Hitachi, Ltd.

Masaetsu Matsumoto

Hideyuki Horiuchi

Isao Yamazaki

Ryo Miyake

Hiroshi Ohki

Ryohei Yabe

Shinichi Sakuraba

Masaharu Ishii

Koji Suda

In order to investigate particles in a fluid, a flow cell causes the fluid to flow past a sensor which receives light from a continuous light emission system. When the sensor detects a change in light, a particle detector is triggered, which in turn triggers a pulse generator and hence an intermittent light emission system. Light then illuminates the flow cell to allow a CCD camera to photograph the particle. The photographs taken by the CCD camera are analyzed by an image processor. In order to obtain an accurate particle concentration measurement, it is necessary to modify the initial concentration measurement derived from the analysis of particle images by the image processor by a compensation coefficient. This operation is carried out by a concentration compensator. The result may then be displayed. Additional analysis may be carried out by changing the magnification of the CCD camera, or by selecting for analysis only those particles of a selected size or type.

Apparatus for investigating particles in a fluid, and a method of

A flow cell apparatus, useful in an apparatus for measuring particles suspended in a liquid, comprises a sample liquid, supply device, a sheath liquid supply device, a flow cell which has a flow passage passing through a transparent measuring portion, and a nozzle for causing the sample liquid, from the supply device to flow in the flow passage of the flow cell. The nozzle has at least one discharge port which is disposed in the flow passage in a spaced relation from the inner wall of the flow cell flow passage. The sheath liquid supply device causes the sheath liquid to flow around the nozzle discharge port and surround the sample liquid flow to form a sheath flow. The flow passage of the flow cell and the nozzle are so formed as to ensure a sample liquid flow of a fixed width through the measuring portion. A stable sample flow having a fixed width can be formed in the measuring portion even when the flow is at a high velocity, and particles in the sample liquid can efficiently be photographed with high accuracy.

Flow cell apparatus

A flow type particle image analyzing method and apparatus in which high-speed and high-precision image analysis can be achieved with a simple configuration are realized. A flow chamber is structured so that the dimension of the sample fluid in a direction substantially orthogonal to the direction of the light beam remains substantially constant in a direction of flow in an imaging zone. Furthermore, when particles have small diameters, a power for imaging is set to a fixed high value. When particles have large diameters, the thickness of a sample fluid is increased in order to provide a sufficient number of sample particles. Accordingly, no switching operation of an optical systems is required.

Flow type particle image analyzing method and apparatus

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Sendai, Japan

Masaetsu Matsumoto