Test & Measurement

A Portable, Projection Focusing Schlieren System

Heating, ventilation, and air conditioning systems can be monitored using this system, especially those used in commercial kitchens and industrial ventilation. John H. Glenn Research Center, Cleveland, Ohio A new type of projection schlieren camera system (schlierenscope) is more portable, easier to align, and more versatile than existing systems. The schlierenscope is a projection focusing schlieren camera system that can acquire images of shock waves, vortices, gas jets, and other disturbances that create gradients in the refractive index of a transparent medium. These gradients appear as streaks (called schlieren in German) in the resulting image. Thus, a schlierenscope is an apparatus for looking at disturbances in transparent media. The schlierenscope constructed in the project utilizes fast strobes that freeze motion and capture images with a scientific CCD (charge-coupled device) camera. The schlierenscope is unique among schlieren instruments because all of the critical controls are contained within the instrument housing.

Posted in: Briefs, TSP, Test & Measurement, Imaging and visualization


Cryogenic and Non-Cryogenic Optical Liquid Level Instrument for Stratified Conditions

Marshall Space Flight Center, Alabama Typical cryogenic tank metering systems use a series of thermocouple, RTD, or other temperature or resistive devices in a rake or array configurations. Since these operate using the thermal change between the liquid and gas fluid phases, they are limited by thermal latency (the time it takes the sensing element to respond to the temperature). In addition, cryogenic fluids often create a volatile boundary or sloshing layer. This layer causes uncertainties of the true fluid boundary in a tank. Finally, accuracy and resolution are determined by the number of sensing segments used. These are typically tied to individual data channels, which puts a strain on data acquisition systems to achieve continuous and high-accuracy values.

Posted in: Briefs, Test & Measurement, Test equipment and instrumentation


Low-Pressure Ion Chromatography for Planetary Exploration

NASA’s Jet Propulsion Laboratory, Pasadena, California Ion chromatography is the state-of-the-art technique for anion separation and analysis on Earth, but it typically requires a large, powerful pump to operate at high pressures in order to speed up analysis time. The weight and power requirements of the pump interfere with creating an ideal instrument for flight. The solution is to run the ion chromatography system at low pressure to allow the use of a smaller, lower-power pump for flight, but at the expense of longer analysis time.

Posted in: Briefs, Test & Measurement, Parts, Test equipment and instrumentation


Universal Mechanical Testers for Tribology Testing in the Automotive Industry

Universal mechanical testers provide tribology testing for friction, wear, coatings, and lubrication in macro, micro, and nano regimes. Very few industries are as affected by strict test standards as the automotive sector. Nearly every automobile component (engine parts, accelerators, clutches, brakes, tires, seatbelts, etc.) must exhibit adequate tribological properties in accordance with ASTM, DIN, JIS, ISO, and other comprehensive international standards. Universal mechanical testers (UMTs) that are able to perform multiple tests in a single platform with interchangeable modules can help manufacturers meet test specifications quickly and economically. For example, crankshafts and camshafts have critical requirements for proper functioning under diverse service conditions. Tests include evaluation of base materials, heat-treated parts, surface coatings, and lubricants. Tests can be run with diverse loads, velocities, and temperatures that simulate actual service conditions using various lubricants and liquids.

Posted in: Briefs, Mechanical Components, Mechanics, Test & Measurement, Lubricants, Coatings, colorants, and finishes, Tribology, Wear, Test equipment and instrumentation, Test procedures


Photogrammetric Recession Measurement

This method can be used to measure the recession of ablative materials in insulation coatings, ceramics and composites, arc-jet systems, and soil erosion.The testing of materials that ablate as a design function requires detailed time history of the ablation process. The rate at which the surface recedes during testing is a critically important measure of the performance of thermal protection system (TPS) materials like heat shields for aerospace vehicles. Photogrammetric recession measurement (PRM) meets these needs by recording the surface of the ablating model during heating in hyperthermal test facilities (arc-jets), using two high-resolution digital cameras capable of recording simultaneously. The cameras are calibrated to yield three-dimensional object space measurement for each stereo pair of images, producing surface recession data over the portion of the model for which both cameras share a view.

Posted in: Briefs, Physical Sciences, Test & Measurement, Failure modes and effects analysis, Optics, Protective structures, Thermal testing


Tissue-Equivalent Radiation Dosimeteron-a-Chip with Plastic Scintillation Material

This innovation uses solid-state technology to create a compact, lightweight, personal space radiation monitor.The complexity of spaceflight design requires reliable, fault-tolerant equipment capable of providing real-time dosimetry during a mission, which is not feasible with existing thermoluminescent dosimeter (TLD) technology. Real-time monitoring is important for low-Earth-orbiting spacecraft and interplanetary spaceflight to alert the crew when solar particle events (SPE) increase the particle flux of the spacecraft environment. In this innovation, the personal dosimeter is comprised of a tissue-equivalent scintillator coupled to a solid-state photomultiplier.

Posted in: Briefs, Physical Sciences, Test & Measurement, Plastics, Test equipment and instrumentation, Spacecraft


Measurement of Cryogenic Fluid Level with Laser Propagation and Surface Floor Reflection

The current float sensing system can be augmented with this new development.The risks associated with introducing new hardware and methods into an operational environment have in part prohibited cryogen level measurement technology from advancing. In prior art, measurements have been made with invasive probes immersed in the cryogenic fluid. Implementing this approach would require physical retrofitting, as well as requiring the measuring instrument to make contact with the harsh cryogen fluid environment. However, an externally mounted optical measurement system would mitigate these concerns. Therefore, an optical approach was developed that uses and augments existing validated technology in a manner that does not interfere with the current infrastructure.

Posted in: Briefs, Physical Sciences, Test & Measurement, Optics, Test equipment and instrumentation


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