Industrial systems for the measurement in motion
Disadvantages of conventional measurement methods for moving objects and surfaces
Whenever it comes to checking the coating thickness of moving objects of any length, conventional approaches have only made it possible with an enormous amount of effort.
For extended surfaces, the heating and detection range has been expanded to date in order to achieve the necessary measuring time. The larger the surface, the greater the technical demands on the measuring equipment – and that quickly makes it very expensive.
Motion measurement is problematic for conventional measuring instruments because the object to be measured is only within the heating range or in the field of view of the detector for a limited time. The entire measuring system must be moved. This approach is technically complex and cannot be implemented in confined spaces. Furthermore, no measurement can be taken during the “return trip”.
New scanning 3D inspection method fulfils all requirements
The PaintCheckermove result is a scanning measurement process that utilises the movement between the component and the sensor instead of compensating for it in a complex manner. The object is not captured once as a whole, but is scanned continuously as it passes the measuring device.. As an interesting side effect, it is also no longer necessary to stimulate with pulsed light. On the contrary - constantly illuminated excitation sources are actually an advantage.
The modular architecture of the PaintChecker Move
The new, scanning OptiSense system PaintChecker Move has a completely modular design so that the measuring device can always be optimally adapted to the respective application:
The excitation and detection modules are separate and can be configured independently of each other. They are connected by a mounting wedge that also contains the data cable connection and provides the mechanical connection to the customer's system. The angle of the wedge is selected according to the respective test situation.
Lasers of different power classes and wavelengths are used as excitation sources. What all variants have in common is that the laser itself is installed in the external controller housing and is connected to the excitation module via an optical fibre. This means that the excitation module does not require cooling, as it only contains passive optical components.
Measurement procedure and measurement variants
The spatially resolved calculation of the coating thickness and visualisation takes place seamlessly on the fly. The PaintChecker Move is flexible and can also be easily integrated into existing production lines at a later date. In particular, the condition of the coating (wet, moist, soft, dry, baked) and the dimensions of the workpiece hardly play a role.
This allows the coating thickness to be determined in real time, even for continuous measurements such as coil coating, so that process parameters can be adjusted immediately if necessary. There are three different variants of the modular concept:
High-resolution surface scan
This configuration enables the continuous measurement of coating thickness maps; the test result is a 2D image with the spatially resolved coating thickness. The width across the scan direction is up to 100 mm. The length in the scanning direction is virtually unlimited.
High-resolution profile scan
In applications with a high relative speed between the sensor and the component, the available excitation power is rearranged so that less light power is applied to the measurement object in the width and more in the length.
This setup allows higher speeds or longer measuring times (equivalent to greater coating thickness) to be addressed. The detector field of view is also adapted. The result is a 2D scan with a reduced width transverse to the scan direction or, in the extreme case, a profile scan.
Non-scanning profile check
A non-scanning mode is also possible. In this case, the matrix of IR sensors is replaced by a single, highly sensitive IR sensor. In this way, the accuracy of the coating thickness measurement can be further increased at the expense of the spatial resolution. This configuration is suitable, for example, for very high speeds or for applications in which a resolution in the mm range is not essentially needed
Clear Benefits
- Scanning 3D coating thickness testing method marks significant progress for the coating industry
- Objects of any size are inspected accurately and repeatably without contact and without having to move the measuring system
- Very suitable for any condition of the coating (wet, moist, soft, dry, baked)
- Material and cost savings as well as the increase in quality make this new technology a worthwhile investment
- Precise and continuous measurement of coating thickness increases both production quality and efficiency
