OPTICAL DEVICE FOR INSPECTING THE INTERIOR OF AN ENCLOSURE

摘要

The interior of an enclosure is inspected from the outside through an opening by a device comprising an observation or measuring instrument. Deflectors are arranged so that radiation from the interior of the enclosure passing through an observation orifice of the device is transmitted to the instrument along a folded optical path, one end part of which coincides with the sighting axis of the instrument. One of the deflectors is rotatable about an axis perpendicular to a plane containing the sighting axis and the said path in order to vary the angle of the end part or the said path adjacent the orifice. The assembly of deflectors is rotatable relative to the instrument about the sighting axis.