Scratch and dig inspector
SavvyInspector® is designed to measure surface imperfections. The factory-calibrated inspection head uses invariant illumination and detection optics and proprietary analysis software to provide an objective, repeatable and recordable evaluation of the surface quality of optical components. It operates in accordance with ANSI/OEOSC OP1.002, Appendix C of MIL-PRF-13830B, Appendix A.3 of ISO 14997, and ISO 10110. It comes with calibration files traceable to the common standards.
Manual, software assisted inspection
The SavvyInspector® SIF-4E is a software assisted scratch and dig system.
The SavvyInspector® SIF-4M is the motorized version of the SavvyInspector® SIF-4.
Motorized inspection for larger samples
The SavvyInspector® SIL-8M is a 200 mm motorized version of the popular SavvyInspector® SIL-4.
The SavvyInspector® is used in optical factories for the quality inspection of surface imperfections such as scratches, wipe marks, holes, coating imperfection or coating defects as well as edge chip.
The SavvyInspector® operator interface is designed for easy factory-floor operation, while expanding its application in the role of “Master Inspector” for QA, QC and MRB decisions. The operator enters the inspection level required, and then uses the manual x-y stage or the joystick to locate the desired defect on the real-time viewing screen. In motorizied systems the “autoscan” feature creates indexed image files for the entire surface, documenting the condition of the optic and allowing the operator to identify regions on the part which require further review. The coordinates can be entered and the system returns to the desired location with the push of a button.
The software reports the scratch grade or dig value automatically. Scratch lengths are measured with the click of the mouse. The “always on” inspection mode and programmable grade bars allow the operator to get real-time feedback on whether a selected imperfection is acceptable or not with a simple visual interface.
For careful review and documentation of a lens surface, SavvyInspector® software offers data management tools. These allow the proper capture and archiving of screenshots as well as the grade for each error on a surface. Additionally, a summary log in CSV format or an inspection report is generated.
Accumulation rules can be applied using the SavvyAccumulator™ spreadsheet. Custom calibration files can be created for specific project or customer needs by the Quality Engineer as needed. The calibration data can then be saved and accessed from the inspection mode.
Scratch and dig
Especially in the last steps of glass processing, polishing and coating, defects can occur which locally impair the optical image of the glass. These defects are classified as follows:
- General surface imperfection, e.g., scratches, wipe marks and holes
- Coating imperfection/coating defects
- Edge chip
These imperfections are classified in the dimensional method of ISO 10110-7/ISO 14997 by their geometric sizes or in MIL-PRF-13830B by the visibility or appearance of imperfections. Recently, this visibility type of specifications, known as the “scratch and dig” specification, was added to ISO 10110-7/ISO 14997 as well.
Tests for surface imperfections are carried out in practice both by random sampling and by 100 % inspection. The inspection process is usually carried out purely subjectively by an inspector who classifies the imperfection purely visually. In the case of testing according to MIL, the sample is rate according to its appearance by compared with artifact standards (scratch and dig masters) that show the standardized defect of each class to the greatest possible extend.
MIL-PRF-13830 describes defects by their visual appearance. The scratch morphology drives its brightness.
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