Abstract: A highly sensitive accelerometer for determining the acceleration of a structure includes a mass within a housing suspended by opposing support members. The support members are alternately wound around a pair of fixed mandrels and the mass in a push pull arrangement. At least a portion of one of the support members comprises a transducer capable measuring the displacement of the mass within the housing. An embodiment of the invention employs optical fiber coils as the support members for use in interferometric sensing processes. Arrays of such interferometer based accelerometers may be multiplexed using known techniques.

Abstract: A clamp mechanism for actively coupling an in-well seismic station to the casing of a well is disclosed. The clamp mechanism is capable of associating a sensor to production tubing for deployment in the well and is capable of actively coupling the sensor to the casing of the well. The clamp mechanism includes a body capable of being coupled to the deployment member. A carrier mechanism is attached to the sensor and positions adjacent the body. A release mechanism releases the carrier mechanism when subjected to a predetermined pressure in the well or when subjected to fluid in the well for a predetermined amount of time. A biasing mechanism is disposed between the body and the carrier mechanism and displaces the carrier mechanism with attached sensor towards the surface of the casing when released. A guiding mechanism guides the displacement of the carrier mechanism towards the surface of the casing.

Abstract: An apparatus and method for transporting, deploring, and retrieving an array is disclosed. The array has a plurality of nodes interconnected by sections of cable and can be transported, deployed, and retrieved with the apparatus and method of the present invention. The apparatus includes a plurality of first divisions and a plurality of second divisions. The first divisions have first portions or holders capable of individually accommodating the nodes. The second divisions are alternatingly positioned adjacent the first divisions. The second divisions have second portions or surfaces capable of individually accommodating the sections of cable. The first and second divisions can be integral portions of the apparatus, can be separate members positioned on the apparatus, or can be used with a standard cable drum. Preferably, the second divisions can be rotated relative to the first divisions to tightly wind and easily unwind the sections of cable.

Abstract: A multiple component mechanism for housing one or more fiber optic based sensors and one or more fiber organizers and other devices for the sensors is disclosed. The mechanism includes a splice component and a sensor component, which are hermetically sealed. The sensor and splice components include substantially tubular bodies having lids welded to the ends. The fiber organizer and other devices are installed in the cylindrical splice component. The one or more sensors are installed in the tubular body of the sensor component with wedging devices. In one embodiment, the sensor component is acoustically decoupled from the splice component by a tube welded to the lids of the components. The tube communicates optical fiber from the fiber organizer to the one or more sensors.

Abstract: Method and system for obtaining scale factor calibration of a fiber optic sensor head (3, 6) comprising a conversion unit (3) with a conversion element (14) made from a material being subject to changes in its shape or physical dimensions under the influence of magnetic or electric fields, e.g. a magnetostrictive, electrostrictive, or piezoelectric material, and an optical fiber (4) being attached to the conversion element (14), the conversion element (14) thus straining the optical fiber causing a phase and/or intensity modulation of the optical signal in the fiber when subject to the fields. The method is characterized in that a chosen electrical energy is applied to the sensor head (3, 6) resulting in a change in the optical signal being received by the optical interrogation device, and calculating a calibration signal, e.g. a calibration scale factor, based on the applied electrical energy and the measured change in the optical signal.

Abstract: A highly sensitive accelerometer for determining the acceleration of a structure includes a mass within a housing suspended by opposing support members. The support members are alternately wound around a pair of fixed mandrels and the mass in a push pull arrangement. At least a portion of one of the support members comprises a transducer capable measuring the displacement of the mass within the housing. An embodiment of the invention employs optical fiber coils as support members for use in interferometric sensing processes. Arrays of such interferometer based accelerometers maybe multiplexed using WDM or similar methods.

Abstract: A chemical sensing probe comprises an optical fiber or may be mounted on an optical fiber. The probe has a chemically sensitive measuring material which exhibits a change in volume and/or a change in refractive index in the presence of a given chemical. The change in volume and/or refractive index gives a change in an optical path length through the probe which can be measured interferometrically.

Abstract: A highly sensitive accelerometer for determining the acceleration of a structure includes a mass within a housing suspended by opposing support members. The support members are alternately wound around a pair of fixed mandrels and the mass in a push pull arrangement. At least a portion of one of the support members comprises a transducer capable measuring the displacement of the mass within the housing. An embodiment of the invention employs optical fiber coils as the support members for use in interferometric sensing processes. Arrays of such interferometer based accelerometers may be multiplexed using known techniques.

Abstract: A highly sensitive accelerometer for determining the acceleration of a structure includes a mass within a housing rotationally supported by a hinge and opposing support members. The support members are alternately wound around a fixed mandrel and the mass in a pendulum arrangement. At least a portion of one of the support members comprises a transducer capable measuring the rotation of the mass within the housing. An embodiment of the invention employs optical fiber coils as support members for use in interferometric sensing processes. Arrays of such interferometer based accelerometers maybe multiplexed using WDM or similar methods.

