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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1994

Mirror Attachment For Borescope

Attachment for articulated borescope provides views into small, normally inaccessible spaces. Simple small round mirror on extension arm welded to borescope head. Tilted at angle to axis of borescope head, mirror provides views sideways to borescope head. Disassembly of turbopump blades not necessary to enable fluorescent-penetrant-dye inspection. Attachment used to inspect difficult-to-reach internal parts of other assemblies. Also used for inspection with ordinary white light.

Gearhart, John F.↗
NASA NTRS2001

Borescope Imaging System Developed for Luminescent Paint Measurements

The luminescent paint measurement technique utilizes a coating that is applied to a test article, allowing the air pressure or temperature of a surface to be measured. These coatings are commonly referred to as pressure- or temperature-sensitive paints. These paints are excited with short wavelength light and emit light at a longer wavelength. By measuring the change of intensity of the emitted light from a known reference condition, researchers can determine the pressure or temperature. The technique of measuring full-field surface pressure and temperatures using luminescent coatings has required a direct line-of-sight from the camera to the surface under study. In most experiments that have used pressure-or temperature-sensitive paints, the test surfaces are mounted so it is straightforward to position the camera and excitation source. In other cases, the luxury of having optical access through a window is not available or even possible. We developed a borescope imaging system to gain optical access in these confined areas. The commercially available 10-mm-diameter rigid borescope contains relay optics to transmit the detected light to a charge-coupled device (CCD) camera as well as an internal fiber-optic light guide to provide the excitation source for the luminescent coatings. The coupled light source can be continuous for the intensity method but also can be pulsed or have a variable intensity for a newer method of acquisition that measures the decay or phase lag of the emitted light. This type of borescope focuses the image directly on the CCD chip without using a fiber-optic relay, eliminating unwanted honeycomb patterns that are typical of fiber-optic type borescopes. This produces images of much higher clarity and uniformity, which are critical for acquiring accurate measurements from the luminescent coatings.

Bencic, Timothy J.↗
NASA NTRS1988

Support For Fragile Borescopes

Fixture supports thin borescopes during inspections through 0.0405-in. orifices. Porescopes, which have diameter of 0.037 in., extremely fragile and often fractured during inspections, contaminating inspected cavitites with debris. Nylon guide tip and acrylic support sleeve and body protect and guide a fragile borescope. Support sleeve press-fitted on body and removed when little clearance around orifice inspected. Otherwise, it helps to stablize fixture. Helps to prevent damage caused by vibrations and eliminates constantly moving view that afflicts unsupported small-diameter borescopes.

Brown, William S.↗
NASA NTRS1995

Flexible Borescope For Inspecting Ducts

Borescope and associated equipment developed specifically for use in optical inspection of inside of flexible joints in rocket-engine fuel duct. Apparatus includes assembly, characterized as "mouse/canoe," at sensing end of 10-ft borescope cable. Borescope tip rides in mouse/canoe. The mouse/canoe made laterally compressible, to facilitate movement past constrictions and provides fixed distance from inspection point permitting accurate description in duct inspected.

Shinozaki, Keith↗
NASA NTRS1987

Surgical Borescopes Remove Contaminants

Borescope instruments put to use in extracting hard-to-reach particles. Surgical instruments in flexible borescopes used for removing contaminant particles from normally inaccessible places within equipment. Instruments readily enter small openings, turn corners, and reach far.

Vallow, K.↗
NASA NTRS1990

Filter Enhances Fluorescent-Penetrant-Inspecting Borescope

Slip-on eyepiece for commercial ultraviolet-light borescope reduces both amount of short-wave ultraviolet light that reaches viewer's eye and apparent intensity of unwanted reflections of white light from surfaces undergoing inspection. Fits on stock eyepiece of borescope, which illuminates surface inspected with intense ultraviolet light. Surface, which is treated with fluorescent dye, emits bright-green visible light wherever dye penetrates - in cracks and voids. Eyepiece contains deep-yellow Wratten 15 (G) filter, which attenuates unwanted light strongly but passes yellow-green fluorescence so defects seen clearly.

