公开(公告)号：NO20013152L

公开(公告)日：2001-06-22

申请号：NO20013152

申请日：2001-06-22

Applicant: ABB RESEARCH LTD

Inventor： BOHNERT KLAUS ,  BRAENDLE 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.

公开(公告)号：NO20013152D0

公开(公告)日：2001-06-22

申请号：NO20013152

申请日：2001-06-22

Applicant: ABB RESEARCH LTD

Inventor： BOHNERT KLAUS ,  BRAENDLE HUBERT

IPC: G01L11/02 ,  G01L

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.

公开(公告)号：DE19958600A1

公开(公告)日：2001-06-07

申请号：DE19958600

申请日：1999-12-06

Applicant: ABB RESEARCH LTD

Inventor： BOHNERT KLAUS ,  BRAENDLE HUBERT ,  GABUS PHILIPPE

IPC: C03B37/15 ,  G02B6/10 ,  G02B6/255 ,  G02B6/34

公开(公告)号：BR9908236A

公开(公告)日：2000-10-31

申请号：BR9908236

申请日：1999-01-14

Applicant: ABB RESEARCH LTD

Inventor： BOHNERT KLAUS ,  BRAENDLE HUBERT

IPC: G01D5/353 ,  G01L1/24 ,  G01L11/02 ,  G02B6/02 ,  G02B6/10 ,  H01S3/06 ,  G02B6/16

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).

公开(公告)号：DE19808222A1

公开(公告)日：1999-09-02

申请号：DE19808222

申请日：1998-02-27

Applicant: ABB RESEARCH LTD

Inventor： BOHNERT KLAUS ,  BRAENDLE HUBERT ,  BODOR PATRICK

IPC: G01L9/00 ,  G01L11/02 ,  G01K11/32 ,  G02B6/124 ,  E21B47/06

Abstract: The invention relates to a wavelength-coded pressure sensor (1) with fibre-integrated Bragg grating, which is especially suitable for use at high pressures and temperatures in oil wells. The sensor principle provided for in the invention is based on the fact that the hydrostatic pressure of a liquid or gaseous medium (11) is converted by means of a transducer (1) into a longitudinal lengthening or compression of the fibre. The transducer (1) comprises a measurement or pressure cylinder (7a) which exchanges pressure with the medium (11), and a reference cylinder (7b) which is shielded from the medium (11) or subjected to a counter pressure. Temperature-compensated transducers (1) with a temperature-independent Bragg wavelength lambda B can be obtained because a suitable temperature-dependence of the mechanical prestressing of the pressure sensor fibre (3) is achieved through the selection of the materials, lengths and arrangements of the fibre holder support (5a, 5b). A fibre-integrated Bragg grating temperature sensor (19, 20) can also be provided. The invention further relates to transducers (1) with different cylinder arrangements (7a, 7b) and a wavelength multiplex configuration comprising several transducers (1).

公开(公告)号：ZA9503289B

公开(公告)日：1996-01-11

申请号：ZA9503289

申请日：1995-04-24

Applicant: ABB RESEARCH LTD

Inventor： BOHNERT KLAUS ,  NEHRING JUERGEN

IPC: G01D5/26 ,  G01J4/00 ,  G01M11/00 ,  G01N21/23 ,  G01R15/24 ,  G01D ,  G01N ,  G02F

CPC classification number: G01R15/242

公开(公告)号：CA2148310A1

公开(公告)日：1995-11-10

申请号：CA2148310

申请日：1995-05-01

Applicant: ABB RESEARCH LTD

Inventor： BOHNERT KLAUS ,  NEHRING JUERGEN

IPC: G01D5/26 ,  G01J4/00 ,  G01M11/00 ,  G01N21/23 ,  G01R15/24

Abstract: In order to detect, in particular, a high electric voltage (8), use is made of an electrooptic sensor with an electrooptic crystal (4) such as is applied in Pockels cells. Light is irradiated into the electrooptic crystal (4) in a linearly polarized fashion from a light source (L) via a fiber coupler (FK), a fiber-optic cable (F1), a collimator (K1), a 1st polarizer (P1), a beam splitter (1), and 1st and 2nd glass plates (2, 3). Located at the end face of said crystal is a 3rd glass plate (5) having a layer electrode (6) which simultaneously acts as a mirror (7) and retroreflects the incident light through the electrooptic crystal (4). One component beam (T1) of the reflected light passes back to a 1st light detector (D1) via the beam splitter (1) and the 1st polarizer (P1), now acting as an analyzer. A 2nd component beam (T2) passes to a 2nd light detector (D2) via a .lambda./4-delay plate (9), a 2nd polarizer (P2), a 90.degree. prism (10), a collimator (K2) and a 2nd fiber-optic cable (F2). Light intensities (I1) and (I2) are evaluated by means of a microprocessor (14). Owing to the fact that the two phase-shifted light signals are derived from a common optical channel, an intrinsic birefringence of the electrooptic crystal (4) does not affect their phase difference. A 90.degree. prism can be used instead of a mirror (7) for reversing the light. Input and output channels of the light can be separate. Ways are specified for the temperature compensation of a measurement result signal (S).