Abstract: For an easy calibration using calibration particles, provided is a measuring device to capture images of target objects. An image analyzer acquires multiple images obtained at a predetermined time interval, (a) specifies the mean-square displacement of a bright point of a calibration particle based on the displacement of the bright point of the calibration particle in the multiple images in a calibration mode, and (b) specifies the mean-square displacement of a bright point of the target particle based on the displacement of the bright point of the target particle in the multiple images in a measurement mode. A particle size analyzer (c) derives the particle size of the target particle from the mean-square displacement of the bright point of the target particle based on the mean-square displacement of the bright point of the calibration particle and the particle size of the calibration particle in an analysis mode.

Abstract: Provided is a particle measurement device in which irradiation light emitted by a light source is expanded by an expander in a shape satisfying the requirements of a diffractive optical element, converted into parallel light, and made to enter the diffractive optical element. The diffractive optical element shapes the irradiation light entering therein into a flat top beam in which the cross section in the focal position thereof has an elongate rectangle shape. The intensity distribution of light can be made substantially uniform in a detection area formed by the shaped irradiation light.

Abstract: A flow passage is irradiated with irradiation light, and light scattered from a particle contained in a sample passing through a detection region that is formed in a prescribed section is condensed at a position obtained by extending the prescribed section in a flow direction of the sample and captured at a prescribed frame rate. Then movement amount of the particle due to Brownian motion in directions perpendicular to the flow direction on the basis of captured plural frame images. Furthermore, a particle size of the particle is determined by correcting the movement amount using correction values that were obtained in advance corresponding to each of defocus positions for correcting errors of movement amount in the images caused by magnification.

Abstract: For an easy calibration using calibration particles, provided is a measuring device to capture images of target objects. An image analyzer acquires multiple images obtained at a predetermined time interval, (a) specifies the mean-square displacement of a bright point of a calibration particle based on the displacement of the bright point of the calibration particle in the multiple images in a calibration mode, and (b) specifies the mean-square displacement of a bright point of the target particle based on the displacement of the bright point of the target particle in the multiple images in a measurement mode. A particle size analyzer (c) derives the particle size of the target particle from the mean-square displacement of the bright point of the target particle based on the mean-square displacement of the bright point of the calibration particle and the particle size of the calibration particle in an analysis mode.

Abstract: According to one embodiment, a particle measuring method is disclosed. The method includes irradiating a detection liquid with light. The detection liquid contains methyl salicylate. The method further includes converting scattered light from the detection liquid into an electric signal by using photoelectric conversion after irradiating the detection liquid with the light. The method further includes performing a particle measurement on the detection liquid by using the electric signal.

Abstract: Provided is a particle measuring device and a particle measuring method for measuring a particle size with favorable accuracy. A flow cell (1) includes a flow passage (1a) of sample fluid. An irradiation optical system (3) irradiates, with light from a light source (2), the sample fluid in the flow passage (1a). An imaging unit (4) captures, from an extension direction of the flow passage (1a), an image of scattered light from the particle in a detection region in the flow passage (1a), the light passing through the detection region. A particle size specifying unit specifies a movement amount of the particle in a two-dimensional direction by Brownian motion based on multiple still images of a particle image captured at a predetermined frame rate by the imaging unit (4), thereby specifying the particle size of the particle from the movement amount in the two-dimensional direction.

Abstract: According to one embodiment, a particle measuring method is disclosed. The method includes irradiating a detection liquid with light. The detection liquid contains methyl salicylate. The method further includes converting scattered light from the detection liquid into an electric signal by using photoelectric conversion after irradiating the detection liquid with the light. The method further includes performing a particle measurement on the detection liquid by using the electric signal.

Abstract: Provided is a particle measuring device and a particle measuring method for measuring a particle size with favorable accuracy. A flow cell (1) includes a flow passage (1a) of sample fluid. An irradiation optical system (3) irradiates, with light from a light source (2), the sample fluid in the flow passage (1a). An imaging unit (4) captures, from an extension direction of the flow passage (1a), an image of scattered light from the particle in a detection region in the flow passage (1a), the light passing through the detection region. A particle size specifying unit specifies a movement amount of the particle in a two-dimensional direction by Brownian motion based on multiple still images of a particle image captured at a predetermined frame rate by the imaging unit (4), thereby specifying the particle size of the particle from the movement amount in the two-dimensional direction.

Abstract: A light scattering particle counter that improves the signal-to-noise ratio by attenuating the high frequency noise component while suppressing the attenuation of the signal component by irradiating a sample fluid with a laser beam La to form a particle detection area, detecting a particle with a multi-channel light detecting element that receives scattered light Ls from a particle passing through the particle detection area, and with low pass filters having time constants ?c, ?m, ?e that are set to depend on beam diameter of the laser beam La and flow velocity of the fluid which flows through each divided area, to count particles in the sample fluid.

Abstract: [Subject] To offer a light scattering particle counter that improves the SN ratio by sufficiently attenuating the high frequency noise component while suppressing the attenuation of the signal component. [Means for Solving the Problems] A light scattering particle counter which irradiates a laser beam La to a sample fluid and forms a particle detection area 13, a multi-channel light detecting element receives scattered light Ls from a particle passing through the particle detection area and detects the particle, the time constants ?c, ?m, ?e of the low pass filters F1, F2, F3, F4, F5 are set depending on the beam diameter of the laser beam La and the flow velocity of the fluid which flows through each divided area.