Molina, Orlando G.↗
NASA NTRS1990

Combined Borescope And Flushing Wand

Proposed combination borescope/flushing wand lets operator locate contaminant particles in narrow, intricate internal passages and simultaneously remove them. Video monitor displays view of contamination in internal passage, while being flushed away. Operator sees immediately whether contamination removed. Plastic isolator protects borescope. For further protection and for reduction of blurring, borescope slightly recessed from tip of wand.

Trost, Mike J.↗
NASA NTRS1992

Noncontaminating Borescope Viewing Fixture

All-stainless-steel viewing fixture for borescope used without fear of breakage or contaminating internal cavities of equipment. Fixture fits over conventional viewing head on borescope. Used for internal inspections by visible illumination or visible fluorescence from ultraviolet illumination.

Molina, Orlando G.↗
NASA NTRS2003

Design of a Borescope for Extravehicular Non-Destructive Applications

Anomalies such as corrosion, structural damage, misalignment, cracking, stress fiactures, pitting, or wear can be detected and monitored by the aid of a borescope. A borescope requires a source of light for proper operation. Today s current lighting technology market consists of incandescent lamps, fluorescent lamps and other types of electric arc and electric discharge vapor lamp. Recent advances in LED technology have made LEDs viable for a number of applications, including vehicle stoplights, traffic lights, machine-vision-inspection, illumination, and street signs. LEDs promise significant reduction in power consumption compared to other sources of light. This project focused on comparing images taken by the Olympus IPLEX, using two different light sources. One of the sources is the 50-W internal metal halide lamp and the other is a 1 W LED placed at the tip of the insertion tube. Images acquired using these two light sources were quantitatively compared using their histogram, intensity profile along a line segment, and edge detection. Also, images were qualitatively compared using image registration and transformation [l]. The gray-level histogram, edge detection, image profile and image registration do not offer conclusive results. The LED light source, however, produces good images for visual inspection by an operator. Analysis using pattern recognition using Eigenfaces and Gaussian Pyramid in face recognition may be more useful.

Bachnak, Rafic↗
NASA NTRS1989

Borescope Inspects With Visible Or Ultraviolet Light

Quartz optical fibers improve performance at ultraviolet wavelengths. Borescope used to inspect interior of small-diameter tubing by visible light and ultraviolet light. Employs quartz fibers to conduct ultraviolet light and visible light with high efficiency.

Molina, Orlando G.↗
NASA NTRS1990

Borescope Device Takes Impressions In Ducts

Maneuverable device built around borescope equipped to make impression molds of welded joints in interior surfaces of ducts. Molds then examined to determine degress of mismatch in welds. Inserted in duct, and color-coded handles on ends of cables used to articulate head to maneuver around corners. Use of device fairly easy and requires little training.

Walter, Richard F.↗
NASA NTRS1990

Borescope With Large Depth Of Focus

Modification of commercial borescope yields clear, glare-free images of defects on inside of tube. Used to examine diverging wall of tube. Wall illuminated by light from fiber distinct from fused-fiber cable used for viewing. Viewing cable holds right-angle mirror at tip so it can look sideways. Image appears, magnified, on monitor. Instrument offers large depth of focus and therefore used in tubes of varying inside diameter.

Guirguis, Kamal S.↗
NASA NTRS1990

Borescope Aids Welding In Confined Spaces

Welding torch holds video borescope to give operator view of workpiece in enclosed space. Operator sees clear, magnified image on video monitor and manipulates torch accordingly, despite visual obstruction presented by enclosure. Tinted shield tilted up while torch being positioned, then down to block excess light during welding. Reduces welding time by 50 percent, and increases quality of weld substantially.

Carrasco, Eddie↗
NASA NTRS1996

Small, Lightweight Inspection Robot With 12 Degrees Of Freedom

Small serpentine robot weighs only 6 lbs. and has link diameter of 1.5 in. Designed to perform inspections. Multiple degrees of freedom enables it to reach around obstacles and through small openings into simple or complexly shaped confined spaces to positions where difficult or impossible to perform inspections by other means. Fiber-optic borescope incorporated into robot arm, with inspection tip of borescope located at tip of arm. Borescope both conveys light along robot arm to illuminate scene inspected at tip and conveys image of scene back along robot arm to external imaging equipment.

