How Does A Borescope Work?
Understanding what borescope inspection is
a borescope inspection is an investigative procedure employing a borescope—a specialized tool featuring a flexible or rigid tube equipped with a camera and light at one end. this device transmits images back to an operator, allowing for a close-up view of spaces that would otherwise be inaccessible.
used extensively for the internal inspection of engines, pipes, and complex machinery, borescopes can inspect for defects such as corrosion, blockages, and weld integrity without dismantling the entire system.
How does a borescope work?
borescopes consist of an insertion tube with a lens and lighting at the tip, connected to an eyepiece or display. they transmit images or video from the tip back to the viewer, enabling remote inspection.
a borescope works by combining several key technologies. the basic principle is simple – light goes in, images come out. but the engineering behind it is pretty clever.
The core components that make it happen
Light source technology
the led lights at the tip do the heavy lifting here. without proper illumination, you’d just be staring into darkness. modern borescopes use high-intensity leds that can adjust brightness levels.
most professionals prefer units with at least 6 led lights arranged around the camera lens. this setup eliminates shadows and provides even lighting across the inspection area.
boroscopes the light is transmitted through fiber optic fibers and in most cases is a lower quality fiberoptic bundle in that it only has to transmit light and not an image. the fiberscopes rely on an external light source whether it is halogen or led.
the light source will have a screw on connector at the base of the fiberscopes and the light source is adjustable so that you can regulated the light output for your specific inspection.
videoscopes can also utilize the fiberoptic bundle to product light out the tip of the insertion probe however, most all of the portable videoscopes utilize led lighting as it can be installed within the videoscope itself and not require to be tethered to an external light source.
some videoscopes will be designed and built with led lighting at the tip with small led diodes. this led lighting on videoscopes is adjustable as well.
the main purpose to having adjustable lighting is that there are some inspections that too much lighting can adversely affect the image and viewing of the inspection area such as stainless steel or other illuminating or reflective surfaces.
you therefore need the ability to regulated the amount of light that is being introduced to the borescope inspection area.
Image capture system
the tiny camera sensor sits right behind the lens assembly. it’s usually a cmos sensor that converts light into electrical signals. these signals get processed and transmitted back through the cable to your display.
of course, a true videoscope will have an image sensor at the tip which is a big word for micro camera. the technology off the videoscope utilizes the micro camera at the tip which communicates through a ribbon of connections to the color monitor.
Flexible cable assembly
this is where the magic really happens. the flexible endoscope cable contains multiple components:
the semi-rigid cable design allows the borescope to maintain its shape while still being flexible enough to navigate tight spaces.
What are the integral components of borescope?
a standard borescope is made up of:
4mm fiberscope with 10,000 individual fiber optics will not produce the same image quality as a system with 20,000 fiber optic fibers, even though they have the same outside diameter.
fiborscope you will have to utilize an usb camera with a c-mount adapter to capture images. your computer will become the device to view the images as well as capture videos and still images. conversely, a videoscope will have on board capabilities to capture images and video of the inspection area.
How is a videoscope pieced together?
videoscope probe is designed very similar to the fiberscope construction. the main difference is that the micro camera or image sensor at the tip offers a communication ribbon that runs from the tip of the probe and throughout the insertion tube up into the monitor or control station.’
videoscopes that offer a larger led light source in the body of the control station will have fiberoptic fibers running down the full length of the probe out to the distal tip to provide lighting.
other videoscopes will offer mini-led lights at the tip of the probe any typically are installed around the outside diameter of the image sensor to provide unified lighting.
a major difference in the articulation or deflection of the videoscope when compared to the traditional fiberscopes is that joystick articulation is now the choice of inspection professionals.
the joystick articulation provides all way or 360 degrees of articulation and is most commonly performed with a joystick similar to a computer game controller.
some videoscope systems offer direct cable guided joystick articulation and some of the more advanced (and expensive) videoscope systems are offering an electronically assisted articulation.
while the electronically assisted articulation sounds like it’s the ‘latest and greatest’ and sought offer technology, many users prefer the direct cable guided articulation as the inspection professional can ‘feel’ when there is resistance inside the inspection area.
this is important because one of the most common reasons to have a borescope repair is the loss of articulation in one or more directions.
the last couple of inches of the borescope probe called the ‘bending section’ is a very precise design allows the probe tip to be manipulated.
the borescope bending section is a stainless steel almost armadillo like look that allows the probe to be flexed without loosing the form diameter of the probe.
the bending section varies in diameter as well as length.
typically, the larger diameter borescope will offer a larger bending section as well as impact the borescope bending radius.
the bending radius refers to the total length or width of space that is required to complete the manipulation of the borescope tip to 90 degrees.
