EP1896813A2 - Jauge extensometrique optique - Google Patents

Jauge extensometrique optique

Info

Publication number
EP1896813A2
EP1896813A2 EP06762219A EP06762219A EP1896813A2 EP 1896813 A2 EP1896813 A2 EP 1896813A2 EP 06762219 A EP06762219 A EP 06762219A EP 06762219 A EP06762219 A EP 06762219A EP 1896813 A2 EP1896813 A2 EP 1896813A2
Authority
EP
European Patent Office
Prior art keywords
optical
strain gauge
bragg grating
strain
carrier film
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP06762219A
Other languages
German (de)
English (en)
Inventor
Karl-Heinz Haase
Michael Schmidt
Regis Blin
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hottinger Bruel and Kjaer GmbH
Original Assignee
Hottinger Baldwin Messtechnik GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hottinger Baldwin Messtechnik GmbH filed Critical Hottinger Baldwin Messtechnik GmbH
Publication of EP1896813A2 publication Critical patent/EP1896813A2/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L1/00—Measuring force or stress, in general
    • G01L1/24—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet
    • G01L1/242—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet the material being an optical fibre
    • G01L1/246—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet the material being an optical fibre using integrated gratings, e.g. Bragg gratings

Definitions

  • the invention relates to an optical strain gauge according to the preamble of patent claim 1 and its manufacturing method according to the preamble of patent claim 9.
  • Such electrical strain gages usually consist of meander-shaped measuring grids produced photolithographically from an electrical resistance material which is applied to a carrier film made of plastic and for mechanical protection, usually with a further one
  • These electrical strain gauges are applied to a deformation-dependent strain to detect a load-dependent strain and convert the strain by a change in resistance of the measuring grid in an electrical signal that is proportional to the strain or the force.
  • electrical strain gauges are sensitive to electromagnetic fields or high-voltage influence and may not be used in potentially explosive atmospheres.
  • a high voltage insensitive optical strain sensor for measuring the contact force of a current collector for rail vehicles is known from DE 102 49 896 Al. This is between the sanding bar and a Holding frame of the current collector attached to an expansion body whose surface deforms according to the contact force.
  • a so-called fiber Bragg grating sensor is fixed, which obviously consists of an optical waveguide, in whose application area a so-called Bragg grating is embossed, which changes its reflection wavelength according to the detected strain.
  • the waveguide end with the Bragg grating is simply glued to the deformation body and acts as an electrical strain gauge on a load-dependent surface strain.
  • An embedded optical sensor is known from EP 753 130 Bl, which consists of a linear waveguide with a Bragg grating embedded within multiple layers of reinforcing filaments to form a laminated structure. This sensor is designed to measure both stresses and temperatures in the structure within the laminated structure with a single Bragg grating fiber.
  • a voltage sensor must always be embedded in the measurement object, so that the deformation element must always represent a laminated structure, so that it can not produce thin planar optical strain gauges with comparable dimensions as with electrical strain gauges.
  • EP 1 129 327 Bl a sensor for measuring mechanical stresses with fiber-optic Bragg gratings is known, which is designed as a planar flat transducer, which can be applied to a deformation body.
  • This voltage sensor is provided as a rosette for measuring a multi-axis voltage, which consists of a waveguide with preferably three successively arranged Bragg gratings, which are aligned at certain angles to each other. To reduce the sensor surface and to avoid larger reflection losses are therefore the curved
  • the waveguide with the Bragg gratings and the connecting elements is preferably encapsulated in a rigid epoxy or glued between two parallel rigid plates.
  • the plates can be attached to the surface of deformation bodies and thus transfer the strain applied to the plates to the fiber Bragg gratings whose reflected wavelength changes in proportion to the strain and can be detected.
  • Optical fiber unrolled over the middle of the row of holes and glued onto the adhesive strip carrier. Thereafter, the adhesive strip with the fixed optical fiber is positioned on the support surface and coated with a lacquer layer that penetrates through the rows of holes and the
  • the invention is therefore based on the object to provide prefabricated strain gauges of optical waveguides that can be produced in precise uniform manufacturing quality and can be manufactured inexpensively.
  • the invention has the advantage that very compact optical strain gauges can be produced by fixing the waveguide with the Bragg gratings in provided guide channels on a carrier foil.
