Remote Visual Inspection (RVI) equipment such as videoscopes, video borescopes, pipe inspection cameras and remotely operated vehicles (ROV) can be used for a variety of inspection requirements during outages at Nuclear Power Plants. Here are some examples of inspections that can be performed remotely using videoscopes, video borescopes, ROV's and pipe inspection cameras. Foreign Object Search and Retrieval is another common function performed during outages.

Foreign Object Retrieval or Foreign Material Exclusion (FME) utilizes equipment such as videoscopes, video borescopes, pipe inspection cameras and a range of foreign object retriaval tools to locate and remove items from plant system. Foreign Objects, loose parts and other material may become trapped inside piping, turbines, cavities, fuel pool and other difficult to reach areas. Areas that are common to remotely inspect during a plant outage ate Boiling water reactors include: Continue reading →

Many remote visual inspection users rely on rental borescopes to meet their periodic inspection applications. They are faced with choosing from a variety of suppliers and equipment for the best remote visual inspection equipment to use for their inspection. Typically, the most important criteria to consider are the length and diameter of the borescope or videoscope equipment to be rented. Then consider other requirements such as the need to manipulate or articulate the end of the videoscope, direction of view and image capture capability.

To determine the most appropriate length borescope rental you need for your inspection is a fairly simple process:

1. Determine what the distance the working length of the borescope rental will need to travel to reach the target inspection area.
2. Consider the access area and keep in mind any external components that will keep the borescope at a distance from the inspection access.
3. Can the area that needs to be inspected be access from several locations?

The best choice is to select the shortest borescope rental equipment possible. This allows for greatest light transmission to the target and therefore the best possible borescope rental image. Just as important a shorter scope is the easiest is the easiest to use. Remember that any unused length of borescope rental equipment not only costs more but will be coiled at your feet or protruding from the inspection area and far more susceptible to damage.

Beware misdirected advice that recommends the longest length borescope as a rule of thumb. Chances are they have never conducted a field inspection with a borescope and have only sold them over the telephone.

To determine the most appropriate Diameter borescope rental you need for your inspection is also simple to determine:

1. Determine what the opening of the initial access to the target inspection area.
2. Consider the internal diameters and how they will affect the ability of the borescope rental equipment to reach the inspection area.
3. Consider the number of twists and turns such as 90 degree bends. These will affect the ability of the borescope or videoscope to reach the target area and the instrument ability to articulate the distal end.

The best choice is to select the largest diameter borescope rental equipment possible. This provides maximum light output, durability, ease of use and image quality.

Other considerations to select the best possible borescope or videoscope rental equipment include:

• What direction will you need to view with your borescope? Will you need to look straight or to the side? Different side view and forward view objectives are available to best suite your requirements.
• Does your inspection allow for straight in access or will you need to bend around corners? A flexible fiberscope or videoscope will be needed if straight access is not achievable.
• Define the area being inspected and what you expect the environment to be like when where you want to view. Will you have enough light at a given distance? Will the light reflect internally (polished metal surface) or will it be absorbed (combustion chambers and large vessels). Will you be close enough for proper magnification or far enough away for overall viewing?
• Define how close the scope tip will be from the area of interest. The closer you are, the increased magnification you achieve. The depth of field of most borescopes is huge compared to many other lens systems. Most scopes stay in focus without adjustment from a couple millimeters from the tip all the way to infinity. The common working range is within 1-2mm from the tip to approx. 5"-6" away.
• Will the remote visual inspection results need permanent documentation from digital still images or video? Ensure that the borescope or videoscope that you rent has the borescope recoding options you need for your inspection.
• Special considerations for a borescope rental may include high temperature applications, water proof requirements and contamination from chemicals and radiation.

Videoscopes or Video Borescopes have many features available that need to be understood when selecting remote visual inspection equipment. Manufacturers of videoscopes and video borescopes have added more and more features over the years that have contributed to a phenomenon know as "feature creep." These unnecessary features have only driven up the cost of equipment and added little or no real value. Most remote visual inspection applications only require certain basic features to to be successfully inspected.

Many are surprised to learn that the CCD that produces a videoscope image are identical regardless of manufacturer. Olympus, General Electric, IT Concepts, Karl Storz and others all used the same CCD manufactured by Sony. The Light Sources also are typically identical across manufacturers as well as the material the videoscope's flexible insertion tube is made of.

In order to differentiate themselves manufacturers have added a dizzying array of features that have only served to make videoscopes or video borescopes difficult to use and expensive. When looking for a videoscope end users need to determine which features are absolutely necessary. To help keep the cost of equipment down and the equipment easy to operate, some basic features are all that 95% of inspections need.

Basic Videoscope Features:

• Articulation. This may be described as "all-way" or "4-way." Articulation is simply the ability of a videoscope to manipulate the tip of the scope at the bending neck. Today most videoscopes 25 feet (7.5 Meters) and shorter have the ability to articulate.
• Tungsten Braided Sheath. Videoscopes are typically used in demanding and harsh industrial environments. A videoscope needs to be constructed of material that will stand up to tough industrial conditions. Professional grade or industrial videoscopes can be distinguished by a tungsten braided sheath for durability. Consumer grade videoscopes with typically have stainless steel or PVC insertions tube.
• Powerful Light Source. A videoscope designed to remotely inspect the interior of gas turbines, heat exchangers, boiler tubes and industrial machinery require powerful light to illuminate these dark areas. Today, most industrial videoscopes use brilliant HID light sources or high output LEDs. Beware an industrial videoscope that utilizes a halogen, xenon or low output LED light sources.
• Digital Image Capture. With all the features that have been added to videoscopes over the years it is difficult to believe that the purpose of remote visual inspection is to view and capture images of the item being inspected. The majority of inspections will require an image to be saved as a record of the condition of the inspected area. Typically, These images will be in .jpeg or .BMP format to be saved on a PC or included in a report.
• Text Annotation. The ability to annotate an inspection location, serial number or condition is very helpful when recalling videoscope inspections for evaluation and determining corrective action.

Keeping the features of a videoscope or video borescope simple is the best way to keep cost low and remote visual inspection equipment user friendly.

Micro borescopes are typically used to remotely inspect the smallest application. Some remote visual inspection applications require access through tiny holes that are less than 2.0 mm (0.078 in). A micro borescope or mini borescope may be semi-flexible or rigid. Typically these small borescopes are limited in length and direction of view is 0° forward with the option for side view mirror sleeves.

These small inspection areas provide remote visual inspection professionals with many challenges. The access dictates the inspection requirements more than any other factor. The smaller the inspection area the more limited the choice of micro borescopes available and the number of manufacturers of these mini borescopes.  Finally, Due to the nature of a micro borescope, it is more susceptible to damage. Users need to be aware of the limitations of smaller diameter borescopes and fiberscopes and work within these.

Applications for Micro Borescopes:

• Engineering & Manufacturing. Micro Borescopes provide cost-effective examination of internal structures without tear down. A micro borescope allows engineers to check for pitting, cracking, corrosion, erosion, weld and other defects.

• Quality Control. Micro Borescope instruments allow manufactures to inspect components for defects. Mini borescopes provide the ability to inspect internal components, bore holes, castings and other manufactured items such as turbine blades, automotive components, circuit boards, rifle barrels and welds.

• Castings. Micro Borescopes can be used to inspect inside casting of engine blocks and other high quality casted components. Micro Borescope instruments as small as 0.5 mm in diameter and larger are offered to accommodate all casting inspection needs.