Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “measuring instruments”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS2009

Compact Instruments Measure Heat Potential

Based in Huntsville, Alabama, AZ Technology Inc. is a woman- and veteran-owned business that offers expertise in electromechanical-optical design and advanced coatings. AZ Technology has received eight Small Business Innovation Research (SBIR) contracts with Marshall Space Flight Center for the development of spectral reflectometers and the measurement of surface thermal properties. The company uses a variety of measurement services and instruments, including the Spectrafire, a portable spectral emissometer it used to assist General Electric with the design of its award-winning Giraffe Warmer for neonatal intensive care units.

Source record↗
NASA NTRS1973

Vibrational sensitivity of a measuring instrument and methods of increasing the accuracy of its determinations

The properties and peculiarities of two groups of measuring systems reacting to vibrations are discussed. Specifically, results of the action of a three dimensional, cophasal, monoharmonic vibration on the linear system of a measuring instrument was analyzed. Data are also given on the connection between vibration sensitivity and vibration resistance for instruments, methods for estimating vibration resistance, and formulas for expressing test results of vibration resistance. Experimental data are also given for decreasing errors in nonlinear systems during vibrations.

Mironov, Y. S.↗
NASA NTRS1972

Problems affecting the fidelity of pressure measuring instruments for planetary probes

Determination is made of the nature and magnitude of surface-related effects that cause errors in pressure measuring instruments, with special reference being made to instruments intended for use in planetary probes. The interaction of gases with clean surfaces of metals likely to be used as gage construction materials was studied. Special emphasis was placed on the adsorption, chemical reaction, and electron-induced desorption processes. The results indicated that all metals tested were subject to surface processes which would degrade gage fidelity. It was also found, however, that the formation of inert adsorbed layers on these metal surfaces, such as carbon on platinum, greatly reduced or eliminated these effects. This process, combined with a system design which avoids contact between reactive gases and hot filaments, appears to offer the most promising solution to the gage fidelity problem.

Hudson, J. B.↗
DOE OSTI2022

The fluctuation–dissipation measurement instrument at the Linac Coherent Light Source

The development of new modes at x-ray free electron lasers has inspired novel methods for studying fluctuations at different energies and timescales. For closely spaced x-ray pulses that can be varied on ultrafast time scales, we have constructed a pair of advanced instruments to conduct studies targeting quantum materials. We first describe a prototype instrument built to test the proof-of-principle of resonant magnetic scattering using ultrafast pulse pairs. This is followed by a description of a new endstation, the so-called fluctuation–dissipation measurement instrument, which was used to carry out studies with a fast area detector. In addition, we describe various types of diagnostics for single-shot contrast measurements, which can be used to normalize data on a pulse-by-pulse basis and calibrate pulse amplitude ratios, both of which are important for the study of fluctuations in materials. Furthermore, we present some new results using the instrument that demonstrates access to higher momentum resolution.

Assefa, T. A.↗
NASA NTRS1982

Mathematical enhancement of data from scientific measuring instruments

The accuracy of any physical measurement is limited by the instruments performing it. The proposed activities of this grant are related to the study of and application of mathematical techniques of deconvolution. Two techniques are being investigated: an iterative method and a function continuation Fourier method. This final status report describes the work performed during the period July 1 to December 31, 1982.

Ioup, J. W.↗
NASA NTRS1972

Two-laser optical distance-measuring instrument that corrects for the atmospheric index of refraction.

The Wave Propagation Laboratory of the Environmental Research Laboratories of the National Oceanic and Atmospheric Administration has been engaged in the development of dual-wavelength, optical distance-measuring instruments. Recently a new generation of this type of high-accuracy instrument has been completed. Preliminary testing of the new instrument indicates that the original goal of the project, accuracy of better than one part in a million over distances of 5-10 km using averaging times of less than 1 min, is being met. This paper describes the instrument and preliminary test results.

Earnshaw, K. B.↗
NASA NTRS2003

Compact Instruments Measure Helium-Leak Rates

Compact, lightweight instruments have been developed for measuring small flows of helium and/or detecting helium leaks in solenoid valves when the valves are nominally closed. These instruments do not impede the flows when the valves are nominally open. They can be integrated into newly fabricated valves or retrofitted to previously fabricated valves. Each instrument includes an upstream and a downstream thermistor separated by a heater, plus associated analog and digital heater-control, signal- conditioning, and data-processing circuits. The thermistors and heater are off-the-shelf surface mount components mounted on a circuit board in the flow path. The operation of the instrument is based on a well-established thermal mass-flow-measurement technique: Convection by the flow that one seeks to measure gives rise to transfer of heat from the heater to the downstream thermistor. The temperature difference measured by the thermistors is directly related to the rate of flow. The calibration curve from temperature gradient to helium flow is closely approximated via fifth-order polynomial. A microprocessor that is part of the electronic circuitry implements the calibration curve to compute the flow rate from the thermistor readings.

