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At least 163 records · Page 9

Third Annual Report on Development of Microwave Resonant Cavity Transducer for Fluid Flow Sensing

We are investigating a microwave resonant cavity transducer for flow sensing in the vessel of a high temperature fluid advanced reactor (AR), such as a molten salt cooled reactor (MSCR) or a sodium fast reactor (SFR). This transducer is a hollow metallic cylindrical cavity, with one of the flat walls of the cylinder flexible enough to undergo microscopic deflection due to dynamic fluid pressure. Membrane deflection leads to a shift in the microwave resonant frequency, which can be detected with a spectrum analyzer.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Miniature stress transducer has directional capability

Miniature stress transducer uses a semiconductive piezoresistive element to detect stress only on specific axes. Measurement of internal mass stress is based on the compressive deformation of the transducer. The device is applicable to constant stress monitoring in building and dam structural parts.

San Miguel, A.↗

Seismic transducer measures small horizontal displacements

Pendular seismic transducer mounted on base plate measures small horizontal displacements of structures subjected to vibration where no fixed reference point is available. Enclosure of transducer in transparent plastic case prevents air currents from disturbing the pendulum balance.

Greenwood, T. L.↗

Metal diaphragm used to calibrate miniature transducers

Dynamic comparative calibration system measures response of miniature pressure transducers. The system is composed of an electromechanically driven metal diaphragm, a calibrated and an uncalibrated transducer and an oscillator.

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Noncontacting vibration transducer has constant sensitivity

Noncontacting transducer with constant sensitivity automatically measures the vibration amplitudes along the span of a vibrating structure of irregular contour. A system employing a feedback control positions the transducer at a constant height above the test surfaces. A differential transformer facilitates calibration and extends the amplitude range of the system.

Flagge, B.↗

Transducer measures force in vacuum environment

Transducer assembly measures force in a vacuum environment. The assembly consist of a standard capacitance probe and a torque beam. This transducer can be used in high-pressure as well as in low-pressure environments for static and dynamic force measurements.

Glenn, D. C.↗

Acceleration-compensated pressure transducer has fast response

Flush-diaphragm transducer accurately measures small dynamic pressures when it is subjected to high accelerations and severe temperature environments. The transducer uses piezoelectric crystals for measuring the pressure and balancing out acceleration forces.

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Automatic calibration system for pressure transducers

Fifty-channel automatic pressure transducer calibration system increases quantity and accuracy for test evaluation calibration. The pressure transducers are installed in an environmental tests chamber and manifolded to connect them to a pressure balance which is uniform.

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New type pressure transducer for severe thermal environments

Pressure transducer used in a rocket motor chamber to measure the amplitudes and frequencies of dynamic pressures /exceeding 2000 psi/ occurring during unstable combustion. the transducer utilizes a transpirational cooled porous beryllium plug and pressure transmitting column.

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Piezoelectric transducer

Transducer consists of a hybrid thin film and a piezoelectric transistor that acts as a stress-sensitive device with built-in gain. It provides a stress/strain transducer that incorporates a signal amplification stage and sensor in a single package.

Conragan, J.↗

Subminiature transducer measures unsteady pressures

Transducer has thin piezoelectric sensing element of 0.051-cm-thick lead zirconate titanate crystal which is cut as a conical frustum. Sensing crystal and titanium wire are protected from mechanical shock and vibration. Transducer is insensitive to mechanical vibrations of instrument plug on which it is mounted.

Raman, K. R.↗

Pressure transducer with four-decade dynamic range

Adjustable resistor taps in gain-control feedback loop of the transducer permit wide sensing range, shorting the pins on electrical connector allows selection of appropriate range. Electrical specifications of the transducer and its applications are cited.

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Dynamic response of high-frequency pressure transducers to large amplitude sinusoidal pressure oscillations

Dynamic response characteristics of six currently used dynamic pressure transducers were investigated by using a large-amplitude sinusoidal-pressure generator. Frequencies between 1 and 15 kilohertz with corresponding peak-to-peak pressure-oscillation amplitudes ranging between 73 and 8 percent of bias pressure and bias pressures between 15 and 300 psia were utilized. Amplitude-ratio data as functions of frequency and pressure level are given for all transducers. The generator design and performance and associated instrumentation are described.

Robinson, R. E.↗

Miniature biaxial strain transducer

Transducer is completely reusable and permits relocation to alternate points to be accomplished quickly. Size permits measurements to be made simultaneously over small areas and yields outputs directly proportional to strains measured. Transducer verifies elastic modulus, Poisson's ratio, and principal strain axes on materials.

Hoffman, I. S.↗

Transducer technology transfer to bio-engineering applications

The results of a technology transfer of a miniature unidirectional stress transducer, developed for experimental stress analysis in the aerospace field, to applications in bioengineering are reported. By modification of the basic design and innovations in attachment techniques, the transducer was successfully used in vivo on the myocardium of large dogs to record the change in contractile force due to coronary occlusion, reperfusion, and intervention.

Duran, E. N.↗