Sensors & Test

Test & Measurement

Learn what's trending in test, measurement, and monitoring technologies. Explore the latest products, applications, and technical briefs covering advanced measuring instruments, monitoring systems, devices, and instrumentation.

Briefs : Test & Measurement
Small Low-Temperature Thermometer With Nanokelvin Resolution

An improved high-resolution thermometer (HRT) for use in scientific experiments at temperatures

Briefs : Test & Measurement
A Lightweight Ambulatory Physiological Monitoring System

The Autogenic-Feedback System-2 (AFS-2) is a biomedical instrumentation package that was designed and built at Ames Research Center for use during the September 1992 Spacelab-J (STS-47) mission. The AFS-2 performed successfully during that mission and was rated by members of NASA's...

Briefs : Test & Measurement
Improvements in a Lightning-Measuring Instrument

Some improvements have been made in the instrument described in "Instrument Records Magnetic Fields Generated by Lightning" (KSC-11769) NASA Tech Briefs, Vol. 19, No. 4 (April 1995), page 38. To conserve battery energy, the instrument was made to record the output of only one of three mutually...

Briefs : Test & Measurement
Web-Based Technology Distributes Lean Models

Everybody creates models. These models are used to understand how products will hold up to the stresses, use, and abuse of real-world deployment; analyze the impact of design decisions on cost; simulate interactions; or evaluate numerous other metrics. Unfortunately, because of the variety of software...

Briefs : Test & Measurement
Broad-Band, Noninvasive Radio-Frequency Current Probe

An instrument that noninvasively measures alternating current over a broad frequency band (typically from about 0.3 to about 110 MHz) has been invented. This instrument could be especially useful for assessing radio-frequency hazards by measuring currents in various parts of humans or...

Briefs : Test & Measurement
Improved Methods of Testing Cryogenic Insulation Materials

Two improved methods have been developed for testing continuously rolled blankets and blanketlike thermal-insulation materials typically used in cryogenic vacuum systems. Both methods, and their corresponding apparatuses, are based on the cryogen boiloff calorimeter method according to...

Briefs : Test & Measurement
Real-Time Optoelectronic Particle-Fallout Monitors

Optoelectronic instruments for real-time, in situ monitoring of particle fallout are undergoing development. Settings in which these instruments could prove useful include clean rooms for assembly of optical and electronic equipment, food-packaging facilities, and other industrial facilities in...

Briefs : Test & Measurement
Program for Controlling Digital Instrumentation Recorders

A computer program enables the simultaneous monitoring and control of two commercial digital instrumentation recorders, each comprising a variable-rate buffer and a data tape recorder. The program can issue all standard tape-motion-related commands (fast forward, rewind, record, forward,...

Briefs : Test & Measurement
Helium Leak Detector With Improved Sample-Delivery System

The figure schematically depicts a portable helium leak detector that includes an improved sample-delivery system. This instrumentation is designed for detecting leaks in the fuel and oxidizer systems of the space shuttle main engines. In a helium leak test, helium is used as a tracer gas...

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
Gas Analyzer Measures Concentrations of H2, O2, and H2O

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 tube through which liquid hydrogen is transferred:

Briefs : Test & Measurement
Room-Temperature Infrared Instrument Detects Trace Gases

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 gases in air. The instrument utilizes infrared absorption spectroscopy in a sample cell which either holds...

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
Algorithm for Calibrating an Imaging Interferometer

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. Prior to the advent of this algorithm, such calibration was achieved by means of a conventional...

Briefs : Test & Measurement
Miniature Birefringence-Measuring System

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 general optical-retardation and dichroism measurements, to measure stresses with high sensitivity, to...

Briefs : Test & Measurement
Thrust Stand Measures Thrusts of

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 thrusts ranging from 0.04 to 0.8 lb (0.2 to 3.6 N). In addition, there was a need to measure thrust in a...

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...

Briefs : Test & Measurement
Measuring NO and OH Concentrations at High Pressure

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 radicals (OH) in a laboratory flat flame at a pressure up to 30 atm ≈3 MPa). The basic measurement...

Briefs : Test & Measurement
Automated Apparatus for Testing Gyroscopes

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 testing-system/tested-device interface circuitry that is part of the apparatus, one can set up the apparatus to test...

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...

Briefs : Test & Measurement
Mechanism for Adjusting and Measuring Tension in a Cable

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 cable-tensioning mechanisms, this mechanism also facilitates direct measurement of the tension in the...

Briefs : Test & Measurement
Power Supply for Miniature Quadrupole Mass Spectrometer

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 mass spectrometer that could operate unattended in the field for a long time, possibly using a battery as...

Briefs : Test & Measurement
Instrument Measures Fluorescence From Chlorophyll in Plants

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 that provides a means of discerning plant stress at very early stages. With sufficient warning, the...

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...

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...

Briefs : Test & Measurement
FT-IR Measurement of Hydraulic Fluids in Perchloroethylene

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 hydraulic fluids, oils, and greases on hardware that is required to be cleansed of such residues. The...

Briefs : Test & Measurement
Passive Optical Measurement of Velocity in a Luminous Flow

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 velocity perpendicular to its line of sight. This instrument is not only nonintrusive but is also passive in...

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 Axial/Torsional Thermomechanical Fatigue Testing

A technique for thermomechanical fatigue testing of thin-walled tubular specimens involves the application of cyclic axial (tension/compression) and torsional (shear) strains, along with thermal cycling. In this technique, the phase relationships among the two strain waveforms and...