Tech Briefs

Sensors & Test

Access our comprehensive library of technical briefs on sensors and test, from engineering experts at NASA and government, university, and commercial laboratories.

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Briefs: Test & Measurement
Fiber-Optic Sensors for Measuring Oxygen Dissolved in Water
Fiber-optic sensors for measuring concentrations of oxygen dissolved in water are undergoing development. In comparison with electrochemical dissolved-oxygen sensors, the fiber-optic sensors are expected to be easier to use and maintain. Also, unlike electrochemical dissolved-oxygen...
Briefs: Test & Measurement
An apparatus measures small concentrations of H2, O2, and H2O in flowing He gas. In the original application for which the apparatus was developed, the flow of He gas is used to purge a...
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Briefs: Test & Measurement
A compact, portable, mid-infrared, laser-based instrument that operates at room temperature has been developed for use in detecting trace concentrations of CO or any of several other...
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Briefs: Test & Measurement
Personal Cabin Pressure Alarm
Compact instruments, similar in appearance to common personal pagers, have been proposed for warning aircraft crewmembers that cabin air pressure has decreased to a potentially dangerous level. An instrument of this type, called a "personal cabin pressure monitor and warning system" (PCPMWS), implements a warning...
Briefs: Test & Measurement
An algorithm has been devised to greatly simplify and improve the calibration and the reduction of systematic noise of an imaging interferometer or other similar interferometric instrument....
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Briefs: Test & Measurement
A miniature birefringence-measuring system has been developed for use in investigating extensional flows of non-Newtonian polymers in microgravity. The system could also be used on Earth to perform...
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Briefs: Test & Measurement
The development of miniature, cold- gas thrusters for on-orbit propulsion of such small devices as remotely piloted cameras and for inclusion in astronaut propulsion backpacks gave rise to a need to measure...
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Briefs: Test & Measurement
Software for Designing Model Rockets for Base-Heating Tests
The Impulse Combustion Excel (ICE) computer program was developed to facilitate and accelerate the design and analysis of subscale rocket engines for use in base-heating tests. Such tests are performed on the ground to obtain data for estimating the heating effects of hot exhaust plumes on...
Briefs: Test & Measurement
Efforts are under way to develop a technique of noncontact acousto-ultrasonic testing in which (1) a pulsed laser beam excites ultrasonic waves in a plate specimen and (2) the ultrasonic...
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Briefs: Test & Measurement
An apparatus based on line-of-sight resonant absorption of ultraviolet light yields measurement data from which one can calculate the concentrations of nitric oxide (NO) and of hydroxyl...
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Briefs: Test & Measurement
The Gyroscope Automated Testbed is a computer-controlled apparatus designed primarily for automated testing of vibratory gyroscopes. It can also be used to test other devices: By changing...
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Briefs: Test & Measurement
Electromechanical Testing of Microelectromechanical Devices
A method of electromechanical testing has been proposed for general diagnosis, evaluation of performance, and burn-in (accelerated life testing) of microelectromechanical devices. The tests would ordinarily be performed at the wafer level; that is, after the devices have been fabricated on...
Briefs: Test & Measurement
The figure illustrates a simple mechanism designed for anchoring one end of a cable on a structure and for adjusting the tension in the cable. Unlike turnbuckles and other conventional...
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Briefs: Test & Measurement
A lightweight, low-power-consumption power supply has been developed to generate a combination of radio-frequency (RF) and dc voltages needed for the operation of a miniature quadrupole...
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Briefs: Sensors/Data Acquisition
Electrobiotic sensors have been proposed for detecting toxic substances in a variety of environments. Electrobiotic sensors would be inexpensive, compact units that would be easy to use and could be deployed...
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Briefs: Test & Measurement
Laser Heating for Testing Rocket-Engine Insulating Phenolic
A continuous-wave CO2 laser has been selected as a source of heat for testing the thermal response of carbon-cloth phenolic like that used as insulating material in a reusable solid-fuel rocket motor (RSRM). The particular thermal response of interest, observed during operation of an RSRM,...
Briefs: Test & Measurement
An optoelectronic instrument, known as a plant fluorescence sensor, is being developed for use as a working tool in agricultural settings. This instrument is a remote, passive monitor...
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Briefs: Test & Measurement
Improved Electrical-Impedance Body-Fluids Monitor
The Johnson Space Center (JSC) body-fluids monitor advances the state of the art of measuring hydration levels in humans during spaceflight. Neither bulky nor heavy, this noninvasive instrument is built around a commercial inductance-capacitance-resistance meter, which is used to obtain...
Briefs: Test & Measurement
Software for Testing Access List Integrity
Many networks rely on firewalls or filtering routers for frontline network security. Packet filtering firewalls or routers filter incoming or outgoing packets based on a set of access rules. The IP (Internet Protocol) Packet Generator computer program assists in verifying that a packet filtering firewall...
Briefs: Sensors/Data Acquisition
Improved miniature biotelemetric units resembling large pills have been proposed for use in physiological monitoring of the gastrointestinal tract. The broad principles of design, operation,...
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Briefs: Robotics, Automation & Control
A six-legged robot resembling an insect and a legless segmented robot resembling a worm (see figure) have been proposed as prototypes of biomorphic explorers  small, mobile, exploratory robots that...
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Briefs: Test & Measurement
A proposed miniature turbomolecular pump would be a prototype of high-vacuum sources for a forthcoming generation of miniature, portable mass spectrometers and other scientific instruments. The...
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Briefs: Test & Measurement
The Dryden Flight Research Center (DFRC) has been a partner in many uninhabited-aerial-vehicle (UAV) test programs. Our participation has largely been in the areas of...
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Briefs: Physical Sciences
A robust sensor based on the electrochemical oxidation of methanol has been developed for use in measuring the concentration of methanol dissolved in water. The sensor is expected to be...
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Briefs: Test & Measurement
An improved solvent-extraction/infrared-analysis technique has been devised to replace an older technique for measuring very small concentrations of nonvolatile residues of industrial...
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Briefs: Test & Measurement
A segmented-image emission velocimeter (SIEVE) is an optical instrument for measuring the velocity of a luminous turbulent flow. More specifically, it measures a component of flow...
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Briefs: Test & Measurement
Pressurization and Leak Testing of Sample-Return Canisters
A technique that involves pressurization with a radioactive gas has been proposed to solve two problems associated with canisters used to transport samples from remote bodies (planets, moons, asteroids, or comets) back to Earth. The canisters must be sealed at the sampling locations. The...
Briefs: Test & Measurement
A technique for thermomechanical fatigue testing of thin-walled tubular specimens involves the application of cyclic axial (tension/compression) and torsional (shear) strains,...
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Briefs: Materials
A surface-micromachining process has been devised for use in fabricating microscopic polycrystalline diamond structures (e.g., bridges and cantilevers) as integral parts...
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