Abstract: In the method for measuring the velocity of fluid or visualizing the distribution of fluid by feeding tracer particles to the fluid, irradiating the fluid with light and observing return light from the tracer particles, tracer particles containing a flourescent substance are fed at least partially to the fluid and the fluid is irradiated with exciting light to cause the tracer particles to output flourescent emissions. A filter which does not transmit the exciting light is used to substantially selectively observe the flourecent emissions of the tracer particles. This method results in a remarkable improvement in the accuracy of flow velocity measurement or visualization of fluid distribution. Moreover, in a mixed fluid system consisting of two or more different fluids, the pattern of behavior of each fluid and the intermingled state of the fluids can be observed by using a plurality of different tracer particles.

Abstract: In the method for measuring the velocity of fluid or visualizing the distribution of fluid by feeding tracer particles to the fluid, irradiating the fluid with light and observing return light from the tracer particles, tracer particles containing a flourescent substance are fed at least partially to the fluid and the fluid is irradiated with exciting light to cause the tracer particles to output flourescent emissions. A filter which does not transmit the exciting light is used to substantially selectively observe the flourecent emissions of the tracer particles. This method results in a remarkable improvement in the accuracy of flow velocity measurement or visualization of fluid distribution. Moreover, in a mixed fluid system consisting of two or more different fluids, the pattern of behavior of each fluid and the intermingled state of the fluids can be observed by using a plurality of different tracer particles.

Abstract: In the method for measuring the velocity of fluid or visualizing the distribution of fluid by feeding tracer particles to the fluid, irradiating the fluid with light and observing return light from the tracer particles, tracer particles containing a flourescent substance are fed at least partially to the fluid and the fluid is irradiated with exciting light to cause the tracer particles to output flourescent emissions. A filter which does not transmit the exciting light is used to substantially selectively observe the flourecent emissions of the tracer particles. This method results in a remarkable improvement in the accuracy of flow velocity measurement or visualization of fluid distribution. Moreover, in a mixed fluid system consisting of two or more different fluids, the pattern of behavior of each fluid and the intermingled state of the fluids can be observed by using a plurality of different tracer particles.

Abstract: In the method for measuring the velocity of fluid or visualizing the distribution of fluid by feeding tracer particles to the fluid, irradiating the fluid with light and observing return light from the tracer particles, tracer particles containing a fluorescent substance are fed at least partially to the fluid and the fluid is irradiated with exciting light to cause the tracer particles to output fluorescent emissions. A filter which does not transmit the exciting light is used to substantially selectively observe the fluorescent emissions of the tracer particles. This method results in a remarkable improvement in the accuracy of flow velocity measurement or visualization of fluid distribution. Moreover, in a mixed fluid system consisting of two or more different fluids, the pattern of behavior of each fluid and the intermingled state of the fluids can be observed by using a plurality of different tracer particles.

Abstract: In the method for measuring the velocity of fluid or visualizing the distribution of fluid by feeding tracer particles to the fluid, irradiating the fluid with light and observing return light from the tracer particles, tracer particles containing a fluorescent substance are fed at least partially to the fluid and the fluid is irradiated with exciting light to cause the tracer particles to output fluorescent emissions. A filter which does not transmit the exciting light is used to substantially selectively observe the fluorescent emissions of the tracer particles. This method results in a remarkable improvement in the accuracy of flow velocity measurement or visualization of fluid distribution. Moreover, in a mixed fluid system consisting of two or more different fluids, the pattern of behavior of each fluid and the intermingled state of the fluids can be observed by using a plurality of different tracer particles.