  • the provided guide channels are preferably by a photolithographic etching process or a mechanical processing method made very accurately, so that such optical strain gauges have a high reproducibility and can advantageously be prefabricated as serial parts in large quantities at low cost to be applied in a simple manner on intended deformation bodies or other expansion bodies.
  • Such prefabricated flat and small-area optical strain gauges can also be advantageously fixed in or on fiber composites, which affect the fiber structure only slightly and advantageously also withstand strain changes up to 10% undamaged, as are common in deformation bodies made of fiber composites.
  • the optical strain gages of the invention have the advantage over electrical strain gauges that they are largely insensitive to electromagnetic fields and high voltage areas. They advantageously have no power supply, so that they are insensitive to power fluctuations on the transmission line and may also be used in hazardous areas. Furthermore, the non-positive connection of the Bragg gratings in the guide channels allows an enclosed connection structure with the flat carrier film, so that a good and defined power transmission is ensured on the Bragg gratings, whereby a high measurement accuracy and in particular a low hysteresis effect can be achieved.
  • a particular embodiment of the invention in which the optical waveguides are cast over the entire surface in the guide channels, has the advantage that it can be made very flat easy to manufacture optical strain gauges. Because these optical strain gauges too can be produced from ceramic or glass carrier foils and optical waveguides made of glass materials, these can be advantageously used even at very high temperature loads.
  • Strain gauge and the adjacent remaining components can be detected.
  • Fig. 1 the top view of an optical
  • an optical strain gauge 1 is shown, which is designed for biaxial strain measurement as a rosette and basically consists of three juxtaposed optical waveguides 2, 3, 4 with embossed Bragg gratings 5 in the incorporated guide channels 7, 8, 9 a carrier film 6 are fixed.
  • a thin elastic carrier film 6 is provided, which is preferably made of plastic, such as. B. polyimide.
  • the carrier film 6 can but also made of other hard elastic plastics, metals, glass or ceramics. In practice, an elastic silica glass film has proven to be very thin and in which the guide channels can be precisely ground.
  • the carrier film 6 is used to apply the prefabricated optical strain gauges 1 on provided deformation bodies or to integrate in loaded components in a positionally and non-positively.
  • the prefabricated support film 6 is planar, preferably has a rectangular or square base and a thickness of about 0.3 mm. For special designs but also film thicknesses of 0.2 to 0.8 mm are possible.
  • the base depends essentially on the length of the Bragg gratings 5 at the ends of the optical waveguides 2, 3, 4 and the formation of the optical strain gauges 1 for one or two-axis strain detections.
  • a linearly aligned optical waveguide 3 is provided in a guide channel 2 of the carrier film 6, which has a length of about 8 to 15 mm and a width of about 2 to 5 mm, depending on the required Stör- Nutzsignalabstand.
  • an optical strain gauge 1 for biaxial strain detection by means of three angularly offset disposed Bragg gratings 5 a size of the support film 6 of about 26 x 30 mm is provided. The size is determined not only by the 10 mm long Bragg gratings 5, but essentially also by the
  • optical waveguide 2, 3, 4 guide channels 7, 8, 9 or recesses incorporated, whose cross section corresponds at least to the cross section of the optical waveguides 2, 3, 4.
  • optical waveguides 2, 3, 4 are preferably used made of mineral glass fibers with an outer diameter of 0.25 mm, so that the guide channels 7, 8, 9 or depressions at least in the lead-in area 12 to the cross-sectional edge AA each have a depth and width of 0.25 mm have.
  • optical waveguides 2, 3, 4 The arrangement of the optical waveguides 2, 3, 4 is shown in detail in detail in Fig. 2 of the drawing. From the section of the sectional image A-A it can be seen that four optical waveguides 2, 3, 4, 13 are arranged parallel next to one another in the lead-in region 12. There are three
  • Optical waveguide 2, 3, 4 provided for strain measurement and an end in the lead-in optical waveguide 13 is used only for temperature compensation.
  • This fourth optical waveguide 13 ends about 2 mm behind the introduction edge and has outside the carrier film 6, a Bragg grating 14 for temperature detection.
  • the other three optical waveguides 2, 3, 4 are continued after the introduction region 12 only with their fiber cladding region.
  • These glass fibers 2, 3, 4 are preferably made of a fiber core 15, a fiber cladding 16 and a fiber protection layer 17, which may also be omitted. Since the optical light-guiding effect occurs exclusively in the core 15 and cladding region 16 of the glass fiber, the fiber protection layer 17 has been removed as a mechanical protection region behind the introduction region 12. This is also necessary in order to impress the Bragg gratings 5 at the end of the glass fibers 2, 3, 4.
