| 摘要 |
Inspection apparatus comprising a transparent or translucent tubular member having at least a frusto-conical portion, illuminating elements disposed externally of the tubular member for producing an illuminated zone within the frusto-conical portion, and a viewing arrangement disposed externally of the tubular member and arranged to view objects passing through the illuminated zone in the frusto-conical portion so as to respond to the value of a property of said objects, the tubular member reflecting substantially no light from the illuminated zone onto the viewing arrangement.
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