Lee, Thomas S.↗
NASA NTRS1973

A high-speed photographic system for flow visualization in a steam turbine

A photographic system was designed to visualize the moisture flow in a steam turbine. Good performance of the system was verified using dry turbine mockups in which an aerosol spray simulated, in a rough way, the moisture flow in the turbine. Borescopes and fiber-optic light tubes were selected as the general instrumentation approach. High speed motion-picture photographs of the liquid flow over the stator blade surfaces were taken using stroboscopic lighting. Good visualization of the liquid flow was obtained. Still photographs of drops in flight were made using short duration flash sources. Drops with diameters as small as 30 micrometers (0.0012 in.) could be resolved. In addition, motion pictures of a spray of water simulating the spray off the rotor blades and shrouds were taken at normal framing rates. Specially constructed light tubes containing small tungsten-halogen lamps were used. Sixteen millimeter photography was used in all cases. Two potential problems resulting from the two-phase turbine flow (attenuation and scattering of light by the fog present and liquid accumulation on the borescope mirrors) were taken into account in the photographic system design but not evaluated experimentally.

Barna, G. J.↗
NASA NTRS1988

Sizing Dye-Penetrant Indications Of Defects

Sizes of cracks and holes viewed through borescope measured. Reference chart makes it possible to estimate sizes of borescope-observed defects on inner walls of tubes or otherwise hidden. Used both for round defects like pits or pores and for elongated ones like cracks.

Molina, Orlando G.↗
NASA NTRS2001

Environmentally Compatible Vapor-Phase Corrosion Inhibitor for Space Shuttle Hardware

USA-SRB Element is responsible for the assembly and refurbishment of the non-motor components of the SRB as part of Space Shuttle. Thrust Vector Control (TVC) frames structurally support components of the TVC system located in the aft skirt of the SRB. TVC frames are exposed to the seacoast environment after refurbishment and, also, to seawater immersion after splashdown, and during tow-back to CCAFS-Hangar AF refurbishment facilities. During refurbishment operations it was found that numerous TVC frames were experiencing internal corrosion and coating failures, both from salt air and seawater intrusions. Inspectors using borescopes would visually examine the internal cavities of the complicated aluminum alloy welded tubular structure. It was very difficult for inspectors to examine cavity corners and tubing intersections and particularly, to determine the extent of the corrosion and coating anomalies. Physical access to TVC frame internal cavities for corrosion removal and coating repair was virtually impossible, and an improved method using a Liquid (water based) Vapor-phase Corrosion Inhibitor (LVCI) for preventing initiation of new corrosion, and mitigating and/or stopping existing corrosion growth was recommended in lieu of hazardous paint solvents and high VOC/solvent based corrosion inhibitors. In addition, the borescopic inspection method used to detect corrosion, and/or coating anomalies had severe limitations because of part geometry, and an improved non-destructive inspection (NDI) method using Neutron Radiography (N-Ray) was also recommended.

Novak, Howard L.↗
NASA NTRS2002

Environmentally Compatible Vapor-Phase Corrosion Inhibitor for Space Shuttle Hardware

USA-SRB Element is responsible for the assembly and refurbishment of the non-motor components of the SRB as part of Space Shuttle. Thrust Vector Control (TVC) frames structurally support components of the TVC system located in the aft skirt of the SRB (Solid Rocket Booster). TVC frames are exposed to the seacoast environment after refurbishment and, also, to seawater immersion after splashdown, and during tow-back to CCAFS-Hangar AF refurbishment facilities. During refurbishment operations it was found that numerous TVC frames were experiencing internal corrosion and coating failures, both from salt air and seawater intrusions. Inspectors using borescopes would visually examine the internal cavities of the complicated aluminum alloy welded tubular structure. It was very difficult for inspectors to examine cavity corners and tubing intersections and particularly. to determine the extent of the corrosion and coating anomalies. Physical access to TVC frame internal cavities for corrosion removal and coating repair was virtually impossible, and an improved method using a Liquid (water based) Vapor-phase Corrosion Inhibitor (LVCI) for preventing initiation of new corrosion, and mitigating and/or stopping existing corrosion growth was recommended in lieu of hazardous paint solvents and high VOC/solvent based corrosion inhibitors. In addition, the borescopic inspection method used to detect corrosion, and/or coating anomalies had severe limitations because of part geometry, and an improved non-destructive inspection (NDI) method using Neutron Radiography (N-Ray) was also recommended.

Novak, Howard L.↗