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Patent Agency Ranking
公开(公告)号：AU2003204491A1
公开(公告)日：2003-05-26
申请号：AU2003204491
申请日：2003-02-14
Applicant: ABB RESEARCH LTD
Inventor： BOHNERT KLAUS , BRANDLE HUBERT , GABUS PHILIPPE
IPC: G01R15/24
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公开(公告)号：AU1544700A
公开(公告)日：2000-07-31
申请号：AU1544700
申请日：1999-12-16
Applicant: ABB RESEARCH LTD
Inventor： BOHNERT KLAUS , BRANDLE HUBERT
Abstract: The present invention relates to a fiber laser pressure sensor 1 which is suitable in particular for measuring differential pressures and flow velocities v1 in oil boreholes. The fiber laser 2 according to the invention comprises two sensor fiber segments 5a, 5b subjected to different pressure loading, in which segments a birefringence proportional to the differential pressure DELTAp=p1-p2, and consequently a beat frequency, is induced between the polarization modes or spatial modes in the fiber laser 2. Exemplary embodiments with polarimetric monomode fibers 5a, 5b and/or with elliptical two-mode fibers 5a, 5b are specified. Furthermore, pressure-resistant multichamber sensor housings 25 and wavelength division multiplex arrangements are disclosed for the fiber laser pressure sensor 1. One advantage is that the pressure signal is wavelength-coded and thus highly insensitive to interference. It can be read out directly fiber-optically over large distances between the passively optical sensor head 1 and the optoelectronic measuring device 12, 17. One application concerns the measurement of a flow velocity v1 with the aid of a Venturi tube 23.
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公开(公告)号：AU5385800A
公开(公告)日：2001-03-19
申请号：AU5385800
申请日：2000-07-05
Applicant: ABB RESEARCH LTD
Inventor： BOHNERT KLAUS , BRANDLE HUBERT
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公开(公告)号：AU1502600A
公开(公告)日：2000-07-31
申请号：AU1502600
申请日：1999-12-16
Applicant: ABB RESEARCH LTD
Inventor： BOHNERT KLAUS , BRANDLE HUBERT
IPC: G01L11/02
Abstract: The subject matter of the present invention is a fiber Bragg grating sensor 1, 25 which is suitable, in particular, for measuring differential pressures and flow rates v1 in oil drill holes. The sensor principle according to the invention is based on using a transducer 1 with two pressure chambers 7a, 7b to convert a hydrostatic pressure difference between two liquid or gaseous media 11a, 11b into a longitudinal fiber elongation or fiber compression and measuring it via the displacement of the Bragg wavelength DeltalambdaB of at least one fiber Bragg grating 3, 4. Exemplary embodiments are specified which have two fiber Bragg gratings 3, 4 which are sensitive to elongation in opposite senses and which have temperature-compensating transducers 1, and which have a plurality of transducers 1 in a wavelength-division-multiplexing configuration. One embodiment relates to measuring a flow rate v1 with the aid of a venturi tube 23.
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公开(公告)号：AU1746999A
公开(公告)日：1999-09-15
申请号：AU1746999
申请日：1999-01-14
Applicant: ABB RESEARCH LTD
Inventor： BOHNERT KLAUS , BRANDLE HUBERT
Abstract: The invention relates to a frequency-coded fiber laser pressure sensor (1) which is especially suitable for measuring isotropic pressures in oil wells. The sensor principle provided for in the invention is based on the fact that in a fiber laser (2) doped with Er a monomode or bimodal sensor fiber (5, 5a, 5b) is positioned whose pressure-related birefraction results in a frequency shift and beat frequencies between the orthogonal linear polarisation modes x, y or the spatial modes LP01 and LP11 line. The beat frequencies are easily measured using a frequency counter (19). Temperature-related variations in birefraction are compensated in a differential arrangement of two sensor fiber segments (5a, 5b). Fiber-integrated Bragg gratings (4a, 4b) with low bandwidths (0.2 nm) are especially suitable as laser end reflectors. The pressure sensor (1) is characterized by a large measurement range (100 Mpa) and a high triggering capacity , (kPa), is readily multiplexed and can be housed in a very compact, light-weight and robust pressure-resistant housing (25).
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