Test & Measurement

Achieving Reliable Inline Measurements in Production Environments

One of the most important changes in metrology in the past few decades has been the development of portable measuring devices. This has brought inspection right to the production line, as close to the part as possible. The change—sparked by the development of portable measuring arms and the emergence of laser trackers—has turned conventional industry inspection methods completely upside down.

Posted in: White Papers, Manufacturing & Prototyping, Software, Test & Measurement

New GASOMETER Design Uses Active Accommodation Offering Significant Improvements Vs. Liquid-sealed Methods

Active Accommodation means using a precision controlled and driven cylinder/piston assembly to collect and measure gas sample volumes without requiring energy to be extracted from the process that generates the gas. The mechanism uses lubricated O-Rings to seal the measuring chamber unlike classical Wet Test Meters that require a water or oil bath to produce an isolation seal.

Posted in: White Papers, Green Design & Manufacturing, Instrumentation, Test & Measurement

Developing and Testing Electronic Control Units for Electric Drives

Air framers are looking to build more eco-friendly and economical aircraft, and they are turning to electric drives. One growing trend is to build more electrical aircraft by replacing pneumatic and hydraulic systems with electric actuators. Electric drives, therefore, will play an important role in the aircraft of the future. This paper examines the current state of technology for developing and testing electric drives.

Posted in: White Papers, White Papers, Aeronautics, Electronics, Electronics & Computers, Test & Measurement

Small-Body Testbed

The system can simulate a microgravity environment with a wide range of terrain types and topographies.

This technology allows one to test small-body surface mobility and sampling systems in the laboratory. It is capable of simulating a microgravity environment with relevant terrain. The magnitude of the gravity, the terrain properties, and the surface system being tested are all easily modified to allow for a broad range of experimental setups.

Posted in: Briefs, Test & Measurement, Simulation and modeling, Terrain, Test equipment and instrumentation, Test facilities, Test procedures

Neutral Mounting of Whispering Gallery Mode Resonators for Suppression of Mechanical Frequency Fluctuations

This technology can be used in laser devices, chemical sensing, navigation, aerospace, and scientific instrumentation.

NASA’s Jet Propulsion Laboratory has developed a neutral mounting scheme that eliminates the acceleration sensitivity of whispering gallery mode resonators (WGMRs), making them suitable for use in high-precision portable instruments such as optical atomic clocks and high-resolution laser ranging systems. With state-of-the-art WGMR mounting schemes, accelerations induce deformations in the resonator structure, changing its resonant frequency and limiting their usefulness in precision devices. JPL’s novel coaxial mounting scheme is capable of reducing and even eliminating these vibration- and acceleration-induced frequency fluctuations, yielding a WGMR with superior frequency stability that can be used for creating ultra-compact, highly stabilized lasers that are ideally suited for use in spectroscopy, sensing, and frequency metrology applications.

Posted in: Briefs, Instrumentation, Amplifiers, Architecture, Acoustics, Mountings, Reliability

Photogrammetry System and Method for Determining Relative Motion Between Two Bodies

Highly accurate, flexible system measures relative dynamics in six degrees of freedom.

NASA’s Langley Research Center has developed a novel method to calculate the relative position and orientation between two rigid objects using a simplified photogrammetric technique. The system quantitatively captures the relative orientation of objects in six degrees of freedom (6-DOF), using one or more cameras with non-overlapping fields of view (FOV) that record strategically placed photogrammetric targets.

Posted in: Briefs, Test & Measurement, Mathematical models, Measurements, Optics

Directed Design of Experiments for Validating Probability of Detection Capability of a Testing System

NASA’s Langley Research Center has developed new software that enables users of critical inspection systems to validate the capability of the inspection system. Traditionally, inspection systems are validated using various methodologies to determine probability of detection (POD). One widely accepted metric of an adequate inspection system is that there is 95% confidence that the POD is greater than 90% (90/95 POD). Directed Design of Experiments for Probability of Detection (DOEPOD) is a user-friendly software package that enables detailed analysis of 90/95 POD or at any specified confidence level. Although it was designed to validate the capability of inspection systems to find fracture- critical flaws in materials, DOEPOD can be applied to systems to locate any type of flaw as well as to validate the detection capability of personnel. DOEPOD can also be employed as the core of an NDE (nondestructive evaluation) system, and provide accurate on-demand validation of the inspection system.

Posted in: Briefs, Test & Measurement, Failure modes and effects analysis, Measurements, Computer software and hardware, Inspections

Method and Apparatus for Measuring Surface Air Pressure

This technology enhances the predictive capabilities of weather forecasting models.

NASA’s Langley Research Center has developed a novel method for long-range atmospheric pressure sensing. Based on known properties involving oxygen density, the technology is able to measure small pressure changes over a wide area. NASA developed the technology to address known gaps in the area of weather forecasting as a result of the inability to accurately detect atmospheric pressure above the ocean. Oxygen band reading can be performed remotely, most likely from a satellite-based system. The technology is particularly applicable in the area of storm forecasting.

Posted in: Briefs, Test & Measurement, Measurements, Radar, Weather and climate, Oxygen

HEIST Ironbird to Test Cutting-Edge Hybrid Electric Propulsion Technologies

Testbed will study the system complexities of powering an aircraft with two different power sources.

A key goal of NASA’s aeronautics research is to help the aircraft industry transition to low-carbon propulsion. Many potential power architectures for electric propulsion have been proposed, and design considerations for turbo-electric distributed propulsion have been studied. However, few mid- to full-scale testbeds have been built to validate these different architectures.

Posted in: Briefs, Test & Measurement, Electric hybrid power, Electric motors, Turbojet engines, Turboprop engines

Saturn Net Flux Radiometer (SNFR)

A Saturn Net Flux Radiometer (SNFR) is being developed as part of a payload for a future NASA-led Saturn Probe Mission. The current design has two spectral channels i.e., a solar channel (0.4-to-5 μm) and a thermal channel (4-to-50 μm). The SNFR is capable of viewing five distinct viewing angles during the descent. Non-imaging Winston cones with window and filter combinations define the spectral channels, each with a 5° field-of-view. Un - cooled thermopile detectors are used in each spectral channel and are read out using a custom-designed Application Specific Integrated Circuit (ASIC). The SNFR measures the radiative energy anisotropies with altitude. In the solar channel, the downward flux will determine the solar energy deposition profile and the upward flux will yield information about cloud particle absorption and scattering. In the thermal channel, the net flux will define sources and sinks of planetary radiation. In conjunction with calculated gas and particulate opacities, these observations will determine the atmosphere’s radiative balance.

Posted in: Briefs, Test & Measurement, Measurements, Radar, Solar energy, Radiation, Thermal testing, Entry, descent, and landing

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