Test & Measurement

Small-Bolt Torque-Tension Tester

Bolts as small as #0–80 can be tested. Current torque-tension measurement techniques involve using load washers as the force measuring transducer. The disadvantage of load washers is that they are too large to be used with fasteners smaller than about size #8. The device described here measures the torque-tension relationship for fasteners as small as #0.

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Desktop Application Program To Simulate Cargo-Air-Drop Tests

The DSS Application is a computer program comprising a Windows version of the UNIX-based Decelerator System Simulation (DSS) coupled with an Excel front end. The DSS is an executable code that simulates the dynamics of air-dropped cargo from first motion in an aircraft through landing. The bare DSS is difficult to use; the front end makes it easy to use. All inputs to the DSS, control of execution of the DSS, and postprocessing and plotting of outputs are handled in the front end. The front end is graphics-intensive.

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Rover Attitude and Pointing System Simulation Testbed

The MER (Mars Exploration Rover) Attitude and Pointing System Simulation Testbed Environment (RAPSSTER) provides a simulation platform used for the development and test of GNC (guidance, navigation, and control) flight algorithm designs for the Mars rovers, which was specifically tailored to the MERs, but has since been used in the development of rover algorithms for the Mars Science Laboratory (MSL) as well.

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Multimodal Friction Ignition Tester

Responses of material specimens to vibrational friction in pressurized oxygen are recorded. The multimodal friction ignition tester (MFIT) is a testbed for experiments on the thermal and mechanical effects of friction on material specimens in pressurized, oxygen-rich atmospheres. In simplest terms, a test involves recording sensory data while rubbing two specimens against each other at a controlled normal force, with either a random stroke or a sinusoidal stroke having controlled amplitude and frequency. The term “multimodal” in the full name of the apparatus refers to a capability for imposing any combination of widely ranging values of the atmospheric pressure, atmospheric oxygen content, stroke length, stroke frequency, and normal force. The MFIT was designed especially for studying the tendency toward heating and combustion of nonmetallic composite materials and the fretting of metals subjected to dynamic (vibrational) friction forces in the presence of liquid oxygen or pressurized gaseous oxygen — test conditions approximating conditions expected to be encountered in proposed composite-material oxygen tanks aboard aircraft and spacecraft in flight.

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Cryogenic Chamber for Servo-Hydraulic Materials Testing

A compact cryogenic test chamber can be cooled to approximately 5 to 6 Kelvin for materials testing. The system includes a temperature controller and multiple sensors to measure specimen temperature at different locations. The testing chamber provides a fast and easy method to perform materials testing at lower than liquid nitrogen temperature (77 K). The advantage of this chamber is that lower than 77 K temperatures are achievable, and the temperature can be controlled and stabilized during a test.

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Power Supply for Miniature Quadrupole Mass Spectrometer

This lightweight, low-power system is designed to operate unattended for a long time. 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 an energy source. More specifically, the circuit is designed to supply large, variable, frequency- and amplitude-stable RF voltages, variously floating or superimposed on positive or negative dc voltages, for application to primarily capacitive mass-spectrometer loads with capacitances of the order of 50 pF.

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Instrument Measures Fluorescence From Chlorophyll in Plants

Effective discrimination against solar background radiation is achieved without critical optical and mechanical parts. 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 user could provide timely applications of fertilizer, water, and/or pesticide to achieve maximum crop yield at minimum cost. Figure 1 presents two views of the plant fluorescence sensor. The instrument is the subject of U. S. Patent 5,567,947.

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