VisionScope Technologies Ltd for all your Industrial Inspection

As from the 1st July 2015, VisionScope Technologies and INSPECTION OPTICS LTD will be merging together to provide multiple brands and own make Industrial Imaging devices. Endoscopes, Camera systems, Light Sources, Pipe Camera and Machine Vision components.

Combined we are agents for Heine Technoscopes GmbH, HIPP Endoskopie GmbH, Wohler GmbH, IT Concepts, Endoscan Ltd, MC Medical Ltd and Moritex. Additionally we offer second user equipment and provide service support for Medical Devices.

Do you know what types of industrial inspection systems are available, what they are or how to use them?

From aerospace to locksmiths; from power stations to the emergency services, industrial inspection systems are used on a daily basis to examine, identify and evaluate, often very inaccessible, objects.

Throughout our website you will find information and advice on what systems are available, how to chose the correct system for your application and much more.

What is Industrial Inspection?

Industrial inspection is, most generally, an organised examination or formal evaluation exercise. It involves the measurements, tests, and gauges applied to certain characteristics in regards to an object or activity.

The results are usually compared to specified requirements and standards for determining whether the item or activity is in line with these targets.

Inspections are usually non-destructive.

Non-Destructive Examination (NDE) or Non-Destructive Testing (NDT) describes a number of technologies used to analyse materials for either inherent flaws or damage from use.

Some common methods are Visual, Magnetic Particle, Radiography, Ultrasonic, Eddy Current, Acoustic Emission and Thermography.

During their service lives, many industrial components need regular non-destructive tests to detect damage that may be difficult or expensive to find by everyday methods. For example:

  • aircraft skins need regular checking to detect cracks;
  • automotive and aero engines need regular internal inspection to prevent or diagnose failure;
  • underground pipelines are subject to corrosion and stress corrosion cracking;
  • pipes in industrial plants may be subject to erosion and corrosion from the products they carry;
  • concrete structures may be weakened if the inner reinforcing steel is corroded;
  • pressure vessels may develop cracks in welds;
  • wire ropes in suspension bridges are subject to weather, vibration, and high loads, so testing for broken wires and other damage is important.


What are Endoscopes? Flexible or Rigid?


There are many different terms used to explain and describe types of Endoscopes. Here I will attempt to explain some of the differences and first off is the one of the most crucial things to understand is the difference between a flexible & rigid endoscope.


Rigid Endoscopes


All rigid endoscopes are a solid metal tube with a series of lens inserted in the tube. There are a few different methods for this, but the principle is the same. Light is delivered through the endoscope using fibre optic bundles around the outside of the lens housing. These endoscopes do not bend, but will give the user the highest resolution images.


Flexible Endoscopes


As the name suggests, you can bend these! The principle optical component is either a plastic or glass fibre bundle for delivery of the image, plus additional fibres for the light. These are still quite delicate and easy to break and quite expensive to repair. Many people mention seeing the honeycomb effect, yes that is normal as you can see through the fibre bundles, so you can see the fibre bundle itself. How defined that effect is depends on the type of fibre, the size of fibres and the volume of fibres used.

The better quality of fibre, smallest size and higher volume used will generate the best image. Cost is often a deciding factor in deciding!

One recent development is the use of fused quartz fibres to create a single large fibre that behaves as a flexible, but the image is closer to that of a rigid.


Glass Fiber Borescopes


When it comes to defects, out of sight can be out of mind. Many industries (including aerospace and automotive manufacturing) machine, weld, and cast parts with complex internal structures and surfaces that aren’t visible to the naked eye. The parts are often vital to performance and safety. Glass Fiber Borescopes are optical instruments that give you the inside view. They are first cousins to the medical endoscopes now used widely to view inside the human body for minimally invasive surgical or diagnostic procedures. Surgeons work while watching video images from an endoscope inserted in the patient’s abdomen or knee, just as inspectors examine cross holes in a machined part for burrs caused by drilling or cutting. Borescopes frequently form the front end of complete inspection systems, with powerful light sources, digital and video cameras, and laptop computers to store, print and e-mail images.

Advances in the optics and illumination of modern borescopes give bright, clear, crisp images that allow definitive decisions. Every borescope has an objective lens to form an image of the subject, relay optics to carry the image from end to end and an eyepiece lens to magnify the image for the viewer. Relay optics are most important to borescope image quality. Rigid borescopes use one of three technologies to relay images:

  • Achromatic doublets, which are cost effective in large-diameter borescopes.
  • Hopkins design relays, which give excellent quality for medium diameters but require precise grinding, polishing and centering of many tiny lenses and optical glass rods. (See figure 1.)
  • Gradient index lenses, which afford the best combination of quality and price for medium and small-diameter borescopes, because the relay optics are simple, chemically treated glass rods. One gradient index rod, for example, can replace 24 optical elements in a Hopkins design scope.


