Abstract
A self-scanning one-dimensional photo-diode array (an image sensor), such as is usually used in the card reader of electronic computer or for image analysis, was experimentally employed in the measurement of velocity and turbulence in liquid in a stirring vessel.
Measurement was first performed using a transmitted-light method by which light was focussed at a certain point inside the vessel using the optical system provided. In order to catch precisely the tracers (minute spherical particles) flowing into the measuring area (the focal point), a special circuit was assembled which would be activated only by signals detected simultaneously by the optical systems of both the image sensor and the photo-transistor.
The output signals detected by the image sensor were fed into wave-form memory and processed by mini-computer after A-D conversion. In this way, the diameter of a particle, its speed and two-dimensional direction of motion were obtained. On the basis of these results, velocity and turbulence were calculated.
It is concluded that measurement of liquid velocity and turbulence in a stirring vessel can be performed with high accuracy using the present method.
