Nowadays, you can find increasing applications for many different types of cameras for remote kind of visual inspection, which is not only used by many equipment manufacturers, but also in many other kinds of businesses too.
Essentially, non-destructive testing technique uses the visual inspection of any object or some area under test by not sending their technician in the actual test area, i.e. performing inspection from remote location.
Huge technological progress have been made during the last few years, due to introduction of few early optical instruments through fiber-scopes that introduced flexible fiber optic bundle which links to the eyepiece by using lens and finally to more complex video-scopes.
Remote visual inspection has been around almost for about last 80 years. Earliest version of such inspection systems were just simple tubes shaped thin telescopes, having an eyepiece on its proximal end and one angled mirror that is pointed toward tube opening on distal end.
They were called as “borescopes”, and were used for looking inside bores in any machine, vat, pipe or tank. You can think of periscope on submarine as borescope looking via a “bore” in surface of ocean.
Fiberscopes in fact arrived in the market almost 35 years back with the development new fiber optics technology, which are actually extremely thin glass strands. Fiberscopes will usually bundle together about 3,000 to 30,000 or even more of these strands.
One lens with push camera of Wohler will be attached to distal end of fiber optic bundle. An eyepiece will be attached to proximal end. Image captured by lens will be carried via bundle and will show up on eyepiece.
The user will be able to put eyepiece to his eyes and see at the image, or eyepiece will be attached to camera that will display image on the monitor.
In few systems, outer fiber ring in the bundle will be used for transmitting light onto inspection target, while inner fibers will be used for carrying image back to eyepiece.
In such cases, system must include separate light source at proximal end, and light will be transmitted down outer circle of the fibers for providing the illumination.
What is the advantage of fiberscope?
Main advantage of these fiber-scopes over borescopes will mainly be the flexibility and therefore can be used for various inspections where straight-line access will not be available.
Many fiber-scopes also have articulation that simply means that distal approximately 2”of the scope will be pointed towards any of the direction, by means of any control knobs located near the proximal end.
Also, a number of low cost fiber-scopes, that is carried by many auto parts stores, use plastic fibers in place of glass fibers. Quality of image for these scopes will be quite poor.
Also, video-scopes are similar to fiber-scopes where there can be both articulating and non-articulating video-scopes.
Main technical difference between these video-scopes and the fiber-scopes is usually video-scope has micro video camera that is located at distal end of your insertion tube.
This directly captures inspection image and also electronically carries video signal down insertion tube to video processor and the display, which are integrated into this unit.