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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:
Issue Date:
OSTI Identifier:
6227700
Patent Number(s):
5226730
Application Number:
PPN: US 7-889217
Assignee:
Babcock and Wilcox Co., New Orleans, LA (United States)
DOE Contract Number:  
FC07-89ID12875
Resource Type:
Patent
Resource Relation:
Patent File Date: 27 May 1992
Country of Publication:
United States
Language:
English
Subject:
47 OTHER INSTRUMENTATION; THERMOMETERS; DESIGN; DATA PROCESSING; LASER RADIATION; LASERS; MEASURING METHODS; OPTICAL FIBERS; REFLECTION; SIGNALS; TEMPERATURE MEASUREMENT; THICKNESS; TIME-OF-FLIGHT METHOD; ULTRASONIC WAVES; WAVE PROPAGATION; DIMENSIONS; ELECTROMAGNETIC RADIATION; FIBERS; MEASURING INSTRUMENTS; PROCESSING; RADIATIONS; SOUND WAVES; 440500* - Thermal Instrumentation- (1990-)

Citation Formats

Berthold, J W. Internal temperature monitor for work pieces. United States: N. p., 1993. Web.
Berthold, J W. Internal temperature monitor for work pieces. United States.
Berthold, J W. Tue . "Internal temperature monitor for work pieces". United States.
@article{osti_6227700,
title = {Internal temperature monitor for work pieces},
author = {Berthold, J 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 = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1993},
month = {7}
}