Patent ID: 7679039
Filing Date: 2010-03-16
Classification: G01N

Abstract:
1. An apparatus for determining the position of a radiation beam relative to a fluid stream, comprising: (a) a radiation source for producing said radiation beam; (b) an optionally positionally adjustable nozzle having a discharge opening, wherein said fluid stream exits through said discharge opening, said nozzle positioned to cause said fluid stream and said radiation beam to intersect; (c) one or more transparent members having a first reflective inner surface and a second reflective inner surface placed to reflect radiation scattered by said fluid stream, wherein said reflective inner surfaces are placed to form the reflective exterior of a wedge; (d) a first detector placed to selectively detect radiation reflected from said first reflective inner surface; (e) a second detector placed to selectively detect radiation reflected from said second reflective inner surface; (f) a differential amplifier, wherein said differential amplifier compares the intensity of radiation detected at said first and second detectors; (g) a third reflective surface placed to reflect radiation through said fluid stream; (h) a positioning device attached to said third reflective surface; and (i) a feed back circuit, wherein a signal from said amplifier directs said positioning device to change the position of said third reflective surface.