  • three further guiding channels 7, 8, 9 of only 0.125 mm (or less) depth and width are incorporated into the carrier film 6, which corresponds to the diameter of the fiber jacket 16.
  • the middle guide channel 8 for fixing the second optical waveguide 3 extends linearly and simultaneously represents the center line of the symmetrical optical strain gauge 1.
  • the second optical waveguide 3 with the two outer optical waveguides 4, 3 in each case an angle of 45 ° and the two outer to each other an angle of 90 °, so that so that all strains in the two surface axes can be detected.
  • the optical waveguides 2, 3, 4 are inserted into the three guide channels 7, 8, 9 which are diverging, at the ends of which the three Bragg gratings 5 have already been embossed.
  • the three optical fibers 2, 3, 4 are very flexible and with 0.125 mm diameter or less relatively thin, the insertion into the guide channels 7, 8, 9 can be done easily both mechanically and manually, as this by the accurately fitting guide channel dimensions Pressure can be fixed in this. In this case, a firm connection can be achieved both by pressing and by gluing to the carrier film 6, so that not only a form-fitting, but also a firm frictional connection between the optical waveguides 2, 3, 4 and the carrier film 6 takes place.
  • a so-called strain gauge rosette is basically formed, with which all horizontally extending force or expansion components can be detected.
  • a curable epoxy resin adhesive has been proven in practice, which also has only low hysteresis and excellent transmission of the strain on the optical waveguide 2, 3, 4 guaranteed.
  • the optical waveguide 2, 3, 4 is designed as a planar optical waveguide, which is preferably cast in the guide channels 7, 8, 9, 10.
  • an optically conductive polymer substrate or another so-called photoresist is introduced into the guide channel 7, 8, 9, 10 of the plastic carrier film 6, which has a higher refractive index than the carrier film 6.
  • the polymer substrate is basically the core and the carrier film 6 the sheath with the lower refractive index.
  • the light line of certain wavelengths as glass fibers is suitable.
  • strip-shaped irregularities are imprinted at a distance ⁇ before introducing the photoconductive layer into the guide channels 7, 8, 9, which then act as Bragg gratings 5.
  • These can represent comb-like elevations or depressions which form a Bragg grating over a length L of 3 to 10 mm, which reflects the light waves fed in at a predetermined wavelength ⁇ B. Because the
  • Optical waveguides 2, 3, 4 firmly embedded in the guide channels 7, 8, 9 of the support layer 6 and are firmly connected to these, so that all strains acting on the support layer 6 can be accurately detected.
  • these polymeric optical waveguides 2, 3, 4 as optical strip conductors, very flat designs of optical strain gauges 1 which are thinner than 0.5 mm can be realized.
  • Such embodiments of optically conductive media embedded in the guide channels 7, 8, 9 as optical waveguides 2, 3, 4 can also be carried out with heat-resistant glass or ceramic films as carrier layer 6, in whose guide channels 7, 8, 9 photonic crystals are cast with quartz glass substrates.
  • the Bragg gratings are formed with the help of photonic crystals, with which the strain is detected.
  • the channels can preferably also be realized by a field-assisted ion exchange.
  • the Bragg gratings are then introduced into these channels from outside through a chemical etching process.
  • Such embodiments of optical strain gauges 1 can be used at temperatures up to 900 0 C. .._
  • the guide channels 7, 8, 9, 10 are additionally coated with the inserted waveguides 2, 3, 4 with a thin cover film 19.
  • the cover 19 is preferably also made of the material of the carrier film 6 such. As polyimide and preferably has a thickness of 0.05 mm and is welded or glued to the support sheet 6, so that the optical strain gauge 1 is hermetically sealed.
  • Such an optical strain gauge 1 can be applied both to metallic deformation bodies as conventional electrical strain gauges or inserted or glued in fiber composites. With such optical strain gauges 1 are not only strain measurements, but also
  • optical strain gauge 1 If such an optical strain gauge 1 is applied to a force-loaded deformation body, it can thus be described as follows, the applied force or strain can be detected. Because of the force acting on the expansion body force takes place on the surface of an expansion effect, which is transmitted via the applied thereto carrier sheet 6 on the non-positively fixed therein optical waveguides 2, 3, 4. This also creates a change in length within the Bragg grating region L, since this is formed from a piece of the core 15 of the optical fiber 2, 3, 4, which is surrounded by the shell 16, which has a lower refractive index than the core 15.
  • the optical fiber 2, 3, 4 is formed above as a single-mode fiber in which the diameter of the 9 ⁇ m fiber core 15 is sufficiently small so that the light from a preferably infrared light source can propagate along the core 15 in only a single mode. This single mode is essentially guided by the refractive index jump at the core-cladding boundary.
