| 摘要 |
PURPOSE:To enhance measuring accuracy, by projecting photometric luminous flux to the surface of the laser beam irradiation surface of a specimen particle flowing part and detecting the focus matching state of a photometric objective lens from the positional relation of the obtained reflected image detected by a photoelectric detector. CONSTITUTION:An opening 23 is projected to the surface of a flow cell 1 by a light source 22 through a convex lens 24, an iris 27 and a convex lens 25 and the slit image of the opening 23 reflected from said surface is formed onto a position detector 28 through lenses 24, 25 and a mirror 26. If the distance from the center of a flowing part 2 to the surface of the flow cell 1 has been preliminarily cleared, the focus of an objective lens 8 is also necessarily matched with the center of the flowing part 2 when the focus of the opening 23 is matched on the surface of the flow cell 1 by the lenses 24, 25 and the parallel luminous flux of a specimen particle image is always obtained from the lens 8. By this method, the focus adjustment of the photometric objective lens can be easily and accurately performed on the basis of the bit position of the detector 28 to which the slit image of the opening 23 was formed and highly accurate analysis is enabled. |
