Abstract: A fiber optic pressure sensor for measuring unsteady pressures within a pipe include at least one optical fiber disposed circumferentially around a portion of a circumference of the pipe, which provides an optical signal indicative of the length of the optical fiber. An optical instrument measures the change in length of the optical fiber to determine the unsteady pressure within the pipe. The pressure sensor may include a plurality of optical fiber sections disposed circumferentially around a portion of the circumference of the pipe that are optically connected together by optical fiber sections disposed axially along the pipe. The optical fiber sections may include fiber Bragg gratings having substantially the same or different reflection wavelengths to permit for example the sensors to be axially distributed along the fiber using wavelength division multiplexing and/or time division multiplexing.

Abstract: An apparatus for non-intrusively sensing fluid flow within a pipe is provided. The apparatus includes a first sensing array for sensing acoustic signals traveling at the speed of sound through fluid flow within the pipe, a second sensing array for sensing local pressure variations traveling with the fluid flow, and a housing attached to the pipe for enclosing the sensing arrays. The first sensing array includes a plurality of first optical pressure sensors and the second sensing array includes a plurality of second optical pressure sensors.

Abstract: Non-intrusive pressure sensors 14-18 for measuring unsteady pressures within a pipe 12 include an optical fiber 10 wrapped in coils 20-24 around the circumference of the pipe 12. The length or change in length of the coils 20-24 is indicative of the unsteady pressure in the pipe. Bragg gratings 310-324 impressed in the fiber 10 may be used having reflection wavelengths &lgr; that relate to the unsteady pressure in the pipe. One or more of sensors 14-18 may be axially distributed along the fiber 10 using wavelength division multiplexing and/or time division multiplexing.

Abstract: An apparatus for non-intrusively sensing fluid flow within a pipe is provided. The apparatus includes an array of sensors that include a plurality of optical fiber coils. The array of sensors senses the fluid flow inside the pipe. At least one optical reflective device is disposed between adjacent optical fiber coils. An isolation pad is disposed between each optical reflective device and the pipe.

Abstract: Non-intrusive pressure sensors 14-18 for measuring unsteady pressures within a pipe 12 include an optical fiber 10 wrapped in coils 20-24 around the circumference of the pipe 12. The length or change in length of the coils 20-24 is indicative of the unsteady pressure in the pipe. Bragg gratings 310-324 impressed in the fiber 10 may be used having reflection wavelengths &lgr; that relate to the unsteady pressure in the pipe. One or more of sensors 14-18 may be axially distributed along the fiber 10 using wavelength division multiplexing and/or time division multiplexing.

Abstract: An apparatus for non-intrusively sensing fluid flow within a pipe is provided. The apparatus includes a first sensing array for sensing acoustic signals traveling at the speed of sound through fluid flow within the pipe, a second sensing array for sensing local pressure variations traveling with the fluid flow, and a housing attached to the pipe for enclosing the sensing arrays. The first sensing array includes a plurality of first optical pressure sensors and the second sensing array includes a plurality of second optical pressure sensors.

Abstract: An apparatus for non-intrusively sensing fluid flow within a pipe is provided. The apparatus includes an array of sensors that include a plurality of optical fiber coils. The array of sensors senses the fluid flow inside the pipe. At least one optical reflective device is disposed between adjacent optical fiber coils. An isolation pad is disposed between each optical reflective device and the pipe.