High bandwidth fiber optic vibration sensor
First Claim
1. An apparatus for monitoring vibration levels in rotatable machinery comprising:
- a source for generating coherent radiation;
a first partially transmissive and partially reflective device positioned to receive radiation from the source and transmit a part of the radiation there through;
a second partially transmissive and partially reflective device mounted to the machinery, positioned to reflect a first signal and transmit radiation transmitted by the first device;
a third device mounted to the machinery and positioned to reflect radiation transmitted through the second device to provide a second signal;
circuitry configured to generate an electrical signal based on a combination of the first and second signals; and
processing circuitry configured to provide a value indicative of vibration amplitude occurring in the machinery based on the combination of the first and second signals.
2 Assignments
0 Petitions
Accused Products
Abstract
Apparatus and method for monitoring vibration levels in rotatable machinery (52). In one embodiment, a system (50) includes a source (66) for generating coherent radiation (70) and a first partially transmissive, partially reflective device (90) positioned to receive radiation (70) from the source (66) and transmit a part of the radiation there through. A second partially transmissive, partially reflective device (100) is mounted to the machinery (52), positioned to reflect a first signal (72) and transmit radiation (70) transmitted by the first device (90). A third device 104) is mounted to the machinery (52) and positioned to reflect radiation transmitted through the second device to provide a second signal (78). Circuitry (82, 86) is configured to generate an electrical signal based on a combination of the first and second signals (72, 78), and processing circuitry (114) provides a value indicative of vibration amplitude occurring in the machinery (52) based on the combination of the first and second signals. An embodiment of an associated method includes providing a first radiation signal (70) of a first frequency, deriving second and third radiation signals (78A, 78B) each having a time-varying Doppler shifting frequency relative to the first signal, and providing a value indicative of vibration amplitude occurring in the machinery (52) based on a combination of the second and third signals.
30 Citations
22 Claims
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1. An apparatus for monitoring vibration levels in rotatable machinery comprising:
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a source for generating coherent radiation; a first partially transmissive and partially reflective device positioned to receive radiation from the source and transmit a part of the radiation there through; a second partially transmissive and partially reflective device mounted to the machinery, positioned to reflect a first signal and transmit radiation transmitted by the first device; a third device mounted to the machinery and positioned to reflect radiation transmitted through the second device to provide a second signal; circuitry configured to generate an electrical signal based on a combination of the first and second signals; and processing circuitry configured to provide a value indicative of vibration amplitude occurring in the machinery based on the combination of the first and second signals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A method for monitoring vibration levels in a rotatable machine comprising the steps of:
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providing a first radiation signal of a first frequency; deriving a second radiation signal of a variable doppler shifting frequency from the first signal; providing a value indicative of vibration amplitude occurring in the machinery based on a beat frequency generated with the second signal; and deriving a third radiation signal having a time-varying doppler shifting frequency relative to the first signal, wherein the beat frequency is generated based on a combination of the third signal. - View Dependent Claims (19, 20, 21, 22)
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Specification