LASER CENTRALISER FOR X-RAY EMITTER Russian patent published in 2011 - IPC H05G1/00 

FIELD: physics.

SUBSTANCE: laser centraliser has a housing in which there is a laser whose optical axis of which is parallel to the longitudinal axis of the X-ray emitter, two reflectors, the first of which is placed at the intersection of the axes of the laser and the X-ray beam, and the second is placed on the axis of the laser in front of its emitting face between it and the first reflector at a distance H from the centre of the first reflector, equal to the distance from that centre to the focal point of the X-ray tube on the axis of the X-ray beam, a spherical lens placed in front of the emitting face of the laser and the second reflector and which forms a conical laser beam, geometrical parameters of which are identical to parameters of the X-ray beam, the degree ellipticity of the light disc formed by that beam on the object determines the perpendicularity of its surface to the axis of the X-ray beam, a television camera, the optical axis of the objective lens of which coincides with the axis running from the centre of the second reflector perpendicular the axis of the laser and measurement scales for quantitative estimation of the dimensions of defects on the surface of the object and its perpendicularity to the X-ray beam, the centraliser also includes a computer and a laser range finder, placed on the housing of the centraliser outside the zone of propagation of the X-ray beam, wherein the optical axis of the range finder is parallel to axis of the X-ray beam, and its digital output is interfaced with the input of the computer, the second reflector has a centre opening D=Dl for passage of the laser beam, where Dl is the diameter of that beam, the computer automatically calculates the current value C of the scale interval in the object plane of the scale lying on the screen of the display or generated by a program from the relationship C=Co/M, where M the total magnification, Co is the scale interval on the screen of the display, M=Mt×Mo, where Mt=B/A is television magnification, A and B are dimensions of the raster of the CCD matrix and the display, respectively, Mo=F/L is the optical magnification, where F is the focal distance of the objective lens of the television camera, L is the current distance from the objective lens to the centraliser measured using the laser range finder, the objective lens of the television camera is a zoom lens and can measure focal distance from Fmin=Lmin/M to Fmax=Lmax/M, where Lmax and Lmin is the minimum and maximum distance from the centraliser to the object in the working range of their measurement, respectively, for a specific model of centraliser, and the value M=Co/C is selected based on the relationship Co/C=K, where K is an integer whose value is selected based on specific requirements for accuracy of the measured defects, wherein in order to increase stability of measurement, the values are generated for fixed values of the focal distance of the zoom lens for which the image of two reference laser points on the object with distance H between them coincides with corresponding marks on the screen of the monitor, the distance between which is equal to H*=H/M.

EFFECT: eliminating subjectiveness of the method of measuring distance to an object, as well as uncertainty of the scale interval on the screen of the monitor, the value of which depends on the distance from the object to the centraliser and the corresponding scale value of the optical image.

1 dwg