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Title: Internal temperature monitor for work pieces

Abstract

A method and apparatus for measuring the internal temperature of a work piece comprises an excitation laser for generating laser pulses which are directed through a water cooled probe, and in an optical fiber, to a first surface of the work piece. The laser is of sufficient intensity to ablate the surface of the work piece, producing a displacement and a resulting ultrasonic pulse which propagates within the thickness of the work piece to an opposite surface. The ultrasonic pulse is reflected from the opposite surface and returns to the first surface to create a second displacement. A second continuous laser also shines its light through an optical fiber in the probe into the first surface and is used in conjunction with signal processing equipment to measure the time between the first and second displacements. This time is proportional to the time-of-flight of the ultrasonic pulse in the work piece which, with a known or detected thickness of the work piece, can be used to calculate the internal temperature of the work piece.

Inventors:
 [1]
  1. Salem, OH
Publication Date:
Research Org.:
Babcock and Wilcox Co., Alliance, OH (USA)
OSTI Identifier:
868849
Patent Number(s):
US 5226730
Assignee:
Babcock & Wilcox Company (New Orleans, LA)
DOE Contract Number:  
FC07-89ID12875
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
internal; temperature; monitor; pieces; method; apparatus; measuring; piece; comprises; excitation; laser; generating; pulses; directed; water; cooled; probe; optical; fiber; surface; sufficient; intensity; ablate; producing; displacement; resulting; ultrasonic; pulse; propagates; thickness; opposite; reflected; returns; create; continuous; shines; light; conjunction; signal; processing; equipment; measure; time; displacements; proportional; time-of-flight; detected; calculate; sufficient intensity; excitation laser; ultrasonic pulse; signal processing; laser pulses; laser pulse; optical fiber; opposite surface; water cooled; processing equipment; internal temperature; signal process; temperature monitor; site surface; cooled probe; /374/73/

Citation Formats

Berthold, John W. Internal temperature monitor for work pieces. United States: N. p., 1993. Web.
Berthold, John W. Internal temperature monitor for work pieces. United States.
Berthold, John W. 1993. "Internal temperature monitor for work pieces". United States. https://www.osti.gov/servlets/purl/868849.
@article{osti_868849,
title = {Internal temperature monitor for work pieces},
author = {Berthold, John W},
abstractNote = {A method and apparatus for measuring the internal temperature of a work piece comprises an excitation laser for generating laser pulses which are directed through a water cooled probe, and in an optical fiber, to a first surface of the work piece. The laser is of sufficient intensity to ablate the surface of the work piece, producing a displacement and a resulting ultrasonic pulse which propagates within the thickness of the work piece to an opposite surface. The ultrasonic pulse is reflected from the opposite surface and returns to the first surface to create a second displacement. A second continuous laser also shines its light through an optical fiber in the probe into the first surface and is used in conjunction with signal processing equipment to measure the time between the first and second displacements. This time is proportional to the time-of-flight of the ultrasonic pulse in the work piece which, with a known or detected thickness of the work piece, can be used to calculate the internal temperature of the work piece.},
doi = {},
url = {https://www.osti.gov/biblio/868849}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Jan 01 00:00:00 EST 1993},
month = {Fri Jan 01 00:00:00 EST 1993}
}