History of Borescopes

by | Sep 8, 2021 | Blog, News

Are you interested in knowing about the history of borescopes?  In this article we discuss the origins of the borescope, why these tools were developed and who invented them.  We also discuss the various designs of borescopes that are available today and how they differ in application. 

While endoscopes and borescopes are similar, endoscopes are used for medical purposes and borescopes are used for mechanical jobs. In this article we mainly focus on borescopes.

Who Invented The Modern Borescope?

The first borescope-type devices arrived on the scene in the late 1930s and early 1940s. As Advanced Turbine Support states, “The first recorded use of borescope-like tools dates all the way back to World War II, when soldiers would use long, primitive, inflexible optical devices to check the inside bores of their guns for defects. This is where the borescope (boroscope, bore scope or boro scope, as it is less commonly spelled) got its name.”

The first modern borescope was invented in the 1960s. “This version of the borescope that would be the first to be talked of in these terms was created in 1960 by Narinder Kapany, an American physicist of Indian descent, and Brian O’Brien, an optical physicist, also from the US.” according to Optics and Lab.

As Advanced Turbine Support states, “Their device used a rigid tube and an optical visual inspection system.” Although the rigid form limited its capacity to fit in certain spaces, it did set the stage for further refinements and developments.

Development of Borescopes Throughout the Years

After their invention in the 1960s, borescopes expanded into diverse industries and took on a variety of forms.  For example, the endoscope was invented so doctors could perform minimally invasive procedures – to the great benefit of patients.  In non-medical applications, borescopes benefit aviation maintenance professionals, inspectors, technicians of all sorts, hobbyists and plumbers – to name a few.  Borescope usage continues to increase for aviation borescope inspections, UV borescope inspections in aerospace manufacturing and explosion proof facilities.

In terms of borescope design, three main types have emerged:  rigid, flexible and video. 

Let’s take a closer look at each one.

1. Rigid Borescopes

Of all the borescopes available today, rigid borescopes most closely resemble the borescopes of the 1960’s.  They are non-flexible scopes made of polished stainless steel.  Why is this original design still used?   There are two main reasons.  This design permits superior resistance to oil, dust, water, diesel, etc.  Rigid borescopes produce unsurpassed image quality as they employ an eyepiece rather than a monitor. 

Since rigid borescopes can be mounted in a fixed position, they are ideal for performing repetitive inspection on similar parts or devices.  Thus, they are often used in manufacturing industries.  Companies that specialize in metal casting and cylinder bore inspections are a good example of this.  There are a variety of sizes to meet the needs across applications; typical diameters range from 2.7mm up to 10mm and lengths from 175mm up to 305mm. 

All rigid borescopes are designed with light fiber bundles that transmit light to the end of the probe. These systems would still require an external light source. Taking pictures and/or videos is still possible by connecting a USB Camera and adaptor to the eyepiece of the borescope along with a high intensity LED light source. These systems are designed for direct view or side viewing angles.

While rigid borescopes have unmatched image quality, if an inspection requires the traversing of elaborate angles, a flexible borescope is recommended.

2. Flexible Borescopes

Flexible fiberscopes are a type of borescope or visual inspection instrument that uses a high-quality fiber bundle to transmit a clear visual image of the inspection area back to the user via a focusable ocular eyepiece.

The flexible borescopes allow users to navigate through areas that involve angles and other obstacles. This tool allows for a thorough inspection of small diameter structures such as mechanical chambers, small mechanical cavities, and other tiny open areas.  

These are much like the rigid borescope but can bend around corners and access spots through tough angles. Due to its ease of use and control, the flexible fiberscope is a top inspection tool of choice for many professionals across several industries.

Features And Benefits Of Flexible Fiberscopes

Possessing many benefits, flexible fiberscopes come in a variety of sizes and features for all inspection needs. The main type of flexible fiberscope is the articulating fiberscope which is used to inspect narrow or limited access points with help from its articulation or maneuverable function. Flexible fiberscopes primarily come with 2-way articulation, but the 4-way articulation fiberscope is available as well. You can find flexible fiberscopes in a variety of sizes ranging from 2.4mm (.09 inches) in diameter up to 6mm (.236 inches).

Fiberscopes are considered to be one of the more durable inspection tools. They contain a well-protected and enclosed optical image bundle that is encased by a group of braided stainless steel or tungsten to ensure protection from the outside elements.

Whether you are looking for a flexible borescope to inspect dark or poorly lit areas or add additional lighting for visual clarity, there is a large variety of light sources to match your exact needs. LED light sources, available as either a portable light source or a stationary one, are the most popular option due to being brighter and more energy-efficient than traditional halogen light sources.

Fiberscope video camera attachments & adaptor kits are also available which allow users to not only connect their fiberscope to their computers for an enhanced inspection visual, but it also provides users the ability to image capture and record video. A camera attachment can be added to a fiberscope by attaching the camera to the ocular eyepiece via a C-mount adapter.

3. Video Borescopes

A videoscope is a tool used by technicians to inspect hard-to-reach spaces. Typically, it is comprised of a fiber optic rod attached to a camera; this camera sends video to a monitor so the operator can view it.

Videoscopes use articulated tips that give operators more control over the direction of the camera, allowing for better maneuvering in tight spots. Most of these tools come with external lights that can illuminate dark areas within machinery or pipes.

An insertion probe section allows for easy entry into whatever piece of equipment might need inspecting. Typically, less than 8 millimeters in diameter and up to 7 meters in length, videoscopes can be tailored to the precise task at hand.

Videoscopes are used in various industries, particularly aviation and aerospace, to inspect turbines, engines and other components of aerospace/aviation machinery. Videoscopes are also often used in the plumbing and manufacturing industry; they are a useful tool for inspecting expensive machinery without needing to disassemble the entire apparatus.

4. Portable Video Scopes

A portable videoscope is a type of borescope you can easily take on the go. It is a flexible style inspection camera with an insertion tube made up of either poly/vinyl, stainless steel or tungsten sheathing. Typical diameters for portable borescopes range from 2.1mm through 8mm and average probe lengths range from 1 meter to 7.5meters.

Contact Us!

Borescopes have come a long way since WWII, and will only continue to evolve as time goes on. Finding the right borescope product can be difficult, but USA Borescopes is here to help. If you have any questions about borescopes, videoscopes or fiberscopes, don’t hesitate to contact us. We have a full staff of seasoned professionals who are eager and ready to help you.