Different types and how they function
Rigid borescopes
these borescopes are straight and can’t bend. they’re best for inspecting areas that you can see directly. their main benefit is that they give very clear images, which is great for finding small cracks or other tiny problems. however, they can’t bend to look around corners, so they’re not good for inspecting twisty areas.
these work like a periscope. light travels through a series of lenses and prisms to relay the image. they’re incredibly durable but limited in terms of maneuverability.
Flexible borescopes
also called fiberscopes, these borescopes are bendy. they use fiber optics to light up dark or hidden areas. their flexibility is useful for checking out curved or complex spaces. while they don’t show as clear images as rigid borescopes, they’re really handy for reaching places the other types can’t, making them valuable in many industries, like aerospace.
Video borescopes
video borescopes combine features of both rigid and flexible types. they have a camera (ccd or cmos) on a flexible shaft and can show high-quality video or still images on a screen. they can also save these images for later. many of these borescopes have extra features like measuring defects, changing the light level, or even 3d imaging.
these use digital technology. the camera sensor sits at the tip, and electrical signals carry the image back through the cable. way more versatile than rigid models.
Semi-rigid borescopes
these are a mix of rigid and flexible borescopes. they can bend a little and keep their shape during inspection. this is useful in situations where you need some bending ability but also want clear images.
Articulating automotive borescope models
these have controllable tips that can bend and rotate. tiny cables inside the main cable connect to the tip mechanism. when you move the joystick, it pulls these cables to articulate the tip.
What is the working principle of video borescope?
video borescopes are optical endoscopes. they are used to inspect areas where a person would not reach due to safety or physical limitations. these scopes come in two basic types, analog and digital.
analog is much more common and uses fiber optics, whereas digital does not use fiber optics but still produces a high-quality image by using charge-coupled device (ccd) sensors.
video has many useful benefits over traditional light-based imaging methods, such as higher resolution, longer working distance, and a wider field of view.
digital cameras can easily store their data, so they can be connected to a pc to view images at any time and do not require constant handling like film cameras do. this is an overview of the borescope working principle.
Fiber optic borescope
this type of scope comes with an image sensor, a light source, and optical fibers. light travels through these fibers to take images and send them back to you in real-time.
the cables are flexible and lightweight, which means that there’s no risk of damaging whatever you’re looking at. however, they need electricity to work, so they aren’t very portable.
Video borescope
a video borescope is a camera attached to a fiber optic cable. the fiber optic cable allows images to be transmitted back and forth with minimal image loss, even when long distances are involved.
these scopes are used when you want or need to look at things that can’t be accessed directly. if your question pertains to inspecting an engine or boiler, for example, you’ll need a video borescope.
a great benefit of video scopes is that they can send pictures back and forth that can be recorded. avi files for later review or sharing purposes.
depending on the functionality you are looking for, you can have the following features as a plus on your borescope for digital connectivity.
The inspection process step by step
Setup phase
first, you need to identify the access point. most automotive applications use existing ports like spark plug holes or drain plugs. the small diameter borescope works perfect for these tight spaces.
the appropriate type of borescope is chosen based on the inspection requirements, and the equipment is prepared, including camera adjustments and calibration if necessary.
Insertion and navigation
you feed the cable through the access point slowly. the real-time video feed helps you navigate around obstacles. good borescopes have depth markings on the cable so you know how far you’ve gone.
an entry point into the component is accessed, which may involve removing covers or panels or using existing openings like spark plug holes or inspection ports. the borescope is carefully inserted and navigated through the structure.
for flexible or video borescopes, this involves bending and rotating the scope to ensure a comprehensive view of the area.
Image capture and analysis
modern units let you capture still images and record video. the small inspection camera technology has gotten so good that you can spot hairline cracks and minor wear patterns.
as the camera relays images back to the monitor, the inspector scrutinizes the visuals for any irregularities, such as cracks, corrosion, abrasions, or misalignments.
any notable findings are documented. with video borescopes, capturing high-resolution images or video recordings for further analysis is possible.
the collected data is analyzed to understand the severity of any detected issues and determine the necessary corrective actions.
a detailed report is generated, often including visual evidence. this serves as a basis for maintenance decisions.
Image quality
how is the image quality in a borescope determined?
image quality depends on factors like resolution, lighting, lens quality, and the camera if it’s a video borescope.
can a borescope be used for both visual inspections and video recording?
yes, many modern borescopes offer both real-time visual inspection and video recording capabilities.
what are the typical diameters of borescope insertion tubes?
insertion tube diameters can range from a few millimeters to several centimeters, depending on the borescope’s purpose and design.
