Optical measurement for precise quality control of tubes and round bars

High-precision measuring systems are required for the precise quality control of tubes or round bars. The challenges include measuring the outer diameter, length, roundness and straightness. In addition, the end faces must also be checked for defects and any color deviations on the surface must be detected. Mechanical measuring methods reach their limits here, especially with uneven or corrugated surfaces.

A multi-stage sensor system optically records the relevant geometric data. The outer contour is fully measured with four 3D scanners, while a high-resolution camera also checks color and surface characteristics. The end faces are analyzed for diameter, geometric deviations and defects using additional cameras. To ensure measurement accuracy, referencing is carried out with a standard part. Among other things, “best-fit” algorithms are used for data processing, which are validated in cooperation with the customer’s measurement technology. Depending on the component properties and customer requirements, measured values in the hundredths range can be achieved.

Optical measurement enables fast and non-contact quality control. Precise measurement results, even with complex geometries, reduce rejects and reworking. Automated measurement ensures high repeatability and comparability with existing measurement methods. The resulting transparency with regard to production quality opens up new dimensions compared to random sample measurement on tactile measuring machines or old-fashioned gauges.