Internal temperature monitor for work pieces

Patent · Tue Jul 13 04:00:00 EDT 1993

OSTI ID:6227700

Berthold, J W

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.

• DOE Contract Number: FC07-89ID12875
• Assignee: Babcock and Wilcox Co., New Orleans, LA (United States)
• Patent Number(s): US 5226730; A
• Application Number: PPN: US 7-889217
• OSTI ID: 6227700
• Country of Publication: United States
• Language: English

Related Subjects

440500* -- Thermal Instrumentation-- (1990-)
47 OTHER INSTRUMENTATION
DATA PROCESSING
DESIGN
DIMENSIONS
ELECTROMAGNETIC RADIATION
FIBERS
LASER RADIATION
LASERS
MEASURING INSTRUMENTS
MEASURING METHODS
OPTICAL FIBERS
PROCESSING
RADIATIONS
REFLECTION
SIGNALS
SOUND WAVES
TEMPERATURE MEASUREMENT
THERMOMETERS
THICKNESS
TIME-OF-FLIGHT METHOD
ULTRASONIC WAVES
WAVE PROPAGATION