How Does Electromagnetic Scanning Detect Steel Cord Damage?

Electromagnetic scanning uses permanent magnet arrays to condition the steel cord carcass of a conveyor belt, followed by an inductive sensor transducer that reads the magnetic signature of each individual cord. Damage — broken wires, corrosion, fatigue, kinks, and splice anomalies — produces distinctive signal patterns that are identified and quantified through analysis software.

• Magnets installed 35mm from belt surface (non-contact)
• Up to 90 inductive sensors per transducer bar
• Individual cord-level resolution
• Belt passes between upper and lower magnet arrays

Conditioning heads: Permanent magnet arrays housed in stainless steel tubing, installed above and below the belt. They create a magnetic field that temporarily magnetises the steel cords as the belt passes through.

Sensor transducer: A stainless steel bar containing up to 90 individual inductive sensors that read the magnetic signature of each cord after conditioning.

Disastrous Event Detection (DED): A continuous monitoring mode that triggers an automatic belt stop when critical damage thresholds are violated — typically within seconds of detection.

Two conditioning heads are installed on the conveyor structure — one above the belt, one below — facing each other with the belt passing between them at a distance of 35mm from each surface. As the belt moves through the magnetic field, the steel cords become temporarily magnetised.

Downstream of the conditioning heads, the sensor transducer reads the residual magnetic signature of each cord. Healthy cords produce a consistent, predictable signal. Damaged cords — whether broken, corroded, kinked, or fatigued — produce anomalous signatures that the BSMF Data Viewer analysis software identifies and categorises.

• Broken cords: Complete wire breaks within a cord
• Corroded/rusted cords: Corrosion-induced changes in magnetic properties
• Kinked cords: Vertical plane deformation from belt handling damage
• Fatigued cords: Filament discontinuities from cyclic loading
• Missing cords: Absent cords in the belt cross-section
• Splice anomalies: Deterioration detected via magnetic signature comparison between scans

• Steel cord belting only — does not work on fabric or PVC belts
• Requires a flat belt path with minimal flap and droop
• Must be installed away from electrically noisy locations (drive motors, switchgear)
• Conditioning head distance must be consistent (±10mm between upper and lower) to avoid weak signatures
• Periodic light washdown required to keep system free from product build-up

An Australian alumina producer operates seven Belt Scanner MF systems across two bauxite bauxite mines in Western Australia. The systems have been providing continuous cord-by-cord condition data for over a decade, supporting a transition from reactive to condition-based belt management. DED remains armed 24/7 for automated belt stop protection.

Q: Is the Belt Scanner MF non-contact?
Yes. The conditioning heads are installed 35mm from the belt surface and the sensor transducer does not contact the belt. No belt modification is required.

Q: Can it detect rips?
DED provides real-time protection against catastrophic events. For dedicated rip detection with Warn/Trip thresholds, a purpose-built rip detection system is required.

Q: How long does installation take?
Typically 1 day. Magnets and sensor can be installed while the conveyor is running; commissioning requires a period of belt operation.

Learn more about the Belt Scanner MF.