An inspection apparatus for viewing and making video recordings of the interior of an enclosed space of an enclosure having an elongated body. A pair of housings are mounted on the lower end of the elongated body and respectively contain a light source for illuminating an area of the enclosed space and a video camera for creating an image of the illuminated area of the enclosed space. The video camera includes a video magnetic tape media for recording the images illuminated by the light source. A television monitor is mounted on the upper portion of the elongated body for simultaneously viewing the images created by the video camera.

A protective camera housing is designed to protect a high speed film or video camera (16) or other delicate instrumentation whilst it films or operates in close proximity to a blast in an underground mine, or other destructive environment. A faceplate with an obtuse angle of attack to the direction of travel of forces generated during underground blasting, an inbuilt shock absorbing gasket between all body plates and chassis members, rubber mounting pods and a construction material which is "bullet proof" all combine to give a high degree of protection against explosion debris and blast shock waves. An optical prism (15) built into the said faceplate bends the camera field of view through 90 degrees, allowing the camera housing to be placed in a prepared "hole in the mine tunnel wall" where the high speed camera can "look around the corner" but remain protected from the destructive forces of the blast.

Protective sleeve, into which a conventional fiberscope or videoscope is inserted, is mounted so as to extend into a high pressure or high/ultra-high vacuum chamber to permit inspections or monitoring therewithin. In a first embodiment the protective sleeve comprises first and second body portions, each comprised of bellows-like flexible stainless steel. The second section has a length substantially corresponding to the articulatable distal end of a fiberscope or videoscope to be articulatable therewith. In a second embodiment, the first body portion is rigid, and axially displaceable relative to a gimballed mounting assembly through which it passes into the chamber. In a third embodiment, the first body portion comprises a shape memory ally. In both the second and third embodiments the second body portion, as in the first embodiment, comprises flexible stainless steel so as to be articulatable upon the articulation of a probe disposed therein. In a fourth embodiment, the first body portion is flexible stainless steel and the second body portion is rigid.

Device for determining the straightness of hollow cylindrical surfaces and partial surfaces thereof, and the three-dimensional orientation of several hollow cylindrical surfaces or partial surfaces with reference to at least one of axial parallel offset and angular offset relative to one another. A transmitting/receiving device and a reflector/receiving device are provided which are swingable essentially without play over a respective hollow cylindrical surface or partial hollow cylindrical surface. The transmitting/receiving device has at least one transmitter for emitting light beams and at least one receiver for receiving and for measuring an incidence position of the light beams. The reflector/receiving device has at least one partially-reflective optical element for partial reflection of light beams and at least one receiver for receiving and for measuring an incidence position of a portion of the light beams. The relationship between circular lines produced on the detectors in different phases of measurement is used.