Stout, Stephen↗
NASA NTRS1977

Instrument measures dynamic pressure fluctuations

Pressure probe instrument, incorporating "infinite line" principle, can be used to remotely measure dynamic pressure fluctuations in hot high-pressure environemnts too severe for sensors. System is designed and can be utilized for measurements in core of operating turbofan engine.

Coats, J. W.↗
NASA NTRS1998

Development of a mirror pointing mechanism for an atmospheric gas measurement instrument

Development of the Open Path Tunable Infrared Monitor of the Atmosphere (OPTIMA) instrument involved designing a pair of motion systems that could maintain a precise alignment and spatial distance between two mirrors installed on the NASA DC-8 research laboratory aircraft. This is the first airborne optical instrument that allows direct measurement of the gases in the freestream airflow on the exterior of the aircraft. One mirror is mounted within a specially constructed open port cavity in the cabin of the aircraft and the second is mounted 6 meters away on top of the inboard port side (number 2) engine pylon. Three co-aligned laser beams are reflected between the two mirrors 64 times in a Herriott pattern. The resulting sample path length of 384 meters is used to perform a spectral absorption analysis of the airflow between the mirrors. To compensate for normal wing movement and engine oscillations both mirrors were designed as continuously driven mechanisms to maintain alignment within allowable limits. The motion systems of the two mirror assemblies provide five degrees of freedom and are designed to maintain a pointing accuracy within seven arc-sec with a response frequency in excess of 10 Hz. The pylon motion system incorporates controlled pitch and yaw movement. The fuselage motion system compensates for pitch variation as well as linear translation for focal length and vertical aiming of the laser beam via a controlled beam guidance mechanism.

Graham, Michael↗
NASA NTRS1998

Development of a Mirror Pointing Mechanism for an Atmospheric Gas Measurement Instrument

Development of the Open Path Tunable Infrared Monitor of the Atmosphere (OPTIMA) instrument involved designing a pair of motion systems that could maintain a precise alignment and spatial distance between two mirrors installed on the NASA DC-8 research laboratory aircraft. This is the first airborne optical instrument that allows direct measurement of the gases in the freestream airflow on the exterior of the aircraft. One mirror is mounted within a specially constructed open port cavity in the cabin of the aircraft and the second is mounted 6 meters away on top of the inboard port side (number 2) engine pylon. Three co-aligned laser beams are reflected between the two mirrors 64 times in a Herriott pattern. The resulting sample path length of 384 meters is used to perform a spectral absorption analysis of the airflow between the mirrors. To compensate for normal wing movement and engine oscillations both mirrors were designed as continuously driven mechanisms to maintain alignment within allowable limits. The motion systems of the two mirror assemblies provide five degrees of freedom and are designed to maintain a pointing accuracy within seven arc-sec with a response frequency in 6xcess of 10 Hz. The pylon motion system incorporates controlled pitch and yaw movement. The fuselage motion system compensates for pitch variation as well as linear translation for focal length and vertical aiming of the laser beam via a controlled beam guidance mechanism.

Graham, Michael↗
NASA NTRS1971

Electrical instrument measures position and velocity of shock waves

Instrument employs a sensor consisting of twin-electrode probe mounted in shock tube wall, with small dc voltage impressed across electrodes. Power supply, amplifier, and gate pulse generator complete the system. Instrument provides data for construction of wave diagrams, as well as measurement of shock velocity.

Dannenberg, R. E.↗
NASA NTRS1967

Web belt load measuring instrument has excellent stability

Web belt system measures belt or strap load. It is partially disassembled and installed on an existing belt without cutting or re-threading the belt. A strain gage, installed on one of the support beams, eliminates errors due to uneven loading.

Walker, R. R.↗
NASA NTRS1974

ASRDI oxygen technology survey. Volume 6: Flow measurement instrumentation

A summary is provided of information available on liquid and gaseous oxygen flowmetering including an evaluation of commercial meters. The instrument types, physical principles of measurement, and performance characteristics are described. Problems concerning flow measurements of less than plus or minus two percent uncertainty are reviewed. Recommendations concerning work on flow reference systems, the use of surrogate fluids, and standard tests for oxygen flow measurements are also presented.

Mann, D. B.↗