摘要 |
A method and device for the accurate manual inspection of three-dimensional (not flat) samples, such as pharmaceutically injectable vials, for particle contamination, which samples are illuminated with diffused (non-point) light. Opposing vertically positioned and spaced illumination sources are provided above and below the vial, with the vial being positioned in an inspection volume at the illumination midpoint (lumen light balance) between the illumination sources. The illumination midpoint, for light sources of equal intensity, is also the physical midpoint therebetween. Though the mid-point is not the position of maximum illumination for light sources, normal variation in manual inspections, e.g., variations in inspector height and deviations caused by manual handling of the vial, at the mid-point, result in minimal deviations in illumination, with resulting greater accuracy and replicability of inspection results. The station further optionally includes a light-dark-light changeable background for inspection of different contrast particles which may be in the vial, without removal of the vial from the inspection point at the illumination midpoint.
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