  • the lines 20 of the Bragg grating 5 are a series of preferably regularly spaced perturbations of the effective refractive index n of the core 15.
  • the Bragg grating 5 extends along a length L of the optical fiber 2, 3, 4, where L is normally in the range of 3 up to 20 mm.
  • the refractive indices n in the core 15 are generated by masking the optical fibers 2, 3, 4 with a phase mask and irradiating them with strong ultraviolet light.
  • the index perturbations n are formed by exposing the optical fibers 2, 3, 4 to an interference pattern generated from two intersecting halves of a UV laser beam. The distance ⁇ between the index perturbations n is determined by the angle at which the two halves of the beam intersect.
  • the Bragg gratings 5 are formed by disturbances in the carrier film 6.
  • a comb-like line pattern is mechanically impressed into the carrier film 6 with the distance ⁇ , through which the light waves are reflected.
  • the Bragg grating 5 is preferably formed by irradiation with UV light and a phase mask. The disturbances caused by these methods Nuclear refractive index n is usually on the order of one-thousandth or less.
  • the optical fibers 2, 3, 4 used for the production of Bragg gratings 5 generally have a protective layer 17 outside of the jacket 16, which preferably consists of a polymer and has no significance for the actual light-guiding function. This protective layer 17 is removed before the optical fiber 2, 3, 4 is exposed to the UV light to form the Bragg grating 5. After irradiation, the stripped portion of the optical fiber 2, 3, 4 may also be recoated to restore its durability. However, since the optical fibers 2, 3, 4 in the present exemplary embodiment run in the guide channels 7, 8, 9 and are protected by both the carrier film 6 and the cover film 19, sufficient mechanical protection of the optical fibers 2, 3 is provided in the optical strain gauge 1 according to the invention , 4 guaranteed.
  • the Bragg grating 5 When the Bragg grating 5 is supplied with a broad spectrum of light as an input signal, most wavelengths penetrate the grating area and form a transmitted output signal. The periodic disturbances of the refractive index n, however, produce a strong Bragg reflection with components of the input signal
  • the lightwave signals reflected by the Bragg grating 5 can be detected.
  • the determined wavelength ⁇ at which a peak occurs in reflection, a value which is dependent on the grating period ⁇ .
  • a longitudinal strain acts on the Bragg grating 5 changes the distance ⁇ , so that the Bragg wavelength ⁇ B shifts.
  • the Bragg wavelength ⁇ B behaves approximately proportionally to the strain along the longitudinal axis of the optical waveguides 2, 3, 4.
  • the wavelength change ⁇ B is thus a measure of the introduced into the deformation body
  • optical strain gauges 1 can be used similarly to electrical strain gauges on provided deformation body preferably in load cells, torque shafts or other force transducers.
  • optical strain gauges 1 can be used similarly to electrical strain gauges on provided deformation body preferably in load cells, torque shafts or other force transducers.
  • Strain gauges 1 also used in load tests, for example in aerospace, where the optical strain gauges 1 are then applied directly to the loaded components, in particular the rosettes according to the invention for measuring the unknown force introduction directions are useful. But also for monitoring the operating state of loaded components such optical strain gauges 1 can be used, which can detect a fatigue damage or cracking when exceeding a predetermined limit strain.
  • this evaluation unit 21 contains a transmitting and receiving unit 23 for optical waveguides 2, 3, 4, in which the evaluation unit 21 detects the wavelength ⁇ B reflected by the Bragg gratings 5, 14. It is first in the unloaded state by means of a preferably infrared light source as
  • K E the sensitivity factor of the elongation
  • ⁇ the strain
  • K ⁇ the sensitivity factor of the temperature
  • ⁇ T the temperature change.
  • a fourth optical waveguide 13 with Bragg grating 14 located outside the optical strain gauge 1 additionally becomes provided for temperature compensation.
  • the fourth optical waveguide 13 could also be integrated into the carrier foil 6 in the case of a modified optical strain gauge 1. Then, however, the associated guide channel 10 would have to be dimensioned such that the Bragg grating 14 rests loosely to exclude the effects of stretching.
  • Such an additional optical fiber with a Bragg grating 14 for temperature compensation is also provided for linear optical strain gauges 1 with only a straight optical fiber 3. It can be the additional Optical fiber are also used simultaneously to a pure temperature measurement.
  • optical strain gauges 1 can be formed, in which a plurality of rosettes or a plurality of linear optical fibers are arranged on a larger support film surface, which allow a flat strain detection, to determine an analysis of the voltage curve, for example, on complicated components.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Length Measuring Devices By Optical Means (AREA)
  • Optical Transform (AREA)
  • Light Guides In General And Applications Therefor (AREA)

