摘要 |
There is disclosed a transducer for measuring extremely small rates of flow of a liquid under high pressure. A transparent tube has a small channel within which is contained a ball having a diameter substantially that of the channel. The tube is housed in a pressure vessel in such a manner that the high pressure liquid to be measured surrounds the tube over most of its length. The liquid flows externally of the tube toward the inlet end of the channel, thereby equalizing the pressure differential within and without the tube. As the fluid passes through the channel from the inlet to the outlet, it propels the ball past a sensor, such as a photoelectric device. The velocity of the ball past the sensor indicates the volumetric flow rate of the fluid. The device is periodically reset by momentarily reversing the direction of flow through the tube to return the ball to its starting position. |