Piezoresistive gage tests pin-connector sockets
Connector pin consisting of a piezoresistive crystal, retainer spring and a bridge circuit with voltmeter is used to test connector sockets and may be adapted for multiple socket testing.
Bond, W. W.↗
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Results for “bridge circuits”
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.
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Coaxial capacitor used to determine fluid density
Sensing device measures directly the density of compressible fluid existing simultaneously in both liquid and gaseous phases. The device is comprised of a capacitor connected as one leg of a bridge circuit, a power source, and an indicator calibrated to indicate density as a direct measurement.
Atkisson, E. A.↗
Ferroelectric bolometer measures RF absolute power at submillimeter wavelengths
Two ferroelectric bolometer sensing elements measure low rf absolute power at millimeter and submillimeter wavelengths. The sensing elements are mounted in sections of waveguide and connected in series in a standard temperature compensating bridge circuit.
Cohn, M.↗
Resistance thermometer has linear resistance-temperature coefficient at low temperatures
Resistance thermometer incorporating a germanium resistance element with a platinum resistance element in a wheatstone bridge circuit has a linear temperature-resistance coefficient over a range from approximately minus 140 deg C to approximately minus 253 deg C.
Kuzyk, W.↗
Motor brush wear measured with strain gages
Balanced bridge circuit, supplied with low-voltage direct current and connected to a readout device, measures remaining brush material, rate of brush wear, armature runout, and brush signature.
Farrell, W. T.↗
Chemical and metabolic characteristics of brain tissue - Electrical impedance correlates
Brain cerebral tissues electrical impedance measurement by electrodes and bridge circuit, discussing chemical and metabolic properties
Adey, W. R.↗
Conductive elastomeric extensometer
Bridge circuit, in which conductive elastomeric material is the variable leg, precisely measures surface area changes in the human body. Circuits are used singularly, or in quantity by adding elements and amplifier circuits. Elastomeric strips can be located in a form-fitting garment.
Gause, F. L.↗
Self-balancing strain gage transducer Patent
Self-balancing strain gage transducer with bridge circuit
Babb, B. D.↗
Cavity radiometer Patent
Black body cavity radiometer with thermal resistance wire bridge circuit
Haley, F. C.↗
Improved device measures performance of batteries under load
Kordesch-Marko interrupter bridge circuit includes capability of varying frequency of interruption in steps from 60 Hz to 2000 Hz range extension, and addition of operating modes to allow instrument to serve as steady dc constant-current source or load, or source of interrupted constant current.
Powell, J. D.↗
Thin-film temperature sensor.
A new device has been developed for sensing small and rapid temperature changes accompanying biochemical reactions. The active element consists of an evaporated thin-film capacitor having a relatively strong temperature dependence. This dependence is derived from electron trapping effects in the thin amorphous dielectric film. A voltage output of at least 50 mV/deg can be obtained prior to amplification by using a resonant ac bridge circuit operating at 100 kHz. The corresponding noise output for a 10 kHz bandwidth can with an optimum circuit be as low as 4 microvolts. Therefore, the minimum detectable temperature change would be 80 microdegrees at 10 kHz. Rapid thermal response is assured by supporting the thin-film capacitor on a thin anodic tantalum oxide film suspended across an electrolytically etched window in a tantalum foil.
Maserjian, J.↗
Thin-film temperature sensor
Sensor measures rapid temperature changes in fluid streams. Sensor withstands contacts with various corrosive fluids, high fluid-flow rates, and turbulences caused by rapid changes in flow rates. Capacitor is part of resonant bridge circuit which produces ac voltage that is proportional to temperature.
Maserjian, J.↗
Mounting technique for pressure transducers minimizes measurement interferences
Miniaturized transducers are fabricated from commercially available four-arm semiconductor gages; transducers are connected as bridge circuit and mounted on internal face of small diaphragm. Jacket made of conductive plastic may be needed to avoid buildup or static charges.
Lanham, R. N.↗
Vacuum leak detector
A leak detector for use with high vacuum seals as used in feedthroughs and hatch covers for manned spacecraft and vacuum systems is described. Two thermistors are used, one exposed directly to vacuum and the other exposed to a secondary chamber formed by the seal being monitored and a second auxiliary seal. Leakage into the secondary chamber causes an unbalance of an electrical bridge circuit in which the thermistors are connected.
Kazokas, G. P.↗
Program to design, fabricate, test, and deliver a thermal control-mixing control device, phase 1
The development of a sensor capable of detecting temperature changes as a function of viscosity changes, was completed. This type of sensor, consisting of an orifice bridge circuit, resulted in a device with a threshold above internally generated noise of 0.8C (1.5F). Data were obtained using a noise free Freon source provided by an air pressurized bladder. Tests conducted to operate the sensor from a typical Freon centrifugal pump system employing an air bubble accumulator for noise attentuation disclosed the sensor could be used only to sense temperature changes greater than 3.3C (6F) because of the excessively noisy output. This is attributed to the high frequency-pressure fluctuations in the Freon supply to the sensor.
Thurston, T. S.↗
Helium refrigerator
An improved helium refrigerator of the type which includes a plurality of counter-flow heat exchangers and has a maximum reserve cooling capacity when the final or low-temperature heat exchanger is substantially filled with liquid helium, and a minimum reserve cooling capacity when the low-temperature heat exchanger is substantially filled with gas. An electrical bridge circuit including a pair of temperature responsive resistors is mounted on the low-temperature heat exchanger for providing a continuous indication of the reserve cooling capacity of the refrigerator.
Ervin R Wiebe↗
Program to design, fabricate, test, and deliver a thermal control-mixing control device for the George C. Marshall Space Flight Center
The development and testing of a temperature sensor and pulse duration modulation (PDM) diverter valve for a thermal control-mixing control device are described. The temperature sensor selected for use uses a fluidic pin amplifier in conjunction with an expansion device. This device can sense changes of less than 0.25 F with greater than 15:1 signal to noise ratio when operating with a typical Freon pump supplied pressure. The pressure sensitivity of the sensor is approximately 0.0019 F/kPa. The valve which was selected was tested and performed with 100% flow diversion. In addition, the valve operates with a flow efficiency of at least 95%, with the possibility of attaining 100% if the vent flow of the PDM can be channeled through the last stage of the diverter valve. A temperature sensor which utilized an orifice bridge circuit and proportional-vortex combination mixing valve were also evaluated, but the concepts were rejected due to various problems.
Thurston, T. S.↗
A Simple Tiltmeter
Bubble vial with external aluminum-foil electrodes is sensing element for simple indicating tiltmeter. To measure bubble displacement, bridge circuit detects difference in capacitance between two sensing electrodes and reference electrode. Tiltmeter was developed for experiment on forecasting seismic events by changes in Earth's magnetic field.
Dix, M. G.↗