Diffraction monitoring of Rayleigh mode jets
AssigneeXerox Corporation
InventorsArmand P. Neukermans, Dale R. Ims
Life of this patent
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Abstract
A light diffraction technique is set forth for monitoring the behavior of small liquid jets operating in the Rayleigh mode. This monitoring enables measurement of jet parameters, and thereby further enables on-line control of these parameters.
Claims6
A method for monitoring the behavior of jets producing streams of droplets by operating in the Rayleigh mode, comprising:
- a. intercepting in the proximity of said jets said streams of droplets with coherent radiation, .lambda..sub.1, said radiation being directed orthogonal to the direction of travel of said stream of droplets, wherein said radiation is diffracted into a pattern of concentric, alternating light and dark rings superimposed upon at least one pair of dark bands;
- and
- b. intercepting said pattern upon a screen at a distance, d, from said streams;
- said pattern being characterized by the distance between the dark bands .DELTA.X = .lambda..sub.1 d/s where s is the separation between individual droplets in a stream of droplets and by the distance from the center of the concentric bands to the middle of the second dark ring p where the droplet radius a = 7.016 .div. p/d.
A method for monitoring separation, s, between individual droplets in a stream of droplets produced by a jet operating in the Rayleigh mode, comprising:
- a. intercepting in the proximity of said jet said stream of droplets with coherent radiation, .lambda..sub.1, said radiation being directed orthogonal to the direction of travel of said stream of droplets, wherein said radiation is diffracted into a pattern of concentric, alternating light and dark rings superimposed upon at least one pair of dark bands;
- b. intercepting said pattern upon a screen at a distance, d, from said stream wherein the distance between the dark bands of the intercepted pattern .DELTA.X = .lambda..sub.1 d/s;
- and
- c. monitoring .DELTA.X for indication of any change in the value of s.
A method for determining the velocity, V.sub.j, of a stream of droplets produced by a jet operating in the Rayleigh mode at a frequency f, comprising:
- a. intercepting in the proximity of said jet said stream of droplets with coherent radiation, .lambda..sub.1, said radiation being directed orthogonal to the direction of travel of said stream of droplets, wherein said radiation is diffracted into a pattern of concentric, alternating light and dark rings superimposed upon at least one pair of dark bands;
- b. intercepting said pattern upon a screen at a distance d, from said stream wherein the distance between the dark bands of the intercepted pattern, .DELTA.X = .lambda..sub.1 d/s, where s is the separation distance between individual droplets in said stream of droplets;
- c. measuring .DELTA.X and determining s = .lambda..sub.1 d/ X;
- and
- d. determining V.sub.j by obtaining the product of s and f.
Dependencies are inferred from the claim text.