Abstract: Method and system for obtaining scale factor calibration of a fiber optic sensor head (3, 6) comprising a conversion unit (3) with a conversion element (14) made from a material being subject to changes in its shape or physical dimensions under the influence of magnetic or electric fields, e.g. a magnetostrictive, electrostrictive, or piezoelectric material, and an optical fiber (4) being attached to the conversion element (14), the conversion element (14) thus straining the optical fiber causing a phase and/or intensity modulation of the optical signal in the fiber when subject to the fields. The method is characterized in that a chosen electrical energy is applied to the sensor head (3, 6) resulting in a change in the optical signal being received by the optical interrogation device, and calculating a calibration signal, e.g. a calibration scale factor, based on the applied electrical energy and the measured change in the optical signal.

Abstract: A combination of an optical fiber, a device for fastening the optical fiber to at least one Bragg grating including a generally cylindrical sleeve through which the fiber passes, and a bond between the fiber and the sleeve at one end thereof. The end of the sleeve to which the fiber is bonded permits expansion of the bond radially with respect to the optical fiber.

Abstract: A device is provided for measuring a bending load in mechanical constructions, which device enables measurement over a broad range of stresses with high precision and which simultaneously compensates for deviations caused by temperature fluctuations.

Abstract: A body compatible fiber optic sensor probe for invasive medical use is provided. The probe includes at least one sensing location at which the fiber is configured to provide at least one detectable changeable optical property responsive to strain within the fiber, and at least one sensing element which undergoes a volumetric change in response to an in body parameter to be sensed. The sensing element is coupled to the fiber in such a way that the volumetric change induces strain within the fiber so as to vary the detectable optical property or properties.

Abstract: A device (100) for measurement of pressure in fluids is disclosed that includes a cylindrical housing (101) having a pressure port (103), an inner cavity (102) and an opening (102b). A closed pipe (131) is situated in the cavity (102) and closes the opening (102b) in the housing (101) and establishes a cavity (134) between the pipe (131) and the inner wall of the housing (101). A connection element (133) is situated in the pipe (131), so that one end of the element (133) is connected to the free end of the pipe (131) for transfer of axial length change of the pipe (131), whereas the connected element (133) is arranged for establishing a cavity (132) between the connection element (133) and the pipe (131). An optical fiber (171) is laid in a slot (171) in the external surface of the housing (101), and includes a Bragg grating (150) fixed between the housing (101) and the connection organ (133) by fastening points (151, 152).

Abstract: The invention provides low viscosity iodinated aryl compounds, useful as X-ray contrast agents, of formula C6R6 wherein three non-adjacent R groups are iodine and the remaining R groups are non-ionic, hydrophilic moieties, said compound being water soluble at 20° C. to a concentration of at least 350 mgl/ml and which in aqueous solution at 20° C. at a concentration of 350 mgl/ml has a viscosity no greater than 13.8 mPas.

Abstract: The use in diagnostic imaging, in particular X-ray, MRI, ultrasound and scintigraphy, of contrast agents comprising bismuth clusters and/or organic bismuth compounds, and contrast media containing such bismuth compounds. The bismuth compounds are also useful in therapy, in particular as antimicrobial agents and antiulcer agents. Novel bismuth compounds are also disclosed.

Abstract: Oil-in-water emulsions in which the oil phase comprises condensed or dissolved oil-soluble gas/fluid or gas precursor are useful as ultrasound contrast agents. Such products contain insignificant amounts of free gas bubbles or microbubbles in their stored form and exhibit good stability, but may be designed to promote rapid microbubble generation immediately before or upon administration.

Abstract: A tension sensor including an optical fibre having a Bragg grating is disclosed, the sensor including a housing and a support member shorter that the housing coaxially disposed therein and connected to the housing at one end. The fiber runs along the longitudinal axis of the housing and is connected to one end of the housing and to at least one location on the support member. A second Bragg grating may be provided within the support member to allow for additional measurements for temperature compensation purposes.

Abstract: The invention provides low viscosity iodinated aryl compounds, useful as X-ray contrast agents, of formula I ##STR1## (wherein n is 0 or 1, and where n is 1 each C.sub.6 R.sub.5 moeity may be the same or different; each group R is a hydrogen atom, an iodine atom or a hydrophilic moiety M or M.sub.1, two or three non-adjacent R groups in each C.sub.6 R.sub.5 moiety being iodine and at least one, and preferably two or three, R groups in each C.sub.6 R.sub.5 moiety being M or M.sub.1 moieties; X denotes a bond or a group providing a 1 to 7 atom chain linking two C.sub.6 R.sub.5 moieties or, where n is 0, X denotes a group R; each M independently is a non-ionic hydrophilic moiety; and each M.sub.1 independently represents a C.sub.1-4 alkyl group substituted by at least one hydroxyl group and optionally linked to the phenyl ring via a carbonyl, sulphone or sulphoxide group, at least one R group being an M.sub.1 moiety; with the proviso that where n is zero either at least one M.sub.

Abstract: There is provided a contrast medium composition comprising: (a) a first contrast agent comprising a physiologically tolerable manganese compound, a physiologically tolerable reducing compound containing an .alpha.-hydroxy ketone group, or salt thereof, having a manganese concentration of at least 0.3 mM or being in a dosage unit form containing at least 300 .mu.mol manganese, together with (b) a second contrast agent. Such compositions have been found to be particularly suited to imaging of the liver.