| 摘要 |
PROBLEM TO BE SOLVED: To provide a particle counter capable of counting small-diameter particles in fluid with a good S/N ratio.SOLUTION: An irradiation optical system 12 is configured to irradiate fluid flowing through a flow channel 2a with one of a plurality of light rays obtained by splitting light from a light source 1 to form a detection area. A detection optical system 13 guides scattered light rays traveling in directions different from an optical axis of the irradiation optical system, from among light rays scattered from the particles in the fluid in the detection area, into a beam splitter 17. In the meanwhile, a beam expander 16 guides another of the plurality of light rays into the beam splitter 17 as reference light. A detection unit 4 receives interference light of the scattered light and the reference light obtained by the beam splitter 17 using a photoreceptor, and generates a detection signal corresponding to the interference light. A counter unit 6 counts the particles using the detection signal.SELECTED DRAWING: Figure 1 |
