What are borescopes? Borescopes are simply instruments that allow you to view close-up images in very restricted places. Typically, these instruments consist of a small-diameter tube (sometimes flexible) with a lens on one end and an eyepiece on another. The advantage of using a borescope is that the tube containing the lens can be made exceedingly small — these very small diameter tubes can therefore fit into very small holes and spaces.
One of the most common applications for the use of borescopes is in inspection work. Borescope inspection is useful — sometimes necessary — in the automotive and aeronautical industries, for the close-up examination of machine and engine parts. In these environments the usual instrument is a rigid borescope — a borescope with a straight tube, but some borescopes used are flexible borescopes — they can be adjusted to fit around various obstacles.
Some major manufacturers of borescopes are Olympus borescopes and Hawkeye borescopes. These companies manufacture ultra-sophisticated borescopes for specialized applications, including digital video recording. Rigid borescopes use a series of positioned lenses to transmit the viewed image. Video borescopes are borescopes which are specially designed to be able to accommodate a video camera configuration.
Flexible borescopes, on the other hand, do not normally use optical lenses; instead they use a series of fiber optic filaments — fiber-optic borescopes have an advantage in that they are flexible and so can be maneuvered past obstacles and bends that would normally obstruct the field of view. A prominent manufacturer of inexpensive, flexible borescopes is ProVision. ProVision specializes in the manufacture of hand-held flexible borescopes — a favorite of mechanics everywhere.
In addition to the borescopes themselves, you can also purchase various types of accessories — protective eyepiece hoods, camera couplers, portable battery lighting units, etc. Because borescopes are typically very expensive to purchase, it is also possible to rent them. Companies specializing in borescope rentals will ship your borescope to you, and for a fixed fee will allow you to use it on your premises during the rental period. When you are finished using it, you simply return it to the borescope rental company (in good condition, of course).
A very important development in the use of borescopes today is the coupling of these devices to a personal computer. In fact, specialized computer applications have been developed which allow you to control your borescope from a remote location, capture and record the viewed images, and even help you prepare necessary documentation on your inspection. These specialized applications will run on nearly any PC, and some are made available as a part of the total equipment purchase package, thereby saving you money.
One final note: One of the biggest fields where borescopes are used today is medicine. These are special-purpose borescopes which are called endoscopes. If you have ever had a colonoscopy, then you may have seen these in action.