Coating Thickness Measurement in Material Testing

Particular Challenge: For the assessment of rotating parts, numerous parameters have to be taken into consideration: Concentricity, radial run-out and axial run-out (i.e. wobble); furthermore thickness, diameter, planarity and the absence of surface defects had to be examined. The solution developed by QuellTech consists in a configuration of three Q6 Laser Laser Scanners.Each of the lateral surfaces is assigned to its own scanner. In order to enable the thickness precisely to be determined, both laser lines are mutually oriented in opposite direction. The third scanner inspects the outer circumference of the wheel, this way measuring diameter and radial run-out. All of these scanners are subject to encoder signals supplied by the rotary axis and synchronously triggered, so possible defects on the wheel can precisely be localized. The measurement takes place at a resolution of ca. 30 µm, and a cloud comprising several millions of points are obtained.

The QS View software package is intended for dimensional control in 2D or 3D QS-View 2D / 3D software for all measuring tasks 3D representation of an irregular body for determination of volume and weight. With the 2D / 3D software a wide variety of parameters can be processed and displayed, e.g. length, width, angle height, gap, presence, volume (resp. weight), seam geometry (height, width), gap dimensions. Due to the modular structure of the software, customized specialties can be added any time. Each module delivers the results to an individual output module. The universal SPC interface allows simple connection to S7 controllers via Ethernet. 2D / 3D software developer kits are available for integrators with corresponding knowhow.

Particular Challenges of the Application: By tactile equipment, determination of the deepest point on a rough metal surface is neither simple or precise. As a consequence, often either too much material is removed, or the surface is still covered with defects which have to be eliminated by a following milling cycle. The equipment is arranged in parallel, so that the complete width of the slabs is covered. The sensors are calibrated to a common coordinate system and mounted on a movable gantry. Before measurement, the slabs are fixed in place. The scanners mounted on the gantry are guided over the measuring object, driven by an electric motor. The point cloud recorded by the four scanners is consolidated in a PC by means of the QuellTech image processing software which calculates the difference between highest and lowest point of the corresponding surface and compensates for possible inclination of the slab (detrending).

The QuellTech laser sensor family Q4 or Q5 used for these tasks is generally mounted on an arm of a rotational axis, to scan along the complete 360° angle of the internal surface in a sequence of strips. The Q4 sensors can also be used to control the weld seam tracking itself for rapid setup and ease of use. Even during a project, the range and scope of the Q Series sensor demonstrates the advantages of a modular system to quickly adapt to project needs, where the smallest system has provided fast analysis of pipes as small as 105mm. The low power, with standard communication protocols, enable battery powered systems to transmit wireless data to other systems for review and cloud back up.