초록 ▼

A device for determining the values of a parameter of particles, especially of water droplets, includes a measuring element having a measuring region that is intended to accommodate the particles. An illumination device illuminates the measuring region with a light beam, and an image acquisition dev

A device for determining the values of a parameter of particles, especially of water droplets, includes a measuring element having a measuring region that is intended to accommodate the particles. An illumination device illuminates the measuring region with a light beam, and an image acquisition device, having a camera, acquires an image of the measuring region illuminated by the illumination device. A processing device determines the values of the parameter from the image acquired by the camera. To determine the values of the parameter, the illumination device produces point illumination using a light beam whose light rays are focused on an objective optic of the image acquisition devices.

대표청구항 ▼

1. A device for determining values of at least one parameter of particles, said device comprising:a measuring element comprising a measuring region to accommodate said particles;illumination means for illuminating said measuring region;image acquisition means, comprising at least one camera, for acq

1. A device for determining values of at least one parameter of particles, said device comprising:a measuring element comprising a measuring region to accommodate said particles;illumination means for illuminating said measuring region;image acquisition means, comprising at least one camera, for acquiring at least one image of said measuring region illuminated by said illumination means; andprocessing means for determining the values of said parameter, from said image acquired by the camera,wherein said illumination means produce a point illumination source using a light beam having light rays focused onto an objective optic of the image acquisition means, said illumination means comprising at least one optical assembly including:a light source that generates the light beam;an optical fiber, connected at a first end to said light source, that transmits the light beam generated by said light source; anda field optic, fitted to a second end opposite said first end of said optical fiber, that focuses the light beam emerging from said optical fiber on the center of the objective optic of the acquisition means. 2. The device as claimed in claim 1, wherein said optical fiber is a monomode fiber. 3. The device as claimed in claim 1, wherein said light source generates a coherent light beam. 4. A device for determining values of at least one parameter of particles, said device comprising:a measuring element comprising a measuring region to accommodate said particles;illumination means for illuminating said measuring region;image acquisition means, comprising at least one camera, for acquiring at least one image of said measuring region illuminated by said illumination means; andprocessing means for determining the values of said parameter, from said image acquired by the camera, wherein:said illumination means produce a point illumination source using a light beam having light rays focused onto an objective optic of the image acquisition means,said camera comprises means for opening the camera in order to acquire the image,said illumination means produce illumination in the form of light flashes, andsaid illumination means emit at least two light flashes during one and the same opening of the camera on acquiring the image. 5. The device as claimed in claim 4, wherein said illumination means comprise at least one pulsed laser with a saturable absorber, in order to emit said light flashes. 6. A device for determining values of at least one parameter of particles, said device comprising:a measuring element comprising a measuring region to accommodate said particles;illumination means for illuminating said measuring region;image acquisition means, comprising at least one camera, for acquiring at least one image of said measuring region illuminated by said illumination means; andprocessing means for determining the values of said parameter, from said image acquired by the camera, wherein:said illumination means produce a point illumination source using a light beam having light rays focused onto an objective optic of the image acquisition means, andsaid illumination means emit in a sequential manner at least two light beams having different diameters. 7. The device as claimed in claim 6, wherein:said illumination means comprise two laser sources associated with optics, respectively, of different magnifications, andsaid image acquisition means comprise a single camera and optical means for directing the two laser beams emitted by said two laser sources onto said camera. 8. The device as claimed in claim 1, wherein said processing means determine said parameter by shadowgraphy. 9. A device for determining values of at least one parameter of particles, said device comprising:a measuring element comprising a measuring region to accommodate said particles;illumination means for illuminating said measuring region;image acquisition means, comprising at least one camera, for acquiring at least one image of said measuring region illuminated by sai d illumination means; andprocessing means for determining the values of said parameter, from said image acquired by the camera, wherein:said illumination means produce a point illumination source using a light beam having light rays focused onto an objective optic of the image acquisition means,said illumination means emit two light flashes spaced apart by a predetermined duration,said camera acquires an image on emission of each of said two light flashes, andsaid processing means determine, as the parameter, the velocity vector of said particles, from the two images relating to said two light flashes and from said predetermined duration. 10. The device as claimed in claim 9, wherein an optical fiber is connected to said light source. 11. The device as claimed in claim 1, further comprising an interference filter which is fitted to the entrance of said camera. 12. The device as claimed in claim 1, wherein the objective and field optics have an applied antireflection treatment. 13. The device as claimed in claim 1, wherein said measuring region is delimited by at least one window. 14. The device as claimed in claim 13, further comprising means for blowing air over the external face of said window. 15. The device as claimed in claim 1, wherein said measuring element is a rod provided with a through opening at a first of its ends, said through opening containing said measuring region. 16. The device as claimed in claim 15, further comprising a protection which protects the entire said device, except for at least said first end of the rod which is placed in an environment containing said particles, against said particles. 17. The device as claimed in claim 15, wherein at least said first end of the rod is electrically insulated. 18. An aircraft, comprising the device specified in claim 1, wherein the device determines the values of said parameter of water droplets present outside said aircraft. 19. An aircraft comprising the device in claim 15 and further comprising a sleeve:which is fitted into a fuselage of the aircraft so as to create a through opening;which has a diameter adapted to the diameter of said rod such that the rod can be fitted in a sealed manner in said sleeve; andwhich may be closed in a sealed manner, in the absence of said rod.