Choosing a borescope


In choosing a borescope, start by considering access to the area to be inspected. If the path is straight, use a rigid borescope; if it’s indirect or curved, choose a flexible borescope, which uses flexible optical glass fibers to relay the image. Videoscopes offer similar flexibility but house a very small CCD camera chip near the tip of the scope and relay the image electronically to a monitor rather than an eyepiece.

Both rigid and flexible borescopes use optical glass fibers, in a separate illumination channel, to bring light to the subject. A lightpost at the eyepiece end provides a standard plug-and-play interface for a wide variety of possible light sources, ranging from compact, battery-powered lights to powerful, line-powered metal halide arc lights.

For the best results, use the largest borescope that will fit the hole. Larger borescopes are sturdier and give brighter, sharper images. More illumination fibers carry more light, and the larger imaging optics also transmit more light and give crisper, better-quality images.

Direction of view is the next decision in buying a borescope. The most common direction is straight ahead (i.e., 0° to the borescope axis). Some rigid borescopes come with mirror tubes that slide over the borescope tube, placing a 45° mirror at the end of the scope to give a view perpendicular (90°) to the scope axis. This makes them essentially two borescopes in one.

Control of the direction of view is the most important issue, after diameter, when choosing a flexible borescope. The simplest flexible borescopes have a gooseneck sheath that allows you to set the shape before insertion. More expensive flexible borescopes have articulated tips, allowing you to control the direction of the tip back and forth in a single plane (two-way) or in two perpendicular planes (four-way), using levers on the borescope body. You can use the articulation to steer the scope to its destination, then look around.

Flexible borescopes allow the inspection of complex castings like engine blocks and turbochargers, tubes, pipes and turbine engines. The best flexible borescopes relay images through bundles of up to 25,000 optical glass fibers. The fibers are acid-leached to separate each fiber from its neighbors, reducing crosstalk between them and increasing contrast for whiter whites and blacker blacks. An impermeable plastic sheath prevents entry of fluids, such as fuel or oil. A tough, durable, woven tungsten wire sheath that reduces friction and protects the scope from damage by burrs and sharp edges surrounds and protects the plastic sheath.


Foundries that cast automotive engine blocks, turbochargers and exhaust manifolds find it very difficult to check for residual sand, blockages, flash or voids because the castings often have complex, inaccessible cavities and winding pathways. They use flexible borescopes that range in diameter from 0.100 in. (2.5 mm) up to 0.5 in. (12 mm). By controlling the articulated tip, they steer the borescope as it snakes through the part.


Safety in the balance


Hartzell Propeller, of Piqua, Ohio, has been manufacturing airplane propellers since 1917, when Orville Wright encouraged young Robert Hartzell to make propellers at his father’s sawmill. Today, Hartzell makes more than 300 different two- to six-blade propellers for everything from piston engines to large turboprops. The company even makes propellers for the Goodyear blimps. On airplane takeoff, propeller tips approach the speed of sound. Centrifugal forces of up to 20 tons try to pull each blade out of the hub. They must twist and flex, absorbing both the punishing vibrations of the engine’s power pulses and the oncoming air stream. It is imperative that propellers are balanced.

Each metal blade has a small-diameter axial bore of varying length to contain static balance weights. Hartzell “shot peens” the interior of this bore by spraying it with metal beads at high velocity, creating a compressive surface layer that improves fatigue strength. Hartzell then examines this bore with a 12 in. borescope, a 90° mirror tube and a video camera. A metal halide arc light provides intense illumination. The operator compares the part to an inspection standard, using an LCD display, to ensure that each bore receives proper coverage.

Prism borescopes

Some rigid borescopes have prisms built into their working ends. Prisms allow alternate directions of view, such as 30°, 70° and 90°, like a mirror tube. Because illumination and imaging are completely independent, prism borescopes are particularly well suited for maximum image clarity and contrast in inspecting large, dark cavities such as those found in diesel cylinders or tanks. Prism borescopes also give “right reading” images, making them easier and more intuitive to control. The prism can even pivot, in the aptly named swing prism borescopes, allowing the user to change the direction of view.


Prism design minimizes glare


A major defense contractor makes transmissions for armored vehicles. Machinists use gun drills to drill 16 in. long, 5/16 in. diameter holes in the aluminum housing for hydraulic fluid circulation. When a drill crosses an existing hole, it often forms a burr. Burrs can restrict or even block fluid flow or break loose and move to another part of the system, causing damage there. The company uses 0.157 in. (4.0 mm) diameter, 17 in. long borescopes with a prism to obtain a 90° direction of view. Video cameras attached to the scopes give clear, definitive views of the cross-holes on an LCD video monitor so inspectors spot burrs every time. Aluminum is highly reflective but the prism design minimizes glare, despite the use of the intense metal halide arc light. The company’s technicians have found that plastic bushings on the tube help center it in the hole, providing consistent, focused images.


