Ensuring Perfection in Both Taste and Looks

The consumption of chocolate brings joy to many people lives. But it’s not only the taste that matters; it should also be enjoyable from a visual perspective too. The customer expects a faultless appearance which showcases a combination of sophistication and full chocolate flavor. Modern laser scanners from Micro-Epsilon can be integrated into the processing line and various chocolate products can undergo real-time inspection using non-contact, efficient, high speed measurements whilst monitoring their geometrical characteristics.

Prince Wilhelm von der Lippe founded the first German chocolate factory in 1765. In those days, chocolate was handmade. Famous people such as Goethe, Schiller and Frederick the Great all loved chocolate. However, it’s not just about how good the chocolate tastes – the appearance is also deciding factor in the buying process. In contrast to past times, the production of chocolate has now become a highly automated process.

Different methods can be used to ensure chocolate undergoes a quality inspection during the production process. If the final quality control check is a visual inspection, the results can be dependent upon the mood of the employees on that day and will not possess a constant characteristic throughout the whole production process. Tactile systems are slower than optical systems and contact measurements can become a time-consuming process. In addition, many points of the surface must be analyzed.

Furthermore, it should not be forgotten that contact measurements also affect the sensor and the product, as the wear is increased. While laser point sensors produce non-contact measurements, they can only create a point-shaped laser beam. To generate the values needed to profile a chocolate sample, many individual measurements must be obtained. This can be a time-consuming and costly procedure. These individual procedures can limit the highly automated production process. On the other hand, laser scanners offer some advantages here. When faced with changes in the properties of the surface, the conveyor belt or multiple colors from light to dark chocolate, the scanCONTROL system ensures reliable results.

To meet the strict hygiene standards in the food industry, the user can place the scanner in a special protection housing which fulfills the requirements of the food industry. It withstands high-pressure cleaning, disinfectants including hydrogen peroxide and other alkaline and chlorine-based chemicals.

scanCONTROL Laser Profile Scanner

Laser scanners from Micro-Epsilon provide a solution that can introduce significant time savings against standard inspection procedures and, at the same time, providing extremely fast high precision quality control of the chocolate bars, while adhering to stringent hygiene safety standards. As well as performing random sampling procedures, laser profile scanners also master the inspection for the entire production line. Therefore, the scanner is placed in a fixed position above the conveyor belt. The normal measuring range in this application is 100mm but can be expanded to around 143mm. An encoder on the conveyor belt ensures equidistant profile detection when using varying belt speeds, which ensures a high repeatability. Because of the high-profile frequency, the scanner can easily cope with short cycle times in the production process.

With a throughput rate of more than 30 m/min, high speed laser scanners detect the profile of each of the finished chocolate bars without touching them and the data is evaluated in the sensor head. Sensor set up and configuration can be performed using the scanCONTROL Configuration Tools software Overall, the scanCONTROL 2960-100 laser profile scanner ensures 100% monitoring of all chocolate bars in the processing line.

This sensor series can impart a much more efficient quality control compared to other optical sensors. The scanner detects the overall profile with only one scan, and defects on the surface can be isolated. Typical measured features such as the number of recesses, profile, width, height, depth, edge, groove, flatness and deformation are defined and determined by the scanner. Depending on your requirements, the measurement values can be calculated directly in the sensor head in real-time and then compared to predetermined parameters and outputted as OK or NOK signals.

Therefore, any profiles that do not match up with the predetermined specifications are rejected. Another mode of operation is that the scanner can be set up to talk directly with a PLC and transmit the calculated values. In this case, the PLC takes further steps and evaluates the measurement results. This means that the line controls can be intervened with immediately e.g. by readjusting the process. Real-time quality controls using laser scanners ensures a rapid response and intervention in the process, while reducing the waste and cost.

As modern laser scanners from Micro-Epsilon are integrated in the processing line, different chocolate products undergo real-time inspection based on non-contact, efficient, high speed measurements whilst their geometrical characteristics are also monitored.

When comparing their size, accuracy and measuring rate, the scanCONTROL laser scanners are some of the highest performing laser profile sensors in the world. Even the smallest of parts can be measured with micrometer accuracy, enabling new depths of quality control to be explored. For the quality control of chocolate, a red laser diode scanner is used because of its higher intensity and robustness. The red laser is also utilized across numerous measurement tasks e.g. in the automotive area, with uniform airbag stitching, gaps between vehicle parts and applied adhesive beadings being a few examples.

This sensor series enables much more efficient quality control compared to other optical sensors. The scanner detects the overall profile with only one scan. Typical measured quantities such as the number of recesses, profile, width, height, depth, edge, groove, flatness and deformation are defined

However, in some measurements where a red laser is at its operating limit, laser scanners with a blue laser can be used in their place. Blue laser scanners provide more precise measurements in some circumstance because the blue light does not penetrate as deeply into the material, e.g. with semi-transparent surfaces and organic materials. Furthermore, the blue laser is an ideal choice for red-hot glowing surfaces where the sensor would not be able recognize the red laser light due to it having a similar wavelength. For example, when measuring the blade angles of razors, the blue laser provides very accurate results on the highly polished blade surfaces. The requirements of the given application are decisive in choosing the most suitable type of laser. Micro-Epsilon has registered a worldwide patent for the application on red-hot glowing and semi-transparent measurement objects.


Micro-Epsilon laser profile scanners are specifically designed for applications in quality control, production processes and automation. The operating principle utilizes the laser triangulation technique for the detection of two-dimensional profiles. They detect, measure and evaluate the profiles on the surface of different objects. In situations involving moving objects or a traversing sensor, it is also possible to obtain 3D measurement values, thereby generating a 3D profile.

This information has been sourced, reviewed and adapted from materials provided by Micro Epsilon.

For more information on this source, please visit Micro Epsilon.

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