Process control system using polarizing interferometer
- Maumee, OH
- Waban, MA
- North Reading, MA
- Newton, MA
A system for non-destructively measuring an object and controlling industrial processes in response to the measurement is disclosed in which an impulse laser generates a plurality of sound waves over timed increments in an object. A polarizing interferometer is used to measure surface movement of the object caused by the sound waves and sensed by phase shifts in the signal beam. A photon multiplier senses the phase shift and develops an electrical signal. A signal conditioning arrangement modifies the electrical signals to generate an average signal correlated to the sound waves which in turn is correlated to a physical or metallurgical property of the object, such as temperature, which property may then be used to control the process. External, random vibrations of the workpiece are utilized to develop discernible signals which can be sensed in the interferometer by only one photon multiplier. In addition the interferometer includes an arrangement for optimizing its sensitivity so that movement attributed to various waves can be detected in opaque objects. The interferometer also includes a mechanism for sensing objects with rough surfaces which produce speckle light patterns. Finally the interferometer per se, with the addition of a second photon multiplier is capable of accurately recording beam length distance differences with only one reading.
- Research Organization:
- Surface Combustion, Inc. (Maumee, OH)
- DOE Contract Number:
- FC07-89ID12830
- Assignee:
- Surface Combustion, Inc. (Maumee, OH)
- Patent Number(s):
- US 5286313
- OSTI ID:
- 869157
- Country of Publication:
- United States
- Language:
- English
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Method and apparatus for measuring surface movement of an object using a polarizing interferometer
Related Subjects
control
polarizing
interferometer
non-destructively
measuring
controlling
industrial
processes
response
measurement
disclosed
impulse
laser
generates
plurality
sound
waves
timed
increments
measure
surface
movement
caused
sensed
phase
shifts
signal
beam
photon
multiplier
senses
shift
develops
electrical
conditioning
arrangement
modifies
signals
generate
average
correlated
physical
metallurgical
property
temperature
external
random
vibrations
workpiece
utilized
discernible
addition
optimizing
sensitivity
attributed
various
detected
opaque
mechanism
sensing
surfaces
produce
speckle
light
patterns
finally
capable
accurately
recording
length
distance
differences
reading
random vibrations
recording beam
movement attributed
signal correlated
various waves
timed increments
speckle light
average signal
produce speckle
accurately recording
beam length
arrangement modifies
non-destructively measuring
metallurgical property
measure surface
multiplier senses
laser generates
light pattern
impulse laser
controlling industrial
conditioning arrangement
length distance
discernible signals
distance differences
industrial processes
photon multiplier
process control
phase shift
electrical signals
sound waves
electrical signal
signal beam
industrial process
polarizing interferometer
phase shifts
surface movement
signal conditioning
light patterns
pulse laser
sound wave
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