The combined solution integrates two distinct laser-based systems into a single pass-line framework:
Thickness Measurement (The "Flying Micrometer"): This uses two opposing laser displacement sensors—one mounted precisely above the strip, one below. By simultaneously measuring the distance to the top and bottom surfaces and subtracting the sum from a known fixed gap, the system calculates absolute thickness. Modern lasers offer micron-level resolution, unaffected by material color or surface finish (e.g., dull or bright).
Width Measurement (The "Edge Hunter"): Two additional laser profilometers (or a single, wide-field scanner) are positioned above the strip edges. They project a laser line across the full width. By detecting the sudden drop in return signal at the strip's edges, the system triangulates the exact position of both boundaries in real-time.
Separate systems create data silos and alignment errors. A unified solution provides:
Edge-to-Edge Profiling: The system captures thickness not just at the center, but across the entire width (crown and wedge profile), while simultaneously recording the width. This reveals edge wave or center buckling.
Dynamic Compensation: As the strip vibrates or "floats" between rollers, a single thickness sensor would see false variation. The dual-opposing laser design cancels out vertical flutter. Similarly, the width lasers ignore lateral movement.
Real-Time Correlation: Software instantly links a width deviation (e.g., necking) with a thickness change (e.g., tension variation), allowing mill operators to correct process parameters before scrap is produced.
A typical installation occurs just after the final rolling stand or before the slitter. The system operates at line speeds exceeding 500 m/min. When a width tolerance of ±0.5 mm or a thickness tolerance of ±10 microns is breached, the control system receives an alarm within milliseconds.For flat metal strip—steel, aluminum, copper, or brass—combining dual-laser thickness gauges with laser edge detectors eliminates the lag and mechanical wear of contact gauges or camera-based systems prone to light interference. It provides a single, synchronized, high-speed digital twin of the strip’s geometry, enabling tighter tolerances and higher yield. In modern metal forming, measuring one dimension is no longer enough; you need the full picture, captured by light.
