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Title: Noninvasive valve monitor using alternating electromagnetic field

One or more electrical coils are carefully located on the outside of a valve body. An alternating current passing through the coil(s) results in an alternating electromagnetic field being transmitted into the valve body and valve internals. The electromagnetic field varies in intensity and polarity in the valve. As the position of a valve internal part is changed, the electromagnetic field throughout the valve body and its internals is altered. A passive receiver coil carefully located on the outside of the valve body detects the intensity of the electromagnetic field at that location as an induced electrical voltage in the coil. With the change in position of the valve internal part, there is a corresponding change in the induced voltage as a result of the alteration in the alternating electromagnetic field at that location. Changes in the voltage provide an indication of the position and motion of valve internals.
Authors:
 [1] ;  [2] ;  [2]
  1. (Oak Ridge, TN)
  2. (Knoxville, TN)
Publication Date:
OSTI Identifier:
868694
Report Number(s):
US 5193568
DOE Contract Number:
AC05-84OR21400
Resource Type:
Patent
Research Org:
LOCKHEED MARTIN ENRGY SYST INC
Country of Publication:
United States
Language:
English
Subject:
noninvasive; valve; monitor; alternating; electromagnetic; field; electrical; coils; carefully; located; outside; valve; alternating; current; passing; coil; results; alternating; electromagnetic; field; transmitted; valve; valve; internals; electromagnetic; field; varies; intensity; polarity; valve; position; valve; internal; changed; electromagnetic; field; throughout; valve; internals; altered; passive; receiver; coil; carefully; located; outside; valve; detects; intensity; electromagnetic; field; location; induced; electrical; voltage; coil; change; position; valve; internal; corresponding; change; induced; voltage; result; alteration; alternating; electromagnetic; field; location; changes; voltage; provide; indication; position; motion; valve; internals; alternating electromagnetic; alternating electromagnetic; alternating electromagnetic; valve internals; valve internals; electromagnetic field; electromagnetic field; electromagnetic field; electromagnetic field; electromagnetic field; electromagnetic field; magnetic field; magnetic field; magnetic field; magnetic field; magnetic field; magnetic field; alternating current; valve internal; valve internal; valve internal; valve internal; current passing; electrical coils; corresponding change; carefully located; carefully located; noninvasive valve; field throughout; valve monitor; induced electrical; voltage provide; electrical coil; current pass /137/324/