| 摘要 |
A method and apparatus for measuring flow in a closed conduit under both full and less than full conditions is disclosed. The method and apparatus incorporate a tubular Venturi metering device. The cross section of the throat of the device is configured relative to the upstream section of the meter so that the throat will fill with liquid substantially simultaneously with the upstream section's filling with liquid. The present method and apparatus incorporate an improved pressure transmitting and sensing means, a data logger/controller and a data converter. The pressure transmitting and sensing means is designed to overcome the limitations of prior art means of transmitting and sensing pressures. One embodiment involves using submersible sensors to measure invert liquid pressures and a single bubbler system to transmit the throat (reference) pressure to the ends of the sensor vents (in the instrument case), thus allowing differential pressures to be measured. A second design involves transmitting pressures from sensing diaphragms via liquid-filled capillaries to both the pressure and reference ports of each of two (submersible) pressure sensors. The data logger/controller is a conventional element programmed to accomplish its functions. The data converter includes a computer program needed to convert pressure data into flow rate data.
|