Abstract

La présente invention concerne une jauge extensométrique optique (1) qui est constituée d'une couche de support plane (6), de préférence en matière plastique, et d'une couche de revêtement (19), au moins un guide d'ondes optiques (2, 3, 4) étant placé par liaison de force entre celles-ci. Le guide d'ondes optiques (2, 3, 4) présente au moins une section (L) avec un réseau de Bragg (5) qui permet de détecter l'allongement d'un corps de déformation ou d'une autre zone du composant. Cette invention est caractérisée en ce que le guide d'ondes optiques (2, 3, 4) est intégré à l'intérieur d'au moins un canal de guidage (7, 8, 9) dans le film de support servant de couche de support (6). Le canal de guidage (7, 8, 9), ainsi que le guide d'ondes optiques (2, 3, 4) et le réseau de Bragg imprimé à l'intérieur (5) sont scellés avec un film de recouvrement servant de couche de revêtement (19), qui est constitué de la même matière que le film de support (6).
EP06762219A 2005-06-29 2006-06-27 Jauge extensometrique optique Withdrawn EP1896813A2 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE200510030751 DE102005030751A1 (de) 2005-06-29 2005-06-29 Optischer Dehnungsmessstreifen
PCT/EP2006/006214 WO2007000324A2 (fr) 2005-06-29 2006-06-27 Jauge extensometrique optique

Publications (1)

Publication Number Publication Date
EP1896813A2 true EP1896813A2 (fr) 2008-03-12

Family

ID=37440640

Family Applications (1)

Application Number Title Priority Date Filing Date
EP06762219A Withdrawn EP1896813A2 (fr) 2005-06-29 2006-06-27 Jauge extensometrique optique

Country Status (3)

