Visual inspection in transmitted light
in standardized light Ri 97 or bright version

Translucent materials are illuminated from behind using a suitable light source. This allows various features and defects to be detected, including:

• Material inclusions
• Purity (foreign body detection)
• Level control
• Inspection of seals
• General damage, etc.

The brightness and light colour must be optimally matched to the respective inspection object. Relevant features must neither be overexposed by excessive brightness nor insufficiently visible due to inadequate illumination.

For translucent trays, uniform backlighting facilitates visual inspection and enables missing or incorrectly placed components to be detected quickly and reliably. The enhanced contrast between correctly and incorrectly assembled trays (OK/NOK) reduces eye strain and helps employees maintain concentration.

When inspecting populated PCBs and electronic assemblies, backlighting also provides a clear view of component positions. Missing, incorrectly positioned or improperly installed components can therefore be identified reliably. LED backlighting supports dependable quality control and helps reduce errors in the production process.

The inspection objects are placed on a uniformly illuminated light surface. The enhanced contrast makes edges, contours and holes significantly easier to assess. This allows the following features and defects to be detected:

• Chipping (outer edges and holes)
• Edge roughness
• Material damage
• Deviations in contours and outlines

The brightness must be optimally adjusted to the respective inspection object. Excessive illuminance can cause overexposure around the edges, making relevant features and defects difficult to detect reliably.

For the visual inspection of reflective surfaces, the illuminated surface faces the operator. By combining transmitted and incident light, the light is reflected by the inspection object in a controlled manner. This creates a high contrast, making the following features visible:

• Surface Defects
• Scratches
• Fingerprints
• Residues and contamination.

The size of the illuminated surface must be matched to the inspection object. If it is too small, the usable reflection area—and therefore the inspection area—may be insufficient, particularly for irregularly shaped components. The correct brightness is equally important, which is why we recommend a dimmable version.

For the inspection of glossy surfaces, defined patterns can also be applied directly to the illuminated surface. Their reflection makes even the smallest irregularities and deviations in shape visible. The type, size and arrangement of these patterns—such as stripes or grids—can be customised to suit the specific inspection task.