Zero tolerance for burrs


Tell Tool Inc., of Westfield, Massachusetts, is a world-class manufacturer of precision machining for components in the aerospace industry, including fuel-control housings for helicopters, and military and commercial aircraft. Tell Tool drills more than 500 holes in the large, complex fuel-control housing, all of which cross other holes. Many holes are as small as 0.10 in. and may be 4 in., 6 in. or even 9 in. deep. Burrs can form where the holes intersect, and it’s critical to remove every one of them before assembly. Even a single loose burr could potentially shut down the engine, with disastrous consequences. Five Tell Tool technicians take three to four days to deburr 30 units by hand. Using 0.095 in. (2.4 mm) diameter precision borescopes, they examine every hole in every part. The video system provides comfortable viewing of highly magnified images from some borescopes, using the metal halide arc light for illumination. The technicians also use the borescopes for direct viewing, using a compact, portable light. After inspection, the technicians ultrasonically wash the part, flush it, dry it and then inspect it again. There is zero tolerance for burrs in this critical application.




Andrew Feist, an officer of the police department in Albuquerque, New Mexico, was shooting an urban rifle qualification with his LAR-15 rifle when a serious malfunction occurred. Feist, who is left-handed, was lucky to escape injury as hot gases blew out of the ejection port toward his face at high pressure and velocity.

Feist took the rifle to Michael Haag, a forensic scientist and firearm and tool mark examiner at the department’s crime lab. Haag used a 0.165 in. (4.2 mm), 17 in. borescope to examine the casing while it was still in place. Excessive pressure during extraction had caused the casing brass and primer to give way in the extractor area, where it was least supported. Inserted from the muzzle end, the borescope and 0.188 in. (4.8 mm) diameter, 90° mirror tube allowed Haag to see that the mouth of the casing had moved rearward slightly and begun to extract. This viewpoint and the critical information it showed, especially prior to movement of the bolt, could only be achieved with the 90° mirror tube. Looking straight ahead (0°) into the casing showed that brass had melted and molded to the breech face. Taking the path of least resistance, escaping gases blew out the receiver, dust cover and magazine, bent the extractor outward and even split the bolt carrier.

The Albuquerque police department was understandably concerned that there might have been a flaw in the ubiquitous and highly reliable LAR-15. Haag was quickly able to show that the problem originated in the casing. The ammunition company took full responsibility, replacing the weapon as well as the ammunition.




Modern borescopes give clear, unambiguous images that enable you to make confident quality decisions. By using borescopes with video or digital cameras, an image can be comfortably viewed at high magnification, shared with others and stored. Borescopes are powerful, and indeed essential, in many quality assurance procedures, yet are simple and intuitive to apply.


Industrial Inspection and Endoscope uses


Here is a Short List of Industrial Inspection and Endoscope uses:



Endoscopes & Related camera systems are very popular within the maintence sector of aviation. This can be for both engines and aircraft bodywork. There are also many specialised inspection systems developed for engine maintence.




This market covers applications for both manufacturing and maintence. Most engine manufacturers will carry out manual inspections with Borescopes, checking the drilled oil ways in cylinder heads and blocks.

Endoscopes are perfect for in-situ engine inspections as well, such as checking the combustions chambers via the injection or spark plug holes.

Manufacturing and maintence of gearboxes and axles are also target applications for endoscopes.




Wall cavity inspection is an application that is frequently mentioned. Checking for insulation and damp can be extremely cost & time effective. Any cavity within a building can be inspected with an Endoscope or Camera system.

There is also a demand for using borescopes in fiberglass insulation.

Organisations carrying out building or monument restorations are frequent Endoscope users.




Requirements are for checking all pipe work, air ducts & chimneys. This can be for both domestic and industrial buildings. The same applications exist for facilities management.




Larger Industrial buildings (hospitals for example), will have facilities teams constantly working to maintain that building. Often these organisations rent inspection equipment without realising they could probably buy the equipment for the cost of three inspections!




Applications are closely related to Automotive, machinery for all purposes has to be maintained. Larger camera equipment is often more suitable than regular Endoscopes, such as the SnakeEye system.




Another engineering cross over, similar to Automotive/aviation. Including the inspection of marine engines and hulls.



Internal structures are constantly inspected for damage. Larger camera systems are more frequently used.




Borescopes are very popular for inspecting the components to mix chemicals and the production of the finished pharmaceuticals. Quality has to be 100% are all times within the manufacturing process.




Borescopes used for cracking locks on doors and safes, all strictly legal of course!




Inspection of gun barrels during manufacturing or repair.




I have had experience of some unusual applications, such as long Flexible Endoscopes uses to study the nests of lizards and the insides of Beaver dams!




Camera systems such as the SnakeEye system are popular for track inspections. With the level of magnification provided, it is an ideal method to locate track damage.




Used for searching vehicles & buildings, illegal substances and people being the main target. Security surveillance also uses infrared camera systems.




Endoscopes & Cameras are used for Search & Rescue, often within collapsed buildings where space becomes an issue.


You may also like...