Country Link
EP (1) EP1896813A2 (fr)
DE (1) DE102005030751A1 (fr)
WO (1) WO2007000324A2 (fr)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102006002500B4 (de) * 2006-01-13 2008-02-28 Hottinger Baldwin Messtechnik Gmbh Optisches Spektrometer
DE102007007047A1 (de) 2007-02-08 2008-08-14 Hottinger Baldwin Messtechnik Gmbh Vorrichtung zur Erfassung von Schwingungen oder Durchbiegungen von Rotorblättern einer Windkraftanlage
DE102008027931A1 (de) * 2008-06-12 2010-01-07 Hottinger Baldwin Messtechnik Gmbh Optischer Dehnungssensor
DE102009018927A1 (de) 2009-04-28 2010-11-04 Deutsche Bahn Ag Vorrichtung zur Messung der zwischen Rad und Schiene auftretenden Kräfte, insbesondere Messradsatz für Schienenfahrzeuge
DE102011084579B4 (de) 2011-10-14 2013-11-07 Bauhaus Universität Weimar Vorrichtung und Verfahren zur Überwachung des Zustands einer Klebverbindung
DE102013219149A1 (de) 2013-09-24 2015-04-09 Schaeffler Technologies AG & Co. KG Messsystem und Messverfahren zur Messung einer Oberflächendehnung mittels eines plasmonischen Reflektors
CN104613890B (zh) * 2015-02-09 2017-04-19 清华大学 光栅应变测量装置
DE102018108399B4 (de) * 2018-04-10 2024-02-29 Dr. Ing. H.C. F. Porsche Aktiengesellschaft Kraftfahrzeugkarosserieelement mit einem Formüberwachungssystem für eine Kraftfahrzeugkarosserie

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4750796A (en) * 1985-05-31 1988-06-14 Sumitomo Electric Industries, Ltd. Optical sensor

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2727203B1 (fr) * 1994-11-18 1996-12-13 Commissariat Energie Atomique Micro-systeme optique de type rosette de jauges de contraintes a guides dielectriques pour la mesure d'une contrainte longitudinale en structure plane
US6778735B2 (en) * 2001-03-19 2004-08-17 Micron Optics, Inc. Tunable fiber Bragg gratings

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4750796A (en) * 1985-05-31 1988-06-14 Sumitomo Electric Industries, Ltd. Optical sensor

Also Published As

Publication number Publication date
WO2007000324A2 (fr) 2007-01-04
DE102005030751A1 (de) 2007-01-11
WO2007000324A3 (fr) 2007-03-22

Similar Documents

Publication Publication Date Title
EP1899700B1 (fr) Jauge extensometrique optique
EP1122528B1 (fr) Arrangement et méthode pour déterminer dilatations et températures et ses variations d'une couche de couverture appliquée sur un support
DE69912301T2 (de) Sensor zur messung mechanischer spannungen mit fiber-optischen bragg gittern
WO2007000324A2 (fr) Jauge extensometrique optique
DE102016100432B4 (de) Automatisch vorgespannte und vollständig von einer Feder ummantelte Lichtleiter-Sensorstruktur
DE69636019T2 (de) Integriert-optischer interferometrischer Sensor
EP2126511B1 (fr) Jauge optique d'allongement
DE2819590A1 (de) Vorrichtung zur messung der in einem festen koerper vorliegenden spannung
EP1134566A1 (fr) Procédé pour mesurer la température à l'aide d'un fibre optique et capteur de température à fibre optique
EP0342192B1 (fr) Capteur optique de mesure de force
DE102011050717B4 (de) Messsystem und Verfahren zum Validieren eines faseroptischen Sensor
DE3418247A1 (de) Durchbiegungsmesser
DE102011084579B4 (de) Vorrichtung und Verfahren zur Überwachung des Zustands einer Klebverbindung
DE3608599C2 (fr)
EP2812667B1 (fr) Dispositif de mesure et procédé pour détecter la sollicitation de force d'un objet souple en flexion
DE102012221067A1 (de) Dehnungsmessstreifen und mechanische Komponente
EP2294374B1 (fr) Capteur optique d allongement
EP2926104A2 (fr) Procédé de mesure de pression à résolution spatiale
DE102017201523A1 (de) Faseroptische Erfassungseinrichtung sowie Verfahren zum Betreiben einer solchen faseroptischen Erfassungseinrichtung
WO2019180161A1 (fr) Capteur de température
WO2015024915A1 (fr) Module de détection
DE3701548A1 (de) Optischer kraftmessensor
DE19755739A1 (de) Lichtwellenleiter-Dehnungsmeßstreifen (LWL-DMS)

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20071220

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI SK TR

DAX Request for extension of the european patent (deleted)
RIN1 Information on inventor provided before grant (corrected)

Inventor name: HAASE, KARL-HEINZ

Inventor name: SCHMIDT, MICHAEL

Inventor name: BLIN, REGIS

DAX Request for extension of the european patent (deleted)
17Q First examination report despatched

Effective date: 20090420

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20160823