auxiliary magnet including first and second auxiliary magnetic poles oppositely polarized relative to each other and spaced from one another for positioning and movement longitudinally relative to an elongated magnetically permeable object to be tested. The auxiliary magnet is to be interposed between primary magnets of the magnetic inspection device. A ferromagnetic member couples the first and second auxiliary magnetic poles. Compliant pole pieces such as magnetically permeable brushes are coupled to the auxiliary poles and are to be interposed between the auxiliary poles and the object to be inspected.

Abstract: A magnetic inspection device for detecting structural faults in elongated magnetically permeable objects has two primary and opposite poles which induce a magnetic flux to place the object at least near magnetic saturation. At least one auxiliary pole is positioned on the inspection device between the primary poles and serves to change the level of the magnetic flux induced by the primary poles so as to induce eddy currents during relative movement of the inspection device and the object. At least one sensor positioned on the inspection device detects eddy current changes which are representative of structural faults.

Abstract: A magnetic inspection device for detecting structural faults in elongated magnetically permeable objects has two opposite magnetic poles, at least one pole being an end pole, that induce a first magnetic flux axially in a first section of an object between the poles, and an oppositely directed magnetic flux in another section adjacent the end pole. As the device and object move relative to one another, eddy currents induced in the object by the changing longitudinal fluxes at the end pole are detected to locate structural faults in the object.

Abstract: A magnetic inspection device for non-destructively testing elongated objects such as large diameter wire cables is constructed with a number of flux carrying components that are assembled and disassembled in sections with a magnetic flux detector for detecting the loss of metallic cross-section and local discontinuities in the cable. The inspection device is moved bodily along a cable during the inspection process and in another embodiment the flux detector itself is the only component movable along the cable. Jack screws are utilized to mechanically separate or bring together the flux carrying components which are normally attracted to one another by powerful magnetic forces. Draw screws are also employed to pull together flux carrying components which are naturally repulsed from one another by the magnetic forces. Alignment pins are utilized to guide the components together in predetermined positional relationships during assembly processes.

Abstract: A magnetic device for nondestructively inspecting elongated objects such as wire cables and the like, for loss of metallic cross-section due to abrasion and corrosion and internal defects has magnets which induce a saturated magnetic field axially through a short section of the cable as the device and the cable move relative to one another. A sensing coil located in close proximity to the cable between the magnetic field poles detects small changes in leakage flux at the surface of the cable in the saturated condition. The sensed flux changes are applied to an integrator to measure the net variation in flux and correspondingly the total change in cross section. Multiple sense coils mounted on core pieces conforming to the external surface of the cable ensure complete continuity of the inspection process and allow the magnetic device to be installed and removed at intermediate stations along the cable.

Abstract: Magnetic flux is induced in the tape by applying a magnetic field to the tape. Where there is a perforation or a crack air gaps are created and magnetic flux radiates outwardly from the tape across these air gaps. The presence of the crack is detected by sensing the radiating flux at two distances from the tape. At one distance, close to the tape, the total flux is the sum of the flux from the crack and the perforation. At the other distance, further from the tape, the flux is solely that produced by the perforation. A coil is placed at each position to sense the flux. The tape is moved, which causes the flux to intersect the coils. The intersection produces an output signal from each coil. The signal produced by the coil further from the tape is subtracted from the signal produced by the coil closer to the tape; the difference being a signal caused by the additional flux produced by the crack. An alarm is sounded and in indicator lights when the signal is present.