Remote Visual Inspection – Videsocopy
While vision may be the most acute of human senses, there is a limit to what our eyes can see. Unless a material is transparent like glass, we cannot see what lies behind it. In the field of nondestructive examination (NDE), there are situations where it is useful to look deep inside engines, gas turbines, machinery, behind walls, inside pipes and tanks, and into similar places where access is limited. Remote visual inspection (RVI) is a nondestructive technique that permits a user to visually inspect an area that has no direct visual access. In RVI, a slim and often flexible viewing device, commonly referred to as a “scope,” is inserted into the inspection area through a small opening providing an image for the operator to examine. Like all NDE tools, RVI allows an inspector to discover hidden defects before they cause major problems.
LED Lighting – Because the vast majority of RVI applications are done in areas where natural or ambient light is not present, most RVI setups include illumination systems to light up the area of inspection. Older systems would typically be AC powered and utilize high wattage bulbs to transmit light through fiber bundles into the area of interest to allow for visual inspection. With the incorporation of light-emitting diode (LED) technology, however, RVI systems have become less power hungry and been able to cut the cord. With the reduced power consumption of LEDs, current videoscopes are often battery powered and highly portable. In addition, new advances in technology allow the LEDs to be incorporated directly in the distal end of the insertion tube surrounding the CCD camera within. In the same way the image fiber bundle was eliminated via use of the CCD camera, the light guide cable can now also be removed, which increases the overall durability of the system. Furthermore, as the LED technology evolves and becomes brighter and more efficient, locating the LEDs within the tip permits upgrades in the field by swapping out a single interchangeable component.
Where Videoscopes Are Used – Important markets for RVI include the aerospace industry, power generation, pharmaceuticals, and petrochemical plants, as well as the automotive and manufacturing industries . The range of equipment spans from small-diameter borescopes used to pick locks to advanced videoscopes to inspect large turbine engines. For example, inspection of jet engines during periodic maintenance is a major application, permitting visual inspection of critical components with minimal teardown. RVI is also used for examining several other areas of aircraft where access is limited, such as flaps and rudder control mechanisms and airframes. Similarly, power generation turbines can be inspected for internal wear or other problems. In manufacturing, RVI can be used to inspect the inside of parts for hidden defects.