| 摘要 |
PURPOSE:To reduce background noises and to improve the reliability of measurement by irradiating a particle group to be measured with laser light emitted by a laser device through an optical shield body which has an opening part where the laser light is transmitted. CONSTITUTION:The probe 1 composed of an irradiating part 5 and a photodetecting part 7 arranged opposite each other across a scattering area P is connected to a main body 2 through an optical fiber 3 for light irradiation and optical fibers 41-4n for photodetection. Further, the irradiating part 5 consists of a light tube 10, cylindrical shield body 11 which has the opening part 13, and collimator lens 12, and a photodetection tube 15 which includes photodetection end parts of the optical fibers 41-4n arranged at equal distance from the scattering area P and having a specific scatter angle is provided. Then, the laser light from the laser device 22 is shaped by the lens 12 into a parallel laser beam and the light shield body 11 cuts off scattered light, thereby obtaining the parallel laser beam as an irradiating beam. |
