Borescope

The borescope is an optical device featuring a rigid or a flexible tube with an eyepiece on one end, an objective lens on the other linked together by a relay optical system in between. Such tools find application in inspection jobs where a given area has to be inspected but are are inaccessible by other means. Borescopes are either flexible or rigid. Each type has its own advantages, therefore you must pick one depending on the type of area that must be inspected.

The rigid borescopes are the more commonly used type, because of their better cost vs. performance ratio. Basically, the rigid borescopes give higher quality images, are easier to use and are less expensive than flexible scopes of similar quality. Such tools can identify flaws as small as 0.001. They feature fibereoptic illumination and are available in a wide variety of price ranges. In addition to that, they are video and digital adaptable. Bottom line is that unless the rigidity is not a problem, it’s always better to buy a rigid one. The advantage of the flexible borescop is that it lets you see inside spaces that a rigid borescope can't penetrate.

When buying a borescope, it is important to know the environment in which you will use it. Probably the most important parameter is the diameter. For example, the Hawkeye MicroSlim borescope can fit into a 0.075" (1.85mm) diameter hole. The rule is to select one that will fit through the smallest hole required. It’s a good idea to have a diameter smaller than the minimum allowed, because a slightly smaller scope may allow "wiggle room" so that you can see more by tilting the scope. So, the Hawkeye bore scope mentioned as an example, will be perfect for holes of with a diameter of minimum 2mm. Of course, as with all other tools, the best thing is to try it. But remember that you can’t do all tasks with only one borescope. There is no universal borescope, that is ideal for all tasks. If you need to see into very small holes and relatively large ones, it is usually best to optimize for each, by using two borescopes.

In terms of the length, select a borescope that will penetrate to the greatest depth required, but not so long as to be unwieldy outside the hole.

The other important borescope characteristics are: direction-of-view, field-of-view, magnification, illumination. The latest models have fiber optic illumination. The magnification is greater as the object gets closer to the lens of the borescope. The other must known rule when working with such devices is that the wider the field-of-view, the lower the magnification, and vice versa. The conclusion here is that, if you have plenty of space to maneuver inside the cavity, but want to see both detailed close-ups and big picture views you might choose a 67° moderate wide angle. If you can’t get close, use a 30° angle.

Upper Endoscopy | Borescope Lens | Camera Lens | Gradient Lens | Optical Lens | Rod Lens |