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Title: Ultra-wideband impedance sensor

Abstract

The ultra-wideband impedance sensor (UWBZ sensor, or Z-sensor) is implemented in differential and single-ended configurations. The differential UWBZ sensor employs a sub-nanosecond impulse to determine the balance of an impedance bridge. The bridge is configured as a differential sample-and-hold circuit that has a reference impedance side and an unknown impedance side. The unknown impedance side includes a short transmission line whose impedance is a function of the near proximity of objects. The single-ended UWBZ sensor eliminates the reference side of the bridge and is formed of a sample and hold circuit having a transmission line whose impedance is a function of the near proximity of objects. The sensing range of the transmission line is bounded by the two-way travel time of the impulse, thereby eliminating spurious Doppler modes from large distant objects that would occur in a microwave CW impedance bridge. Thus, the UWBZ sensor is a range-gated proximity sensor. The Z-sensor senses the near proximity of various materials such as metal, plastic, wood, petroleum products, and living tissue. It is much like a capacitance sensor, yet it is impervious to moisture. One broad application area is the general replacement of magnetic sensors, particularly where nonferrous materials need to bemore » sensed. Another broad application area is sensing full/empty levels in tanks, vats and silos, e.g., a full/empty switch in water or petroleum tanks.« less

Inventors:
 [1]
  1. Livermore, CA
Issue Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
OSTI Identifier:
872200
Patent Number(s):
5883591
Assignee:
Regents of University of California (Oakland, CA)
Patent Classifications (CPCs):
G - PHYSICS G01 - MEASURING G01S - RADIO DIRECTION-FINDING
G - PHYSICS G01 - MEASURING G01F - MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
ultra-wideband; impedance; sensor; uwbz; z-sensor; implemented; differential; single-ended; configurations; employs; sub-nanosecond; impulse; determine; balance; bridge; configured; sample-and-hold; circuit; reference; transmission; line; function; near; proximity; eliminates; formed; sample; hold; sensing; range; bounded; two-way; travel; time; eliminating; spurious; doppler; modes; distant; occur; microwave; cw; range-gated; senses; various; materials; metal; plastic; wood; petroleum; products; living; tissue; capacitance; impervious; moisture; broad; application; replacement; magnetic; sensors; particularly; nonferrous; sensed; empty; levels; tanks; vats; silos; switch; water; near proximity; petroleum products; proximity sensor; broad application; transmission line; hold circuit; sensor employs; various materials; petroleum product; uwbz sensor; travel time; magnetic sensors; ultra-wideband impedance; impedance sensor; various material; capacitance sensor; magnetic sensor; /342/

Citation Formats

McEwan, Thomas E. Ultra-wideband impedance sensor. United States: N. p., 1999. Web.
McEwan, Thomas E. Ultra-wideband impedance sensor. United States.
McEwan, Thomas E. Fri . "Ultra-wideband impedance sensor". United States. https://www.osti.gov/servlets/purl/872200.
@article{osti_872200,
title = {Ultra-wideband impedance sensor},
author = {McEwan, Thomas E},
abstractNote = {The ultra-wideband impedance sensor (UWBZ sensor, or Z-sensor) is implemented in differential and single-ended configurations. The differential UWBZ sensor employs a sub-nanosecond impulse to determine the balance of an impedance bridge. The bridge is configured as a differential sample-and-hold circuit that has a reference impedance side and an unknown impedance side. The unknown impedance side includes a short transmission line whose impedance is a function of the near proximity of objects. The single-ended UWBZ sensor eliminates the reference side of the bridge and is formed of a sample and hold circuit having a transmission line whose impedance is a function of the near proximity of objects. The sensing range of the transmission line is bounded by the two-way travel time of the impulse, thereby eliminating spurious Doppler modes from large distant objects that would occur in a microwave CW impedance bridge. Thus, the UWBZ sensor is a range-gated proximity sensor. The Z-sensor senses the near proximity of various materials such as metal, plastic, wood, petroleum products, and living tissue. It is much like a capacitance sensor, yet it is impervious to moisture. One broad application area is the general replacement of magnetic sensors, particularly where nonferrous materials need to be sensed. Another broad application area is sensing full/empty levels in tanks, vats and silos, e.g., a full/empty switch in water or petroleum tanks.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1999},
month = {1}
}

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