Laser monitor improves part welds

Sensor Review

ISSN: 0260-2288

Article publication date: 1 December 1998



(1998), "Laser monitor improves part welds", Sensor Review, Vol. 18 No. 4.



Emerald Group Publishing Limited

Copyright © 1998, MCB UP Limited

Laser monitor improves part welds

Laser monitor improves part welds

Engineers at Argonne National Laboratory in Argonne, Illinois, and Deiphi Energy and Engine Management Systems in Flint, Michigan, have jointly developed a new monitor to identify defects in laser welding. This device is expected to assist domestic car manufacturers in producing higher-quality parts at lower cost, improving competitiveness. The laser monitor is equipped with a passive sensor and associated optics to measure the infrared light emitted from a weld during processing. This information is sent to a computer that uses it to calculate the depth of the weld in real time. These welds have to penetrate to a sufficient depth to provide a strong join, yet not so deeply that the heat or spattered material of the weld will damage the part. By sensing the weld penetration, the monitor can flag bad welds or automatically adjust laser power levels to provide a proper weld. Additional applications for the device include detection of surface contamination and misalignment, as well as the monitoring of full penetration welds.

The monitor is being offered commercially by Spawr Industries Inc. in Lake Havasu City, Arizona. Spawr engineers have made further refinements to the original design, such as by integrating the weld monitor into the focusing optics assembly so that the instrument does not have to be aligned on the factory floor. There are two versions of the monitor: one equipped with laser aiming to suit research and development applications, and another that can be retrofitted on existing laser-welding systems.

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